[profiler] Ensure that we zero out thread IDs for buffers written from helper/writer...

[mono.git] / mono / profiler / proflog.c

/*
 * proflog.c: mono log profiler
 *
 * Authors:
 *   Paolo Molaro (lupus@ximian.com)
 *   Alex Rønne Petersen (alexrp@xamarin.com)
 *
 * Copyright 2010 Novell, Inc (http://www.novell.com)
 * Copyright 2011 Xamarin Inc (http://www.xamarin.com)
 * Licensed under the MIT license. See LICENSE file in the project root for full license information.
 */

#include <config.h>
#include "../mini/jit.h"
#include "../metadata/metadata-internals.h"
#include <mono/metadata/profiler.h>
#include <mono/metadata/threads.h>
#include <mono/metadata/mono-gc.h>
#include <mono/metadata/debug-helpers.h>
#include <mono/metadata/mono-perfcounters.h>
#include <mono/metadata/appdomain.h>
#include <mono/metadata/assembly.h>
#include <mono/metadata/tokentype.h>
#include <mono/metadata/tabledefs.h>
#include <mono/utils/atomic.h>
#include <mono/utils/mono-membar.h>
#include <mono/utils/mono-counters.h>
#include <mono/utils/mono-os-mutex.h>
#include <mono/utils/mono-conc-hashtable.h>
#include <mono/utils/lock-free-queue.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include <glib.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#ifdef HAVE_SCHED_GETAFFINITY
#include <sched.h>
#endif
#include <fcntl.h>
#include <errno.h>
#if defined(HOST_WIN32) || defined(DISABLE_SOCKETS)
#define DISABLE_HELPER_THREAD 1
#endif

#ifndef _GNU_SOURCE
#define _GNU_SOURCE
#endif
#ifdef HAVE_DLFCN_H
#include <dlfcn.h>
#endif
#ifdef HAVE_EXECINFO_H
#include <execinfo.h>
#endif
#ifdef HAVE_LINK_H
#include <link.h>
#endif

#ifndef DISABLE_HELPER_THREAD
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <sys/select.h>
#endif

#ifdef HOST_WIN32
#include <windows.h>
#else
#include <pthread.h>
#endif

#ifdef HAVE_SYS_STAT_H
#include <sys/stat.h>
#endif

#include "utils.c"
#include "proflog.h"

#if defined (HAVE_SYS_ZLIB)
#include <zlib.h>
#endif

#if defined(__linux__)

#include <unistd.h>
#include <sys/syscall.h>

#ifdef ENABLE_PERF_EVENTS
#include <linux/perf_event.h>

#define USE_PERF_EVENTS 1

static int read_perf_mmap (MonoProfiler* prof, int cpu);
#endif

#endif

#define BUFFER_SIZE (4096 * 16)

/* Worst-case size in bytes of a 64-bit value encoded with LEB128. */
#define LEB128_SIZE 10
/* Size in bytes of the event ID prefix. */
#define EVENT_SIZE 1

static int nocalls = 0;
static int notraces = 0;
static int use_zip = 0;
static int do_report = 0;
static int do_heap_shot = 0;
static int max_call_depth = 100;
static volatile int runtime_inited = 0;
static int need_helper_thread = 0;
static int command_port = 0;
static int heapshot_requested = 0;
static int sample_type = 0;
static int sample_freq = 0;
static int do_mono_sample = 0;
static int in_shutdown = 0;
static int do_debug = 0;
static int do_counters = 0;
static int do_coverage = 0;
static gboolean debug_coverage = FALSE;
static MonoProfileSamplingMode sampling_mode = MONO_PROFILER_STAT_MODE_PROCESS;

typedef struct _LogBuffer LogBuffer;

/*
 * file format:
 * [header] [buffer]*
 *
 * The file is composed by a header followed by 0 or more buffers.
 * Each buffer contains events that happened on a thread: for a given thread
 * buffers that appear later in the file are guaranteed to contain events
 * that happened later in time. Buffers from separate threads could be interleaved,
 * though.
 * Buffers are not required to be aligned.
 *
 * header format:
 * [id: 4 bytes] constant value: LOG_HEADER_ID
 * [major: 1 byte] [minor: 1 byte] major and minor version of the log profiler
 * [format: 1 byte] version of the data format for the rest of the file
 * [ptrsize: 1 byte] size in bytes of a pointer in the profiled program
 * [startup time: 8 bytes] time in milliseconds since the unix epoch when the program started
 * [timer overhead: 4 bytes] approximate overhead in nanoseconds of the timer
 * [flags: 4 bytes] file format flags, should be 0 for now
 * [pid: 4 bytes] pid of the profiled process
 * [port: 2 bytes] tcp port for server if != 0
 * [sysid: 2 bytes] operating system and architecture identifier
 *
 * The multiple byte integers are in little-endian format.
 *
 * buffer format:
 * [buffer header] [event]*
 * Buffers have a fixed-size header followed by 0 or more bytes of event data.
 * Timing information and other values in the event data are usually stored
 * as uleb128 or sleb128 integers. To save space, as noted for each item below,
 * some data is represented as a difference between the actual value and
 * either the last value of the same type (like for timing information) or
 * as the difference from a value stored in a buffer header.
 *
 * For timing information the data is stored as uleb128, since timing
 * increases in a monotonic way in each thread: the value is the number of
 * nanoseconds to add to the last seen timing data in a buffer. The first value
 * in a buffer will be calculated from the time_base field in the buffer head.
 *
 * Object or heap sizes are stored as uleb128.
 * Pointer differences are stored as sleb128, instead.
 *
 * If an unexpected value is found, the rest of the buffer should be ignored,
 * as generally the later values need the former to be interpreted correctly.
 *
 * buffer header format:
 * [bufid: 4 bytes] constant value: BUF_ID
 * [len: 4 bytes] size of the data following the buffer header
 * [time_base: 8 bytes] time base in nanoseconds since an unspecified epoch
 * [ptr_base: 8 bytes] base value for pointers
 * [obj_base: 8 bytes] base value for object addresses
 * [thread id: 8 bytes] system-specific thread ID (pthread_t for example)
 * [method_base: 8 bytes] base value for MonoMethod pointers
 *
 * event format:
 * [extended info: upper 4 bits] [type: lower 4 bits] [data]*
 * The data that follows depends on type and the extended info.
 * Type is one of the enum values in proflog.h: TYPE_ALLOC, TYPE_GC,
 * TYPE_METADATA, TYPE_METHOD, TYPE_EXCEPTION, TYPE_MONITOR, TYPE_HEAP.
 * The extended info bits are interpreted based on type, see
 * each individual event description below.
 * strings are represented as a 0-terminated utf8 sequence.
 *
 * backtrace format:
 * [flags: uleb128] must be 0
 * [num: uleb128] number of frames following
 * [frame: sleb128]* num MonoMethod pointers as differences from ptr_base
 *
 * type alloc format:
 * type: TYPE_ALLOC
 * exinfo: flags: TYPE_ALLOC_BT
 * [time diff: uleb128] nanoseconds since last timing
 * [ptr: sleb128] class as a byte difference from ptr_base
 * [obj: sleb128] object address as a byte difference from obj_base
 * [size: uleb128] size of the object in the heap
 * If the TYPE_ALLOC_BT flag is set, a backtrace follows.
 *
 * type GC format:
 * type: TYPE_GC
 * exinfo: one of TYPE_GC_EVENT, TYPE_GC_RESIZE, TYPE_GC_MOVE, TYPE_GC_HANDLE_CREATED[_BT],
 * TYPE_GC_HANDLE_DESTROYED[_BT]
 * [time diff: uleb128] nanoseconds since last timing
 * if exinfo == TYPE_GC_RESIZE
 *      [heap_size: uleb128] new heap size
 * if exinfo == TYPE_GC_EVENT
 *      [event type: uleb128] GC event (MONO_GC_EVENT_* from profiler.h)
 *      [generation: uleb128] GC generation event refers to
 * if exinfo == TYPE_GC_MOVE
 *      [num_objects: uleb128] number of object moves that follow
 *      [objaddr: sleb128]+ num_objects object pointer differences from obj_base
 *      num is always an even number: the even items are the old
 *      addresses, the odd numbers are the respective new object addresses
 * if exinfo == TYPE_GC_HANDLE_CREATED[_BT]
 *      [handle_type: uleb128] GC handle type (System.Runtime.InteropServices.GCHandleType)
 *      upper bits reserved as flags
 *      [handle: uleb128] GC handle value
 *      [objaddr: sleb128] object pointer differences from obj_base
 *      If exinfo == TYPE_GC_HANDLE_CREATED_BT, a backtrace follows.
 * if exinfo == TYPE_GC_HANDLE_DESTROYED[_BT]
 *      [handle_type: uleb128] GC handle type (System.Runtime.InteropServices.GCHandleType)
 *      upper bits reserved as flags
 *      [handle: uleb128] GC handle value
 *      If exinfo == TYPE_GC_HANDLE_DESTROYED_BT, a backtrace follows.
 *
 * type metadata format:
 * type: TYPE_METADATA
 * exinfo: one of: TYPE_END_LOAD, TYPE_END_UNLOAD (optional for TYPE_THREAD and TYPE_DOMAIN)
 * [time diff: uleb128] nanoseconds since last timing
 * [mtype: byte] metadata type, one of: TYPE_CLASS, TYPE_IMAGE, TYPE_ASSEMBLY, TYPE_DOMAIN,
 * TYPE_THREAD, TYPE_CONTEXT
 * [pointer: sleb128] pointer of the metadata type depending on mtype
 * if mtype == TYPE_CLASS
 *      [image: sleb128] MonoImage* as a pointer difference from ptr_base
 *      [flags: uleb128] must be 0
 *      [name: string] full class name
 * if mtype == TYPE_IMAGE
 *      [flags: uleb128] must be 0
 *      [name: string] image file name
 * if mtype == TYPE_ASSEMBLY
 *      [flags: uleb128] must be 0
 *      [name: string] assembly name
 * if mtype == TYPE_DOMAIN
 *      [flags: uleb128] must be 0
 * if mtype == TYPE_DOMAIN && exinfo == 0
 *      [name: string] domain friendly name
 * if mtype == TYPE_CONTEXT
 *      [flags: uleb128] must be 0
 *      [domain: sleb128] domain id as pointer
 * if mtype == TYPE_THREAD && (format_version < 11 || (format_version > 10 && exinfo == 0))
 *      [flags: uleb128] must be 0
 *      [name: string] thread name
 *
 * type method format:
 * type: TYPE_METHOD
 * exinfo: one of: TYPE_LEAVE, TYPE_ENTER, TYPE_EXC_LEAVE, TYPE_JIT
 * [time diff: uleb128] nanoseconds since last timing
 * [method: sleb128] MonoMethod* as a pointer difference from the last such
 * pointer or the buffer method_base
 * if exinfo == TYPE_JIT
 *      [code address: sleb128] pointer to the native code as a diff from ptr_base
 *      [code size: uleb128] size of the generated code
 *      [name: string] full method name
 *
 * type runtime format:
 * type: TYPE_RUNTIME
 * exinfo: one of: TYPE_JITHELPER
 * [time diff: uleb128] nanoseconds since last timing
 * if exinfo == TYPE_JITHELPER
 *      [type: uleb128] MonoProfilerCodeBufferType enum value
 *      [buffer address: sleb128] pointer to the native code as a diff from ptr_base
 *      [buffer size: uleb128] size of the generated code
 *      if type == MONO_PROFILER_CODE_BUFFER_SPECIFIC_TRAMPOLINE
 *              [name: string] buffer description name
 *
 * type monitor format:
 * type: TYPE_MONITOR
 * exinfo: TYPE_MONITOR_BT flag and one of: MONO_PROFILER_MONITOR_(CONTENTION|FAIL|DONE)
 * [time diff: uleb128] nanoseconds since last timing
 * [object: sleb128] the lock object as a difference from obj_base
 * if exinfo.low3bits == MONO_PROFILER_MONITOR_CONTENTION
 *      If the TYPE_MONITOR_BT flag is set, a backtrace follows.
 *
 * type heap format
 * type: TYPE_HEAP
 * exinfo: one of TYPE_HEAP_START, TYPE_HEAP_END, TYPE_HEAP_OBJECT, TYPE_HEAP_ROOT
 * if exinfo == TYPE_HEAP_START
 *      [time diff: uleb128] nanoseconds since last timing
 * if exinfo == TYPE_HEAP_END
 *      [time diff: uleb128] nanoseconds since last timing
 * if exinfo == TYPE_HEAP_OBJECT
 *      [object: sleb128] the object as a difference from obj_base
 *      [class: sleb128] the object MonoClass* as a difference from ptr_base
 *      [size: uleb128] size of the object on the heap
 *      [num_refs: uleb128] number of object references
 *      if (format version > 1) each referenced objref is preceded by a
 *      uleb128 encoded offset: the first offset is from the object address
 *      and each next offset is relative to the previous one
 *      [objrefs: sleb128]+ object referenced as a difference from obj_base
 *      The same object can appear multiple times, but only the first time
 *      with size != 0: in the other cases this data will only be used to
 *      provide additional referenced objects.
 * if exinfo == TYPE_HEAP_ROOT
 *      [num_roots: uleb128] number of root references
 *      [num_gc: uleb128] number of major gcs
 *      [object: sleb128] the object as a difference from obj_base
 *      [root_type: uleb128] the root_type: MonoProfileGCRootType (profiler.h)
 *      [extra_info: uleb128] the extra_info value
 *      object, root_type and extra_info are repeated num_roots times
 *
 * type sample format
 * type: TYPE_SAMPLE
 * exinfo: one of TYPE_SAMPLE_HIT, TYPE_SAMPLE_USYM, TYPE_SAMPLE_UBIN, TYPE_SAMPLE_COUNTERS_DESC, TYPE_SAMPLE_COUNTERS
 * if exinfo == TYPE_SAMPLE_HIT
 *      [sample_type: uleb128] type of sample (SAMPLE_*)
 *      [timestamp: uleb128] nanoseconds since startup (note: different from other timestamps!)
 *      if (format_version > 10)
 *              [thread: sleb128] thread id as difference from ptr_base
 *      [count: uleb128] number of following instruction addresses
 *      [ip: sleb128]* instruction pointer as difference from ptr_base
 *      if (format_version > 5)
 *              [mbt_count: uleb128] number of managed backtrace info triplets (method + IL offset + native offset)
 *              [method: sleb128]* MonoMethod* as a pointer difference from the last such
 *              pointer or the buffer method_base (the first such method can be also indentified by ip, but this is not neccessarily true)
 *              [il_offset: sleb128]* IL offset inside method where the hit occurred
 *              [native_offset: sleb128]* native offset inside method where the hit occurred
 * if exinfo == TYPE_SAMPLE_USYM
 *      [address: sleb128] symbol address as a difference from ptr_base
 *      [size: uleb128] symbol size (may be 0 if unknown)
 *      [name: string] symbol name
 * if exinfo == TYPE_SAMPLE_UBIN
 *      [time diff: uleb128] nanoseconds since last timing
 *      [address: sleb128] address where binary has been loaded
 *      [offset: uleb128] file offset of mapping (the same file can be mapped multiple times)
 *      [size: uleb128] memory size
 *      [name: string] binary name
 * if exinfo == TYPE_SAMPLE_COUNTERS_DESC
 *      [len: uleb128] number of counters
 *      for i = 0 to len
 *              [section: uleb128] section of counter
 *              if section == MONO_COUNTER_PERFCOUNTERS:
 *                      [section_name: string] section name of counter
 *              [name: string] name of counter
 *              [type: uleb128] type of counter
 *              [unit: uleb128] unit of counter
 *              [variance: uleb128] variance of counter
 *              [index: uleb128] unique index of counter
 * if exinfo == TYPE_SAMPLE_COUNTERS
 *      [timestamp: uleb128] sampling timestamp
 *      while true:
 *              [index: uleb128] unique index of counter
 *              if index == 0:
 *                      break
 *              [type: uleb128] type of counter value
 *              if type == string:
 *                      if value == null:
 *                              [0: uleb128] 0 -> value is null
 *                      else:
 *                              [1: uleb128] 1 -> value is not null
 *                              [value: string] counter value
 *              else:
 *                      [value: uleb128/sleb128/double] counter value, can be sleb128, uleb128 or double (determined by using type)
 *
 * type coverage format
 * type: TYPE_COVERAGE
 * exinfo: one of TYPE_COVERAGE_METHOD, TYPE_COVERAGE_STATEMENT, TYPE_COVERAGE_ASSEMBLY, TYPE_COVERAGE_CLASS
 * if exinfo == TYPE_COVERAGE_METHOD
 *  [assembly: string] name of assembly
 *  [class: string] name of the class
 *  [name: string] name of the method
 *  [signature: string] the signature of the method
 *  [filename: string] the file path of the file that contains this method
 *  [token: uleb128] the method token
 *  [method_id: uleb128] an ID for this data to associate with the buffers of TYPE_COVERAGE_STATEMENTS
 *  [len: uleb128] the number of TYPE_COVERAGE_BUFFERS associated with this method
 * if exinfo == TYPE_COVERAGE_STATEMENTS
 *  [method_id: uleb128] an the TYPE_COVERAGE_METHOD buffer to associate this with
 *  [offset: uleb128] the il offset relative to the previous offset
 *  [counter: uleb128] the counter for this instruction
 *  [line: uleb128] the line of filename containing this instruction
 *  [column: uleb128] the column containing this instruction
 * if exinfo == TYPE_COVERAGE_ASSEMBLY
 *  [name: string] assembly name
 *  [guid: string] assembly GUID
 *  [filename: string] assembly filename
 *  [number_of_methods: uleb128] the number of methods in this assembly
 *  [fully_covered: uleb128] the number of fully covered methods
 *  [partially_covered: uleb128] the number of partially covered methods
 *    currently partially_covered will always be 0, and fully_covered is the
 *    number of methods that are fully and partially covered.
 * if exinfo == TYPE_COVERAGE_CLASS
 *  [name: string] assembly name
 *  [class: string] class name
 *  [number_of_methods: uleb128] the number of methods in this class
 *  [fully_covered: uleb128] the number of fully covered methods
 *  [partially_covered: uleb128] the number of partially covered methods
 *    currently partially_covered will always be 0, and fully_covered is the
 *    number of methods that are fully and partially covered.
 */

/*
 * Format oddities that we ought to fix:
 *
 * - Methods written in emit_bt () should be based on the buffer's base
 *   method instead of the base pointer.
 * - The TYPE_SAMPLE_HIT event contains (currently) pointless data like
 *   always-one unmanaged frame count and always-zero IL offsets.
 *
 * These are mostly small things and are not worth a format change by
 * themselves. They should be done when some other major change has to
 * be done to the format.
 */

// Pending data to be written to the log, for a single thread.
// Threads periodically flush their own LogBuffers by calling safe_send
struct _LogBuffer {
        // Next (older) LogBuffer in processing queue
        LogBuffer *next;

        uint64_t time_base;
        uint64_t last_time;
        uintptr_t ptr_base;
        uintptr_t method_base;
        uintptr_t last_method;
        uintptr_t obj_base;
        uintptr_t thread_id;
        int locked;
        int call_depth;

        // Bytes allocated for this LogBuffer
        int size;

        // Start of currently unused space in buffer
        unsigned char* cursor;

        // Pointer to start-of-structure-plus-size (for convenience)
        unsigned char* buf_end;

        // Start of data in buffer. Contents follow "buffer format" described above.
        unsigned char buf [1];
};

static inline void
ign_res (int G_GNUC_UNUSED unused, ...)
{
}

#define ENTER_LOG(lb,str) if ((lb)->locked) {ign_res (write(2, str, strlen(str))); ign_res (write(2, "\n", 1));return;} else {(lb)->locked++;}
#define EXIT_LOG(lb) (lb)->locked--;

// Shared queue of sample snapshots taken at signal time.
// The queue is written into by signal handlers for all threads;
// the helper thread later unqueues and writes into its own LogBuffer.
typedef struct _StatBuffer StatBuffer;
struct _StatBuffer {
        // Next (older) StatBuffer in processing queue
        StatBuffer *next;

        // Bytes allocated for this StatBuffer
        uintptr_t size;

        // Start of currently unused space in buffer
        uintptr_t *cursor;

        // Pointer to start-of-structure-plus-size (for convenience)
        uintptr_t *buf_end;

        // Start of data in buffer.
        // Data consists of a series of sample packets consisting of:
        // 1 ptrword: Metadata
        //    Low 8 bits: COUNT, the count of native stack frames in this sample (currently always 1)
        //    Next 8 bits: MBT_COUNT, the count of managed stacks in this sample
        //    Next 8 bits: TYPE. See "sampling sources" enum in proflog.h. Usually SAMPLE_CYCLES (1)
        // 1 ptrword: Thread ID
        // 1 ptrword: Timestamp
        // COUNT ptrwords: Native stack frames
        //   Each word is an IP (first is IP where the signal did the interruption)
        // MBT_COUNT * 4 ptrwords: Managed stack frames (AsyncFrameInfo, repacked)
        //    Word 1: MonoMethod ptr
        //    Word 2: MonoDomain ptr
        //    Word 3: Base address of method
        //    Word 4: Offset within method
        uintptr_t buf [1];
};

typedef struct _BinaryObject BinaryObject;

struct _BinaryObject {
        BinaryObject *next;
        void *addr;
        char *name;
};

struct _MonoProfiler {
        StatBuffer *stat_buffers;
        FILE* file;
#if defined (HAVE_SYS_ZLIB)
        gzFile gzfile;
#endif
        uint64_t startup_time;
        int pipe_output;
        int last_gc_gen_started;
        int command_port;
        int server_socket;
        int pipes [2];
#ifndef HOST_WIN32
        pthread_t helper_thread;
        pthread_t writer_thread;
#endif
        volatile gint32 run_writer_thread;
        MonoLockFreeQueue writer_queue;
        MonoConcurrentHashTable *method_table;
        mono_mutex_t method_table_mutex;
        BinaryObject *binary_objects;
        GPtrArray *coverage_filters;
        GPtrArray *sorted_sample_events;
};

typedef struct _WriterQueueEntry WriterQueueEntry;
struct _WriterQueueEntry {
        MonoLockFreeQueueNode node;
        GPtrArray *methods;
        LogBuffer *buffer;
};

typedef struct _MethodInfo MethodInfo;
struct _MethodInfo {
        MonoMethod *method;
        MonoJitInfo *ji;
        uint64_t time;
};

#ifdef TLS_INIT
#undef TLS_INIT
#endif

#ifdef HOST_WIN32
#define TLS_SET(x,y) (TlsSetValue (x, y))
#define TLS_GET(t,x) ((t *) TlsGetValue (x))
#define TLS_INIT(x) (x = TlsAlloc ())
static int tlsbuffer;
static int tlsmethodlist;
#elif HAVE_KW_THREAD
#define TLS_SET(x,y) (x = y)
#define TLS_GET(t,x) (x)
#define TLS_INIT(x)
static __thread LogBuffer* tlsbuffer = NULL;
static __thread GPtrArray* tlsmethodlist = NULL;
#else
#define TLS_SET(x,y) (pthread_setspecific (x, y))
#define TLS_GET(t,x) ((t *) pthread_getspecific (x))
#define TLS_INIT(x) (pthread_key_create (&x, NULL))
static pthread_key_t tlsbuffer;
static pthread_key_t tlsmethodlist;
#endif

static void safe_send (MonoProfiler *profiler, LogBuffer *logbuffer);

static char*
pstrdup (const char *s)
{
        int len = strlen (s) + 1;
        char *p = (char *)malloc (len);
        memcpy (p, s, len);
        return p;
}

static StatBuffer*
create_stat_buffer (void)
{
        StatBuffer* buf = (StatBuffer *)alloc_buffer (BUFFER_SIZE);
        buf->size = BUFFER_SIZE;
        buf->buf_end = (uintptr_t*)((unsigned char*)buf + buf->size);
        buf->cursor = buf->buf;
        return buf;
}

static LogBuffer*
create_buffer (void)
{
        LogBuffer* buf = (LogBuffer *)alloc_buffer (BUFFER_SIZE);
        buf->size = BUFFER_SIZE;
        buf->time_base = current_time ();
        buf->last_time = buf->time_base;
        buf->buf_end = (unsigned char*)buf + buf->size;
        buf->cursor = buf->buf;
        return buf;
}

static void
init_thread (void)
{
        if (!TLS_GET (LogBuffer, tlsbuffer)) {
                LogBuffer *logbuffer = create_buffer ();
                TLS_SET (tlsbuffer, logbuffer);
                logbuffer->thread_id = thread_id ();
        }
        if (!TLS_GET (GPtrArray, tlsmethodlist)) {
                GPtrArray *methodlist = g_ptr_array_new ();
                TLS_SET (tlsmethodlist, methodlist);
        }

        //printf ("thread %p at time %llu\n", (void*)logbuffer->thread_id, logbuffer->time_base);
}

static LogBuffer *
ensure_logbuf_inner (LogBuffer *old, int bytes)
{
        if (old && old->cursor + bytes + 100 < old->buf_end)
                return old;

        LogBuffer *new_ = (LogBuffer *)create_buffer ();
        new_->thread_id = thread_id ();
        new_->next = old;

        if (old)
                new_->call_depth = old->call_depth;

        return new_;
}

static LogBuffer*
ensure_logbuf (int bytes)
{
        LogBuffer *old = TLS_GET (LogBuffer, tlsbuffer);
        LogBuffer *new_ = ensure_logbuf_inner (old, bytes);

        if (new_ == old)
                return old; // Still enough space.

        TLS_SET (tlsbuffer, new_);
        init_thread ();

        return new_;
}

static void
emit_byte (LogBuffer *logbuffer, int value)
{
        logbuffer->cursor [0] = value;
        logbuffer->cursor++;
        assert (logbuffer->cursor <= logbuffer->buf_end);
}

static void
emit_value (LogBuffer *logbuffer, int value)
{
        encode_uleb128 (value, logbuffer->cursor, &logbuffer->cursor);
        assert (logbuffer->cursor <= logbuffer->buf_end);
}

static void
emit_time (LogBuffer *logbuffer, uint64_t value)
{
        uint64_t tdiff = value - logbuffer->last_time;
        //if (value < logbuffer->last_time)
        //      printf ("time went backwards\n");
        //if (tdiff > 1000000)
        //      printf ("large time offset: %llu\n", tdiff);
        encode_uleb128 (tdiff, logbuffer->cursor, &logbuffer->cursor);
        /*if (tdiff != decode_uleb128 (p, &p))
                printf ("incorrect encoding: %llu\n", tdiff);*/
        logbuffer->last_time = value;
        assert (logbuffer->cursor <= logbuffer->buf_end);
}

static void
emit_svalue (LogBuffer *logbuffer, int64_t value)
{
        encode_sleb128 (value, logbuffer->cursor, &logbuffer->cursor);
        assert (logbuffer->cursor <= logbuffer->buf_end);
}

static void
emit_uvalue (LogBuffer *logbuffer, uint64_t value)
{
        encode_uleb128 (value, logbuffer->cursor, &logbuffer->cursor);
        assert (logbuffer->cursor <= logbuffer->buf_end);
}

static void
emit_ptr (LogBuffer *logbuffer, void *ptr)
{
        if (!logbuffer->ptr_base)
                logbuffer->ptr_base = (uintptr_t)ptr;
        emit_svalue (logbuffer, (intptr_t)ptr - logbuffer->ptr_base);
        assert (logbuffer->cursor <= logbuffer->buf_end);
}

static void
emit_method_inner (LogBuffer *logbuffer, void *method)
{
        if (!logbuffer->method_base) {
                logbuffer->method_base = (intptr_t)method;
                logbuffer->last_method = (intptr_t)method;
        }
        encode_sleb128 ((intptr_t)((char*)method - (char*)logbuffer->last_method), logbuffer->cursor, &logbuffer->cursor);
        logbuffer->last_method = (intptr_t)method;
        assert (logbuffer->cursor <= logbuffer->buf_end);
}

/*
typedef struct {
        MonoMethod *method;
        MonoJitInfo *found;
} MethodSearch;

static void
find_method (MonoDomain *domain, void *user_data)
{
        MethodSearch *search = user_data;

        if (search->found)
                return;

        MonoJitInfo *ji = mono_get_jit_info_from_method (domain, search->method);

        // It could be AOT'd, so we need to get it from the AOT runtime's cache.
        if (!ji) {
                void *ip = mono_aot_get_method (domain, search->method);

                // Avoid a slow path in mono_jit_info_table_find ().
                if (ip)
                        ji = mono_jit_info_table_find (domain, ip);
        }

        if (ji)
                search->found = ji;
}
*/

static void
register_method_local (MonoProfiler *prof, MonoMethod *method, MonoJitInfo *ji)
{
        if (!mono_conc_hashtable_lookup (prof->method_table, method)) {
                /*
                 * FIXME: In some cases, we crash while looking up JIT info for AOT'd methods.
                 * This usually happens for static constructors. This code is disabled for now
                 * as we don't need this info for anything critical.
                 *
                 * https://bugzilla.xamarin.com/show_bug.cgi?id=35171
                 */
                /*
                if (!ji) {
                        MethodSearch search = { method, NULL };

                        mono_domain_foreach (find_method, &search);

                        ji = search.found;
                }
                */

                /*
                 * FIXME: We can't always find JIT info for a generic shared method, especially
                 * if we obtained the MonoMethod during an async stack walk. For now, we deal
                 * with this by giving the generic shared method name and dummy code start/size
                 * information (i.e. zeroes).
                 */
                //g_assert (ji);

                MethodInfo *info = (MethodInfo *)malloc (sizeof (MethodInfo));

                info->method = method;
                info->ji = ji;
                info->time = current_time ();

                g_ptr_array_add (TLS_GET (GPtrArray, tlsmethodlist), info);
        }
}

static void
emit_method (MonoProfiler *prof, LogBuffer *logbuffer, MonoMethod *method)
{
        register_method_local (prof, method, NULL);
        emit_method_inner (logbuffer, method);
}

static void
emit_method_as_ptr (MonoProfiler *prof, LogBuffer *logbuffer, MonoMethod *method)
{
        register_method_local (prof, method, NULL);
        emit_ptr (logbuffer, method);
}

static void
emit_obj (LogBuffer *logbuffer, void *ptr)
{
        if (!logbuffer->obj_base)
                logbuffer->obj_base = (uintptr_t)ptr >> 3;
        emit_svalue (logbuffer, ((uintptr_t)ptr >> 3) - logbuffer->obj_base);
        assert (logbuffer->cursor <= logbuffer->buf_end);
}

static void
emit_string (LogBuffer *logbuffer, const char *str, size_t size)
{
        size_t i = 0;
        if (str) {
                for (; i < size; i++) {
                        if (str[i] == '\0')
                                break;
                        emit_byte (logbuffer, str [i]);
                }
        }
        emit_byte (logbuffer, '\0');
}

static void
emit_double (LogBuffer *logbuffer, double value)
{
        int i;
        unsigned char buffer[8];
        memcpy (buffer, &value, 8);
#if G_BYTE_ORDER == G_BIG_ENDIAN
        for (i = 7; i >= 0; i--)
#else
        for (i = 0; i < 8; i++)
#endif
                emit_byte (logbuffer, buffer[i]);
}

static char*
write_int16 (char *buf, int32_t value)
{
        int i;
        for (i = 0; i < 2; ++i) {
                buf [i] = value;
                value >>= 8;
        }
        return buf + 2;
}

static char*
write_int32 (char *buf, int32_t value)
{
        int i;
        for (i = 0; i < 4; ++i) {
                buf [i] = value;
                value >>= 8;
        }
        return buf + 4;
}

static char*
write_int64 (char *buf, int64_t value)
{
        int i;
        for (i = 0; i < 8; ++i) {
                buf [i] = value;
                value >>= 8;
        }
        return buf + 8;
}

static void
dump_header (MonoProfiler *profiler)
{
        char hbuf [128];
        char *p = hbuf;
        p = write_int32 (p, LOG_HEADER_ID);
        *p++ = LOG_VERSION_MAJOR;
        *p++ = LOG_VERSION_MINOR;
        *p++ = LOG_DATA_VERSION;
        *p++ = sizeof (void*);
        p = write_int64 (p, ((uint64_t)time (NULL)) * 1000); /* startup time */
        p = write_int32 (p, get_timer_overhead ()); /* timer overhead */
        p = write_int32 (p, 0); /* flags */
        p = write_int32 (p, process_id ()); /* pid */
        p = write_int16 (p, profiler->command_port); /* port */
        p = write_int16 (p, 0); /* opsystem */
#if defined (HAVE_SYS_ZLIB)
        if (profiler->gzfile) {
                gzwrite (profiler->gzfile, hbuf, p - hbuf);
        } else {
                fwrite (hbuf, p - hbuf, 1, profiler->file);
        }
#else
        fwrite (hbuf, p - hbuf, 1, profiler->file);
        fflush (profiler->file);
#endif
}

static void
send_buffer (MonoProfiler *prof, GPtrArray *methods, LogBuffer *buffer)
{
        WriterQueueEntry *entry = (WriterQueueEntry *)calloc (1, sizeof (WriterQueueEntry));
        mono_lock_free_queue_node_init (&entry->node, FALSE);
        entry->methods = methods;
        entry->buffer = buffer;
        mono_lock_free_queue_enqueue (&prof->writer_queue, &entry->node);
}

static void
dump_buffer (MonoProfiler *profiler, LogBuffer *buf)
{
        char hbuf [128];
        char *p = hbuf;
        if (buf->next)
                dump_buffer (profiler, buf->next);
        p = write_int32 (p, BUF_ID);
        p = write_int32 (p, buf->cursor - buf->buf);
        p = write_int64 (p, buf->time_base);
        p = write_int64 (p, buf->ptr_base);
        p = write_int64 (p, buf->obj_base);
        p = write_int64 (p, buf->thread_id);
        p = write_int64 (p, buf->method_base);
#if defined (HAVE_SYS_ZLIB)
        if (profiler->gzfile) {
                gzwrite (profiler->gzfile, hbuf, p - hbuf);
                gzwrite (profiler->gzfile, buf->buf, buf->cursor - buf->buf);
        } else {
#endif
                fwrite (hbuf, p - hbuf, 1, profiler->file);
                fwrite (buf->buf, buf->cursor - buf->buf, 1, profiler->file);
                fflush (profiler->file);
#if defined (HAVE_SYS_ZLIB)
        }
#endif
        free_buffer (buf, buf->size);
}

static void
process_requests (MonoProfiler *profiler)
{
        if (heapshot_requested)
                mono_gc_collect (mono_gc_max_generation ());
}

static void counters_init (MonoProfiler *profiler);
static void counters_sample (MonoProfiler *profiler, uint64_t timestamp, gboolean threadless);

/*
 * Can be called only at safe callback locations.
 */
static void
safe_send (MonoProfiler *profiler, LogBuffer *logbuffer)
{
        /* We need the runtime initialized so that we have threads and hazard
         * pointers available. Otherwise, the lock free queue will not work and
         * there won't be a thread to process the data.
         *
         * While the runtime isn't initialized, we just accumulate data in the
         * thread local buffer list.
         */
        if (!InterlockedRead (&runtime_inited))
                return;

        int cd = logbuffer->call_depth;

        send_buffer (profiler, TLS_GET (GPtrArray, tlsmethodlist), TLS_GET (LogBuffer, tlsbuffer));

        TLS_SET (tlsbuffer, NULL);
        TLS_SET (tlsmethodlist, NULL);

        init_thread ();

        TLS_GET (LogBuffer, tlsbuffer)->call_depth = cd;
}

static void
safe_send_threadless (MonoProfiler *prof, LogBuffer *buf)
{
        for (LogBuffer *iter = buf; iter; iter = iter->next)
                iter->thread_id = 0;

        safe_send (prof, buf);
}

static int
gc_reference (MonoObject *obj, MonoClass *klass, uintptr_t size, uintptr_t num, MonoObject **refs, uintptr_t *offsets, void *data)
{
        int i;
        uintptr_t last_offset = 0;
        //const char *name = mono_class_get_name (klass);
        LogBuffer *logbuffer = ensure_logbuf (
                EVENT_SIZE /* event */ +
                LEB128_SIZE /* obj */ +
                LEB128_SIZE /* klass */ +
                LEB128_SIZE /* size */ +
                LEB128_SIZE /* num */ +
                num * (
                        LEB128_SIZE /* offset */ +
                        LEB128_SIZE /* ref */
                )
        );
        emit_byte (logbuffer, TYPE_HEAP_OBJECT | TYPE_HEAP);
        emit_obj (logbuffer, obj);
        emit_ptr (logbuffer, klass);
        /* account for object alignment in the heap */
        size += 7;
        size &= ~7;
        emit_value (logbuffer, size);
        emit_value (logbuffer, num);
        for (i = 0; i < num; ++i) {
                emit_value (logbuffer, offsets [i] - last_offset);
                last_offset = offsets [i];
                emit_obj (logbuffer, refs [i]);
        }
        //if (num)
        //      printf ("obj: %p, klass: %s, refs: %d, size: %d\n", obj, name, (int)num, (int)size);
        return 0;
}

static unsigned int hs_mode_ms = 0;
static unsigned int hs_mode_gc = 0;
static unsigned int hs_mode_ondemand = 0;
static unsigned int gc_count = 0;
static uint64_t last_hs_time = 0;

static void
heap_walk (MonoProfiler *profiler)
{
        int do_walk = 0;
        uint64_t now;
        LogBuffer *logbuffer;
        if (!do_heap_shot)
                return;
        logbuffer = ensure_logbuf (
                EVENT_SIZE /* event */ +
                LEB128_SIZE /* time */
        );
        now = current_time ();
        if (hs_mode_ms && (now - last_hs_time)/1000000 >= hs_mode_ms)
                do_walk = 1;
        else if (hs_mode_gc && (gc_count % hs_mode_gc) == 0)
                do_walk = 1;
        else if (hs_mode_ondemand)
                do_walk = heapshot_requested;
        else if (!hs_mode_ms && !hs_mode_gc && profiler->last_gc_gen_started == mono_gc_max_generation ())
                do_walk = 1;

        if (!do_walk)
                return;
        heapshot_requested = 0;
        emit_byte (logbuffer, TYPE_HEAP_START | TYPE_HEAP);
        emit_time (logbuffer, now);
        mono_gc_walk_heap (0, gc_reference, NULL);
        logbuffer = ensure_logbuf (
                EVENT_SIZE /* event */ +
                LEB128_SIZE /* time */
        );
        now = current_time ();
        emit_byte (logbuffer, TYPE_HEAP_END | TYPE_HEAP);
        emit_time (logbuffer, now);
        last_hs_time = now;
}

static void
gc_event (MonoProfiler *profiler, MonoGCEvent ev, int generation) {
        uint64_t now;
        LogBuffer *logbuffer = ensure_logbuf (
                EVENT_SIZE /* event */ +
                LEB128_SIZE /* time */ +
                LEB128_SIZE /* gc event */ +
                LEB128_SIZE /* generation */
        );
        now = current_time ();
        ENTER_LOG (logbuffer, "gcevent");
        emit_byte (logbuffer, TYPE_GC_EVENT | TYPE_GC);
        emit_time (logbuffer, now);
        emit_value (logbuffer, ev);
        emit_value (logbuffer, generation);
        /* to deal with nested gen1 after gen0 started */
        if (ev == MONO_GC_EVENT_START) {
                profiler->last_gc_gen_started = generation;
                if (generation == mono_gc_max_generation ())
                        gc_count++;
        }
        if (ev == MONO_GC_EVENT_PRE_START_WORLD)
                heap_walk (profiler);
        EXIT_LOG (logbuffer);
        if (ev == MONO_GC_EVENT_POST_START_WORLD)
                safe_send (profiler, logbuffer);
        //printf ("gc event %d for generation %d\n", ev, generation);
}

static void
gc_resize (MonoProfiler *profiler, int64_t new_size) {
        uint64_t now;
        LogBuffer *logbuffer = ensure_logbuf (
                EVENT_SIZE /* event */ +
                LEB128_SIZE /* time */ +
                LEB128_SIZE /* new size */
        );
        now = current_time ();
        ENTER_LOG (logbuffer, "gcresize");
        emit_byte (logbuffer, TYPE_GC_RESIZE | TYPE_GC);
        emit_time (logbuffer, now);
        emit_value (logbuffer, new_size);
        //printf ("gc resized to %lld\n", new_size);
        EXIT_LOG (logbuffer);
}

#define MAX_FRAMES 32
typedef struct {
        int count;
        MonoMethod* methods [MAX_FRAMES];
        int32_t il_offsets [MAX_FRAMES];
        int32_t native_offsets [MAX_FRAMES];
} FrameData;
static int num_frames = MAX_FRAMES;

static mono_bool
walk_stack (MonoMethod *method, int32_t native_offset, int32_t il_offset, mono_bool managed, void* data)
{
        FrameData *frame = (FrameData *)data;
        if (method && frame->count < num_frames) {
                frame->il_offsets [frame->count] = il_offset;
                frame->native_offsets [frame->count] = native_offset;
                frame->methods [frame->count++] = method;
                //printf ("In %d %s at %d (native: %d)\n", frame->count, mono_method_get_name (method), il_offset, native_offset);
        }
        return frame->count == num_frames;
}

/*
 * a note about stack walks: they can cause more profiler events to fire,
 * so we need to make sure they don't happen after we started emitting an
 * event, hence the collect_bt/emit_bt split.
 */
static void
collect_bt (FrameData *data)
{
        data->count = 0;
        mono_stack_walk_no_il (walk_stack, data);
}

static void
emit_bt (MonoProfiler *prof, LogBuffer *logbuffer, FrameData *data)
{
        /* FIXME: this is actually tons of data and we should
         * just output it the first time and use an id the next
         */
        if (data->count > num_frames)
                printf ("bad num frames: %d\n", data->count);
        emit_value (logbuffer, 0); /* flags */
        emit_value (logbuffer, data->count);
        //if (*p != data.count) {
        //      printf ("bad num frames enc at %d: %d -> %d\n", count, data.count, *p); printf ("frames end: %p->%p\n", p, logbuffer->cursor); exit(0);}
        while (data->count) {
                emit_method_as_ptr (prof, logbuffer, data->methods [--data->count]);
        }
}

static void
gc_alloc (MonoProfiler *prof, MonoObject *obj, MonoClass *klass)
{
        uint64_t now;
        uintptr_t len;
        int do_bt = (nocalls && InterlockedRead (&runtime_inited) && !notraces)? TYPE_ALLOC_BT: 0;
        FrameData data;
        LogBuffer *logbuffer;
        len = mono_object_get_size (obj);
        /* account for object alignment in the heap */
        len += 7;
        len &= ~7;
        if (do_bt)
                collect_bt (&data);
        logbuffer = ensure_logbuf (
                EVENT_SIZE /* event */ +
                LEB128_SIZE /* time */ +
                LEB128_SIZE /* klass */ +
                LEB128_SIZE /* obj */ +
                LEB128_SIZE /* size */ +
                (do_bt ? (
                        LEB128_SIZE /* flags */ +
                        LEB128_SIZE /* count */ +
                        data.count * (
                                LEB128_SIZE /* method */
                        )
                ) : 0)
        );
        now = current_time ();
        ENTER_LOG (logbuffer, "gcalloc");
        emit_byte (logbuffer, do_bt | TYPE_ALLOC);
        emit_time (logbuffer, now);
        emit_ptr (logbuffer, klass);
        emit_obj (logbuffer, obj);
        emit_value (logbuffer, len);
        if (do_bt)
                emit_bt (prof, logbuffer, &data);
        EXIT_LOG (logbuffer);
        if (logbuffer->next)
                safe_send (prof, logbuffer);
        process_requests (prof);
        //printf ("gc alloc %s at %p\n", mono_class_get_name (klass), obj);
}

static void
gc_moves (MonoProfiler *prof, void **objects, int num)
{
        int i;
        uint64_t now;
        LogBuffer *logbuffer = ensure_logbuf (
                EVENT_SIZE /* event */ +
                LEB128_SIZE /* time */ +
                LEB128_SIZE /* num */ +
                num * (
                        LEB128_SIZE /* object */
                )
        );
        now = current_time ();
        ENTER_LOG (logbuffer, "gcmove");
        emit_byte (logbuffer, TYPE_GC_MOVE | TYPE_GC);
        emit_time (logbuffer, now);
        emit_value (logbuffer, num);
        for (i = 0; i < num; ++i)
                emit_obj (logbuffer, objects [i]);
        //printf ("gc moved %d objects\n", num/2);
        EXIT_LOG (logbuffer);
}

static void
gc_roots (MonoProfiler *prof, int num, void **objects, int *root_types, uintptr_t *extra_info)
{
        int i;
        LogBuffer *logbuffer = ensure_logbuf (
                EVENT_SIZE /* event */ +
                LEB128_SIZE /* num */ +
                LEB128_SIZE /* collections */ +
                num * (
                        LEB128_SIZE /* object */ +
                        LEB128_SIZE /* root type */ +
                        LEB128_SIZE /* extra info */
                )
        );
        ENTER_LOG (logbuffer, "gcroots");
        emit_byte (logbuffer, TYPE_HEAP_ROOT | TYPE_HEAP);
        emit_value (logbuffer, num);
        emit_value (logbuffer, mono_gc_collection_count (mono_gc_max_generation ()));
        for (i = 0; i < num; ++i) {
                emit_obj (logbuffer, objects [i]);
                emit_value (logbuffer, root_types [i]);
                emit_value (logbuffer, extra_info [i]);
        }
        EXIT_LOG (logbuffer);
}

static void
gc_handle (MonoProfiler *prof, int op, int type, uintptr_t handle, MonoObject *obj)
{
        int do_bt = nocalls && InterlockedRead (&runtime_inited) && !notraces;
        uint64_t now;
        FrameData data;

        if (do_bt)
                collect_bt (&data);

        LogBuffer *logbuffer = ensure_logbuf (
                EVENT_SIZE /* event */ +
                LEB128_SIZE /* time */ +
                LEB128_SIZE /* type */ +
                LEB128_SIZE /* handle */ +
                (op == MONO_PROFILER_GC_HANDLE_CREATED ? (
                        LEB128_SIZE /* obj */
                ) : 0) +
                (do_bt ? (
                        LEB128_SIZE /* flags */ +
                        LEB128_SIZE /* count */ +
                        data.count * (
                                LEB128_SIZE /* method */
                        )
                ) : 0)
        );

        now = current_time ();
        ENTER_LOG (logbuffer, "gchandle");

        if (op == MONO_PROFILER_GC_HANDLE_CREATED)
                emit_byte (logbuffer, (do_bt ? TYPE_GC_HANDLE_CREATED_BT : TYPE_GC_HANDLE_CREATED) | TYPE_GC);
        else if (op == MONO_PROFILER_GC_HANDLE_DESTROYED)
                emit_byte (logbuffer, (do_bt ? TYPE_GC_HANDLE_DESTROYED_BT : TYPE_GC_HANDLE_DESTROYED) | TYPE_GC);
        else
                g_assert_not_reached ();

        emit_time (logbuffer, now);
        emit_value (logbuffer, type);
        emit_value (logbuffer, handle);

        if (op == MONO_PROFILER_GC_HANDLE_CREATED)
                emit_obj (logbuffer, obj);

        if (do_bt)
                emit_bt (prof, logbuffer, &data);

        EXIT_LOG (logbuffer);
        process_requests (prof);
}

static char*
push_nesting (char *p, MonoClass *klass)
{
        MonoClass *nesting;
        const char *name;
        const char *nspace;
        nesting = mono_class_get_nesting_type (klass);
        if (nesting) {
                p = push_nesting (p, nesting);
                *p++ = '/';
                *p = 0;
        }
        name = mono_class_get_name (klass);
        nspace = mono_class_get_namespace (klass);
        if (*nspace) {
                strcpy (p, nspace);
                p += strlen (nspace);
                *p++ = '.';
                *p = 0;
        }
        strcpy (p, name);
        p += strlen (name);
        return p;
}

static char*
type_name (MonoClass *klass)
{
        char buf [1024];
        char *p;
        push_nesting (buf, klass);
        p = (char *)malloc (strlen (buf) + 1);
        strcpy (p, buf);
        return p;
}

static void
image_loaded (MonoProfiler *prof, MonoImage *image, int result)
{
        uint64_t now;
        const char *name;
        int nlen;
        LogBuffer *logbuffer;
        if (result != MONO_PROFILE_OK)
                return;
        name = mono_image_get_filename (image);
        nlen = strlen (name) + 1;
        logbuffer = ensure_logbuf (
                EVENT_SIZE /* event */ +
                LEB128_SIZE /* time */ +
                EVENT_SIZE /* type */ +
                LEB128_SIZE /* image */ +
                LEB128_SIZE /* flags */ +
                nlen /* name */
        );
        now = current_time ();
        ENTER_LOG (logbuffer, "image");
        emit_byte (logbuffer, TYPE_END_LOAD | TYPE_METADATA);
        emit_time (logbuffer, now);
        emit_byte (logbuffer, TYPE_IMAGE);
        emit_ptr (logbuffer, image);
        emit_value (logbuffer, 0); /* flags */
        memcpy (logbuffer->cursor, name, nlen);
        logbuffer->cursor += nlen;
        //printf ("loaded image %p (%s)\n", image, name);
        EXIT_LOG (logbuffer);
        if (logbuffer->next)
                safe_send (prof, logbuffer);
        process_requests (prof);
}

static void
image_unloaded (MonoProfiler *prof, MonoImage *image)
{
        const char *name = mono_image_get_filename (image);
        int nlen = strlen (name) + 1;
        LogBuffer *logbuffer = ensure_logbuf (
                EVENT_SIZE /* event */ +
                LEB128_SIZE /* time */ +
                EVENT_SIZE /* type */ +
                LEB128_SIZE /* image */ +
                LEB128_SIZE /* flags */ +
                nlen /* name */
        );
        uint64_t now = current_time ();

        ENTER_LOG (logbuffer, "image-unload");
        emit_byte (logbuffer, TYPE_END_UNLOAD | TYPE_METADATA);
        emit_time (logbuffer, now);
        emit_byte (logbuffer, TYPE_IMAGE);
        emit_ptr (logbuffer, image);
        emit_value (logbuffer, 0); /* flags */
        memcpy (logbuffer->cursor, name, nlen);
        logbuffer->cursor += nlen;
        EXIT_LOG (logbuffer);

        if (logbuffer->next)
                safe_send (prof, logbuffer);

        process_requests (prof);
}

static void
assembly_loaded (MonoProfiler *prof, MonoAssembly *assembly, int result)
{
        if (result != MONO_PROFILE_OK)
                return;

        char *name = mono_stringify_assembly_name (mono_assembly_get_name (assembly));
        int nlen = strlen (name) + 1;
        LogBuffer *logbuffer = ensure_logbuf (
                EVENT_SIZE /* event */ +
                LEB128_SIZE /* time */ +
                EVENT_SIZE /* type */ +
                LEB128_SIZE /* assembly */ +
                LEB128_SIZE /* flags */ +
                nlen /* name */
        );
        uint64_t now = current_time ();

        ENTER_LOG (logbuffer, "assembly-load");
        emit_byte (logbuffer, TYPE_END_LOAD | TYPE_METADATA);
        emit_time (logbuffer, now);
        emit_byte (logbuffer, TYPE_ASSEMBLY);
        emit_ptr (logbuffer, assembly);
        emit_value (logbuffer, 0); /* flags */
        memcpy (logbuffer->cursor, name, nlen);
        logbuffer->cursor += nlen;
        EXIT_LOG (logbuffer);

        mono_free (name);

        if (logbuffer->next)
                safe_send (prof, logbuffer);

        process_requests (prof);
}

static void
assembly_unloaded (MonoProfiler *prof, MonoAssembly *assembly)
{
        char *name = mono_stringify_assembly_name (mono_assembly_get_name (assembly));
        int nlen = strlen (name) + 1;
        LogBuffer *logbuffer = ensure_logbuf (
                EVENT_SIZE /* event */ +
                LEB128_SIZE /* time */ +
                EVENT_SIZE /* type */ +
                LEB128_SIZE /* assembly */ +
                LEB128_SIZE /* flags */ +
                nlen /* name */
        );
        uint64_t now = current_time ();

        ENTER_LOG (logbuffer, "assembly-unload");
        emit_byte (logbuffer, TYPE_END_UNLOAD | TYPE_METADATA);
        emit_time (logbuffer, now);
        emit_byte (logbuffer, TYPE_ASSEMBLY);
        emit_ptr (logbuffer, assembly);
        emit_value (logbuffer, 0); /* flags */
        memcpy (logbuffer->cursor, name, nlen);
        logbuffer->cursor += nlen;
        EXIT_LOG (logbuffer);

        mono_free (name);

        if (logbuffer->next)
                safe_send (prof, logbuffer);

        process_requests (prof);
}

static void
class_loaded (MonoProfiler *prof, MonoClass *klass, int result)
{
        uint64_t now;
        char *name;
        int nlen;
        MonoImage *image;
        LogBuffer *logbuffer;
        if (result != MONO_PROFILE_OK)
                return;
        if (InterlockedRead (&runtime_inited))
                name = mono_type_get_name (mono_class_get_type (klass));
        else
                name = type_name (klass);
        nlen = strlen (name) + 1;
        image = mono_class_get_image (klass);
        logbuffer = ensure_logbuf (
                EVENT_SIZE /* event */ +
                LEB128_SIZE /* time */ +
                EVENT_SIZE /* type */ +
                LEB128_SIZE /* klass */ +
                LEB128_SIZE /* image */ +
                LEB128_SIZE /* flags */ +
                nlen /* name */
        );
        now = current_time ();
        ENTER_LOG (logbuffer, "class");
        emit_byte (logbuffer, TYPE_END_LOAD | TYPE_METADATA);
        emit_time (logbuffer, now);
        emit_byte (logbuffer, TYPE_CLASS);
        emit_ptr (logbuffer, klass);
        emit_ptr (logbuffer, image);
        emit_value (logbuffer, 0); /* flags */
        memcpy (logbuffer->cursor, name, nlen);
        logbuffer->cursor += nlen;
        //printf ("loaded class %p (%s)\n", klass, name);
        if (runtime_inited)
                mono_free (name);
        else
                free (name);
        EXIT_LOG (logbuffer);
        if (logbuffer->next)
                safe_send (prof, logbuffer);
        process_requests (prof);
}

static void
class_unloaded (MonoProfiler *prof, MonoClass *klass)
{
        char *name;

        if (InterlockedRead (&runtime_inited))
                name = mono_type_get_name (mono_class_get_type (klass));
        else
                name = type_name (klass);

        int nlen = strlen (name) + 1;
        MonoImage *image = mono_class_get_image (klass);
        LogBuffer *logbuffer = ensure_logbuf (
                EVENT_SIZE /* event */ +
                LEB128_SIZE /* time */ +
                EVENT_SIZE /* type */ +
                LEB128_SIZE /* klass */ +
                LEB128_SIZE /* image */ +
                LEB128_SIZE /* flags */ +
                nlen /* name */
        );
        uint64_t now = current_time ();

        ENTER_LOG (logbuffer, "class-unload");
        emit_byte (logbuffer, TYPE_END_UNLOAD | TYPE_METADATA);
        emit_time (logbuffer, now);
        emit_byte (logbuffer, TYPE_CLASS);
        emit_ptr (logbuffer, klass);
        emit_ptr (logbuffer, image);
        emit_value (logbuffer, 0); /* flags */
        memcpy (logbuffer->cursor, name, nlen);
        logbuffer->cursor += nlen;
        EXIT_LOG (logbuffer);

        if (runtime_inited)
                mono_free (name);
        else
                free (name);

        if (logbuffer->next)
                safe_send (prof, logbuffer);

        process_requests (prof);
}

#ifndef DISABLE_HELPER_THREAD
static void process_method_enter_coverage (MonoProfiler *prof, MonoMethod *method);
#endif /* DISABLE_HELPER_THREAD */

static void
method_enter (MonoProfiler *prof, MonoMethod *method)
{
        uint64_t now = current_time ();

#ifndef DISABLE_HELPER_THREAD
        process_method_enter_coverage (prof, method);
#endif /* DISABLE_HELPER_THREAD */

        LogBuffer *logbuffer = ensure_logbuf (
                EVENT_SIZE /* event */ +
                LEB128_SIZE /* time */ +
                LEB128_SIZE /* method */
        );
        if (logbuffer->call_depth++ > max_call_depth)
                return;
        ENTER_LOG (logbuffer, "enter");
        emit_byte (logbuffer, TYPE_ENTER | TYPE_METHOD);
        emit_time (logbuffer, now);
        emit_method (prof, logbuffer, method);
        EXIT_LOG (logbuffer);

        process_requests (prof);
}

static void
method_leave (MonoProfiler *prof, MonoMethod *method)
{
        uint64_t now;
        LogBuffer *logbuffer = ensure_logbuf (
                EVENT_SIZE /* event */ +
                LEB128_SIZE /* time */ +
                LEB128_SIZE /* method */
        );
        if (--logbuffer->call_depth > max_call_depth)
                return;
        now = current_time ();
        ENTER_LOG (logbuffer, "leave");
        emit_byte (logbuffer, TYPE_LEAVE | TYPE_METHOD);
        emit_time (logbuffer, now);
        emit_method (prof, logbuffer, method);
        EXIT_LOG (logbuffer);
        if (logbuffer->next)
                safe_send (prof, logbuffer);
        process_requests (prof);
}

static void
method_exc_leave (MonoProfiler *prof, MonoMethod *method)
{
        uint64_t now;
        LogBuffer *logbuffer;
        if (nocalls)
                return;
        logbuffer = ensure_logbuf (
                EVENT_SIZE /* event */ +
                LEB128_SIZE /* time */ +
                LEB128_SIZE /* method */
        );
        if (--logbuffer->call_depth > max_call_depth)
                return;
        now = current_time ();
        ENTER_LOG (logbuffer, "eleave");
        emit_byte (logbuffer, TYPE_EXC_LEAVE | TYPE_METHOD);
        emit_time (logbuffer, now);
        emit_method (prof, logbuffer, method);
        EXIT_LOG (logbuffer);
        process_requests (prof);
}

static void
method_jitted (MonoProfiler *prof, MonoMethod *method, MonoJitInfo *ji, int result)
{
        if (result != MONO_PROFILE_OK)
                return;

        register_method_local (prof, method, ji);

        process_requests (prof);
}

static void
code_buffer_new (MonoProfiler *prof, void *buffer, int size, MonoProfilerCodeBufferType type, void *data)
{
        uint64_t now;
        int nlen;
        char *name;
        LogBuffer *logbuffer;
        if (type == MONO_PROFILER_CODE_BUFFER_SPECIFIC_TRAMPOLINE) {
                name = (char *)data;
                nlen = strlen (name) + 1;
        } else {
                name = NULL;
                nlen = 0;
        }
        logbuffer = ensure_logbuf (
                EVENT_SIZE /* event */ +
                LEB128_SIZE /* time */ +
                LEB128_SIZE /* type */ +
                LEB128_SIZE /* buffer */ +
                LEB128_SIZE /* size */ +
                (name ? (
                        nlen /* name */
                ) : 0)
        );
        now = current_time ();
        ENTER_LOG (logbuffer, "code buffer");
        emit_byte (logbuffer, TYPE_JITHELPER | TYPE_RUNTIME);
        emit_time (logbuffer, now);
        emit_value (logbuffer, type);
        emit_ptr (logbuffer, buffer);
        emit_value (logbuffer, size);
        if (name) {
                memcpy (logbuffer->cursor, name, nlen);
                logbuffer->cursor += nlen;
        }
        EXIT_LOG (logbuffer);
        process_requests (prof);
}

static void
throw_exc (MonoProfiler *prof, MonoObject *object)
{
        int do_bt = (nocalls && InterlockedRead (&runtime_inited) && !notraces)? TYPE_EXCEPTION_BT: 0;
        uint64_t now;
        FrameData data;
        LogBuffer *logbuffer;
        if (do_bt)
                collect_bt (&data);
        logbuffer = ensure_logbuf (
                EVENT_SIZE /* event */ +
                LEB128_SIZE /* time */ +
                LEB128_SIZE /* object */ +
                (do_bt ? (
                        LEB128_SIZE /* flags */ +
                        LEB128_SIZE /* count */ +
                        data.count * (
                                LEB128_SIZE /* method */
                        )
                ) : 0)
        );
        now = current_time ();
        ENTER_LOG (logbuffer, "throw");
        emit_byte (logbuffer, do_bt | TYPE_EXCEPTION);
        emit_time (logbuffer, now);
        emit_obj (logbuffer, object);
        if (do_bt)
                emit_bt (prof, logbuffer, &data);
        EXIT_LOG (logbuffer);
        process_requests (prof);
}

static void
clause_exc (MonoProfiler *prof, MonoMethod *method, int clause_type, int clause_num)
{
        uint64_t now;
        LogBuffer *logbuffer = ensure_logbuf (
                EVENT_SIZE /* event */ +
                LEB128_SIZE /* time */ +
                LEB128_SIZE /* clause type */ +
                LEB128_SIZE /* clause num */ +
                LEB128_SIZE /* method */
        );
        now = current_time ();
        ENTER_LOG (logbuffer, "clause");
        emit_byte (logbuffer, TYPE_EXCEPTION | TYPE_CLAUSE);
        emit_time (logbuffer, now);
        emit_value (logbuffer, clause_type);
        emit_value (logbuffer, clause_num);
        emit_method (prof, logbuffer, method);
        EXIT_LOG (logbuffer);

        process_requests (prof);
}

static void
monitor_event (MonoProfiler *profiler, MonoObject *object, MonoProfilerMonitorEvent event)
{
        int do_bt = (nocalls && InterlockedRead (&runtime_inited) && !notraces && event == MONO_PROFILER_MONITOR_CONTENTION)? TYPE_MONITOR_BT: 0;
        uint64_t now;
        FrameData data;
        LogBuffer *logbuffer;
        if (do_bt)
                collect_bt (&data);
        logbuffer = ensure_logbuf (
                EVENT_SIZE /* event */ +
                LEB128_SIZE /* time */ +
                LEB128_SIZE /* object */ +
                (do_bt ? (
                        LEB128_SIZE /* flags */ +
                        LEB128_SIZE /* count */ +
                        data.count * (
                                LEB128_SIZE /* method */
                        )
                ) : 0)
        );
        now = current_time ();
        ENTER_LOG (logbuffer, "monitor");
        emit_byte (logbuffer, (event << 4) | do_bt | TYPE_MONITOR);
        emit_time (logbuffer, now);
        emit_obj (logbuffer, object);
        if (do_bt)
                emit_bt (profiler, logbuffer, &data);
        EXIT_LOG (logbuffer);
        process_requests (profiler);
}

static void
thread_start (MonoProfiler *prof, uintptr_t tid)
{
        //printf ("thread start %p\n", (void*)tid);
        init_thread ();

        LogBuffer *logbuffer = ensure_logbuf (
                EVENT_SIZE /* event */ +
                LEB128_SIZE /* time */ +
                EVENT_SIZE /* type */ +
                LEB128_SIZE /* tid */ +
                LEB128_SIZE /* flags */
        );
        uint64_t now = current_time ();

        ENTER_LOG (logbuffer, "thread-start");
        emit_byte (logbuffer, TYPE_END_LOAD | TYPE_METADATA);
        emit_time (logbuffer, now);
        emit_byte (logbuffer, TYPE_THREAD);
        emit_ptr (logbuffer, (void*) tid);
        emit_value (logbuffer, 0); /* flags */
        EXIT_LOG (logbuffer);

        if (logbuffer->next)
                safe_send (prof, logbuffer);

        process_requests (prof);
}

static void
thread_end (MonoProfiler *prof, uintptr_t tid)
{
        if (TLS_GET (LogBuffer, tlsbuffer)) {
                LogBuffer *logbuffer = ensure_logbuf (
                        EVENT_SIZE /* event */ +
                        LEB128_SIZE /* time */ +
                        EVENT_SIZE /* type */ +
                        LEB128_SIZE /* tid */ +
                        LEB128_SIZE /* flags */
                );
                uint64_t now = current_time ();

                ENTER_LOG (logbuffer, "thread-end");
                emit_byte (logbuffer, TYPE_END_UNLOAD | TYPE_METADATA);
                emit_time (logbuffer, now);
                emit_byte (logbuffer, TYPE_THREAD);
                emit_ptr (logbuffer, (void*) tid);
                emit_value (logbuffer, 0); /* flags */
                EXIT_LOG (logbuffer);

                send_buffer (prof, TLS_GET (GPtrArray, tlsmethodlist), logbuffer);

                /* Don't process requests as the thread is detached from the runtime. */
        }

        TLS_SET (tlsbuffer, NULL);
        TLS_SET (tlsmethodlist, NULL);
}

static void
domain_loaded (MonoProfiler *prof, MonoDomain *domain, int result)
{
        if (result != MONO_PROFILE_OK)
                return;

        LogBuffer *logbuffer = ensure_logbuf (
                EVENT_SIZE /* event */ +
                LEB128_SIZE /* time */ +
                EVENT_SIZE /* type */ +
                LEB128_SIZE /* domain id */ +
                LEB128_SIZE /* flags */
        );
        uint64_t now = current_time ();

        ENTER_LOG (logbuffer, "domain-start");
        emit_byte (logbuffer, TYPE_END_LOAD | TYPE_METADATA);
        emit_time (logbuffer, now);
        emit_byte (logbuffer, TYPE_DOMAIN);
        emit_ptr (logbuffer, (void*)(uintptr_t) mono_domain_get_id (domain));
        emit_value (logbuffer, 0); /* flags */
        EXIT_LOG (logbuffer);

        if (logbuffer->next)
                safe_send (prof, logbuffer);

        process_requests (prof);
}

static void
domain_unloaded (MonoProfiler *prof, MonoDomain *domain)
{
        LogBuffer *logbuffer = ensure_logbuf (
                EVENT_SIZE /* event */ +
                LEB128_SIZE /* time */ +
                EVENT_SIZE /* type */ +
                LEB128_SIZE /* domain id */ +
                LEB128_SIZE /* flags */
        );
        uint64_t now = current_time ();

        ENTER_LOG (logbuffer, "domain-end");
        emit_byte (logbuffer, TYPE_END_UNLOAD | TYPE_METADATA);
        emit_time (logbuffer, now);
        emit_byte (logbuffer, TYPE_DOMAIN);
        emit_ptr (logbuffer, (void*)(uintptr_t) mono_domain_get_id (domain));
        emit_value (logbuffer, 0); /* flags */
        EXIT_LOG (logbuffer);

        if (logbuffer->next)
                safe_send (prof, logbuffer);

        process_requests (prof);
}

static void
domain_name (MonoProfiler *prof, MonoDomain *domain, const char *name)
{
        int nlen = strlen (name) + 1;
        LogBuffer *logbuffer = ensure_logbuf (
                EVENT_SIZE /* event */ +
                LEB128_SIZE /* time */ +
                EVENT_SIZE /* type */ +
                LEB128_SIZE /* domain id */ +
                LEB128_SIZE /* flags */ +
                nlen /* name */
        );
        uint64_t now = current_time ();

        ENTER_LOG (logbuffer, "domain-name");
        emit_byte (logbuffer, TYPE_METADATA);
        emit_time (logbuffer, now);
        emit_byte (logbuffer, TYPE_DOMAIN);
        emit_ptr (logbuffer, (void*)(uintptr_t) mono_domain_get_id (domain));
        emit_value (logbuffer, 0); /* flags */
        memcpy (logbuffer->cursor, name, nlen);
        logbuffer->cursor += nlen;
        EXIT_LOG (logbuffer);

        if (logbuffer->next)
                safe_send (prof, logbuffer);

        process_requests (prof);
}

static void
context_loaded (MonoProfiler *prof, MonoAppContext *context)
{
        LogBuffer *logbuffer = ensure_logbuf (
                EVENT_SIZE /* event */ +
                LEB128_SIZE /* time */ +
                EVENT_SIZE /* type */ +
                LEB128_SIZE /* context id */ +
                LEB128_SIZE /* flags */ +
                LEB128_SIZE /* domain id */
        );
        uint64_t now = current_time ();

        ENTER_LOG (logbuffer, "context-start");
        emit_byte (logbuffer, TYPE_END_LOAD | TYPE_METADATA);
        emit_time (logbuffer, now);
        emit_byte (logbuffer, TYPE_CONTEXT);
        emit_ptr (logbuffer, (void*)(uintptr_t) mono_context_get_id (context));
        emit_value (logbuffer, 0); /* flags */
        emit_ptr (logbuffer, (void*)(uintptr_t) mono_context_get_domain_id (context));
        EXIT_LOG (logbuffer);

        if (logbuffer->next)
                safe_send (prof, logbuffer);

        process_requests (prof);
}

static void
context_unloaded (MonoProfiler *prof, MonoAppContext *context)
{
        LogBuffer *logbuffer = ensure_logbuf (
                EVENT_SIZE /* event */ +
                LEB128_SIZE /* time */ +
                EVENT_SIZE /* type */ +
                LEB128_SIZE /* context id */ +
                LEB128_SIZE /* flags */ +
                LEB128_SIZE /* domain id */
        );
        uint64_t now = current_time ();

        ENTER_LOG (logbuffer, "context-end");
        emit_byte (logbuffer, TYPE_END_UNLOAD | TYPE_METADATA);
        emit_time (logbuffer, now);
        emit_byte (logbuffer, TYPE_CONTEXT);
        emit_ptr (logbuffer, (void*)(uintptr_t) mono_context_get_id (context));
        emit_value (logbuffer, 0); /* flags */
        emit_ptr (logbuffer, (void*)(uintptr_t) mono_context_get_domain_id (context));
        EXIT_LOG (logbuffer);

        if (logbuffer->next)
                safe_send (prof, logbuffer);

        process_requests (prof);
}

static void
thread_name (MonoProfiler *prof, uintptr_t tid, const char *name)
{
        int len = strlen (name) + 1;
        uint64_t now;
        LogBuffer *logbuffer;
        logbuffer = ensure_logbuf (
                EVENT_SIZE /* event */ +
                LEB128_SIZE /* time */ +
                EVENT_SIZE /* type */ +
                LEB128_SIZE /* tid */ +
                LEB128_SIZE /* flags */ +
                len /* name */
        );
        now = current_time ();
        ENTER_LOG (logbuffer, "tname");
        emit_byte (logbuffer, TYPE_METADATA);
        emit_time (logbuffer, now);
        emit_byte (logbuffer, TYPE_THREAD);
        emit_ptr (logbuffer, (void*)tid);
        emit_value (logbuffer, 0); /* flags */
        memcpy (logbuffer->cursor, name, len);
        logbuffer->cursor += len;
        EXIT_LOG (logbuffer);

        if (logbuffer->next)
                safe_send (prof, logbuffer);

        process_requests (prof);
}

typedef struct {
        MonoMethod *method;
        MonoDomain *domain;
        void *base_address;
        int offset;
} AsyncFrameInfo;

typedef struct {
        int count;
        AsyncFrameInfo *data;
} AsyncFrameData;

static mono_bool
async_walk_stack (MonoMethod *method, MonoDomain *domain, void *base_address, int offset, void *data)
{
        AsyncFrameData *frame = (AsyncFrameData *)data;
        if (frame->count < num_frames) {
                frame->data [frame->count].method = method;
                frame->data [frame->count].domain = domain;
                frame->data [frame->count].base_address = base_address;
                frame->data [frame->count].offset = offset;
                // printf ("In %d at %p (dom %p) (native: %p)\n", frame->count, method, domain, base_address);
                frame->count++;
        }
        return frame->count == num_frames;
}

/*
(type | frame count), tid, time, ip, [method, domain, base address, offset] * frames
*/
#define SAMPLE_EVENT_SIZE_IN_SLOTS(FRAMES) (4 + (FRAMES) * 4)

static void
mono_sample_hit (MonoProfiler *profiler, unsigned char *ip, void *context)
{
        StatBuffer *sbuf;
        AsyncFrameInfo frames [num_frames];
        AsyncFrameData bt_data = { 0, &frames [0]};
        uint64_t now;
        uintptr_t *data, *new_data, *old_data;
        uintptr_t elapsed;
        int timedout = 0;
        int i;
        if (in_shutdown)
                return;
        now = current_time ();

        mono_stack_walk_async_safe (&async_walk_stack, context, &bt_data);

        elapsed = (now - profiler->startup_time) / 10000;
        if (do_debug) {
                int len;
                char buf [256];
                snprintf (buf, sizeof (buf), "hit at %p in thread %p after %llu ms\n", ip, (void*)thread_id (), (unsigned long long int)elapsed/100);
                len = strlen (buf);
                ign_res (write (2, buf, len));
        }
        sbuf = profiler->stat_buffers;
        if (!sbuf)
                return;
        /* flush the buffer at 1 second intervals */
        if (sbuf->cursor > sbuf->buf && (elapsed - sbuf->buf [2]) > 100000) {
                timedout = 1;
        }
        /* overflow: 400 slots is a big enough number to reduce the chance of losing this event if many
         * threads hit this same spot at the same time
         */
        if (timedout || (sbuf->cursor + 400 >= sbuf->buf_end)) {
                StatBuffer *oldsb, *foundsb;
                sbuf = create_stat_buffer ();
                do {
                        oldsb = profiler->stat_buffers;
                        sbuf->next = oldsb;
                        foundsb = (StatBuffer *)InterlockedCompareExchangePointer ((void * volatile*)&profiler->stat_buffers, sbuf, oldsb);
                } while (foundsb != oldsb);
                if (do_debug)
                        ign_res (write (2, "overflow\n", 9));
                /* notify the helper thread */
                if (sbuf->next->next) {
                        char c = 0;
                        ign_res (write (profiler->pipes [1], &c, 1));
                        if (do_debug)
                                ign_res (write (2, "notify\n", 7));
                }
        }
        do {
                old_data = sbuf->cursor;
                new_data = old_data + SAMPLE_EVENT_SIZE_IN_SLOTS (bt_data.count);
                if (new_data > sbuf->buf_end)
                        return; /* Not enough room in buf to hold this event-- lost event */
                data = (uintptr_t *)InterlockedCompareExchangePointer ((void * volatile*)&sbuf->cursor, new_data, old_data);
        } while (data != old_data);

        old_data [0] = 1 | (sample_type << 16) | (bt_data.count << 8);
        old_data [1] = thread_id ();
        old_data [2] = elapsed;
        old_data [3] = (uintptr_t)ip;
        for (i = 0; i < bt_data.count; ++i) {
                old_data [4 + 4 * i + 0] = (uintptr_t)frames [i].method;
                old_data [4 + 4 * i + 1] = (uintptr_t)frames [i].domain;
                old_data [4 + 4 * i + 2] = (uintptr_t)frames [i].base_address;
                old_data [4 + 4 * i + 3] = (uintptr_t)frames [i].offset;
        }
}

static uintptr_t *code_pages = 0;
static int num_code_pages = 0;
static int size_code_pages = 0;
#define CPAGE_SHIFT (9)
#define CPAGE_SIZE (1 << CPAGE_SHIFT)
#define CPAGE_MASK (~(CPAGE_SIZE - 1))
#define CPAGE_ADDR(p) ((p) & CPAGE_MASK)

static uintptr_t
add_code_page (uintptr_t *hash, uintptr_t hsize, uintptr_t page)
{
        uintptr_t i;
        uintptr_t start_pos;
        start_pos = (page >> CPAGE_SHIFT) % hsize;
        i = start_pos;
        do {
                if (hash [i] && CPAGE_ADDR (hash [i]) == CPAGE_ADDR (page)) {
                        return 0;
                } else if (!hash [i]) {
                        hash [i] = page;
                        return 1;
                }
                /* wrap around */
                if (++i == hsize)
                        i = 0;
        } while (i != start_pos);
        /* should not happen */
        printf ("failed code page store\n");
        return 0;
}

static void
add_code_pointer (uintptr_t ip)
{
        uintptr_t i;
        if (num_code_pages * 2 >= size_code_pages) {
                uintptr_t *n;
                uintptr_t old_size = size_code_pages;
                size_code_pages *= 2;
                if (size_code_pages == 0)
                        size_code_pages = 16;
                n = (uintptr_t *)calloc (sizeof (uintptr_t) * size_code_pages, 1);
                for (i = 0; i < old_size; ++i) {
                        if (code_pages [i])
                                add_code_page (n, size_code_pages, code_pages [i]);
                }
                if (code_pages)
                        free (code_pages);
                code_pages = n;
        }
        num_code_pages += add_code_page (code_pages, size_code_pages, ip & CPAGE_MASK);
}

/* ELF code crashes on some systems. */
//#if defined(HAVE_DL_ITERATE_PHDR) && defined(ELFMAG0)
#if 0
static void
dump_ubin (const char *filename, uintptr_t load_addr, uint64_t offset, uintptr_t size)
{
        uint64_t now;
        LogBuffer *logbuffer;
        int len;
        len = strlen (filename) + 1;
        now = current_time ();
        logbuffer = ensure_logbuf (
                EVENT_SIZE /* event */ +
                LEB128_SIZE /* time */ +
                LEB128_SIZE /* load address */ +
                LEB128_SIZE /* offset */ +
                LEB128_SIZE /* size */ +
                nlen /* file name */
        );
        emit_byte (logbuffer, TYPE_SAMPLE | TYPE_SAMPLE_UBIN);
        emit_time (logbuffer, now);
        emit_svalue (logbuffer, load_addr);
        emit_uvalue (logbuffer, offset);
        emit_uvalue (logbuffer, size);
        memcpy (logbuffer->cursor, filename, len);
        logbuffer->cursor += len;
}
#endif

static void
dump_usym (const char *name, uintptr_t value, uintptr_t size)
{
        LogBuffer *logbuffer;
        int len;
        len = strlen (name) + 1;
        logbuffer = ensure_logbuf (
                EVENT_SIZE /* event */ +
                LEB128_SIZE /* value */ +
                LEB128_SIZE /* size */ +
                len /* name */
        );
        emit_byte (logbuffer, TYPE_SAMPLE | TYPE_SAMPLE_USYM);
        emit_ptr (logbuffer, (void*)value);
        emit_value (logbuffer, size);
        memcpy (logbuffer->cursor, name, len);
        logbuffer->cursor += len;
}

/* ELF code crashes on some systems. */
//#if defined(ELFMAG0)
#if 0

#if SIZEOF_VOID_P == 4
#define ELF_WSIZE 32
#else
#define ELF_WSIZE 64
#endif
#ifndef ElfW
#define ElfW(type)      _ElfW (Elf, ELF_WSIZE, type)
#define _ElfW(e,w,t)    _ElfW_1 (e, w, _##t)
#define _ElfW_1(e,w,t)  e##w##t
#endif

static void
dump_elf_symbols (ElfW(Sym) *symbols, int num_symbols, const char *strtab, void *load_addr)
{
        int i;
        for (i = 0; i < num_symbols; ++i) {
                const char* sym;
                sym =  strtab + symbols [i].st_name;
                if (!symbols [i].st_name || !symbols [i].st_size || (symbols [i].st_info & 0xf) != STT_FUNC)
                        continue;
                //printf ("symbol %s at %d\n", sym, symbols [i].st_value);
                dump_usym (sym, (uintptr_t)load_addr + symbols [i].st_value, symbols [i].st_size);
        }
}

static int
read_elf_symbols (MonoProfiler *prof, const char *filename, void *load_addr)
{
        int fd, i;
        void *data;
        struct stat statb;
        uint64_t file_size;
        ElfW(Ehdr) *header;
        ElfW(Shdr) *sheader;
        ElfW(Shdr) *shstrtabh;
        ElfW(Shdr) *symtabh = NULL;
        ElfW(Shdr) *strtabh = NULL;
        ElfW(Sym) *symbols = NULL;
        const char *strtab;
        int num_symbols;

        fd = open (filename, O_RDONLY);
        if (fd < 0)
                return 0;
        if (fstat (fd, &statb) != 0) {
                close (fd);
                return 0;
        }
        file_size = statb.st_size;
        data = mmap (NULL, file_size, PROT_READ, MAP_PRIVATE, fd, 0);
        close (fd);
        if (data == MAP_FAILED)
                return 0;
        header = data;
        if (header->e_ident [EI_MAG0] != ELFMAG0 ||
                        header->e_ident [EI_MAG1] != ELFMAG1 ||
                        header->e_ident [EI_MAG2] != ELFMAG2 ||
                        header->e_ident [EI_MAG3] != ELFMAG3 ) {
                munmap (data, file_size);
                return 0;
        }
        sheader = (void*)((char*)data + header->e_shoff);
        shstrtabh = (void*)((char*)sheader + (header->e_shentsize * header->e_shstrndx));
        strtab = (const char*)data + shstrtabh->sh_offset;
        for (i = 0; i < header->e_shnum; ++i) {
                //printf ("section header: %d\n", sheader->sh_type);
                if (sheader->sh_type == SHT_SYMTAB) {
                        symtabh = sheader;
                        strtabh = (void*)((char*)data + header->e_shoff + sheader->sh_link * header->e_shentsize);
                        /*printf ("symtab section header: %d, .strstr: %d\n", i, sheader->sh_link);*/
                        break;
                }
                sheader = (void*)((char*)sheader + header->e_shentsize);
        }
        if (!symtabh || !strtabh) {
                munmap (data, file_size);
                return 0;
        }
        strtab = (const char*)data + strtabh->sh_offset;
        num_symbols = symtabh->sh_size / symtabh->sh_entsize;
        symbols = (void*)((char*)data + symtabh->sh_offset);
        dump_elf_symbols (symbols, num_symbols, strtab, load_addr);
        munmap (data, file_size);
        return 1;
}
#endif

/* ELF code crashes on some systems. */
//#if defined(HAVE_DL_ITERATE_PHDR) && defined(ELFMAG0)
#if 0
static int
elf_dl_callback (struct dl_phdr_info *info, size_t size, void *data)
{
        MonoProfiler *prof = data;
        char buf [256];
        const char *filename;
        BinaryObject *obj;
        char *a = (void*)info->dlpi_addr;
        int i, num_sym;
        ElfW(Dyn) *dyn = NULL;
        ElfW(Sym) *symtab = NULL;
        ElfW(Word) *hash_table = NULL;
        ElfW(Ehdr) *header = NULL;
        const char* strtab = NULL;
        for (obj = prof->binary_objects; obj; obj = obj->next) {
                if (obj->addr == a)
                        return 0;
        }
        filename = info->dlpi_name;
        if (!filename)
                return 0;
        if (!info->dlpi_addr && !filename [0]) {
                int l = readlink ("/proc/self/exe", buf, sizeof (buf) - 1);
                if (l > 0) {
                        buf [l] = 0;
                        filename = buf;
                }
        }
        obj = calloc (sizeof (BinaryObject), 1);
        obj->addr = (void*)info->dlpi_addr;
        obj->name = pstrdup (filename);
        obj->next = prof->binary_objects;
        prof->binary_objects = obj;
        //printf ("loaded file: %s at %p, segments: %d\n", filename, (void*)info->dlpi_addr, info->dlpi_phnum);
        a = NULL;
        for (i = 0; i < info->dlpi_phnum; ++i) {
                //printf ("segment type %d file offset: %d, size: %d\n", info->dlpi_phdr[i].p_type, info->dlpi_phdr[i].p_offset, info->dlpi_phdr[i].p_memsz);
                if (info->dlpi_phdr[i].p_type == PT_LOAD && !header) {
                        header = (ElfW(Ehdr)*)(info->dlpi_addr + info->dlpi_phdr[i].p_vaddr);
                        if (header->e_ident [EI_MAG0] != ELFMAG0 ||
                                        header->e_ident [EI_MAG1] != ELFMAG1 ||
                                        header->e_ident [EI_MAG2] != ELFMAG2 ||
                                        header->e_ident [EI_MAG3] != ELFMAG3 ) {
                                header = NULL;
                        }
                        dump_ubin (filename, info->dlpi_addr + info->dlpi_phdr[i].p_vaddr, info->dlpi_phdr[i].p_offset, info->dlpi_phdr[i].p_memsz);
                } else if (info->dlpi_phdr[i].p_type == PT_DYNAMIC) {
                        dyn = (ElfW(Dyn) *)(info->dlpi_addr + info->dlpi_phdr[i].p_vaddr);
                }
        }
        if (read_elf_symbols (prof, filename, (void*)info->dlpi_addr))
                return 0;
        if (!info->dlpi_name || !info->dlpi_name[0])
                return 0;
        if (!dyn)
                return 0;
        for (i = 0; dyn [i].d_tag != DT_NULL; ++i) {
                if (dyn [i].d_tag == DT_SYMTAB) {
                        if (symtab && do_debug)
                                printf ("multiple symtabs: %d\n", i);
                        symtab = (ElfW(Sym) *)(a + dyn [i].d_un.d_ptr);
                } else if (dyn [i].d_tag == DT_HASH) {
                        hash_table = (ElfW(Word) *)(a + dyn [i].d_un.d_ptr);
                } else if (dyn [i].d_tag == DT_STRTAB) {
                        strtab = (const char*)(a + dyn [i].d_un.d_ptr);
                }
        }
        if (!hash_table)
                return 0;
        num_sym = hash_table [1];
        dump_elf_symbols (symtab, num_sym, strtab, (void*)info->dlpi_addr);
        return 0;
}

static int
load_binaries (MonoProfiler *prof)
{
        dl_iterate_phdr (elf_dl_callback, prof);
        return 1;
}
#else
static int
load_binaries (MonoProfiler *prof)
{
        return 0;
}
#endif

static const char*
symbol_for (uintptr_t code)
{
#ifdef HAVE_DLADDR
        void *ip = (void*)code;
        Dl_info di;
        if (dladdr (ip, &di)) {
                if (di.dli_sname)
                        return di.dli_sname;
        } else {
        /*      char **names;
                names = backtrace_symbols (&ip, 1);
                if (names) {
                        const char* p = names [0];
                        free (names);
                        return p;
                }
                */
        }
#endif
        return NULL;
}

static void
dump_unmanaged_coderefs (MonoProfiler *prof)
{
        int i;
        const char* last_symbol;
        uintptr_t addr, page_end;

        if (load_binaries (prof))
                return;
        for (i = 0; i < size_code_pages; ++i) {
                const char* sym;
                if (!code_pages [i] || code_pages [i] & 1)
                        continue;
                last_symbol = NULL;
                addr = CPAGE_ADDR (code_pages [i]);
                page_end = addr + CPAGE_SIZE;
                code_pages [i] |= 1;
                /* we dump the symbols for the whole page */
                for (; addr < page_end; addr += 16) {
                        sym = symbol_for (addr);
                        if (sym && sym == last_symbol)
                                continue;
                        last_symbol = sym;
                        if (!sym)
                                continue;
                        dump_usym (sym, addr, 0); /* let's not guess the size */
                        //printf ("found symbol at %p: %s\n", (void*)addr, sym);
                }
        }
}

static gint
compare_sample_events (gconstpointer a, gconstpointer b)
{
        uintptr_t tid1 = (*(uintptr_t **) a) [1];
        uintptr_t tid2 = (*(uintptr_t **) b) [1];

        return tid1 > tid2 ? 1 :
               tid1 < tid2 ? -1 :
               0;
}

static void
dump_sample_hits (MonoProfiler *prof, StatBuffer *sbuf)
{
        LogBuffer *logbuffer;
        if (!sbuf)
                return;
        if (sbuf->next) {
                dump_sample_hits (prof, sbuf->next);
                free_buffer (sbuf->next, sbuf->next->size);
                sbuf->next = NULL;
        }

        g_ptr_array_set_size (prof->sorted_sample_events, 0);

        for (uintptr_t *sample = sbuf->buf; sample < sbuf->cursor;) {
                int count = sample [0] & 0xff;
                int mbt_count = (sample [0] & 0xff00) >> 8;

                if (sample + SAMPLE_EVENT_SIZE_IN_SLOTS (mbt_count) > sbuf->cursor)
                        break;

                g_ptr_array_add (prof->sorted_sample_events, sample);

                sample += count + 3 + 4 * mbt_count;
        }

        g_ptr_array_sort (prof->sorted_sample_events, compare_sample_events);

        for (guint sidx = 0; sidx < prof->sorted_sample_events->len; sidx++) {
                uintptr_t *sample = (uintptr_t *)g_ptr_array_index (prof->sorted_sample_events, sidx);
                int count = sample [0] & 0xff;
                int mbt_count = (sample [0] & 0xff00) >> 8;
                int type = sample [0] >> 16;
                uintptr_t *managed_sample_base = sample + count + 3;
                uintptr_t thread_id = sample [1];

                for (int i = 0; i < mbt_count; ++i) {
                        MonoMethod *method = (MonoMethod*)managed_sample_base [i * 4 + 0];
                        MonoDomain *domain = (MonoDomain*)managed_sample_base [i * 4 + 1];
                        void *address = (void*)managed_sample_base [i * 4 + 2];

                        if (!method) {
                                g_assert (domain);
                                MonoJitInfo *ji = mono_jit_info_table_find (domain, (char *)address);

                                if (ji)
                                        managed_sample_base [i * 4 + 0] = (uintptr_t)mono_jit_info_get_method (ji);
                        }
                }

                logbuffer = ensure_logbuf (
                        EVENT_SIZE /* event */ +
                        LEB128_SIZE /* type */ +
                        LEB128_SIZE /* time */ +
                        LEB128_SIZE /* tid */ +
                        LEB128_SIZE /* count */ +
                        count * (
                                LEB128_SIZE /* ip */
                        ) +
                        LEB128_SIZE /* managed count */ +
                        mbt_count * (
                                LEB128_SIZE /* method */ +
                                LEB128_SIZE /* il offset */ +
                                LEB128_SIZE /* native offset */
                        )
                );
                emit_byte (logbuffer, TYPE_SAMPLE | TYPE_SAMPLE_HIT);
                emit_value (logbuffer, type);
                emit_uvalue (logbuffer, prof->startup_time + (uint64_t)sample [2] * (uint64_t)10000);
                emit_ptr (logbuffer, (void *) thread_id);
                emit_value (logbuffer, count);
                for (int i = 0; i < count; ++i) {
                        emit_ptr (logbuffer, (void*)sample [i + 3]);
                        add_code_pointer (sample [i + 3]);
                }

                sample += count + 3;
                /* new in data version 6 */
                emit_uvalue (logbuffer, mbt_count);
                for (int i = 0; i < mbt_count; ++i) {
                        MonoMethod *method = (MonoMethod *) sample [i * 4 + 0];
                        uintptr_t native_offset = sample [i * 4 + 3];

                        emit_method (prof, logbuffer, method);
                        emit_svalue (logbuffer, 0); /* il offset will always be 0 from now on */
                        emit_svalue (logbuffer, native_offset);
                }
        }

        dump_unmanaged_coderefs (prof);
}

#if USE_PERF_EVENTS

static int
mono_cpu_count (void)
{
#ifdef PLATFORM_ANDROID
        /* Android tries really hard to save power by powering off CPUs on SMP phones which
         * means the normal way to query cpu count returns a wrong value with userspace API.
         * Instead we use /sys entries to query the actual hardware CPU count.
         */
        int count = 0;
        char buffer[8] = {'\0'};
        int present = open ("/sys/devices/system/cpu/present", O_RDONLY);
        /* Format of the /sys entry is a cpulist of indexes which in the case
         * of present is always of the form "0-(n-1)" when there is more than
         * 1 core, n being the number of CPU cores in the system. Otherwise
         * the value is simply 0
         */
        if (present != -1 && read (present, (char*)buffer, sizeof (buffer)) > 3)
                count = strtol (((char*)buffer) + 2, NULL, 10);
        if (present != -1)
                close (present);
        if (count > 0)
                return count + 1;
#endif

#if defined(HOST_ARM) || defined (HOST_ARM64)

        /* ARM platforms tries really hard to save power by powering off CPUs on SMP phones which
         * means the normal way to query cpu count returns a wrong value with userspace API. */

#ifdef _SC_NPROCESSORS_CONF
        {
                int count = sysconf (_SC_NPROCESSORS_CONF);
                if (count > 0)
                        return count;
        }
#endif

#else

#ifdef HAVE_SCHED_GETAFFINITY
        {
                cpu_set_t set;
                if (sched_getaffinity (getpid (), sizeof (set), &set) == 0)
                        return CPU_COUNT (&set);
        }
#endif
#ifdef _SC_NPROCESSORS_ONLN
        {
                int count = sysconf (_SC_NPROCESSORS_ONLN);
                if (count > 0)
                        return count;
        }
#endif

#endif /* defined(HOST_ARM) || defined (HOST_ARM64) */

#ifdef USE_SYSCTL
        {
                int count;
                int mib [2];
                size_t len = sizeof (int);
                mib [0] = CTL_HW;
                mib [1] = HW_NCPU;
                if (sysctl (mib, 2, &count, &len, NULL, 0) == 0)
                        return count;
        }
#endif
#ifdef HOST_WIN32
        {
                SYSTEM_INFO info;
                GetSystemInfo (&info);
                return info.dwNumberOfProcessors;
        }
#endif
        /* FIXME: warn */
        return 1;
}

typedef struct {
        int perf_fd;
        unsigned int prev_pos;
        void *mmap_base;
        struct perf_event_mmap_page *page_desc;
} PerfData ;

static PerfData *perf_data = NULL;
static int num_perf;
#define PERF_PAGES_SHIFT 4
static int num_pages = 1 << PERF_PAGES_SHIFT;
static unsigned int mmap_mask;

typedef struct {
        struct perf_event_header h;
        uint64_t ip;
        uint32_t pid;
        uint32_t tid;
        uint64_t timestamp;
        uint64_t period;
        uint64_t nframes;
} PSample;

static int
perf_event_syscall (struct perf_event_attr *attr, pid_t pid, int cpu, int group_fd, unsigned long flags)
{
        attr->size = PERF_ATTR_SIZE_VER0;
        //printf ("perf attr size: %d\n", attr->size);
#if defined(__x86_64__)
        return syscall(/*__NR_perf_event_open*/ 298, attr, pid, cpu, group_fd, flags);
#elif defined(__i386__)
        return syscall(/*__NR_perf_event_open*/ 336, attr, pid, cpu, group_fd, flags);
#elif defined(__arm__) || defined (__aarch64__)
        return syscall(/*__NR_perf_event_open*/ 364, attr, pid, cpu, group_fd, flags);
#else
        return -1;
#endif
}

static int
setup_perf_map (PerfData *perf)
{
        perf->mmap_base = mmap (NULL, (num_pages + 1) * getpagesize (), PROT_READ|PROT_WRITE, MAP_SHARED, perf->perf_fd, 0);
        if (perf->mmap_base == MAP_FAILED) {
                if (do_debug)
                        printf ("failed mmap\n");
                return 0;
        }
        perf->page_desc = perf->mmap_base;
        if (do_debug)
                printf ("mmap version: %d\n", perf->page_desc->version);
        return 1;
}

static void
dump_perf_hits (MonoProfiler *prof, void *buf, int size)
{
        LogBuffer *logbuffer;
        int count = 1;
        int mbt_count = 0;
        void *end = (char*)buf + size;
        int samples = 0;
        int pid = getpid ();

        while (buf < end) {
                PSample *s = buf;
                if (s->h.size == 0)
                        break;
                if (pid != s->pid) {
                        if (do_debug)
                                printf ("event for different pid: %d\n", s->pid);
                        buf = (char*)buf + s->h.size;
                        continue;
                }
                /*ip = (void*)s->ip;
                printf ("sample: %d, size: %d, ip: %p (%s), timestamp: %llu, nframes: %llu\n",
                        s->h.type, s->h.size, ip, symbol_for (ip), s->timestamp, s->nframes);*/
                logbuffer = ensure_logbuf (
                        EVENT_SIZE /* event */ +
                        LEB128_SIZE /* type */ +
                        LEB128_SIZE /* time */ +
                        LEB128_SIZE /* tid */ +
                        LEB128_SIZE /* count */ +
                        count * (
                                LEB128_SIZE /* ip */
                        ) +
                        LEB128_SIZE /* managed count */ +
                        mbt_count * (
                                LEB128_SIZE /* method */ +
                                LEB128_SIZE /* il offset */ +
                                LEB128_SIZE /* native offset */
                        )
                );
                emit_byte (logbuffer, TYPE_SAMPLE | TYPE_SAMPLE_HIT);
                emit_value (logbuffer, sample_type);
                emit_uvalue (logbuffer, s->timestamp - prof->startup_time);
                /*
                 * No useful thread ID to write here, since throughout the
                 * profiler we use pthread_self () but the ID we get from
                 * perf is the kernel's thread ID.
                 */
                emit_ptr (logbuffer, 0);
                emit_value (logbuffer, count);
                emit_ptr (logbuffer, (void*)(uintptr_t)s->ip);
                add_code_pointer (s->ip);
                /* no support here yet for the managed backtrace */
                emit_uvalue (logbuffer, mbt_count);
                buf = (char*)buf + s->h.size;
                samples++;
        }
        if (do_debug)
                printf ("dumped %d samples\n", samples);
        dump_unmanaged_coderefs (prof);
}

/* read events from the ring buffer */
static int
read_perf_mmap (MonoProfiler* prof, int cpu)
{
        PerfData *perf = perf_data + cpu;
        unsigned char *buf;
        unsigned char *data = (unsigned char*)perf->mmap_base + getpagesize ();
        unsigned int head = perf->page_desc->data_head;
        int diff, size;
        unsigned int old;

        mono_memory_read_barrier ();

        old = perf->prev_pos;
        diff = head - old;
        if (diff < 0) {
                if (do_debug)
                        printf ("lost mmap events: old: %d, head: %d\n", old, head);
                old = head;
        }
        size = head - old;
        if ((old & mmap_mask) + size != (head & mmap_mask)) {
                buf = data + (old & mmap_mask);
                size = mmap_mask + 1 - (old & mmap_mask);
                old += size;
                /* size bytes at buf */
                if (do_debug)
                        printf ("found1 bytes of events: %d\n", size);
                dump_perf_hits (prof, buf, size);
        }
        buf = data + (old & mmap_mask);
        size = head - old;
        /* size bytes at buf */
        if (do_debug)
                printf ("found bytes of events: %d\n", size);
        dump_perf_hits (prof, buf, size);
        old += size;
        perf->prev_pos = old;
        perf->page_desc->data_tail = old;
        return 0;
}

static int
setup_perf_event_for_cpu (PerfData *perf, int cpu)
{
        struct perf_event_attr attr;
        memset (&attr, 0, sizeof (attr));
        attr.type = PERF_TYPE_HARDWARE;
        switch (sample_type) {
        case SAMPLE_CYCLES: attr.config = PERF_COUNT_HW_CPU_CYCLES; break;
        case SAMPLE_INSTRUCTIONS: attr.config = PERF_COUNT_HW_INSTRUCTIONS; break;
        case SAMPLE_CACHE_MISSES: attr.config = PERF_COUNT_HW_CACHE_MISSES; break;
        case SAMPLE_CACHE_REFS: attr.config = PERF_COUNT_HW_CACHE_REFERENCES; break;
        case SAMPLE_BRANCHES: attr.config = PERF_COUNT_HW_BRANCH_INSTRUCTIONS; break;
        case SAMPLE_BRANCH_MISSES: attr.config = PERF_COUNT_HW_BRANCH_MISSES; break;
        default: attr.config = PERF_COUNT_HW_CPU_CYCLES; break;
        }
        attr.sample_type = PERF_SAMPLE_IP | PERF_SAMPLE_TID | PERF_SAMPLE_PERIOD | PERF_SAMPLE_TIME;
//      attr.sample_type |= PERF_SAMPLE_CALLCHAIN;
        attr.read_format = PERF_FORMAT_TOTAL_TIME_ENABLED | PERF_FORMAT_TOTAL_TIME_RUNNING | PERF_FORMAT_ID;
        attr.inherit = 1;
        attr.freq = 1;
        attr.sample_freq = sample_freq;

        perf->perf_fd = perf_event_syscall (&attr, getpid (), cpu, -1, 0);
        if (do_debug)
                printf ("perf fd: %d, freq: %d, event: %llu\n", perf->perf_fd, sample_freq, attr.config);
        if (perf->perf_fd < 0) {
                if (perf->perf_fd == -EPERM) {
                        fprintf (stderr, "Perf syscall denied, do \"echo 1 > /proc/sys/kernel/perf_event_paranoid\" as root to enable.\n");
                } else {
                        if (do_debug)
                                perror ("open perf event");
                }
                return 0;
        }
        if (!setup_perf_map (perf)) {
                close (perf->perf_fd);
                perf->perf_fd = -1;
                return 0;
        }
        return 1;
}

static int
setup_perf_event (void)
{
        int i, count = 0;
        mmap_mask = num_pages * getpagesize () - 1;
        num_perf = mono_cpu_count ();
        perf_data = calloc (num_perf, sizeof (PerfData));
        for (i = 0; i < num_perf; ++i) {
                count += setup_perf_event_for_cpu (perf_data + i, i);
        }
        if (count)
                return 1;
        free (perf_data);
        perf_data = NULL;
        return 0;
}

#endif /* USE_PERF_EVENTS */

#ifndef DISABLE_HELPER_THREAD

typedef struct MonoCounterAgent {
        MonoCounter *counter;
        // MonoCounterAgent specific data :
        void *value;
        size_t value_size;
        short index;
        short emitted;
        struct MonoCounterAgent *next;
} MonoCounterAgent;

static MonoCounterAgent* counters;
static gboolean counters_initialized = FALSE;
static int counters_index = 1;
static mono_mutex_t counters_mutex;

static void
counters_add_agent (MonoCounter *counter)
{
        MonoCounterAgent *agent, *item;

        if (!counters_initialized)
                return;

        mono_os_mutex_lock (&counters_mutex);

        for (agent = counters; agent; agent = agent->next) {
                if (agent->counter == counter) {
                        agent->value_size = 0;
                        if (agent->value) {
                                free (agent->value);
                                agent->value = NULL;
                        }
                        mono_os_mutex_unlock (&counters_mutex);
                        return;
                }
        }

        agent = (MonoCounterAgent *)malloc (sizeof (MonoCounterAgent));
        agent->counter = counter;
        agent->value = NULL;
        agent->value_size = 0;
        agent->index = counters_index++;
        agent->emitted = 0;
        agent->next = NULL;

        if (!counters) {
                counters = agent;
        } else {
                item = counters;
                while (item->next)
                        item = item->next;
                item->next = agent;
        }

        mono_os_mutex_unlock (&counters_mutex);
}

static mono_bool
counters_init_foreach_callback (MonoCounter *counter, gpointer data)
{
        counters_add_agent (counter);
        return TRUE;
}

static void
counters_init (MonoProfiler *profiler)
{
        assert (!counters_initialized);

        mono_os_mutex_init (&counters_mutex);

        counters_initialized = TRUE;

        mono_counters_on_register (&counters_add_agent);
        mono_counters_foreach (counters_init_foreach_callback, NULL);
}

static void
counters_emit (MonoProfiler *profiler, gboolean threadless)
{
        MonoCounterAgent *agent;
        LogBuffer *logbuffer;
        int len = 0;
        int size =
                EVENT_SIZE /* event */ +
                LEB128_SIZE /* len */
        ;

        if (!counters_initialized)
                return;

        mono_os_mutex_lock (&counters_mutex);

        for (agent = counters; agent; agent = agent->next) {
                if (agent->emitted)
                        continue;

                size +=
                        LEB128_SIZE /* section */ +
                        strlen (mono_counter_get_name (agent->counter)) + 1 /* name */ +
                        LEB128_SIZE /* type */ +
                        LEB128_SIZE /* unit */ +
                        LEB128_SIZE /* variance */ +
                        LEB128_SIZE /* index */
                ;

                len += 1;
        }

        if (!len) {
                mono_os_mutex_unlock (&counters_mutex);
                return;
        }

        logbuffer = ensure_logbuf (size);

        ENTER_LOG (logbuffer, "counters");
        emit_byte (logbuffer, TYPE_SAMPLE_COUNTERS_DESC | TYPE_SAMPLE);
        emit_value (logbuffer, len);
        for (agent = counters; agent; agent = agent->next) {
                const char *name;

                if (agent->emitted)
                        continue;

                name = mono_counter_get_name (agent->counter);
                emit_value (logbuffer, mono_counter_get_section (agent->counter));
                emit_string (logbuffer, name, strlen (name) + 1);
                emit_value (logbuffer, mono_counter_get_type (agent->counter));
                emit_value (logbuffer, mono_counter_get_unit (agent->counter));
                emit_value (logbuffer, mono_counter_get_variance (agent->counter));
                emit_value (logbuffer, agent->index);

                agent->emitted = 1;
        }
        EXIT_LOG (logbuffer);

        if (threadless)
                safe_send_threadless (profiler, logbuffer);
        else
                safe_send (profiler, logbuffer);

        mono_os_mutex_unlock (&counters_mutex);
}

static void
counters_sample (MonoProfiler *profiler, uint64_t timestamp, gboolean threadless)
{
        MonoCounterAgent *agent;
        MonoCounter *counter;
        LogBuffer *logbuffer;
        int type;
        int buffer_size;
        void *buffer;
        int size;

        if (!counters_initialized)
                return;

        counters_emit (profiler, threadless);

        buffer_size = 8;
        buffer = calloc (1, buffer_size);

        mono_os_mutex_lock (&counters_mutex);

        size =
                EVENT_SIZE /* event */ +
                LEB128_SIZE /* time */
        ;

        for (agent = counters; agent; agent = agent->next) {
                size +=
                        LEB128_SIZE /* index */ +
                        LEB128_SIZE /* type */ +
                        mono_counter_get_size (agent->counter) /* value */
                ;
        }

        size +=
                LEB128_SIZE /* stop marker */
        ;

        logbuffer = ensure_logbuf (size);

        ENTER_LOG (logbuffer, "counters");
        emit_byte (logbuffer, TYPE_SAMPLE_COUNTERS | TYPE_SAMPLE);
        emit_uvalue (logbuffer, timestamp);
        for (agent = counters; agent; agent = agent->next) {
                size_t size;

                counter = agent->counter;

                size = mono_counter_get_size (counter);
                if (size < 0) {
                        continue; // FIXME error
                } else if (size > buffer_size) {
                        buffer_size = size;
                        buffer = realloc (buffer, buffer_size);
                }

                memset (buffer, 0, buffer_size);

                if (mono_counters_sample (counter, buffer, size) < 0)
                        continue; // FIXME error

                type = mono_counter_get_type (counter);

                if (!agent->value) {
                        agent->value = calloc (1, size);
                        agent->value_size = size;
                } else {
                        if (type == MONO_COUNTER_STRING) {
                                if (strcmp (agent->value, buffer) == 0)
                                        continue;
                        } else {
                                if (agent->value_size == size && memcmp (agent->value, buffer, size) == 0)
                                        continue;
                        }
                }

                emit_uvalue (logbuffer, agent->index);
                emit_uvalue (logbuffer, type);
                switch (type) {
                case MONO_COUNTER_INT:
#if SIZEOF_VOID_P == 4
                case MONO_COUNTER_WORD:
#endif
                        emit_svalue (logbuffer, *(int*)buffer - *(int*)agent->value);
                        break;
                case MONO_COUNTER_UINT:
                        emit_uvalue (logbuffer, *(guint*)buffer - *(guint*)agent->value);
                        break;
                case MONO_COUNTER_TIME_INTERVAL:
                case MONO_COUNTER_LONG:
#if SIZEOF_VOID_P == 8
                case MONO_COUNTER_WORD:
#endif
                        emit_svalue (logbuffer, *(gint64*)buffer - *(gint64*)agent->value);
                        break;
                case MONO_COUNTER_ULONG:
                        emit_uvalue (logbuffer, *(guint64*)buffer - *(guint64*)agent->value);
                        break;
                case MONO_COUNTER_DOUBLE:
                        emit_double (logbuffer, *(double*)buffer);
                        break;
                case MONO_COUNTER_STRING:
                        if (size == 0) {
                                emit_byte (logbuffer, 0);
                        } else {
                                emit_byte (logbuffer, 1);
                                emit_string (logbuffer, (char*)buffer, size);
                        }
                        break;
                default:
                        assert (0);
                }

                if (type == MONO_COUNTER_STRING && size > agent->value_size) {
                        agent->value = realloc (agent->value, size);
                        agent->value_size = size;
                }

                if (size > 0)
                        memcpy (agent->value, buffer, size);
        }
        free (buffer);

        emit_value (logbuffer, 0);
        EXIT_LOG (logbuffer);

        if (threadless)
                safe_send_threadless (profiler, logbuffer);
        else
                safe_send (profiler, logbuffer);

        mono_os_mutex_unlock (&counters_mutex);
}

typedef struct _PerfCounterAgent PerfCounterAgent;
struct _PerfCounterAgent {
        PerfCounterAgent *next;
        int index;
        char *category_name;
        char *name;
        int type;
        gint64 value;
        guint8 emitted;
        guint8 updated;
        guint8 deleted;
};

static PerfCounterAgent *perfcounters = NULL;

static void
perfcounters_emit (MonoProfiler *profiler, gboolean threadless)
{
        PerfCounterAgent *pcagent;
        LogBuffer *logbuffer;
        int len = 0;
        int size =
                EVENT_SIZE /* event */ +
                LEB128_SIZE /* len */
        ;

        for (pcagent = perfcounters; pcagent; pcagent = pcagent->next) {
                if (pcagent->emitted)
                        continue;

                size +=
                        LEB128_SIZE /* section */ +
                        strlen (pcagent->category_name) + 1 /* category name */ +
                        strlen (pcagent->name) + 1 /* name */ +
                        LEB128_SIZE /* type */ +
                        LEB128_SIZE /* unit */ +
                        LEB128_SIZE /* variance */ +
                        LEB128_SIZE /* index */
                ;

                len += 1;
        }

        if (!len)
                return;

        logbuffer = ensure_logbuf (size);

        ENTER_LOG (logbuffer, "perfcounters");
        emit_byte (logbuffer, TYPE_SAMPLE_COUNTERS_DESC | TYPE_SAMPLE);
        emit_value (logbuffer, len);
        for (pcagent = perfcounters; pcagent; pcagent = pcagent->next) {
                if (pcagent->emitted)
                        continue;

                emit_value (logbuffer, MONO_COUNTER_PERFCOUNTERS);
                emit_string (logbuffer, pcagent->category_name, strlen (pcagent->category_name) + 1);
                emit_string (logbuffer, pcagent->name, strlen (pcagent->name) + 1);
                emit_value (logbuffer, MONO_COUNTER_LONG);
                emit_value (logbuffer, MONO_COUNTER_RAW);
                emit_value (logbuffer, MONO_COUNTER_VARIABLE);
                emit_value (logbuffer, pcagent->index);

                pcagent->emitted = 1;
        }
        EXIT_LOG (logbuffer);

        if (threadless)
                safe_send_threadless (profiler, logbuffer);
        else
                safe_send (profiler, logbuffer);
}

static gboolean
perfcounters_foreach (char *category_name, char *name, unsigned char type, gint64 value, gpointer user_data)
{
        PerfCounterAgent *pcagent;

        for (pcagent = perfcounters; pcagent; pcagent = pcagent->next) {
                if (strcmp (pcagent->category_name, category_name) != 0 || strcmp (pcagent->name, name) != 0)
                        continue;
                if (pcagent->value == value)
                        return TRUE;

                pcagent->value = value;
                pcagent->updated = 1;
                pcagent->deleted = 0;
                return TRUE;
        }

        pcagent = g_new0 (PerfCounterAgent, 1);
        pcagent->next = perfcounters;
        pcagent->index = counters_index++;
        pcagent->category_name = g_strdup (category_name);
        pcagent->name = g_strdup (name);
        pcagent->type = (int) type;
        pcagent->value = value;
        pcagent->emitted = 0;
        pcagent->updated = 1;
        pcagent->deleted = 0;

        perfcounters = pcagent;

        return TRUE;
}

static void
perfcounters_sample (MonoProfiler *profiler, uint64_t timestamp, gboolean threadless)
{
        PerfCounterAgent *pcagent;
        LogBuffer *logbuffer;
        int size;

        if (!counters_initialized)
                return;

        mono_os_mutex_lock (&counters_mutex);

        /* mark all perfcounters as deleted, foreach will unmark them as necessary */
        for (pcagent = perfcounters; pcagent; pcagent = pcagent->next)
                pcagent->deleted = 1;

        mono_perfcounter_foreach (perfcounters_foreach, perfcounters);

        perfcounters_emit (profiler, threadless);

        size =
                EVENT_SIZE /* event */ +
                LEB128_SIZE /* time */
        ;

        for (pcagent = perfcounters; pcagent; pcagent = pcagent->next) {
                if (pcagent->deleted || !pcagent->updated)
                        continue;

                size +=
                        LEB128_SIZE /* index */ +
                        LEB128_SIZE /* type */ +
                        LEB128_SIZE /* value */
                ;
        }

        size +=
                LEB128_SIZE /* stop marker */
        ;

        logbuffer = ensure_logbuf (size);

        ENTER_LOG (logbuffer, "perfcounters");
        emit_byte (logbuffer, TYPE_SAMPLE_COUNTERS | TYPE_SAMPLE);
        emit_uvalue (logbuffer, timestamp);
        for (pcagent = perfcounters; pcagent; pcagent = pcagent->next) {
                if (pcagent->deleted || !pcagent->updated)
                        continue;
                emit_uvalue (logbuffer, pcagent->index);
                emit_uvalue (logbuffer, MONO_COUNTER_LONG);
                emit_svalue (logbuffer, pcagent->value);

                pcagent->updated = 0;
        }

        emit_value (logbuffer, 0);
        EXIT_LOG (logbuffer);

        if (threadless)
                safe_send_threadless (profiler, logbuffer);
        else
                safe_send (profiler, logbuffer);

        mono_os_mutex_unlock (&counters_mutex);
}

static void
counters_and_perfcounters_sample (MonoProfiler *prof, gboolean threadless)
{
        static uint64_t start = -1;
        uint64_t now;

        if (start == -1)
                start = current_time ();

        now = current_time ();
        counters_sample (prof, (now - start) / 1000/ 1000, threadless);
        perfcounters_sample (prof, (now - start) / 1000/ 1000, threadless);
}

#define COVERAGE_DEBUG(x) if (debug_coverage) {x}
static mono_mutex_t coverage_mutex;
static MonoConcurrentHashTable *coverage_methods = NULL;
static MonoConcurrentHashTable *coverage_assemblies = NULL;
static MonoConcurrentHashTable *coverage_classes = NULL;

static MonoConcurrentHashTable *filtered_classes = NULL;
static MonoConcurrentHashTable *entered_methods = NULL;
static MonoConcurrentHashTable *image_to_methods = NULL;
static MonoConcurrentHashTable *suppressed_assemblies = NULL;
static gboolean coverage_initialized = FALSE;

static GPtrArray *coverage_data = NULL;
static int previous_offset = 0;

typedef struct _MethodNode MethodNode;
struct _MethodNode {
        MonoLockFreeQueueNode node;
        MonoMethod *method;
};

typedef struct _CoverageEntry CoverageEntry;
struct _CoverageEntry {
        int offset;
        int counter;
        char *filename;
        int line;
        int column;
};

static void
free_coverage_entry (gpointer data, gpointer userdata)
{
        CoverageEntry *entry = (CoverageEntry *)data;
        g_free (entry->filename);
        g_free (entry);
}

static void
obtain_coverage_for_method (MonoProfiler *prof, const MonoProfileCoverageEntry *entry)
{
        int offset = entry->iloffset - previous_offset;
        CoverageEntry *e = g_new (CoverageEntry, 1);

        previous_offset = entry->iloffset;

        e->offset = offset;
        e->counter = entry->counter;
        e->filename = g_strdup(entry->filename ? entry->filename : "");
        e->line = entry->line;
        e->column = entry->col;

        g_ptr_array_add (coverage_data, e);
}

static char *
parse_generic_type_names(char *name)
{
        char *new_name, *ret;
        int within_generic_declaration = 0, generic_members = 1;

        if (name == NULL || *name == '\0')
                return g_strdup ("");

        if (!(ret = new_name = (char *)calloc (strlen (name) * 4 + 1, sizeof (char))))
                return NULL;

        do {
                switch (*name) {
                        case '<':
                                within_generic_declaration = 1;
                                break;

                        case '>':
                                within_generic_declaration = 0;

                                if (*(name - 1) != '<') {
                                        *new_name++ = '`';
                                        *new_name++ = '0' + generic_members;
                                } else {
                                        memcpy (new_name, "&lt;&gt;", 8);
                                        new_name += 8;
                                }

                                generic_members = 0;
                                break;

                        case ',':
                                generic_members++;
                                break;

                        default:
                                if (!within_generic_declaration)
                                        *new_name++ = *name;

                                break;
                }
        } while (*name++);

        return ret;
}

static int method_id;
static void
build_method_buffer (gpointer key, gpointer value, gpointer userdata)
{
        MonoMethod *method = (MonoMethod *)value;
        MonoProfiler *prof = (MonoProfiler *)userdata;
        MonoClass *klass;
        MonoImage *image;
        char *class_name;
        const char *image_name, *method_name, *sig, *first_filename;
        LogBuffer *logbuffer;
        guint i;

        previous_offset = 0;
        coverage_data = g_ptr_array_new ();

        mono_profiler_coverage_get (prof, method, obtain_coverage_for_method);

        klass = mono_method_get_class (method);
        image = mono_class_get_image (klass);
        image_name = mono_image_get_name (image);

        sig = mono_signature_get_desc (mono_method_signature (method), TRUE);
        class_name = parse_generic_type_names (mono_type_get_name (mono_class_get_type (klass)));
        method_name = mono_method_get_name (method);

        if (coverage_data->len != 0) {
                CoverageEntry *entry = (CoverageEntry *)coverage_data->pdata[0];
                first_filename = entry->filename ? entry->filename : "";
        } else
                first_filename = "";

        image_name = image_name ? image_name : "";
        sig = sig ? sig : "";
        method_name = method_name ? method_name : "";

        logbuffer = ensure_logbuf (
                EVENT_SIZE /* event */ +
                strlen (image_name) + 1 /* image name */ +
                strlen (class_name) + 1 /* class name */ +
                strlen (method_name) + 1 /* method name */ +
                strlen (sig) + 1 /* signature */ +
                strlen (first_filename) + 1 /* first file name */ +
                LEB128_SIZE /* token */ +
                LEB128_SIZE /* method id */ +
                LEB128_SIZE /* entries */
        );
        ENTER_LOG (logbuffer, "coverage-methods");

        emit_byte (logbuffer, TYPE_COVERAGE_METHOD | TYPE_COVERAGE);
        emit_string (logbuffer, image_name, strlen (image_name) + 1);
        emit_string (logbuffer, class_name, strlen (class_name) + 1);
        emit_string (logbuffer, method_name, strlen (method_name) + 1);
        emit_string (logbuffer, sig, strlen (sig) + 1);
        emit_string (logbuffer, first_filename, strlen (first_filename) + 1);

        emit_uvalue (logbuffer, mono_method_get_token (method));
        emit_uvalue (logbuffer, method_id);
        emit_value (logbuffer, coverage_data->len);

        EXIT_LOG (logbuffer);
        safe_send (prof, logbuffer);

        for (i = 0; i < coverage_data->len; i++) {
                CoverageEntry *entry = (CoverageEntry *)coverage_data->pdata[i];

                logbuffer = ensure_logbuf (
                        EVENT_SIZE /* event */ +
                        LEB128_SIZE /* method id */ +
                        LEB128_SIZE /* offset */ +
                        LEB128_SIZE /* counter */ +
                        LEB128_SIZE /* line */ +
                        LEB128_SIZE /* column */
                );
                ENTER_LOG (logbuffer, "coverage-statement");

                emit_byte (logbuffer, TYPE_COVERAGE_STATEMENT | TYPE_COVERAGE);
                emit_uvalue (logbuffer, method_id);
                emit_uvalue (logbuffer, entry->offset);
                emit_uvalue (logbuffer, entry->counter);
                emit_uvalue (logbuffer, entry->line);
                emit_uvalue (logbuffer, entry->column);

                EXIT_LOG (logbuffer);
                safe_send (prof, logbuffer);
        }

        method_id++;

        g_free (class_name);

        g_ptr_array_foreach (coverage_data, free_coverage_entry, NULL);
        g_ptr_array_free (coverage_data, TRUE);
        coverage_data = NULL;
}

/* This empties the queue */
static guint
count_queue (MonoLockFreeQueue *queue)
{
        MonoLockFreeQueueNode *node;
        guint count = 0;

        while ((node = mono_lock_free_queue_dequeue (queue))) {
                count++;
                mono_lock_free_queue_node_free (node);
        }

        return count;
}

static void
build_class_buffer (gpointer key, gpointer value, gpointer userdata)
{
        MonoClass *klass = (MonoClass *)key;
        MonoLockFreeQueue *class_methods = (MonoLockFreeQueue *)value;
        MonoProfiler *prof = (MonoProfiler *)userdata;
        MonoImage *image;
        char *class_name;
        const char *assembly_name;
        int number_of_methods, partially_covered;
        guint fully_covered;
        LogBuffer *logbuffer;

        image = mono_class_get_image (klass);
        assembly_name = mono_image_get_name (image);
        class_name = mono_type_get_name (mono_class_get_type (klass));

        assembly_name = assembly_name ? assembly_name : "";
        number_of_methods = mono_class_num_methods (klass);
        fully_covered = count_queue (class_methods);
        /* We don't handle partial covered yet */
        partially_covered = 0;

        logbuffer = ensure_logbuf (
                EVENT_SIZE /* event */ +
                strlen (assembly_name) + 1 /* assembly name */ +
                strlen (class_name) + 1 /* class name */ +
                LEB128_SIZE /* no. methods */ +
                LEB128_SIZE /* fully covered */ +
                LEB128_SIZE /* partially covered */
        );

        ENTER_LOG (logbuffer, "coverage-class");
        emit_byte (logbuffer, TYPE_COVERAGE_CLASS | TYPE_COVERAGE);
        emit_string (logbuffer, assembly_name, strlen (assembly_name) + 1);
        emit_string (logbuffer, class_name, strlen (class_name) + 1);
        emit_uvalue (logbuffer, number_of_methods);
        emit_uvalue (logbuffer, fully_covered);
        emit_uvalue (logbuffer, partially_covered);
        EXIT_LOG (logbuffer);

        safe_send (prof, logbuffer);

        g_free (class_name);
}

static void
get_coverage_for_image (MonoImage *image, int *number_of_methods, guint *fully_covered, int *partially_covered)
{
        MonoLockFreeQueue *image_methods = (MonoLockFreeQueue *)mono_conc_hashtable_lookup (image_to_methods, image);

        *number_of_methods = mono_image_get_table_rows (image, MONO_TABLE_METHOD);
        if (image_methods)
                *fully_covered = count_queue (image_methods);
        else
                *fully_covered = 0;

        // FIXME: We don't handle partially covered yet.
        *partially_covered = 0;
}

static void
build_assembly_buffer (gpointer key, gpointer value, gpointer userdata)
{
        MonoAssembly *assembly = (MonoAssembly *)value;
        MonoProfiler *prof = (MonoProfiler *)userdata;
        MonoImage *image = mono_assembly_get_image (assembly);
        LogBuffer *logbuffer;
        const char *name, *guid, *filename;
        int number_of_methods = 0, partially_covered = 0;
        guint fully_covered = 0;

        name = mono_image_get_name (image);
        guid = mono_image_get_guid (image);
        filename = mono_image_get_filename (image);

        name = name ? name : "";
        guid = guid ? guid : "";
        filename = filename ? filename : "";

        get_coverage_for_image (image, &number_of_methods, &fully_covered, &partially_covered);

        logbuffer = ensure_logbuf (
                EVENT_SIZE /* event */ +
                strlen (name) + 1 /* name */ +
                strlen (guid) + 1 /* guid */ +
                strlen (filename) + 1 /* file name */ +
                LEB128_SIZE /* no. methods */ +
                LEB128_SIZE /* fully covered */ +
                LEB128_SIZE /* partially covered */
        );

        ENTER_LOG (logbuffer, "coverage-assemblies");
        emit_byte (logbuffer, TYPE_COVERAGE_ASSEMBLY | TYPE_COVERAGE);
        emit_string (logbuffer, name, strlen (name) + 1);
        emit_string (logbuffer, guid, strlen (guid) + 1);
        emit_string (logbuffer, filename, strlen (filename) + 1);
        emit_uvalue (logbuffer, number_of_methods);
        emit_uvalue (logbuffer, fully_covered);
        emit_uvalue (logbuffer, partially_covered);
        EXIT_LOG (logbuffer);

        safe_send (prof, logbuffer);
}

static void
dump_coverage (MonoProfiler *prof)
{
        if (!coverage_initialized)
                return;

        COVERAGE_DEBUG(fprintf (stderr, "Coverage: Started dump\n");)
        method_id = 0;

        mono_os_mutex_lock (&coverage_mutex);
        mono_conc_hashtable_foreach (coverage_assemblies, build_assembly_buffer, prof);
        mono_conc_hashtable_foreach (coverage_classes, build_class_buffer, prof);
        mono_conc_hashtable_foreach (coverage_methods, build_method_buffer, prof);
        mono_os_mutex_unlock (&coverage_mutex);

        COVERAGE_DEBUG(fprintf (stderr, "Coverage: Finished dump\n");)
}

static void
process_method_enter_coverage (MonoProfiler *prof, MonoMethod *method)
{
        MonoClass *klass;
        MonoImage *image;

        if (!coverage_initialized)
                return;

        klass = mono_method_get_class (method);
        image = mono_class_get_image (klass);

        if (mono_conc_hashtable_lookup (suppressed_assemblies, (gpointer) mono_image_get_name (image)))
                return;

        mono_os_mutex_lock (&coverage_mutex);
        mono_conc_hashtable_insert (entered_methods, method, method);
        mono_os_mutex_unlock (&coverage_mutex);
}

static MonoLockFreeQueueNode *
create_method_node (MonoMethod *method)
{
        MethodNode *node = (MethodNode *)g_malloc (sizeof (MethodNode));
        mono_lock_free_queue_node_init ((MonoLockFreeQueueNode *) node, FALSE);
        node->method = method;

        return (MonoLockFreeQueueNode *) node;
}

static gboolean
coverage_filter (MonoProfiler *prof, MonoMethod *method)
{
        MonoError error;
        MonoClass *klass;
        MonoImage *image;
        MonoAssembly *assembly;
        MonoMethodHeader *header;
        guint32 iflags, flags, code_size;
        char *fqn, *classname;
        gboolean has_positive, found;
        MonoLockFreeQueue *image_methods, *class_methods;
        MonoLockFreeQueueNode *node;

        if (!coverage_initialized)
                return FALSE;

        COVERAGE_DEBUG(fprintf (stderr, "Coverage filter for %s\n", mono_method_get_name (method));)

        flags = mono_method_get_flags (method, &iflags);
        if ((iflags & 0x1000 /*METHOD_IMPL_ATTRIBUTE_INTERNAL_CALL*/) ||
            (flags & 0x2000 /*METHOD_ATTRIBUTE_PINVOKE_IMPL*/)) {
                COVERAGE_DEBUG(fprintf (stderr, "   Internal call or pinvoke - ignoring\n");)
                return FALSE;
        }

        // Don't need to do anything else if we're already tracking this method
        if (mono_conc_hashtable_lookup (coverage_methods, method)) {
                COVERAGE_DEBUG(fprintf (stderr, "   Already tracking\n");)
                return TRUE;
        }

        klass = mono_method_get_class (method);
        image = mono_class_get_image (klass);

        // Don't handle coverage for the core assemblies
        if (mono_conc_hashtable_lookup (suppressed_assemblies, (gpointer) mono_image_get_name (image)) != NULL)
                return FALSE;

        if (prof->coverage_filters) {
                /* Check already filtered classes first */
                if (mono_conc_hashtable_lookup (filtered_classes, klass)) {
                        COVERAGE_DEBUG(fprintf (stderr, "   Already filtered\n");)
                        return FALSE;
                }

                classname = mono_type_get_name (mono_class_get_type (klass));

                fqn = g_strdup_printf ("[%s]%s", mono_image_get_name (image), classname);

                COVERAGE_DEBUG(fprintf (stderr, "   Looking for %s in filter\n", fqn);)
                // Check positive filters first
                has_positive = FALSE;
                found = FALSE;
                for (guint i = 0; i < prof->coverage_filters->len; ++i) {
                        char *filter = (char *)g_ptr_array_index (prof->coverage_filters, i);

                        if (filter [0] == '+') {
                                filter = &filter [1];

                                COVERAGE_DEBUG(fprintf (stderr, "   Checking against +%s ...", filter);)

                                if (strstr (fqn, filter) != NULL) {
                                        COVERAGE_DEBUG(fprintf (stderr, "matched\n");)
                                        found = TRUE;
                                } else
                                        COVERAGE_DEBUG(fprintf (stderr, "no match\n");)

                                has_positive = TRUE;
                        }
                }

                if (has_positive && !found) {
                        COVERAGE_DEBUG(fprintf (stderr, "   Positive match was not found\n");)

                        mono_os_mutex_lock (&coverage_mutex);
                        mono_conc_hashtable_insert (filtered_classes, klass, klass);
                        mono_os_mutex_unlock (&coverage_mutex);
                        g_free (fqn);
                        g_free (classname);

                        return FALSE;
                }

                for (guint i = 0; i < prof->coverage_filters->len; ++i) {
                        // FIXME: Is substring search sufficient?
                        char *filter = (char *)g_ptr_array_index (prof->coverage_filters, i);
                        if (filter [0] == '+')
                                continue;

                        // Skip '-'
                        filter = &filter [1];
                        COVERAGE_DEBUG(fprintf (stderr, "   Checking against -%s ...", filter);)

                        if (strstr (fqn, filter) != NULL) {
                                COVERAGE_DEBUG(fprintf (stderr, "matched\n");)

                                mono_os_mutex_lock (&coverage_mutex);
                                mono_conc_hashtable_insert (filtered_classes, klass, klass);
                                mono_os_mutex_unlock (&coverage_mutex);
                                g_free (fqn);
                                g_free (classname);

                                return FALSE;
                        } else
                                COVERAGE_DEBUG(fprintf (stderr, "no match\n");)

                }

                g_free (fqn);
                g_free (classname);
        }

        COVERAGE_DEBUG(fprintf (stderr, "   Handling coverage for %s\n", mono_method_get_name (method));)
        header = mono_method_get_header_checked (method, &error);
        mono_error_cleanup (&error);

        mono_method_header_get_code (header, &code_size, NULL);

        assembly = mono_image_get_assembly (image);

        // Need to keep the assemblies around for as long as they are kept in the hashtable
        // Nunit, for example, has a habit of unloading them before the coverage statistics are
        // generated causing a crash. See https://bugzilla.xamarin.com/show_bug.cgi?id=39325
        mono_assembly_addref (assembly);

        mono_os_mutex_lock (&coverage_mutex);
        mono_conc_hashtable_insert (coverage_methods, method, method);
        mono_conc_hashtable_insert (coverage_assemblies, assembly, assembly);
        mono_os_mutex_unlock (&coverage_mutex);

        image_methods = (MonoLockFreeQueue *)mono_conc_hashtable_lookup (image_to_methods, image);

        if (image_methods == NULL) {
                image_methods = (MonoLockFreeQueue *)g_malloc (sizeof (MonoLockFreeQueue));
                mono_lock_free_queue_init (image_methods);
                mono_os_mutex_lock (&coverage_mutex);
                mono_conc_hashtable_insert (image_to_methods, image, image_methods);
                mono_os_mutex_unlock (&coverage_mutex);
        }

        node = create_method_node (method);
        mono_lock_free_queue_enqueue (image_methods, node);

        class_methods = (MonoLockFreeQueue *)mono_conc_hashtable_lookup (coverage_classes, klass);

        if (class_methods == NULL) {
                class_methods = (MonoLockFreeQueue *)g_malloc (sizeof (MonoLockFreeQueue));
                mono_lock_free_queue_init (class_methods);
                mono_os_mutex_lock (&coverage_mutex);
                mono_conc_hashtable_insert (coverage_classes, klass, class_methods);
                mono_os_mutex_unlock (&coverage_mutex);
        }

        node = create_method_node (method);
        mono_lock_free_queue_enqueue (class_methods, node);

        return TRUE;
}

#define LINE_BUFFER_SIZE 4096
/* Max file limit of 128KB */
#define MAX_FILE_SIZE 128 * 1024
static char *
get_file_content (FILE *stream)
{
        char *buffer;
        ssize_t bytes_read;
        long filesize;
        int res, offset = 0;

        res = fseek (stream, 0, SEEK_END);
        if (res < 0)
          return NULL;

        filesize = ftell (stream);
        if (filesize < 0)
          return NULL;

        res = fseek (stream, 0, SEEK_SET);
        if (res < 0)
          return NULL;

        if (filesize > MAX_FILE_SIZE)
          return NULL;

        buffer = (char *)g_malloc ((filesize + 1) * sizeof (char));
        while ((bytes_read = fread (buffer + offset, 1, LINE_BUFFER_SIZE, stream)) > 0)
                offset += bytes_read;

        /* NULL terminate our buffer */
        buffer[filesize] = '\0';
        return buffer;
}

static char *
get_next_line (char *contents, char **next_start)
{
        char *p = contents;

        if (p == NULL || *p == '\0') {
                *next_start = NULL;
                return NULL;
        }

        while (*p != '\n' && *p != '\0')
                p++;

        if (*p == '\n') {
                *p = '\0';
                *next_start = p + 1;
        } else
                *next_start = NULL;

        return contents;
}

static void
init_suppressed_assemblies (void)
{
        char *content;
        char *line;
        FILE *sa_file;

        suppressed_assemblies = mono_conc_hashtable_new (g_str_hash, g_str_equal);
        sa_file = fopen (SUPPRESSION_DIR "/mono-profiler-log.suppression", "r");
        if (sa_file == NULL)
                return;

        /* Don't need to free @content as it is referred to by the lines stored in @suppressed_assemblies */
        content = get_file_content (sa_file);
        if (content == NULL) {
                g_error ("mono-profiler-log.suppression is greater than 128kb - aborting\n");
        }

        while ((line = get_next_line (content, &content))) {
                line = g_strchomp (g_strchug (line));
                /* No locking needed as we're doing initialization */
                mono_conc_hashtable_insert (suppressed_assemblies, line, line);
        }

        fclose (sa_file);
}

#endif /* DISABLE_HELPER_THREAD */

static void
coverage_init (MonoProfiler *prof)
{
#ifndef DISABLE_HELPER_THREAD
        assert (!coverage_initialized);

        COVERAGE_DEBUG(fprintf (stderr, "Coverage initialized\n");)

        mono_os_mutex_init (&coverage_mutex);
        coverage_methods = mono_conc_hashtable_new (NULL, NULL);
        coverage_assemblies = mono_conc_hashtable_new (NULL, NULL);
        coverage_classes = mono_conc_hashtable_new (NULL, NULL);
        filtered_classes = mono_conc_hashtable_new (NULL, NULL);
        entered_methods = mono_conc_hashtable_new (NULL, NULL);
        image_to_methods = mono_conc_hashtable_new (NULL, NULL);
        init_suppressed_assemblies ();

        coverage_initialized = TRUE;
#endif /* DISABLE_HELPER_THREAD */
}

static void
unref_coverage_assemblies (gpointer key, gpointer value, gpointer userdata)
{
        MonoAssembly *assembly = (MonoAssembly *)value;
        mono_assembly_close (assembly);
}

static void
log_shutdown (MonoProfiler *prof)
{
        void *res;

        in_shutdown = 1;
#ifndef DISABLE_HELPER_THREAD
        counters_and_perfcounters_sample (prof, FALSE);

        dump_coverage (prof);

        if (prof->command_port) {
                char c = 1;
                ign_res (write (prof->pipes [1], &c, 1));
                pthread_join (prof->helper_thread, &res);
        }
#endif
#if USE_PERF_EVENTS
        if (perf_data) {
                int i;
                for (i = 0; i < num_perf; ++i)
                        read_perf_mmap (prof, i);
        }
#endif

        g_ptr_array_free (prof->sorted_sample_events, TRUE);

        if (TLS_GET (LogBuffer, tlsbuffer))
                send_buffer (prof, TLS_GET (GPtrArray, tlsmethodlist), TLS_GET (LogBuffer, tlsbuffer));

        TLS_SET (tlsbuffer, NULL);
        TLS_SET (tlsmethodlist, NULL);

        InterlockedWrite (&prof->run_writer_thread, 0);
        pthread_join (prof->writer_thread, &res);

#if defined (HAVE_SYS_ZLIB)
        if (prof->gzfile)
                gzclose (prof->gzfile);
#endif
        if (prof->pipe_output)
                pclose (prof->file);
        else
                fclose (prof->file);

        mono_conc_hashtable_destroy (prof->method_table);
        mono_os_mutex_destroy (&prof->method_table_mutex);

        if (coverage_initialized) {
                mono_os_mutex_lock (&coverage_mutex);
                mono_conc_hashtable_foreach (coverage_assemblies, unref_coverage_assemblies, prof);
                mono_os_mutex_unlock (&coverage_mutex);

                mono_conc_hashtable_destroy (coverage_methods);
                mono_conc_hashtable_destroy (coverage_assemblies);
                mono_conc_hashtable_destroy (coverage_classes);
                mono_conc_hashtable_destroy (filtered_classes);

                mono_conc_hashtable_destroy (entered_methods);
                mono_conc_hashtable_destroy (image_to_methods);
                mono_conc_hashtable_destroy (suppressed_assemblies);
                mono_os_mutex_destroy (&coverage_mutex);
        }

        free (prof);
}

static char*
new_filename (const char* filename)
{
        time_t t = time (NULL);
        int pid = process_id ();
        char pid_buf [16];
        char time_buf [16];
        char *res, *d;
        const char *p;
        int count_dates = 0;
        int count_pids = 0;
        int s_date, s_pid;
        struct tm *ts;
        for (p = filename; *p; p++) {
                if (*p != '%')
                        continue;
                p++;
                if (*p == 't')
                        count_dates++;
                else if (*p == 'p')
                        count_pids++;
                else if (*p == 0)
                        break;
        }
        if (!count_dates && !count_pids)
                return pstrdup (filename);
        snprintf (pid_buf, sizeof (pid_buf), "%d", pid);
        ts = gmtime (&t);
        snprintf (time_buf, sizeof (time_buf), "%d%02d%02d%02d%02d%02d",
                1900 + ts->tm_year, 1 + ts->tm_mon, ts->tm_mday, ts->tm_hour, ts->tm_min, ts->tm_sec);
        s_date = strlen (time_buf);
        s_pid = strlen (pid_buf);
        d = res = (char *)malloc (strlen (filename) + s_date * count_dates + s_pid * count_pids);
        for (p = filename; *p; p++) {
                if (*p != '%') {
                        *d++ = *p;
                        continue;
                }
                p++;
                if (*p == 't') {
                        strcpy (d, time_buf);
                        d += s_date;
                        continue;
                } else if (*p == 'p') {
                        strcpy (d, pid_buf);
                        d += s_pid;
                        continue;
                } else if (*p == '%') {
                        *d++ = '%';
                        continue;
                } else if (*p == 0)
                        break;
                *d++ = '%';
                *d++ = *p;
        }
        *d = 0;
        return res;
}

//this is exposed by the JIT, but it's not meant to be a supported API for now.
extern void mono_threads_attach_tools_thread (void);

#ifndef DISABLE_HELPER_THREAD

static void*
helper_thread (void* arg)
{
        MonoProfiler* prof = (MonoProfiler *)arg;
        int command_socket;
        int len;
        char buf [64];
        MonoThread *thread = NULL;

        mono_threads_attach_tools_thread ();
        mono_thread_info_set_name (mono_native_thread_id_get (), "Profiler helper");

        //fprintf (stderr, "Server listening\n");
        command_socket = -1;
        while (1) {
                fd_set rfds;
                struct timeval tv;
                int max_fd = -1;
                FD_ZERO (&rfds);
                FD_SET (prof->server_socket, &rfds);
                max_fd = prof->server_socket;
                FD_SET (prof->pipes [0], &rfds);
                if (max_fd < prof->pipes [0])
                        max_fd = prof->pipes [0];
                if (command_socket >= 0) {
                        FD_SET (command_socket, &rfds);
                        if (max_fd < command_socket)
                                max_fd = command_socket;
                }
#if USE_PERF_EVENTS
                if (perf_data) {
                        int i;
                        for ( i = 0; i < num_perf; ++i) {
                                if (perf_data [i].perf_fd < 0)
                                        continue;
                                FD_SET (perf_data [i].perf_fd, &rfds);
                                if (max_fd < perf_data [i].perf_fd)
                                        max_fd = perf_data [i].perf_fd;
                        }
                }
#endif

                counters_and_perfcounters_sample (prof, TRUE);

                tv.tv_sec = 1;
                tv.tv_usec = 0;
                len = select (max_fd + 1, &rfds, NULL, NULL, &tv);

                if (len < 0) {
                        if (errno == EINTR)
                                continue;

                        g_warning ("Error in proflog server: %s", strerror (errno));
                        return NULL;
                }

                if (FD_ISSET (prof->pipes [0], &rfds)) {
                        char c;
                        int r = read (prof->pipes [0], &c, 1);
                        if (r == 1 && c == 0) {
                                StatBuffer *sbufbase = prof->stat_buffers;
                                StatBuffer *sbuf;
                                if (!sbufbase->next)
                                        continue;
                                sbuf = sbufbase->next->next;
                                sbufbase->next->next = NULL;
                                if (do_debug)
                                        fprintf (stderr, "stat buffer dump\n");
                                if (sbuf) {
                                        dump_sample_hits (prof, sbuf);
                                        free_buffer (sbuf, sbuf->size);
                                        safe_send_threadless (prof, ensure_logbuf (0));
                                }
                                continue;
                        }
                        /* time to shut down */
                        dump_sample_hits (prof, prof->stat_buffers);
                        if (thread)
                                mono_thread_detach (thread);
                        if (do_debug)
                                fprintf (stderr, "helper shutdown\n");
#if USE_PERF_EVENTS
                        if (perf_data) {
                                int i;
                                for ( i = 0; i < num_perf; ++i) {
                                        if (perf_data [i].perf_fd < 0)
                                                continue;
                                        if (FD_ISSET (perf_data [i].perf_fd, &rfds))
                                                read_perf_mmap (prof, i);
                                }
                        }
#endif
                        safe_send_threadless (prof, ensure_logbuf (0));
                        return NULL;
                }
#if USE_PERF_EVENTS
                if (perf_data) {
                        int i;
                        for ( i = 0; i < num_perf; ++i) {
                                if (perf_data [i].perf_fd < 0)
                                        continue;
                                if (FD_ISSET (perf_data [i].perf_fd, &rfds)) {
                                        read_perf_mmap (prof, i);
                                        safe_send_threadless (prof, ensure_logbuf (0));
                                }
                        }
                }
#endif
                if (command_socket >= 0 && FD_ISSET (command_socket, &rfds)) {
                        len = read (command_socket, buf, sizeof (buf) - 1);
                        if (len < 0)
                                continue;
                        if (len == 0) {
                                close (command_socket);
                                command_socket = -1;
                                continue;
                        }
                        buf [len] = 0;
                        if (strcmp (buf, "heapshot\n") == 0) {
                                heapshot_requested = 1;
                                //fprintf (stderr, "perform heapshot\n");
                                if (InterlockedRead (&runtime_inited) && !thread) {
                                        thread = mono_thread_attach (mono_get_root_domain ());
                                        /*fprintf (stderr, "attached\n");*/
                                }
                                if (thread) {
                                        process_requests (prof);
                                        mono_thread_detach (thread);
                                        thread = NULL;
                                }
                        }
                        continue;
                }
                if (!FD_ISSET (prof->server_socket, &rfds)) {
                        continue;
                }
                command_socket = accept (prof->server_socket, NULL, NULL);
                if (command_socket < 0)
                        continue;
                //fprintf (stderr, "Accepted connection\n");
        }
        return NULL;
}

static int
start_helper_thread (MonoProfiler* prof)
{
        struct sockaddr_in server_address;
        int r;
        socklen_t slen;
        if (pipe (prof->pipes) < 0) {
                fprintf (stderr, "Cannot create pipe\n");
                return 0;
        }
        prof->server_socket = socket (PF_INET, SOCK_STREAM, 0);
        if (prof->server_socket < 0) {
                fprintf (stderr, "Cannot create server socket\n");
                return 0;
        }
        memset (&server_address, 0, sizeof (server_address));
        server_address.sin_family = AF_INET;
        server_address.sin_addr.s_addr = INADDR_ANY;
        server_address.sin_port = htons (prof->command_port);
        if (bind (prof->server_socket, (struct sockaddr *) &server_address, sizeof (server_address)) < 0) {
                fprintf (stderr, "Cannot bind server socket, port: %d: %s\n", prof->command_port, strerror (errno));
                close (prof->server_socket);
                return 0;
        }
        if (listen (prof->server_socket, 1) < 0) {
                fprintf (stderr, "Cannot listen server socket\n");
                close (prof->server_socket);
                return 0;
        }
        slen = sizeof (server_address);
        if (getsockname (prof->server_socket, (struct sockaddr *)&server_address, &slen) == 0) {
                prof->command_port = ntohs (server_address.sin_port);
                /*fprintf (stderr, "Assigned server port: %d\n", prof->command_port);*/
        }

        r = pthread_create (&prof->helper_thread, NULL, helper_thread, prof);
        if (r) {
                close (prof->server_socket);
                return 0;
        }
        return 1;
}
#endif

static void *
writer_thread (void *arg)
{
        MonoProfiler *prof = (MonoProfiler *)arg;

        mono_threads_attach_tools_thread ();
        mono_thread_info_set_name (mono_native_thread_id_get (), "Profiler writer");

        dump_header (prof);

        while (InterlockedRead (&prof->run_writer_thread)) {
                WriterQueueEntry *entry;

                while ((entry = (WriterQueueEntry *) mono_lock_free_queue_dequeue (&prof->writer_queue))) {
                        LogBuffer *method_buffer = NULL;
                        gboolean new_methods = FALSE;

                        if (entry->methods->len)
                                method_buffer = create_buffer ();

                        /*
                         * Encode the method events in a temporary log buffer that we
                         * flush to disk before the main buffer, ensuring that all
                         * methods have metadata emitted before they're referenced.
                         */
                        for (guint i = 0; i < entry->methods->len; i++) {
                                MethodInfo *info = (MethodInfo *)g_ptr_array_index (entry->methods, i);

                                if (mono_conc_hashtable_lookup (prof->method_table, info->method))
                                        continue;

                                new_methods = TRUE;

                                /*
                                 * Other threads use this hash table to get a general
                                 * idea of whether a method has already been emitted to
                                 * the stream. Due to the way we add to this table, it
                                 * can easily happen that multiple threads queue up the
                                 * same methods, but that's OK since eventually all
                                 * methods will be in this table and the thread-local
                                 * method lists will just be empty for the rest of the
                                 * app's lifetime.
                                 */
                                mono_os_mutex_lock (&prof->method_table_mutex);
                                mono_conc_hashtable_insert (prof->method_table, info->method, info->method);
                                mono_os_mutex_unlock (&prof->method_table_mutex);

                                char *name = mono_method_full_name (info->method, 1);
                                int nlen = strlen (name) + 1;
                                void *cstart = info->ji ? mono_jit_info_get_code_start (info->ji) : NULL;
                                int csize = info->ji ? mono_jit_info_get_code_size (info->ji) : 0;

                                method_buffer = ensure_logbuf_inner (method_buffer,
                                        EVENT_SIZE /* event */ +
                                        LEB128_SIZE /* time */ +
                                        LEB128_SIZE /* method */ +
                                        LEB128_SIZE /* start */ +
                                        LEB128_SIZE /* size */ +
                                        nlen /* name */
                                );

                                emit_byte (method_buffer, TYPE_JIT | TYPE_METHOD);
                                emit_time (method_buffer, info->time);
                                emit_method_inner (method_buffer, info->method);
                                emit_ptr (method_buffer, cstart);
                                emit_value (method_buffer, csize);

                                memcpy (method_buffer->cursor, name, nlen);
                                method_buffer->cursor += nlen;

                                mono_free (name);
                                free (info);
                        }

                        g_ptr_array_free (entry->methods, TRUE);

                        if (new_methods) {
                                for (LogBuffer *iter = method_buffer; iter; iter = iter->next)
                                        iter->thread_id = 0;

                                dump_buffer (prof, method_buffer);
                        } else if (method_buffer)
                                free_buffer (method_buffer, method_buffer->size);

                        dump_buffer (prof, entry->buffer);

                        free (entry);
                }
        }

        return NULL;
}

static int
start_writer_thread (MonoProfiler* prof)
{
        InterlockedWrite (&prof->run_writer_thread, 1);

        return !pthread_create (&prof->writer_thread, NULL, writer_thread, prof);
}

static void
runtime_initialized (MonoProfiler *profiler)
{
#ifndef DISABLE_HELPER_THREAD
        if (hs_mode_ondemand || need_helper_thread) {
                if (!start_helper_thread (profiler))
                        profiler->command_port = 0;
        }
#endif

        start_writer_thread (profiler);

        InterlockedWrite (&runtime_inited, 1);
#ifndef DISABLE_HELPER_THREAD
        counters_init (profiler);
        counters_sample (profiler, 0, FALSE);
#endif
        /* ensure the main thread data and startup are available soon */
        safe_send (profiler, ensure_logbuf (0));
}

static MonoProfiler*
create_profiler (const char *filename, GPtrArray *filters)
{
        MonoProfiler *prof;
        char *nf;
        int force_delete = 0;
        prof = (MonoProfiler *)calloc (1, sizeof (MonoProfiler));

        prof->command_port = command_port;
        if (filename && *filename == '-') {
                force_delete = 1;
                filename++;
        }
        if (!filename) {
                if (do_report)
                        filename = "|mprof-report -";
                else
                        filename = "output.mlpd";
                nf = (char*)filename;
        } else {
                nf = new_filename (filename);
                if (do_report) {
                        int s = strlen (nf) + 32;
                        char *p = (char *)malloc (s);
                        snprintf (p, s, "|mprof-report '--out=%s' -", nf);
                        free (nf);
                        nf = p;
                }
        }
        if (*nf == '|') {
                prof->file = popen (nf + 1, "w");
                prof->pipe_output = 1;
        } else if (*nf == '#') {
                int fd = strtol (nf + 1, NULL, 10);
                prof->file = fdopen (fd, "a");
        } else {
                if (force_delete)
                        unlink (nf);
                prof->file = fopen (nf, "wb");
        }
        if (!prof->file) {
                fprintf (stderr, "Cannot create profiler output: %s\n", nf);
                exit (1);
        }
#if defined (HAVE_SYS_ZLIB)
        if (use_zip)
                prof->gzfile = gzdopen (fileno (prof->file), "wb");
#endif
#if USE_PERF_EVENTS
        if (sample_type && !do_mono_sample)
                need_helper_thread = setup_perf_event ();
        if (!perf_data) {
                /* FIXME: warn if different freq or sample type */
                do_mono_sample = 1;
        }
#endif
        if (do_mono_sample) {
                prof->stat_buffers = create_stat_buffer ();
                need_helper_thread = 1;
        }
        if (do_counters && !need_helper_thread) {
                need_helper_thread = 1;
        }

        prof->sorted_sample_events = g_ptr_array_sized_new (BUFFER_SIZE / SAMPLE_EVENT_SIZE_IN_SLOTS (0));

#ifdef DISABLE_HELPER_THREAD
        if (hs_mode_ondemand)
                fprintf (stderr, "Ondemand heapshot unavailable on this arch.\n");

        if (do_coverage)
                fprintf (stderr, "Coverage unavailable on this arch.\n");

#endif

        mono_lock_free_queue_init (&prof->writer_queue);
        mono_os_mutex_init (&prof->method_table_mutex);
        prof->method_table = mono_conc_hashtable_new (NULL, NULL);

        if (do_coverage)
                coverage_init (prof);
        prof->coverage_filters = filters;

        prof->startup_time = current_time ();
        return prof;
}

static void
usage (int do_exit)
{
        printf ("Log profiler version %d.%d (format: %d)\n", LOG_VERSION_MAJOR, LOG_VERSION_MINOR, LOG_DATA_VERSION);
        printf ("Usage: mono --profile=log[:OPTION1[,OPTION2...]] program.exe\n");
        printf ("Options:\n");
        printf ("\thelp                 show this usage info\n");
        printf ("\t[no]alloc            enable/disable recording allocation info\n");
        printf ("\t[no]calls            enable/disable recording enter/leave method events\n");
        printf ("\theapshot[=MODE]      record heap shot info (by default at each major collection)\n");
        printf ("\t                     MODE: every XXms milliseconds, every YYgc collections, ondemand\n");
        printf ("\tcounters             sample counters every 1s\n");
        printf ("\tsample[=TYPE]        use statistical sampling mode (by default cycles/1000)\n");
        printf ("\t                     TYPE: cycles,instr,cacherefs,cachemiss,branches,branchmiss\n");
        printf ("\t                     TYPE can be followed by /FREQUENCY\n");
        printf ("\ttime=fast            use a faster (but more inaccurate) timer\n");
        printf ("\tmaxframes=NUM        collect up to NUM stack frames\n");
        printf ("\tcalldepth=NUM        ignore method events for call chain depth bigger than NUM\n");
        printf ("\toutput=FILENAME      write the data to file FILENAME (-FILENAME to overwrite)\n");
        printf ("\toutput=|PROGRAM      write the data to the stdin of PROGRAM\n");
        printf ("\t                     %%t is subtituted with date and time, %%p with the pid\n");
        printf ("\treport               create a report instead of writing the raw data to a file\n");
        printf ("\tzip                  compress the output data\n");
        printf ("\tport=PORTNUM         use PORTNUM for the listening command server\n");
        printf ("\tcoverage             enable collection of code coverage data\n");
        printf ("\tcovfilter=ASSEMBLY   add an assembly to the code coverage filters\n");
        printf ("\t                     add a + to include the assembly or a - to exclude it\n");
        printf ("\t                     filter=-mscorlib\n");
        printf ("\tcovfilter-file=FILE  use FILE to generate the list of assemblies to be filtered\n");
        if (do_exit)
                exit (1);
}

static const char*
match_option (const char* p, const char *opt, char **rval)
{
        int len = strlen (opt);
        if (strncmp (p, opt, len) == 0) {
                if (rval) {
                        if (p [len] == '=' && p [len + 1]) {
                                const char *opt = p + len + 1;
                                const char *end = strchr (opt, ',');
                                char *val;
                                int l;
                                if (end == NULL) {
                                        l = strlen (opt);
                                } else {
                                        l = end - opt;
                                }
                                val = (char *)malloc (l + 1);
                                memcpy (val, opt, l);
                                val [l] = 0;
                                *rval = val;
                                return opt + l;
                        }
                        if (p [len] == 0 || p [len] == ',') {
                                *rval = NULL;
                                return p + len + (p [len] == ',');
                        }
                        usage (1);
                } else {
                        if (p [len] == 0)
                                return p + len;
                        if (p [len] == ',')
                                return p + len + 1;
                }
        }
        return p;
}

typedef struct {
        const char *name;
        int sample_mode;
} SampleMode;

static const SampleMode sample_modes [] = {
        {"cycles", SAMPLE_CYCLES},
        {"instr", SAMPLE_INSTRUCTIONS},
        {"cachemiss", SAMPLE_CACHE_MISSES},
        {"cacherefs", SAMPLE_CACHE_REFS},
        {"branches", SAMPLE_BRANCHES},
        {"branchmiss", SAMPLE_BRANCH_MISSES},
        {NULL, 0}
};

static void
set_sample_mode (char* val, int allow_empty)
{
        char *end;
        char *maybe_freq = NULL;
        unsigned int count;
        const SampleMode *smode = sample_modes;
#ifndef USE_PERF_EVENTS
        do_mono_sample = 1;
#endif
        if (allow_empty && !val) {
                sample_type = SAMPLE_CYCLES;
                sample_freq = 1000;
                return;
        }
        if (strcmp (val, "mono") == 0) {
                do_mono_sample = 1;
                sample_type = SAMPLE_CYCLES;
                free (val);
                return;
        }
        for (smode = sample_modes; smode->name; smode++) {
                int l = strlen (smode->name);
                if (strncmp (val, smode->name, l) == 0) {
                        sample_type = smode->sample_mode;
                        maybe_freq = val + l;
                        break;
                }
        }
        if (!smode->name)
                usage (1);
        if (*maybe_freq == '/') {
                count = strtoul (maybe_freq + 1, &end, 10);
                if (maybe_freq + 1 == end)
                        usage (1);
                sample_freq = count;
        } else if (*maybe_freq != 0) {
                usage (1);
        } else {
                sample_freq = 1000;
        }
        free (val);
}

static void
set_hsmode (char* val, int allow_empty)
{
        char *end;
        unsigned int count;
        if (allow_empty && !val)
                return;
        if (strcmp (val, "ondemand") == 0) {
                hs_mode_ondemand = 1;
                free (val);
                return;
        }
        count = strtoul (val, &end, 10);
        if (val == end)
                usage (1);
        if (strcmp (end, "ms") == 0)
                hs_mode_ms = count;
        else if (strcmp (end, "gc") == 0)
                hs_mode_gc = count;
        else
                usage (1);
        free (val);
}

/*
 * declaration to silence the compiler: this is the entry point that
 * mono will load from the shared library and call.
 */
extern void
mono_profiler_startup (const char *desc);

extern void
mono_profiler_startup_log (const char *desc);

/*
 * this is the entry point that will be used when the profiler
 * is embedded inside the main executable.
 */
void
mono_profiler_startup_log (const char *desc)
{
        mono_profiler_startup (desc);
}

void
mono_profiler_startup (const char *desc)
{
        MonoProfiler *prof;
        GPtrArray *filters = NULL;
        char *filename = NULL;
        const char *p;
        const char *opt;
        int fast_time = 0;
        int calls_enabled = 0;
        int allocs_enabled = 0;
        int only_counters = 0;
        int only_coverage = 0;
        int events = MONO_PROFILE_GC|MONO_PROFILE_ALLOCATIONS|
                MONO_PROFILE_GC_MOVES|MONO_PROFILE_CLASS_EVENTS|MONO_PROFILE_THREADS|
                MONO_PROFILE_ENTER_LEAVE|MONO_PROFILE_JIT_COMPILATION|MONO_PROFILE_EXCEPTIONS|
                MONO_PROFILE_MONITOR_EVENTS|MONO_PROFILE_MODULE_EVENTS|MONO_PROFILE_GC_ROOTS|
                MONO_PROFILE_INS_COVERAGE|MONO_PROFILE_APPDOMAIN_EVENTS|MONO_PROFILE_CONTEXT_EVENTS|
                MONO_PROFILE_ASSEMBLY_EVENTS;

        p = desc;
        if (strncmp (p, "log", 3))
                usage (1);
        p += 3;
        if (*p == ':')
                p++;
        for (; *p; p = opt) {
                char *val;
                if (*p == ',') {
                        opt = p + 1;
                        continue;
                }
                if ((opt = match_option (p, "help", NULL)) != p) {
                        usage (0);
                        continue;
                }
                if ((opt = match_option (p, "calls", NULL)) != p) {
                        calls_enabled = 1;
                        continue;
                }
                if ((opt = match_option (p, "nocalls", NULL)) != p) {
                        events &= ~MONO_PROFILE_ENTER_LEAVE;
                        nocalls = 1;
                        continue;
                }
                if ((opt = match_option (p, "alloc", NULL)) != p) {
                        allocs_enabled = 1;
                        continue;
                }
                if ((opt = match_option (p, "noalloc", NULL)) != p) {
                        events &= ~MONO_PROFILE_ALLOCATIONS;
                        continue;
                }
                if ((opt = match_option (p, "time", &val)) != p) {
                        if (strcmp (val, "fast") == 0)
                                fast_time = 1;
                        else if (strcmp (val, "null") == 0)
                                fast_time = 2;
                        else
                                usage (1);
                        free (val);
                        continue;
                }
                if ((opt = match_option (p, "report", NULL)) != p) {
                        do_report = 1;
                        continue;
                }
                if ((opt = match_option (p, "debug", NULL)) != p) {
                        do_debug = 1;
                        continue;
                }
                if ((opt = match_option (p, "sampling-real", NULL)) != p) {
                        sampling_mode = MONO_PROFILER_STAT_MODE_REAL;
                        continue;
                }
                if ((opt = match_option (p, "sampling-process", NULL)) != p) {
                        sampling_mode = MONO_PROFILER_STAT_MODE_PROCESS;
                        continue;
                }
                if ((opt = match_option (p, "heapshot", &val)) != p) {
                        events &= ~MONO_PROFILE_ALLOCATIONS;
                        events &= ~MONO_PROFILE_ENTER_LEAVE;
                        nocalls = 1;
                        do_heap_shot = 1;
                        set_hsmode (val, 1);
                        continue;
                }
                if ((opt = match_option (p, "sample", &val)) != p) {
                        events &= ~MONO_PROFILE_ALLOCATIONS;
                        events &= ~MONO_PROFILE_ENTER_LEAVE;
                        nocalls = 1;
                        set_sample_mode (val, 1);
                        continue;
                }
                if ((opt = match_option (p, "hsmode", &val)) != p) {
                        fprintf (stderr, "The hsmode profiler option is obsolete, use heapshot=MODE.\n");
                        set_hsmode (val, 0);
                        continue;
                }
                if ((opt = match_option (p, "zip", NULL)) != p) {
                        use_zip = 1;
                        continue;
                }
                if ((opt = match_option (p, "output", &val)) != p) {
                        filename = val;
                        continue;
                }
                if ((opt = match_option (p, "port", &val)) != p) {
                        char *end;
                        command_port = strtoul (val, &end, 10);
                        free (val);
                        continue;
                }
                if ((opt = match_option (p, "maxframes", &val)) != p) {
                        char *end;
                        num_frames = strtoul (val, &end, 10);
                        if (num_frames > MAX_FRAMES)
                                num_frames = MAX_FRAMES;
                        free (val);
                        notraces = num_frames == 0;
                        continue;
                }
                if ((opt = match_option (p, "calldepth", &val)) != p) {
                        char *end;
                        max_call_depth = strtoul (val, &end, 10);
                        free (val);
                        continue;
                }
                if ((opt = match_option (p, "counters", NULL)) != p) {
                        do_counters = 1;
                        continue;
                }
                if ((opt = match_option (p, "countersonly", NULL)) != p) {
                        only_counters = 1;
                        continue;
                }
                if ((opt = match_option (p, "coverage", NULL)) != p) {
                        do_coverage = 1;
                        events |= MONO_PROFILE_ENTER_LEAVE;
                        debug_coverage = (g_getenv ("MONO_PROFILER_DEBUG_COVERAGE") != NULL);
                        continue;
                }
                if ((opt = match_option (p, "onlycoverage", NULL)) != p) {
                        only_coverage = 1;
                        continue;
                }
                if ((opt = match_option (p, "covfilter-file", &val)) != p) {
                        FILE *filter_file;
                        char *line, *content;

                        if (filters == NULL)
                                filters = g_ptr_array_new ();

                        filter_file = fopen (val, "r");
                        if (filter_file == NULL) {
                                fprintf (stderr, "Unable to open %s\n", val);
                                exit (0);
                        }

                        /* Don't need to free content as it is referred to by the lines stored in @filters */
                        content = get_file_content (filter_file);
                        if (content == NULL)
                                fprintf (stderr, "WARNING: %s is greater than 128kb - ignoring\n", val);

                        while ((line = get_next_line (content, &content)))
                                g_ptr_array_add (filters, g_strchug (g_strchomp (line)));

                        fclose (filter_file);
                        continue;
                }
                if ((opt = match_option (p, "covfilter", &val)) != p) {
                        if (filters == NULL)
                                filters = g_ptr_array_new ();

                        g_ptr_array_add (filters, val);
                        continue;
                }
                if (opt == p) {
                        usage (0);
                        exit (0);
                }
        }
        if (calls_enabled) {
                events |= MONO_PROFILE_ENTER_LEAVE;
                nocalls = 0;
        }
        if (allocs_enabled)
                events |= MONO_PROFILE_ALLOCATIONS;
        if (only_counters)
                events = 0;
        if (only_coverage)
                events = MONO_PROFILE_ENTER_LEAVE | MONO_PROFILE_INS_COVERAGE;

        utils_init (fast_time);

        prof = create_profiler (filename, filters);
        if (!prof)
                return;
        init_thread ();

        mono_profiler_install (prof, log_shutdown);
        mono_profiler_install_gc (gc_event, gc_resize);
        mono_profiler_install_allocation (gc_alloc);
        mono_profiler_install_gc_moves (gc_moves);
        mono_profiler_install_gc_roots (gc_handle, gc_roots);
        mono_profiler_install_appdomain (NULL, domain_loaded, NULL, domain_unloaded);
        mono_profiler_install_appdomain_name (domain_name);
        mono_profiler_install_context (context_loaded, context_unloaded);
        mono_profiler_install_class (NULL, class_loaded, NULL, class_unloaded);
        mono_profiler_install_module (NULL, image_loaded, NULL, image_unloaded);
        mono_profiler_install_assembly (NULL, assembly_loaded, assembly_unloaded, NULL);
        mono_profiler_install_thread (thread_start, thread_end);
        mono_profiler_install_thread_name (thread_name);
        mono_profiler_install_enter_leave (method_enter, method_leave);
        mono_profiler_install_jit_end (method_jitted);
        mono_profiler_install_code_buffer_new (code_buffer_new);
        mono_profiler_install_exception (throw_exc, method_exc_leave, clause_exc);
        mono_profiler_install_monitor (monitor_event);
        mono_profiler_install_runtime_initialized (runtime_initialized);
        if (do_coverage)
                mono_profiler_install_coverage_filter (coverage_filter);

        if (do_mono_sample && sample_type == SAMPLE_CYCLES && !only_counters) {
                events |= MONO_PROFILE_STATISTICAL;
                mono_profiler_set_statistical_mode (sampling_mode, 1000000 / sample_freq);
                mono_profiler_install_statistical (mono_sample_hit);
        }

        mono_profiler_set_events ((MonoProfileFlags)events);

        TLS_INIT (tlsbuffer);
        TLS_INIT (tlsmethodlist);
}