#include "metadata/threads.h"
#include "metadata/sgen-gc.h"
#include "metadata/mono-gc.h"
+#include "metadata/method-builder.h"
+#include "metadata/profiler-private.h"
#include "utils/mono-mmap.h"
#ifdef HAVE_VALGRIND_MEMCHECK_H
#include <valgrind/memcheck.h>
#endif
+#define OPDEF(a,b,c,d,e,f,g,h,i,j) \
+ a = i,
+
+enum {
+#include "mono/cil/opcode.def"
+ CEE_LAST
+};
+
+#undef OPDEF
+
/*
* ######################################################################
* ######## Types and constants used by the GC.
/* If set, do a heap consistency check before each minor collection */
static gboolean consistency_check_at_minor_collection = FALSE;
+/*
void
mono_gc_flush_info (void)
{
fflush (gc_debug_file);
}
+*/
-#define MAX_DEBUG_LEVEL 9
-#define DEBUG(level,a) do {if ((level) <= MAX_DEBUG_LEVEL && (level) <= gc_debug_level) a;} while (0)
+#define MAX_DEBUG_LEVEL 8
+#define DEBUG(level,a) do {if (G_UNLIKELY ((level) <= MAX_DEBUG_LEVEL && (level) <= gc_debug_level)) a;} while (0)
#define TV_DECLARE(name) struct timeval name
#define TV_GETTIME(tv) gettimeofday (&(tv), NULL)
void *data [1]; /* page sizes and free lists are stored here */
};
+/* The method used to clear the nursery */
+/* Clearing at nursery collections is the safest, but has bad interactions with caches.
+ * Clearing at TLAB creation is much faster, but more complex and it might expose hard
+ * to find bugs.
+ */
+typedef enum {
+ CLEAR_AT_GC,
+ CLEAR_AT_TLAB_CREATION
+} NurseryClearPolicy;
+
+static NurseryClearPolicy nursery_clear_policy = CLEAR_AT_TLAB_CREATION;
+
+/*
+ * If this is set, the nursery is aligned to an address aligned to its size, ie.
+ * a 1MB nursery will be aligned to an address divisible by 1MB. This allows us to
+ * speed up ptr_in_nursery () checks which are very frequent. This requires the
+ * nursery size to be a compile time constant.
+ */
+#define ALIGN_NURSERY 1
+
/*
* The young generation is divided into fragments. This is because
* we can hand one fragments to a thread for lock-less fast alloc and
* We should start assigning threads very small fragments: if there are many
* threads the nursery will be full of reserved space that the threads may not
* use at all, slowing down allocation speed.
+ * Thread local allocation is done from areas of memory Hotspot calls Thread Local
+ * Allocation Buffers (TLABs).
*/
typedef struct _Fragment Fragment;
REMSET_LOCATION, /* just a pointer to the exact location */
REMSET_RANGE, /* range of pointer fields */
REMSET_OBJECT, /* mark all the object for scanning */
- REMSET_VTYPE, /* a valuetype described by a gc descriptor */
+ REMSET_OTHER, /* all others */
REMSET_TYPE_MASK = 0x3
};
+/* Subtypes of REMSET_OTHER */
+enum {
+ REMSET_VTYPE, /* a valuetype described by a gc descriptor */
+ REMSET_ROOT_LOCATION, /* a location inside a root */
+};
+
static __thread RememberedSet *remembered_set MONO_TLS_FAST;
static pthread_key_t remembered_set_key;
static RememberedSet *global_remset;
-static int store_to_global_remset = 0;
+//static int store_to_global_remset = 0;
/* FIXME: later choose a size that takes into account the RememberedSet struct
* and doesn't waste any alloc paddin space.
((mword*)(obj))[0] &= ~PINNED_BIT; \
} while (0)
+#ifdef ALIGN_NURSERY
+#define ptr_in_nursery(ptr) (((mword)(ptr) & ~((1 << DEFAULT_NURSERY_BITS) - 1)) == (mword)nursery_start)
+#else
+#define ptr_in_nursery(ptr) ((char*)(ptr) >= nursery_start && (char*)(ptr) < nursery_real_end)
+#endif
/*
* Since we set bits in the vtable, use the macro to load it from the pointer to
return vt->klass->name;
}
-static guint
+static inline guint
safe_object_get_size (MonoObject* o)
{
MonoClass *klass = ((MonoVTable*)LOAD_VTABLE (o))->klass;
} else if (klass->rank) {
MonoArray *array = (MonoArray*)o;
size_t size = sizeof (MonoArray) + mono_array_element_size (klass) * mono_array_length (array);
- if (array->bounds) {
+ if (G_UNLIKELY (array->bounds)) {
size += 3;
size &= ~3;
size += sizeof (MonoArrayBounds) * klass->rank;
}
static inline gboolean
-is_half_constructed (MonoObject *o)
+is_maybe_half_constructed (MonoObject *o)
{
MonoClass *klass;
/* good sizes are 512KB-1MB: larger ones increase a lot memzeroing time */
//#define DEFAULT_NURSERY_SIZE (1024*512*125+4096*118)
#define DEFAULT_NURSERY_SIZE (1024*512*2)
+/* The number of trailing 0 bits in DEFAULT_NURSERY_SIZE */
+#define DEFAULT_NURSERY_BITS 20
#define DEFAULT_MAX_SECTION (DEFAULT_NURSERY_SIZE * 16)
#define DEFAULT_LOS_COLLECTION_TARGET (DEFAULT_NURSERY_SIZE * 2)
/* to quickly find the head of an object pinned by a conservative address
return FALSE;
}
+enum {
+ ROOT_TYPE_NORMAL = 0, /* "normal" roots */
+ ROOT_TYPE_PINNED = 1, /* roots without a GC descriptor */
+ ROOT_TYPE_WBARRIER = 2, /* roots with a write barrier */
+ ROOT_TYPE_NUM
+};
+
/* registered roots: the key to the hash is the root start address */
-static RootRecord **roots_hash = NULL;
-static int roots_hash_size = 0;
+/*
+ * Different kinds of roots are kept separate to speed up pin_from_roots () for example.
+ */
+static RootRecord **roots_hash [ROOT_TYPE_NUM] = { NULL, NULL };
+static int roots_hash_size [ROOT_TYPE_NUM] = { 0, 0, 0 };
static mword roots_size = 0; /* amount of memory in the root set */
-static int num_roots_entries = 0;
+static int num_roots_entries [ROOT_TYPE_NUM] = { 0, 0, 0 };
/*
* The current allocation cursors
* We allocate objects in the nursery.
* The nursery is the area between nursery_start and nursery_real_end.
- * nursery_next is the pointer to the space where the next object will be allocated.
- * nursery_temp_end is the pointer to the end of the temporary space reserved for
- * the allocation: this allows us to allow allocations inside the fragments of the
- * nursery (the empty holes between pinned objects) and it allows us to set the
- * scan starts at reasonable intervals.
- * nursery_next and nursery_temp_end will become per-thread vars to allow lock-free
- * allocations.
+ * Allocation is done from a Thread Local Allocation Buffer (TLAB). TLABs are allocated
+ * from nursery fragments.
+ * tlab_next is the pointer to the space inside the TLAB where the next object will
+ * be allocated.
+ * tlab_temp_end is the pointer to the end of the temporary space reserved for
+ * the allocation: it allows us to set the scan starts at reasonable intervals.
+ * tlab_real_end points to the end of the TLAB.
+ * nursery_frag_real_end points to the end of the currently used nursery fragment.
* nursery_first_pinned_start points to the start of the first pinned object in the nursery
* nursery_last_pinned_end points to the end of the last pinned object in the nursery
* At the next allocation, the area of the nursery where objects can be present is
* between MIN(nursery_first_pinned_start, first_fragment_start) and
- * MAX(nursery_last_pinned_end, nursery_temp_end)
+ * MAX(nursery_last_pinned_end, nursery_frag_real_end)
*/
static char *nursery_start = NULL;
+
+/*
+ * FIXME: What is faster, a TLS variable pointing to a structure, or separate TLS
+ * variables for next+temp_end ?
+ */
+static __thread char *tlab_start;
+static __thread char *tlab_next;
+static __thread char *tlab_temp_end;
+static __thread char *tlab_real_end;
+/* Used by the managed allocator */
+static __thread char **tlab_next_addr;
static char *nursery_next = NULL;
-static char *nursery_temp_end = NULL;
-static char *nursery_real_end = NULL;
static char *nursery_frag_real_end = NULL;
-static char *nursery_first_pinned_start = NULL;
+static char *nursery_real_end = NULL;
+//static char *nursery_first_pinned_start = NULL;
static char *nursery_last_pinned_end = NULL;
+/* The size of a TLAB */
+/* The bigger the value, the less often we have to go to the slow path to allocate a new
+ * one, but the more space is wasted by threads not allocating much memory.
+ * FIXME: Tune this.
+ * FIXME: Make this self-tuning for each thread.
+ */
+static guint32 tlab_size = (1024 * 4);
+
/* fragments that are free and ready to be used for allocation */
static Fragment *nursery_fragments = NULL;
/* freeelist of fragment structures */
/*
* used when moving the objects
* When the nursery is collected, objects are copied to to_space.
- * The area between to_space and gray_objects is used as a stack
+ * The area between gray_first and gray_objects is used as a stack
* of objects that need their fields checked for more references
* to be copied.
* We should optimize somehow this mechanism to avoid rescanning
* test cache misses and other graph traversal orders.
*/
static char *to_space = NULL;
+static char *gray_first = NULL;
static char *gray_objects = NULL;
static char *to_space_end = NULL;
static GCMemSection *to_space_section = NULL;
static void free_internal_mem (void *addr);
static void* get_os_memory (size_t size, int activate);
static void free_os_memory (void *addr, size_t size);
-static void report_internal_mem_usage (void);
+static G_GNUC_UNUSED void report_internal_mem_usage (void);
static int stop_world (void);
static int restart_world (void);
static gboolean search_fragment_for_size (size_t size);
static void mark_pinned_from_addresses (PinnedChunk *chunk, void **start, void **end);
static void clear_remsets (void);
+static void clear_tlabs (void);
+static char *find_tlab_next_from_address (char *addr);
static void sweep_pinned_objects (void);
+static void scan_from_pinned_objects (char *addr_start, char *addr_end);
static void free_large_object (LOSObject *obj);
static void free_mem_section (GCMemSection *section);
+void describe_ptr (char *ptr);
void check_consistency (void);
+char* check_object (char *start);
/*
* ######################################################################
#define ALLOC_ALIGN 8
-/* Root bitmap descriptors are simpler: the lower two bits describe the type
+/* Root bitmap descriptors are simpler: the lower three bits describe the type
* and we either have 30/62 bitmap bits or nibble-based run-length,
- * or a complex descriptor
+ * or a complex descriptor, or a user defined marker function.
*/
enum {
ROOT_DESC_CONSERVATIVE, /* 0, so matches NULL value */
ROOT_DESC_BITMAP,
- ROOT_DESC_RUN_LEN,
- ROOT_DESC_LARGE_BITMAP,
- ROOT_DESC_TYPE_MASK = 0x3,
- ROOT_DESC_TYPE_SHIFT = 2,
+ ROOT_DESC_RUN_LEN,
+ ROOT_DESC_COMPLEX,
+ ROOT_DESC_USER,
+ ROOT_DESC_TYPE_MASK = 0x7,
+ ROOT_DESC_TYPE_SHIFT = 3,
};
+#define MAKE_ROOT_DESC(type,val) ((type) | ((val) << ROOT_DESC_TYPE_SHIFT))
+
+#define MAX_USER_DESCRIPTORS 16
+
static gsize* complex_descriptors = NULL;
static int complex_descriptors_size = 0;
static int complex_descriptors_next = 0;
+static MonoGCMarkFunc user_descriptors [MAX_USER_DESCRIPTORS];
+static int user_descriptors_next = 0;
static int
alloc_complex_descriptor (gsize *bitmap, int numbits)
* This section of code deals with detecting the objects no longer in use
* and reclaiming the memory.
*/
+#if 0
static void __attribute__((noinline))
scan_area (char *start, char *end)
{
/* FIXME: handle big and fixed objects (we remove, don't clear in this case) */
UNLOCK_GC;
}
+#endif
+/*
+ * add_to_global_remset:
+ *
+ * The global remset contains locations which point into newspace after
+ * a minor collection. This can happen if the objects they point to are pinned.
+ */
static void
-add_to_global_remset (gpointer ptr)
+add_to_global_remset (gpointer ptr, gboolean root)
{
RememberedSet *rs;
+
DEBUG (8, fprintf (gc_debug_file, "Adding global remset for %p\n", ptr));
- if (global_remset->store_next < global_remset->end_set) {
- *(global_remset->store_next++) = (mword)ptr;
+
+ /*
+ * FIXME: If an object remains pinned, we need to add it at every minor collection.
+ * To avoid uncontrolled growth of the global remset, only add each pointer once.
+ */
+ if (global_remset->store_next + 3 < global_remset->end_set) {
+ if (root) {
+ *(global_remset->store_next++) = (mword)ptr | REMSET_OTHER;
+ *(global_remset->store_next++) = (mword)REMSET_ROOT_LOCATION;
+ } else {
+ *(global_remset->store_next++) = (mword)ptr;
+ }
return;
}
rs = alloc_remset (global_remset->end_set - global_remset->data, NULL);
rs->next = global_remset;
global_remset = rs;
- *(global_remset->store_next++) = (mword)ptr;
+ if (root) {
+ *(global_remset->store_next++) = (mword)ptr | REMSET_OTHER;
+ *(global_remset->store_next++) = (mword)REMSET_LOCATION;
+ } else {
+ *(global_remset->store_next++) = (mword)ptr;
+ }
+
+ {
+ int global_rs_size = 0;
+
+ for (rs = global_remset; rs; rs = rs->next) {
+ global_rs_size += rs->store_next - rs->data;
+ }
+ DEBUG (4, fprintf (gc_debug_file, "Global remset now has size %d\n", global_rs_size));
+ }
}
/*
static char* __attribute__((noinline))
copy_object (char *obj, char *from_space_start, char *from_space_end)
{
+ static void *copy_labels [] = { &&LAB_0, &&LAB_1, &&LAB_2, &&LAB_3, &&LAB_4, &&LAB_5, &&LAB_6, &&LAB_7, &&LAB_8 };
+
+ /*
+ * FIXME: The second set of checks is only needed if we are called for tospace
+ * objects too.
+ */
if (obj >= from_space_start && obj < from_space_end && (obj < to_space || obj >= to_space_end)) {
MonoVTable *vt;
char *forwarded;
* At the end of major collections, we walk the los list and if
* the object is pinned, it is marked, otherwise it can be freed.
*/
- if (objsize >= MAX_SMALL_OBJ_SIZE || (obj >= min_pinned_chunk_addr && obj < max_pinned_chunk_addr && obj_is_from_pinned_alloc (obj))) {
+ if (G_UNLIKELY (objsize >= MAX_SMALL_OBJ_SIZE || (obj >= min_pinned_chunk_addr && obj < max_pinned_chunk_addr && obj_is_from_pinned_alloc (obj)))) {
DEBUG (9, fprintf (gc_debug_file, "Marked LOS/Pinned %p (%s), size: %zd\n", obj, safe_name (obj), objsize));
pin_object (obj);
return obj;
}
/* ok, the object is not pinned, we can move it */
/* use a optimized memcpy here */
+ if (objsize <= sizeof (gpointer) * 8) {
+ mword *dest = (mword*)gray_objects;
+ goto *copy_labels [objsize / sizeof (gpointer)];
+ LAB_8:
+ (dest) [7] = ((mword*)obj) [7];
+ LAB_7:
+ (dest) [6] = ((mword*)obj) [6];
+ LAB_6:
+ (dest) [5] = ((mword*)obj) [5];
+ LAB_5:
+ (dest) [4] = ((mword*)obj) [4];
+ LAB_4:
+ (dest) [3] = ((mword*)obj) [3];
+ LAB_3:
+ (dest) [2] = ((mword*)obj) [2];
+ LAB_2:
+ (dest) [1] = ((mword*)obj) [1];
+ LAB_1:
+ (dest) [0] = ((mword*)obj) [0];
+ LAB_0:
+ ;
+ } else {
#if 0
{
int ecx;
#else
memcpy (gray_objects, obj, objsize);
#endif
+ }
/* adjust array->bounds */
vt = ((MonoObject*)obj)->vtable;
g_assert (vt->gc_descr);
- if (vt->rank && ((MonoArray*)obj)->bounds) {
+ if (G_UNLIKELY (vt->rank && ((MonoArray*)obj)->bounds)) {
MonoArray *array = (MonoArray*)gray_objects;
array->bounds = (MonoArrayBounds*)((char*)gray_objects + ((char*)((MonoArray*)obj)->bounds - (char*)obj));
DEBUG (9, fprintf (gc_debug_file, "Array instance %p: size: %zd, rank: %d, length: %d\n", array, objsize, vt->rank, mono_array_length (array)));
#undef HANDLE_PTR
#define HANDLE_PTR(ptr,obj) do { \
- if (*(ptr)) { \
- void *__old = *(ptr); \
- *(ptr) = copy_object (*(ptr), from_start, from_end); \
+ void *__old = *(ptr); \
+ if (__old) { \
+ *(ptr) = copy_object (__old, from_start, from_end); \
DEBUG (9, if (__old != *(ptr)) fprintf (gc_debug_file, "Overwrote field at %p with %p (was: %p)\n", (ptr), *(ptr), __old)); \
- if (*(ptr) >= (void*)from_start && *(ptr) < (void*)from_end) \
- add_to_global_remset ((ptr)); \
+ if (G_UNLIKELY (*(ptr) >= (void*)from_start && *(ptr) < (void*)from_end) && !ptr_in_nursery (ptr)) \
+ add_to_global_remset ((ptr), FALSE); \
} \
} while (0)
return NULL;
}
+/*
+ * drain_gray_stack:
+ *
+ * Scan objects in the gray stack until the stack is empty. This should be called
+ * frequently after each object is copied, to achieve better locality and cache
+ * usage.
+ */
+static void inline
+drain_gray_stack (char *start_addr, char *end_addr)
+{
+ char *gray_start = gray_first;
+
+ while (gray_start < gray_objects) {
+ DEBUG (9, fprintf (gc_debug_file, "Precise gray object scan %p (%s)\n", gray_start, safe_name (gray_start)));
+ gray_start = scan_object (gray_start, start_addr, end_addr);
+ }
+
+ gray_first = gray_start;
+}
+
/*
* scan_vtype:
*
}
}
-static void
+static G_GNUC_UNUSED void
print_nursery_gaps (void* start_nursery, void *end_nursery)
{
int i;
* is no write in the old generation area where the pinned object is referenced
* and we may not consider it as reachable.
*/
-static void
+static G_GNUC_UNUSED void
mark_pinned_objects (int generation)
{
}
/*
* Debugging function: find in the conservative roots where @obj is being pinned.
*/
-static void
+static G_GNUC_UNUSED void
find_pinning_reference (char *obj, size_t size)
{
RootRecord *root;
int i;
char *endobj = obj + size;
- for (i = 0; i < roots_hash_size; ++i) {
- for (root = roots_hash [i]; root; root = root->next) {
+ for (i = 0; i < roots_hash_size [0]; ++i) {
+ for (root = roots_hash [0][i]; root; root = root->next) {
/* if desc is non-null it has precise info */
if (!root->root_desc) {
char ** start = (char**)root->start_root;
{
RootRecord *root;
int i;
- DEBUG (3, fprintf (gc_debug_file, "Scanning pinned roots (%d bytes, %d entries)\n", (int)roots_size, num_roots_entries));
+ DEBUG (2, fprintf (gc_debug_file, "Scanning pinned roots (%d bytes, %d/%d entries)\n", (int)roots_size, num_roots_entries [ROOT_TYPE_NORMAL], num_roots_entries [ROOT_TYPE_PINNED]));
/* objects pinned from the API are inside these roots */
- for (i = 0; i < roots_hash_size; ++i) {
- for (root = roots_hash [i]; root; root = root->next) {
- /* if desc is non-null it has precise info */
- if (root->root_desc)
- continue;
+ for (i = 0; i < roots_hash_size [ROOT_TYPE_PINNED]; ++i) {
+ for (root = roots_hash [ROOT_TYPE_PINNED][i]; root; root = root->next) {
DEBUG (6, fprintf (gc_debug_file, "Pinned roots %p-%p\n", root->start_root, root->end_root));
conservatively_pin_objects_from ((void**)root->start_root, (void**)root->end_root, start_nursery, end_nursery);
}
pin_thread_data (start_nursery, end_nursery);
}
+/* Copy function called from user defined mark functions */
+static char *user_copy_n_start;
+static char *user_copy_n_end;
+
+static void*
+user_copy (void *addr)
+{
+ if (addr)
+ return copy_object (addr, user_copy_n_start, user_copy_n_end);
+ else
+ return NULL;
+}
+
/*
* The memory area from start_root to end_root contains pointers to objects.
* Their position is precisely described by @desc (this means that the pointer
while (desc) {
if ((desc & 1) && *start_root) {
*start_root = copy_object (*start_root, n_start, n_end);
- DEBUG (9, fprintf (gc_debug_file, "Overwrote root at %p with %p\n", start_root, *start_root)); \
+ DEBUG (9, fprintf (gc_debug_file, "Overwrote root at %p with %p\n", start_root, *start_root));
+ drain_gray_stack (n_start, n_end);
}
desc >>= 1;
start_root++;
}
return;
+ case ROOT_DESC_COMPLEX: {
+ gsize *bitmap_data = complex_descriptors + (desc >> ROOT_DESC_TYPE_SHIFT);
+ int bwords = (*bitmap_data) - 1;
+ void **start_run = start_root;
+ bitmap_data++;
+ while (bwords-- > 0) {
+ gsize bmap = *bitmap_data++;
+ void **objptr = start_run;
+ while (bmap) {
+ if ((bmap & 1) && *objptr) {
+ *objptr = copy_object (*objptr, n_start, n_end);
+ DEBUG (9, fprintf (gc_debug_file, "Overwrote root at %p with %p\n", objptr, *objptr));
+ drain_gray_stack (n_start, n_end);
+ }
+ bmap >>= 1;
+ ++objptr;
+ }
+ start_run += GC_BITS_PER_WORD;
+ }
+ break;
+ }
+ case ROOT_DESC_USER: {
+ MonoGCMarkFunc marker = user_descriptors [desc >> ROOT_DESC_TYPE_SHIFT];
+
+ user_copy_n_start = n_start;
+ user_copy_n_end = n_end;
+ marker (start_root, user_copy);
+ break;
+ }
case ROOT_DESC_RUN_LEN:
- case ROOT_DESC_LARGE_BITMAP:
+ g_assert_not_reached ();
+ default:
g_assert_not_reached ();
}
}
char *data;
int scan_starts;
Fragment *frag;
+ int alloc_size;
if (nursery_section)
return;
*/
/* FIXME: handle OOM */
section = get_internal_mem (sizeof (GCMemSection));
- data = get_os_memory (nursery_size, TRUE);
- nursery_start = nursery_next = data;
- nursery_real_end = data + nursery_size;
- nursery_temp_end = data + SCAN_START_SIZE;
+
+#ifdef ALIGN_NURSERY
+ /* Allocate twice the memory to be able to put the nursery at an aligned address */
+ g_assert (nursery_size == DEFAULT_NURSERY_SIZE);
+
+ alloc_size = nursery_size * 2;
+ data = get_os_memory (alloc_size, TRUE);
+ nursery_start = (void*)(((mword)data + (1 << DEFAULT_NURSERY_BITS) - 1) & ~((1 << DEFAULT_NURSERY_BITS) - 1));
+ g_assert ((char*)nursery_start + nursery_size <= ((char*)data + alloc_size));
+ /* FIXME: Use the remaining size for something else, if it is big enough */
+#else
+ alloc_size = nursery_size;
+ data = get_os_memory (alloc_size, TRUE);
+ nursery_start = data;
+#endif
+ nursery_real_end = nursery_start + nursery_size;
UPDATE_HEAP_BOUNDARIES (nursery_start, nursery_real_end);
- total_alloc += nursery_size;
+ nursery_next = nursery_start;
+ total_alloc += alloc_size;
DEBUG (4, fprintf (gc_debug_file, "Expanding heap size: %zd, total: %zd\n", nursery_size, total_alloc));
section->data = section->next_data = data;
- section->size = nursery_size;
+ section->size = alloc_size;
section->end_data = nursery_real_end;
- scan_starts = nursery_size / SCAN_START_SIZE;
+ scan_starts = alloc_size / SCAN_START_SIZE;
section->scan_starts = get_internal_mem (sizeof (char*) * scan_starts);
section->num_scan_start = scan_starts;
section->role = MEMORY_ROLE_GEN0;
* Update roots in the old generation. Since we currently don't have the
* info from the write barriers, we just scan all the objects.
*/
-static void
+static G_GNUC_UNUSED void
scan_old_generation (char *start, char* end)
{
GCMemSection *section;
Fragment *fragment;
DEBUG (4, fprintf (gc_debug_file, "Found empty fragment: %p-%p, size: %zd\n", frag_start, frag_end, frag_size));
/* memsetting just the first chunk start is bound to provide better cache locality */
- memset (frag_start, 0, frag_size);
+ if (nursery_clear_policy == CLEAR_AT_GC)
+ memset (frag_start, 0, frag_size);
/* Not worth dealing with smaller fragments: need to tune */
if (frag_size >= FRAGMENT_MIN_SIZE) {
fragment = alloc_fragment ();
fragment->next = nursery_fragments;
nursery_fragments = fragment;
fragment_total += frag_size;
+ } else {
+ /* Clear unused fragments, pinning depends on this */
+ memset (frag_start, 0, frag_size);
}
}
}
static void
-drain_gray_stack (char *start_addr, char *end_addr)
+finish_gray_stack (char *start_addr, char *end_addr)
{
TV_DECLARE (atv);
TV_DECLARE (btv);
* We need to walk the LO list as well in search of marked big objects
* (use a flag since this is needed only on major collections). We need to loop
* here as well, so keep a counter of marked LO (increasing it in copy_object).
+ * To achieve better cache locality and cache usage, we drain the gray stack
+ * frequently, after each object is copied, and just finish the work here.
*/
- TV_GETTIME (btv);
- gray_start = to_space;
- DEBUG (6, fprintf (gc_debug_file, "Precise scan of gray area: %p-%p, size: %d\n", gray_start, gray_objects, (int)(gray_objects - gray_start)));
+ gray_start = gray_first;
while (gray_start < gray_objects) {
DEBUG (9, fprintf (gc_debug_file, "Precise gray object scan %p (%s)\n", gray_start, safe_name (gray_start)));
gray_start = scan_object (gray_start, start_addr, end_addr);
}
TV_GETTIME (atv);
- DEBUG (2, fprintf (gc_debug_file, "Gray stack scan: %d usecs\n", TV_ELAPSED (btv, atv)));
//scan_old_generation (start_addr, end_addr);
DEBUG (2, fprintf (gc_debug_file, "Old generation done\n"));
/* walk the finalization queue and move also the objects that need to be
static int last_num_pinned = 0;
static void
-build_nursery_fragments (int start_pin, int end_pin, char *nursery_last_allocated)
+build_nursery_fragments (int start_pin, int end_pin)
{
char *frag_start, *frag_end;
size_t frag_size;
* (zero initialized) object. Find the end of the object by scanning forward.
*
*/
- if (is_half_constructed (pin_queue [i])) {
- /* Can't use nursery_next as the limit as it is modified in collect_nursery () */
- while ((frag_start < nursery_last_allocated) && *(mword*)frag_start == 0)
- frag_start += sizeof (mword);
+ if (is_maybe_half_constructed (pin_queue [i])) {
+ char *tlab_end;
+
+ /* This is also hit for zero length arrays/strings */
+
+ /* Find the end of the TLAB which contained this allocation */
+ tlab_end = find_tlab_next_from_address (pin_queue [i]);
+
+ if (tlab_end) {
+ while ((frag_start < tlab_end) && *(mword*)frag_start == 0)
+ frag_start += sizeof (mword);
+ } else {
+ /*
+ * FIXME: The object is either not allocated in a TLAB, or it isn't a
+ * half constructed object.
+ */
+ }
}
}
nursery_last_pinned_end = frag_start;
}
degraded_mode = 1;
}
+
+ nursery_next = nursery_frag_real_end = NULL;
+
+ /* Clear TLABs for all threads */
+ clear_tlabs ();
}
/* FIXME: later reduce code duplication here with the above
}
static void
-scan_from_registered_roots (char *addr_start, char *addr_end)
+scan_from_registered_roots (char *addr_start, char *addr_end, int root_type)
{
int i;
RootRecord *root;
- for (i = 0; i < roots_hash_size; ++i) {
- for (root = roots_hash [i]; root; root = root->next) {
- /* if desc is non-null it has precise info */
- if (!root->root_desc)
- continue;
+ for (i = 0; i < roots_hash_size [root_type]; ++i) {
+ for (root = roots_hash [root_type][i]; root; root = root->next) {
DEBUG (6, fprintf (gc_debug_file, "Precise root scan %p-%p (desc: %p)\n", root->start_root, root->end_root, (void*)root->root_desc));
precisely_scan_objects_from ((void**)root->start_root, (void**)root->end_root, addr_start, addr_end, root->root_desc);
}
GCMemSection *section;
size_t max_garbage_amount;
int i;
- char *nursery_last_allocated;
+ char *orig_nursery_next;
+ Fragment *frag;
TV_DECLARE (all_atv);
TV_DECLARE (all_btv);
TV_DECLARE (atv);
TV_DECLARE (btv);
degraded_mode = 0;
- nursery_last_allocated = nursery_next;
+ orig_nursery_next = nursery_next;
nursery_next = MAX (nursery_next, nursery_last_pinned_end);
/* FIXME: optimize later to use the higher address where an object can be present */
nursery_next = MAX (nursery_next, nursery_real_end);
DEBUG (1, fprintf (gc_debug_file, "Start nursery collection %d %p-%p, size: %d\n", num_minor_gcs, nursery_start, nursery_next, (int)(nursery_next - nursery_start)));
max_garbage_amount = nursery_next - nursery_start;
+
+ /* Clear all remaining nursery fragments, pinning depends on this */
+ if (nursery_clear_policy == CLEAR_AT_TLAB_CREATION) {
+ g_assert (orig_nursery_next <= nursery_frag_real_end);
+ memset (orig_nursery_next, 0, nursery_frag_real_end - orig_nursery_next);
+ for (frag = nursery_fragments; frag; frag = frag->next) {
+ memset (frag->fragment_start, 0, frag->fragment_end - frag->fragment_start);
+ }
+ }
+
/*
* not enough room in the old generation to store all the possible data from
* the nursery in a single continuous space.
* We reset to_space if we allocated objects in degraded mode.
*/
if (to_space_section)
- to_space = gray_objects = to_space_section->next_data;
+ to_space = gray_objects = gray_first = to_space_section->next_data;
if ((to_space_end - to_space) < max_garbage_amount) {
section = alloc_section (nursery_section->size * 4);
g_assert (nursery_section->size >= max_garbage_amount);
- to_space = gray_objects = section->next_data;
+ to_space = gray_objects = gray_first = section->next_data;
to_space_end = section->end_data;
to_space_section = section;
}
/* we don't have complete write barrier yet, so we scan all the old generation sections */
TV_GETTIME (atv);
DEBUG (2, fprintf (gc_debug_file, "Old generation scan: %d usecs\n", TV_ELAPSED (btv, atv)));
- /* FIXME: later scan also alloc_pinned objects */
/* the pinned objects are roots */
for (i = 0; i < next_pin_slot; ++i) {
scan_object (pin_queue [i], nursery_start, nursery_next);
}
/* registered roots, this includes static fields */
- scan_from_registered_roots (nursery_start, nursery_next);
+ scan_from_registered_roots (nursery_start, nursery_next, ROOT_TYPE_NORMAL);
+ /* alloc_pinned objects */
+ scan_from_pinned_objects (nursery_start, nursery_next);
TV_GETTIME (btv);
DEBUG (2, fprintf (gc_debug_file, "Root scan: %d usecs\n", TV_ELAPSED (atv, btv)));
- drain_gray_stack (nursery_start, nursery_next);
+ finish_gray_stack (nursery_start, nursery_next);
/* walk the pin_queue, build up the fragment list of free memory, unmark
* pinned objects as we go, memzero() the empty fragments so they are ready for the
* next allocations.
*/
- build_nursery_fragments (0, next_pin_slot, nursery_last_allocated);
+ build_nursery_fragments (0, next_pin_slot);
TV_GETTIME (atv);
DEBUG (2, fprintf (gc_debug_file, "Fragment creation: %d usecs, %zd bytes available\n", TV_ELAPSED (btv, atv), fragment_total));
int i;
PinnedChunk *chunk;
FinalizeEntry *fin;
+ Fragment *frag;
int count;
TV_DECLARE (all_atv);
TV_DECLARE (all_btv);
DEBUG (1, fprintf (gc_debug_file, "Start major collection %d\n", num_major_gcs));
num_major_gcs++;
mono_stats.major_gc_count ++;
+
+ /* Clear all remaining nursery fragments, pinning depends on this */
+ if (nursery_clear_policy == CLEAR_AT_TLAB_CREATION) {
+ g_assert (nursery_next <= nursery_frag_real_end);
+ memset (nursery_next, 0, nursery_frag_real_end - nursery_next);
+ for (frag = nursery_fragments; frag; frag = frag->next) {
+ memset (frag->fragment_start, 0, frag->fragment_end - frag->fragment_start);
+ }
+ }
+
/*
* FIXME: implement Mark/Compact
* Until that is done, we can just apply mostly the same alg as for the nursery:
/* allocate the big to space */
DEBUG (4, fprintf (gc_debug_file, "Allocate tospace for size: %zd\n", copy_space_required));
section = alloc_section (copy_space_required);
- to_space = gray_objects = section->next_data;
+ to_space = gray_objects = gray_first = section->next_data;
to_space_end = section->end_data;
to_space_section = section;
scan_object (pin_queue [i], heap_start, heap_end);
}
/* registered roots, this includes static fields */
- scan_from_registered_roots (heap_start, heap_end);
-
+ scan_from_registered_roots (heap_start, heap_end, ROOT_TYPE_NORMAL);
+ scan_from_registered_roots (heap_start, heap_end, ROOT_TYPE_WBARRIER);
+ /* alloc_pinned objects */
+ scan_from_pinned_objects (heap_start, heap_end);
/* scan the list of objects ready for finalization */
for (fin = fin_ready_list; fin; fin = fin->next) {
DEBUG (5, fprintf (gc_debug_file, "Scan of fin ready object: %p (%s)\n", fin->object, safe_name (fin->object)));
/* we need to go over the big object list to see if any was marked and scan it
* And we need to make this in a loop, considering that objects referenced by finalizable
- * objects could reference big objects (this happens in drain_gray_stack ())
+ * objects could reference big objects (this happens in finish_gray_stack ())
*/
scan_needed_big_objects (heap_start, heap_end);
/* all the objects in the heap */
- drain_gray_stack (heap_start, heap_end);
+ finish_gray_stack (heap_start, heap_end);
/* sweep the big objects list */
prevbo = NULL;
* pinned objects as we go, memzero() the empty fragments so they are ready for the
* next allocations.
*/
- build_nursery_fragments (nursery_section->pin_queue_start, nursery_section->pin_queue_end, nursery_next);
+ build_nursery_fragments (nursery_section->pin_queue_start, nursery_section->pin_queue_end);
TV_GETTIME (all_btv);
mono_stats.major_gc_time_usecs += TV_ELAPSED (all_atv, all_btv);
if (!search_fragment_for_size (size)) {
int i;
/* TypeBuilder and MonoMethod are killing mcs with fragmentation */
- DEBUG (1, fprintf (gc_debug_file, "nursery collection didn't find enough room for %zd alloc (%d pinned)", size, last_num_pinned));
+ DEBUG (1, fprintf (gc_debug_file, "nursery collection didn't find enough room for %zd alloc (%d pinned)\n", size, last_num_pinned));
for (i = 0; i < last_num_pinned; ++i) {
DEBUG (3, fprintf (gc_debug_file, "Bastard pinning obj %p (%s), size: %d\n", pin_queue [i], safe_name (pin_queue [i]), safe_object_get_size (pin_queue [i])));
}
/*
* Debug reporting.
*/
-static void
+static G_GNUC_UNUSED void
report_internal_mem_usage (void) {
PinnedChunk *chunk;
int i;
void *end_chunk;
for (chunk = pinned_chunk_list; chunk; chunk = chunk->next) {
end_chunk = (char*)chunk + chunk->num_pages * FREELIST_PAGESIZE;
- DEBUG (6, fprintf (gc_debug_file, "Sweeping pinned chunk %p (ranhe: %p-%p)\n", chunk, chunk->start_data, end_chunk));
+ DEBUG (6, fprintf (gc_debug_file, "Sweeping pinned chunk %p (range: %p-%p)\n", chunk, chunk->start_data, end_chunk));
for (i = 0; i < chunk->num_pages; ++i) {
obj_size = chunk->page_sizes [i];
if (!obj_size)
}
}
+static void
+scan_from_pinned_objects (char *addr_start, char *addr_end)
+{
+ PinnedChunk *chunk;
+ int i, obj_size;
+ char *p, *endp;
+ void **ptr;
+ void *end_chunk;
+ for (chunk = pinned_chunk_list; chunk; chunk = chunk->next) {
+ end_chunk = (char*)chunk + chunk->num_pages * FREELIST_PAGESIZE;
+ DEBUG (6, fprintf (gc_debug_file, "Scanning pinned chunk %p (range: %p-%p)\n", chunk, chunk->start_data, end_chunk));
+ for (i = 0; i < chunk->num_pages; ++i) {
+ obj_size = chunk->page_sizes [i];
+ if (!obj_size)
+ continue;
+ p = i? (char*)chunk + i * FREELIST_PAGESIZE: chunk->start_data;
+ endp = i? p + FREELIST_PAGESIZE: (char*)chunk + FREELIST_PAGESIZE;
+ DEBUG (6, fprintf (gc_debug_file, "Page %d (size: %d, range: %p-%p)\n", i, obj_size, p, endp));
+ while (p + obj_size <= endp) {
+ ptr = (void**)p;
+ DEBUG (9, fprintf (gc_debug_file, "Considering %p (vtable: %p)\n", ptr, *ptr));
+ /* if the first word (the vtable) is outside the chunk we have an object */
+ if (*ptr && (*ptr < (void*)chunk || *ptr >= end_chunk)) {
+ DEBUG (6, fprintf (gc_debug_file, "Precise object scan %d of alloc_pinned %p (%s)\n", i, ptr, safe_name (ptr)));
+ // FIXME: Put objects without references into separate chunks
+ // which do not need to be scanned
+ scan_object ((char*)ptr, addr_start, addr_end);
+ }
+ p += obj_size;
+ }
+ }
+ }
+}
+
/*
* Find the slot number in the freelist for memory chunks that
* can contain @size objects.
{
Fragment *frag, *prev;
DEBUG (4, fprintf (gc_debug_file, "Searching nursery fragment %p, size: %zd\n", nursery_frag_real_end, size));
+
+ if (nursery_frag_real_end > nursery_next && nursery_clear_policy == CLEAR_AT_TLAB_CREATION)
+ /* Clear the remaining space, pinning depends on this */
+ memset (nursery_next, 0, nursery_frag_real_end - nursery_next);
+
prev = NULL;
for (frag = nursery_fragments; frag; frag = frag->next) {
if (size <= (frag->fragment_end - frag->fragment_start)) {
nursery_fragments = frag->next;
nursery_next = frag->fragment_start;
nursery_frag_real_end = frag->fragment_end;
- nursery_temp_end = MIN (nursery_frag_real_end, nursery_next + size + SCAN_START_SIZE);
DEBUG (4, fprintf (gc_debug_file, "Using nursery fragment %p-%p, size: %zd (req: %zd)\n", nursery_next, nursery_frag_real_end, nursery_frag_real_end - nursery_next, size));
frag->next = fragment_freelist;
{
/* FIXME: handle OOM */
void **p;
+ char *new_next;
int dummy;
+ gboolean res;
size += ALLOC_ALIGN - 1;
size &= ~(ALLOC_ALIGN - 1);
g_assert (vtable->gc_descr);
- LOCK_GC;
- if (collect_before_allocs) {
+ if (G_UNLIKELY (collect_before_allocs)) {
int dummy;
if (nursery_section) {
+ LOCK_GC;
+
update_current_thread_stack (&dummy);
stop_world ();
collect_nursery (0);
// FIXME:
g_assert_not_reached ();
}
+ UNLOCK_GC;
}
}
- p = (void**)nursery_next;
+ /* tlab_next and tlab_temp_end are TLS vars so accessing them might be expensive */
+
+ p = (void**)tlab_next;
/* FIXME: handle overflow */
- nursery_next += size;
- if (nursery_next >= nursery_temp_end) {
- /* there are two cases: the object is too big or we need to collect */
- /* there can be another case (from ORP), if we cooperate with the runtime a bit:
- * objects that need finalizers can have the high bit set in their size
- * so the above check fails and we can readily add the object to the queue.
- * This avoids taking again the GC lock when registering, but this is moot when
- * doing thread-local allocation, so it may not be a good idea.
+ new_next = (char*)p + size;
+ tlab_next = new_next;
+
+ if (G_LIKELY (new_next < tlab_temp_end)) {
+ /* Fast path */
+
+ /*
+ * FIXME: We might need a memory barrier here so the change to tlab_next is
+ * visible before the vtable store.
*/
- if (size > MAX_SMALL_OBJ_SIZE) {
- /* get ready for possible collection */
- update_current_thread_stack (&dummy);
- nursery_next -= size;
- p = alloc_large_inner (vtable, size);
- } else {
- if (nursery_next >= nursery_frag_real_end) {
- nursery_next -= size;
- /* when running in degraded mode, we continue allocing that way
- * for a while, to decrease the number of useless nursery collections.
- */
- if (degraded_mode && degraded_mode < DEFAULT_NURSERY_SIZE) {
- p = alloc_degraded (vtable, size);
- UNLOCK_GC;
- return p;
- }
- if (!search_fragment_for_size (size)) {
- /* get ready for possible collection */
- update_current_thread_stack (&dummy);
- minor_collect_or_expand_inner (size);
- if (degraded_mode) {
- p = alloc_degraded (vtable, size);
- UNLOCK_GC;
- return p;
+
+ DEBUG (6, fprintf (gc_debug_file, "Allocated object %p, vtable: %p (%s), size: %zd\n", p, vtable, vtable->klass->name, size));
+ *p = vtable;
+
+ return p;
+ }
+
+ /* Slow path */
+
+ /* there are two cases: the object is too big or we run out of space in the TLAB */
+ /* we also reach here when the thread does its first allocation after a minor
+ * collection, since the tlab_ variables are initialized to NULL.
+ * there can be another case (from ORP), if we cooperate with the runtime a bit:
+ * objects that need finalizers can have the high bit set in their size
+ * so the above check fails and we can readily add the object to the queue.
+ * This avoids taking again the GC lock when registering, but this is moot when
+ * doing thread-local allocation, so it may not be a good idea.
+ */
+ LOCK_GC;
+ if (size > MAX_SMALL_OBJ_SIZE) {
+ /* get ready for possible collection */
+ update_current_thread_stack (&dummy);
+ tlab_next -= size;
+ p = alloc_large_inner (vtable, size);
+ } else {
+ if (tlab_next >= tlab_real_end) {
+ /*
+ * Run out of space in the TLAB. When this happens, some amount of space
+ * remains in the TLAB, but not enough to satisfy the current allocation
+ * request. Currently, we retire the TLAB in all cases, later we could
+ * keep it if the remaining space is above a treshold, and satisfy the
+ * allocation directly from the nursery.
+ */
+ tlab_next -= size;
+ /* when running in degraded mode, we continue allocing that way
+ * for a while, to decrease the number of useless nursery collections.
+ */
+ if (degraded_mode && degraded_mode < DEFAULT_NURSERY_SIZE) {
+ p = alloc_degraded (vtable, size);
+ UNLOCK_GC;
+ return p;
+ }
+
+ if (size > tlab_size) {
+ /* Allocate directly from the nursery */
+ if (nursery_next + size >= nursery_frag_real_end) {
+ if (!search_fragment_for_size (size)) {
+ /* get ready for possible collection */
+ update_current_thread_stack (&dummy);
+ minor_collect_or_expand_inner (size);
+ if (degraded_mode) {
+ p = alloc_degraded (vtable, size);
+ UNLOCK_GC;
+ return p;
+ }
}
}
- /* nursery_next changed by minor_collect_or_expand_inner () */
+
p = (void*)nursery_next;
nursery_next += size;
- if (nursery_next > nursery_temp_end) {
+ if (nursery_next > nursery_frag_real_end) {
// no space left
g_assert (0);
}
+
+ if (nursery_clear_policy == CLEAR_AT_TLAB_CREATION)
+ memset (p, 0, size);
} else {
- /* record the scan start so we can find pinned objects more easily */
+ if (tlab_start)
+ DEBUG (3, fprintf (gc_debug_file, "Retire TLAB: %p-%p [%ld]\n", tlab_start, tlab_real_end, (long)(tlab_real_end - tlab_next - size)));
+
+ if (nursery_next + tlab_size >= nursery_frag_real_end) {
+ res = search_fragment_for_size (tlab_size);
+ if (!res) {
+ /* get ready for possible collection */
+ update_current_thread_stack (&dummy);
+ minor_collect_or_expand_inner (tlab_size);
+ if (degraded_mode) {
+ p = alloc_degraded (vtable, size);
+ UNLOCK_GC;
+ return p;
+ }
+ }
+ }
+
+ /* Allocate a new TLAB from the current nursery fragment */
+ tlab_start = nursery_next;
+ nursery_next += tlab_size;
+ tlab_next = tlab_start;
+ tlab_real_end = tlab_start + tlab_size;
+ tlab_temp_end = tlab_start + MIN (SCAN_START_SIZE, tlab_size);
+
+ if (nursery_clear_policy == CLEAR_AT_TLAB_CREATION)
+ memset (tlab_start, 0, tlab_size);
+
+ /* Allocate from the TLAB */
+ p = (void*)tlab_next;
+ tlab_next += size;
+ g_assert (tlab_next <= tlab_real_end);
+
nursery_section->scan_starts [((char*)p - (char*)nursery_section->data)/SCAN_START_SIZE] = (char*)p;
- /* we just bump nursery_temp_end as well */
- nursery_temp_end = MIN (nursery_frag_real_end, nursery_next + SCAN_START_SIZE);
- DEBUG (5, fprintf (gc_debug_file, "Expanding local alloc: %p-%p\n", nursery_next, nursery_temp_end));
}
+ } else {
+ /* Reached tlab_temp_end */
+
+ /* record the scan start so we can find pinned objects more easily */
+ nursery_section->scan_starts [((char*)p - (char*)nursery_section->data)/SCAN_START_SIZE] = (char*)p;
+ /* we just bump tlab_temp_end as well */
+ tlab_temp_end = MIN (tlab_real_end, tlab_next + SCAN_START_SIZE);
+ DEBUG (5, fprintf (gc_debug_file, "Expanding local alloc: %p-%p\n", tlab_next, tlab_temp_end));
}
}
+
DEBUG (6, fprintf (gc_debug_file, "Allocated object %p, vtable: %p (%s), size: %zd\n", p, vtable, vtable->klass->name, size));
*p = vtable;
*/
static void
-rehash_roots (void)
+rehash_roots (gboolean pinned)
{
int i;
unsigned int hash;
RootRecord **new_hash;
RootRecord *entry, *next;
- int new_size = g_spaced_primes_closest (num_roots_entries);
+ int new_size;
+ new_size = g_spaced_primes_closest (num_roots_entries [pinned]);
new_hash = get_internal_mem (new_size * sizeof (RootRecord*));
- for (i = 0; i < roots_hash_size; ++i) {
- for (entry = roots_hash [i]; entry; entry = next) {
+ for (i = 0; i < roots_hash_size [pinned]; ++i) {
+ for (entry = roots_hash [pinned][i]; entry; entry = next) {
hash = mono_aligned_addr_hash (entry->start_root) % new_size;
next = entry->next;
entry->next = new_hash [hash];
new_hash [hash] = entry;
}
}
- free_internal_mem (roots_hash);
- roots_hash = new_hash;
- roots_hash_size = new_size;
+ free_internal_mem (roots_hash [pinned]);
+ roots_hash [pinned] = new_hash;
+ roots_hash_size [pinned] = new_size;
+}
+
+static RootRecord*
+find_root (int root_type, char *start, guint32 addr_hash)
+{
+ RootRecord *new_root;
+
+ guint32 hash = addr_hash % roots_hash_size [root_type];
+ for (new_root = roots_hash [root_type][hash]; new_root; new_root = new_root->next) {
+ /* we allow changing the size and the descriptor (for thread statics etc) */
+ if (new_root->start_root == start) {
+ return new_root;
+ }
+ }
+
+ return NULL;
}
/*
* We do not coalesce roots.
*/
-int
-mono_gc_register_root (char *start, size_t size, void *descr)
+static int
+mono_gc_register_root_inner (char *start, size_t size, void *descr, int root_type)
{
RootRecord *new_root;
- unsigned int hash = mono_aligned_addr_hash (start);
+ unsigned int hash, addr_hash = mono_aligned_addr_hash (start);
+ int i;
LOCK_GC;
- if (num_roots_entries >= roots_hash_size * 2)
- rehash_roots ();
- hash %= roots_hash_size;
- for (new_root = roots_hash [hash]; new_root; new_root = new_root->next) {
+ for (i = 0; i < ROOT_TYPE_NUM; ++i) {
+ if (num_roots_entries [i] >= roots_hash_size [i] * 2)
+ rehash_roots (i);
+ }
+ for (i = 0; i < ROOT_TYPE_NUM; ++i) {
+ new_root = find_root (i, start, addr_hash);
/* we allow changing the size and the descriptor (for thread statics etc) */
- if (new_root->start_root == start) {
+ if (new_root) {
size_t old_size = new_root->end_root - new_root->start_root;
new_root->end_root = new_root->start_root + size;
+ g_assert (((new_root->root_desc != 0) && (descr != NULL)) ||
+ ((new_root->root_desc == 0) && (descr == NULL)));
new_root->root_desc = (mword)descr;
roots_size += size;
roots_size -= old_size;
new_root->end_root = new_root->start_root + size;
new_root->root_desc = (mword)descr;
roots_size += size;
- num_roots_entries++;
- new_root->next = roots_hash [hash];
- roots_hash [hash] = new_root;
+ hash = addr_hash % roots_hash_size [root_type];
+ num_roots_entries [root_type]++;
+ new_root->next = roots_hash [root_type] [hash];
+ roots_hash [root_type][hash] = new_root;
DEBUG (3, fprintf (gc_debug_file, "Added root %p for range: %p-%p, descr: %p (%d/%d bytes)\n", new_root, new_root->start_root, new_root->end_root, descr, (int)size, (int)roots_size));
} else {
UNLOCK_GC;
return TRUE;
}
+int
+mono_gc_register_root (char *start, size_t size, void *descr)
+{
+ return mono_gc_register_root_inner (start, size, descr, descr ? ROOT_TYPE_NORMAL : ROOT_TYPE_PINNED);
+}
+
+int
+mono_gc_register_root_wbarrier (char *start, size_t size, void *descr)
+{
+ return mono_gc_register_root_inner (start, size, descr, ROOT_TYPE_WBARRIER);
+}
+
void
mono_gc_deregister_root (char* addr)
{
- RootRecord *tmp, *prev = NULL;
- unsigned int hash = mono_aligned_addr_hash (addr);
+ RootRecord *tmp, *prev;
+ unsigned int hash, addr_hash = mono_aligned_addr_hash (addr);
+ int root_type;
+
LOCK_GC;
- hash %= roots_hash_size;
- tmp = roots_hash [hash];
- while (tmp) {
- if (tmp->start_root == (char*)addr) {
- if (prev)
- prev->next = tmp->next;
- else
- roots_hash [hash] = tmp->next;
- roots_size -= (tmp->end_root - tmp->start_root);
- num_roots_entries--;
- DEBUG (3, fprintf (gc_debug_file, "Removed root %p for range: %p-%p\n", tmp, tmp->start_root, tmp->end_root));
- free_internal_mem (tmp);
- break;
+ for (root_type = 0; root_type < ROOT_TYPE_NUM; ++root_type) {
+ hash = addr_hash % roots_hash_size [root_type];
+ tmp = roots_hash [root_type][hash];
+ prev = NULL;
+ while (tmp) {
+ if (tmp->start_root == (char*)addr) {
+ if (prev)
+ prev->next = tmp->next;
+ else
+ roots_hash [root_type][hash] = tmp->next;
+ roots_size -= (tmp->end_root - tmp->start_root);
+ num_roots_entries [root_type]--;
+ DEBUG (3, fprintf (gc_debug_file, "Removed root %p for range: %p-%p\n", tmp, tmp->start_root, tmp->end_root));
+ free_internal_mem (tmp);
+ break;
+ }
+ prev = tmp;
+ tmp = tmp->next;
}
- prev = tmp;
- tmp = tmp->next;
}
UNLOCK_GC;
}
int skip;
void *stack_end;
void *stack_start;
+ char **tlab_next_addr;
+ char **tlab_start_addr;
+ char **tlab_temp_end_addr;
+ char **tlab_real_end_addr;
RememberedSet *remset;
};
DEBUG (2, fprintf (gc_debug_file, "Skipping dead thread %p, range: %p-%p, size: %zd\n", info, info->stack_start, info->stack_end, (char*)info->stack_end - (char*)info->stack_start));
continue;
}
- DEBUG (2, fprintf (gc_debug_file, "Scanning thread %p, range: %p-%p, size: %zd\n", info, info->stack_start, info->stack_end, (char*)info->stack_end - (char*)info->stack_start));
+ DEBUG (2, fprintf (gc_debug_file, "Scanning thread %p, range: %p-%p, size: %zd, pinned=%d\n", info, info->stack_start, info->stack_end, (char*)info->stack_end - (char*)info->stack_start, next_pin_slot));
conservatively_pin_objects_from (info->stack_start, info->stack_end, start_nursery, end_nursery);
}
}
- DEBUG (2, fprintf (gc_debug_file, "Scanning current thread registers\n"));
+ DEBUG (2, fprintf (gc_debug_file, "Scanning current thread registers, pinned=%d\n", next_pin_slot));
conservatively_pin_objects_from ((void*)cur_thread_regs, (void*)(cur_thread_regs + ARCH_NUM_REGS), start_nursery, end_nursery);
}
switch ((*p) & REMSET_TYPE_MASK) {
case REMSET_LOCATION:
ptr = (void**)(*p);
+ //__builtin_prefetch (ptr);
if (((void*)ptr < start_nursery || (void*)ptr >= end_nursery) && ptr_in_heap (ptr)) {
*ptr = copy_object (*ptr, start_nursery, end_nursery);
DEBUG (9, fprintf (gc_debug_file, "Overwrote remset at %p with %p\n", ptr, *ptr));
- if (!global && *ptr >= start_nursery && *ptr < end_nursery)
- add_to_global_remset (ptr);
+ if (!global && *ptr >= start_nursery && *ptr < end_nursery) {
+ /*
+ * If the object is pinned, each reference to it from nonpinned objects
+ * becomes part of the global remset, which can grow very large.
+ */
+ DEBUG (9, fprintf (gc_debug_file, "Add to global remset because of pinning %p (%p %s)\n", ptr, *ptr, safe_name (*ptr)));
+ add_to_global_remset (ptr, FALSE);
+ }
} else {
DEBUG (9, fprintf (gc_debug_file, "Skipping remset at %p holding %p\n", ptr, *ptr));
}
*ptr = copy_object (*ptr, start_nursery, end_nursery);
DEBUG (9, fprintf (gc_debug_file, "Overwrote remset at %p with %p (count: %d)\n", ptr, *ptr, (int)count));
if (!global && *ptr >= start_nursery && *ptr < end_nursery)
- add_to_global_remset (ptr);
+ add_to_global_remset (ptr, FALSE);
++ptr;
}
return p + 2;
return p + 1;
scan_object (*ptr, start_nursery, end_nursery);
return p + 1;
- case REMSET_VTYPE:
+ case REMSET_OTHER: {
ptr = (void**)(*p & ~REMSET_TYPE_MASK);
- if (((void*)ptr >= start_nursery && (void*)ptr < end_nursery) || !ptr_in_heap (ptr))
+
+ switch (p [1]) {
+ case REMSET_VTYPE:
+ if (((void*)ptr >= start_nursery && (void*)ptr < end_nursery) || !ptr_in_heap (ptr))
+ return p + 3;
+ desc = p [2];
+ scan_vtype ((char*)ptr, desc, start_nursery, end_nursery);
+ return p + 3;
+ case REMSET_ROOT_LOCATION:
+ /* Same as REMSET_LOCATION, but the address is not required to be in the heap */
+ *ptr = copy_object (*ptr, start_nursery, end_nursery);
+ DEBUG (9, fprintf (gc_debug_file, "Overwrote root location remset at %p with %p\n", ptr, *ptr));
+ if (!global && *ptr >= start_nursery && *ptr < end_nursery) {
+ /*
+ * If the object is pinned, each reference to it from nonpinned objects
+ * becomes part of the global remset, which can grow very large.
+ */
+ DEBUG (9, fprintf (gc_debug_file, "Add to global remset because of pinning %p (%p %s)\n", ptr, *ptr, safe_name (*ptr)));
+ add_to_global_remset (ptr, TRUE);
+ }
return p + 2;
- desc = p [1];
- scan_vtype ((char*)ptr, desc, start_nursery, end_nursery);
- return p + 2;
+ default:
+ g_assert_not_reached ();
+ }
+ break;
+ }
default:
g_assert_not_reached ();
}
int i;
SgenThreadInfo *info;
RememberedSet *remset, *next;
- mword *p;
+ mword *p, *next_p, *store_pos;
/* the global one */
for (remset = global_remset; remset; remset = remset->next) {
DEBUG (4, fprintf (gc_debug_file, "Scanning global remset range: %p-%p, size: %zd\n", remset->data, remset->store_next, remset->store_next - remset->data));
- for (p = remset->data; p < remset->store_next;) {
- p = handle_remset (p, start_nursery, end_nursery, TRUE);
+ store_pos = remset->data;
+ for (p = remset->data; p < remset->store_next; p = next_p) {
+ mword ptr;
+
+ next_p = handle_remset (p, start_nursery, end_nursery, TRUE);
+
+ /*
+ * Clear global remsets of locations which no longer point to the
+ * nursery. Otherwise, they could grow indefinitely between major
+ * collections.
+ */
+ ptr = (p [0] & ~REMSET_TYPE_MASK);
+ if ((p [0] & REMSET_TYPE_MASK) == REMSET_LOCATION) {
+ if (ptr_in_nursery (*(void**)ptr))
+ *store_pos ++ = p [0];
+ } else {
+ g_assert ((p [0] & REMSET_TYPE_MASK) == REMSET_OTHER);
+ g_assert (p [1] == REMSET_ROOT_LOCATION);
+ if (ptr_in_nursery (*(void**)ptr)) {
+ *store_pos ++ = p [0];
+ *store_pos ++ = p [1];
+ }
+ }
}
+
+ /* Truncate the remset */
+ remset->store_next = store_pos;
}
+
/* the per-thread ones */
for (i = 0; i < THREAD_HASH_SIZE; ++i) {
for (info = thread_table [i]; info; info = info->next) {
}
}
+/*
+ * Clear the thread local TLAB variables for all threads.
+ */
+static void
+clear_tlabs (void)
+{
+ SgenThreadInfo *info;
+ int i;
+
+ for (i = 0; i < THREAD_HASH_SIZE; ++i) {
+ for (info = thread_table [i]; info; info = info->next) {
+ /* A new TLAB will be allocated when the thread does its first allocation */
+ *info->tlab_start_addr = NULL;
+ *info->tlab_next_addr = NULL;
+ *info->tlab_temp_end_addr = NULL;
+ *info->tlab_real_end_addr = NULL;
+ }
+ }
+}
+
+/*
+ * Find the tlab_next value of the TLAB which contains ADDR.
+ */
+static char*
+find_tlab_next_from_address (char *addr)
+{
+ SgenThreadInfo *info;
+ int i;
+
+ for (i = 0; i < THREAD_HASH_SIZE; ++i) {
+ for (info = thread_table [i]; info; info = info->next) {
+ if (addr >= *info->tlab_start_addr && addr < *info->tlab_next_addr)
+ return *info->tlab_next_addr;
+ }
+ }
+
+ return NULL;
+}
+
/* LOCKING: assumes the GC lock is held */
static SgenThreadInfo*
gc_register_current_thread (void *addr)
info->skip = 0;
info->signal = 0;
info->stack_start = NULL;
+ info->tlab_start_addr = &tlab_start;
+ info->tlab_next_addr = &tlab_next;
+ info->tlab_temp_end_addr = &tlab_temp_end;
+ info->tlab_real_end_addr = &tlab_real_end;
+
+ tlab_next_addr = &tlab_next;
/* try to get it with attributes first */
#if defined(HAVE_PTHREAD_GETATTR_NP) && defined(HAVE_PTHREAD_ATTR_GETSTACK)
mono_gc_wbarrier_set_field (MonoObject *obj, gpointer field_ptr, MonoObject* value)
{
RememberedSet *rs;
- if ((char*)field_ptr >= nursery_start && (char*)field_ptr < nursery_real_end) {
+ if (ptr_in_nursery (field_ptr)) {
*(void**)field_ptr = value;
return;
}
mono_gc_wbarrier_set_arrayref (MonoArray *arr, gpointer slot_ptr, MonoObject* value)
{
RememberedSet *rs = remembered_set;
- if ((char*)slot_ptr >= nursery_start && (char*)slot_ptr < nursery_real_end) {
+ if (ptr_in_nursery (slot_ptr)) {
*(void**)slot_ptr = value;
return;
}
mono_gc_wbarrier_arrayref_copy (MonoArray *arr, gpointer slot_ptr, int count)
{
RememberedSet *rs = remembered_set;
- if ((char*)slot_ptr >= nursery_start && (char*)slot_ptr < nursery_real_end)
+ if (ptr_in_nursery (slot_ptr))
return;
DEBUG (8, fprintf (gc_debug_file, "Adding remset at %p, %d\n", slot_ptr, count));
if (rs->store_next + 1 < rs->end_set) {
void
mono_gc_wbarrier_generic_store (gpointer ptr, MonoObject* value)
{
- RememberedSet *rs = remembered_set;
- if ((char*)ptr >= nursery_start && (char*)ptr < nursery_real_end) {
+ RememberedSet *rs;
+ if (ptr_in_nursery (ptr)) {
DEBUG (8, fprintf (gc_debug_file, "Skipping remset at %p\n", ptr));
*(void**)ptr = value;
return;
}
- DEBUG (8, fprintf (gc_debug_file, "Adding remset at %p\n", ptr));
+ rs = remembered_set;
+ DEBUG (8, fprintf (gc_debug_file, "Adding remset at %p (%s)\n", ptr, value ? safe_name (value) : "null"));
/* FIXME: ensure it is on the heap */
if (rs->store_next < rs->end_set) {
*(rs->store_next++) = (mword)ptr;
}
void
-mono_gc_wbarrier_value_copy (gpointer dest, gpointer src, int count, MonoClass *klass)
+mono_gc_wbarrier_set_root (gpointer ptr, MonoObject *value)
{
RememberedSet *rs = remembered_set;
- if ((char*)dest >= nursery_start && (char*)dest < nursery_real_end) {
+ if (ptr_in_nursery (ptr))
+ return;
+ DEBUG (8, fprintf (gc_debug_file, "Adding root remset at %p (%s)\n", ptr, value ? safe_name (value) : "null"));
+
+ if (rs->store_next + 2 < rs->end_set) {
+ *(rs->store_next++) = (mword)ptr | REMSET_OTHER;
+ *(rs->store_next++) = (mword)REMSET_ROOT_LOCATION;
+ *(void**)ptr = value;
return;
}
- DEBUG (1, fprintf (gc_debug_file, "Adding value remset at %p, count %d for class %s\n", dest, count, klass->name));
+ rs = alloc_remset (rs->end_set - rs->data, (void*)1);
+ rs->next = remembered_set;
+ remembered_set = rs;
+ thread_info_lookup (ARCH_GET_THREAD ())->remset = rs;
+ *(rs->store_next++) = (mword)ptr | REMSET_OTHER;
+ *(rs->store_next++) = (mword)REMSET_ROOT_LOCATION;
- if (rs->store_next + 1 < rs->end_set) {
- *(rs->store_next++) = (mword)dest | REMSET_VTYPE;
+ *(void**)ptr = value;
+}
+
+void
+mono_gc_wbarrier_value_copy (gpointer dest, gpointer src, int count, MonoClass *klass)
+{
+ RememberedSet *rs = remembered_set;
+ if (ptr_in_nursery (dest))
+ return;
+ DEBUG (8, fprintf (gc_debug_file, "Adding value remset at %p, count %d for class %s\n", dest, count, klass->name));
+
+ if (rs->store_next + 2 < rs->end_set) {
+ *(rs->store_next++) = (mword)dest | REMSET_OTHER;
+ *(rs->store_next++) = (mword)REMSET_VTYPE;
*(rs->store_next++) = (mword)klass->gc_descr;
return;
}
rs->next = remembered_set;
remembered_set = rs;
thread_info_lookup (ARCH_GET_THREAD ())->remset = rs;
- *(rs->store_next++) = (mword)dest | REMSET_VTYPE;
+ *(rs->store_next++) = (mword)dest | REMSET_OTHER;
+ *(rs->store_next++) = (mword)REMSET_VTYPE;
*(rs->store_next++) = (mword)klass->gc_descr;
}
mword desc;
int type;
- if ((ptr >= nursery_start) && (ptr < nursery_real_end)) {
+ if (ptr_in_nursery (ptr)) {
printf ("Pointer inside nursery.\n");
} else {
for (section = section_list; section;) {
if (section) {
printf ("Pointer inside oldspace.\n");
+ } else if (obj_is_from_pinned_alloc (ptr)) {
+ printf ("Pointer is inside a pinned chunk.\n");
} else {
printf ("Pointer unknown.\n");
return;
}
}
+ if (object_is_pinned (ptr))
+ printf ("Object is pinned.\n");
+
+ if (object_is_forwarded (ptr))
+ printf ("Object is forwared.\n");
+
// FIXME: Handle pointers to the inside of objects
- vtable = (MonoVTable*)((mword*)ptr) [0];
+ vtable = (MonoVTable*)LOAD_VTABLE (ptr);
printf ("VTable: %p\n", vtable);
+ if (vtable == NULL) {
+ printf ("VTable is invalid (empty).\n");
+ return;
+ }
+ if (ptr_in_nursery (vtable)) {
+ printf ("VTable is invalid (points inside nursery).\n");
+ return;
+ }
printf ("Class: %s\n", vtable->klass->name);
desc = ((GCVTable*)vtable)->desc;
if ((void**)addr >= ptr && (void**)addr < ptr + count)
*found = TRUE;
return p + 1;
- case REMSET_VTYPE:
- ptr = (void**)(*p & ~REMSET_TYPE_MASK);
- desc = p [1];
-
- switch (desc & 0x7) {
- case DESC_TYPE_RUN_LENGTH:
- OBJ_RUN_LEN_SIZE (skip_size, desc, ptr);
- /* The descriptor includes the size of MonoObject */
- skip_size -= sizeof (MonoObject);
- if ((void**)addr >= ptr && (void**)addr < ptr + (skip_size / sizeof (gpointer)))
- *found = TRUE;
- break;
+ case REMSET_OTHER: {
+ switch (p [1]) {
+ case REMSET_VTYPE:
+ ptr = (void**)(*p & ~REMSET_TYPE_MASK);
+ desc = p [2];
+
+ switch (desc & 0x7) {
+ case DESC_TYPE_RUN_LENGTH:
+ OBJ_RUN_LEN_SIZE (skip_size, desc, ptr);
+ /* The descriptor includes the size of MonoObject */
+ skip_size -= sizeof (MonoObject);
+ if ((void**)addr >= ptr && (void**)addr < ptr + (skip_size / sizeof (gpointer)))
+ *found = TRUE;
+ break;
+ default:
+ // FIXME:
+ g_assert_not_reached ();
+ }
+
+ return p + 3;
+ case REMSET_ROOT_LOCATION:
+ return p + 2;
default:
- // FIXME:
g_assert_not_reached ();
}
-
- return p + 2;
+ break;
+ }
default:
g_assert_not_reached ();
}
DEBUG (1, fprintf (gc_debug_file, "Heap consistency check done.\n"));
}
+/* Check that the reference is valid */
+#undef HANDLE_PTR
+#define HANDLE_PTR(ptr,obj) do { \
+ if (*(ptr)) { \
+ g_assert (safe_name (*(ptr)) != NULL); \
+ } \
+ } while (0)
+
+/*
+ * check_object:
+ *
+ * Perform consistency check on an object. Currently we only check that the
+ * reference fields are valid.
+ */
+char*
+check_object (char *start)
+{
+ GCVTable *vt;
+ size_t skip_size;
+ mword desc;
+
+ if (!start)
+ return NULL;
+
+ vt = (GCVTable*)LOAD_VTABLE (start);
+ //type = vt->desc & 0x7;
+
+ desc = vt->desc;
+ switch (desc & 0x7) {
+ case DESC_TYPE_STRING:
+ STRING_SIZE (skip_size, start);
+ return start + skip_size;
+ case DESC_TYPE_RUN_LENGTH:
+ OBJ_RUN_LEN_FOREACH_PTR (desc,start);
+ OBJ_RUN_LEN_SIZE (skip_size, desc, start);
+ g_assert (skip_size);
+ return start + skip_size;
+ case DESC_TYPE_ARRAY:
+ case DESC_TYPE_VECTOR:
+ OBJ_VECTOR_FOREACH_PTR (vt, start);
+ skip_size = safe_object_get_size ((MonoObject*)start);
+ skip_size += (ALLOC_ALIGN - 1);
+ skip_size &= ~(ALLOC_ALIGN - 1);
+ return start + skip_size;
+ case DESC_TYPE_SMALL_BITMAP:
+ OBJ_BITMAP_FOREACH_PTR (desc,start);
+ OBJ_BITMAP_SIZE (skip_size, desc, start);
+ return start + skip_size;
+ case DESC_TYPE_LARGE_BITMAP:
+ OBJ_LARGE_BITMAP_FOREACH_PTR (vt,start);
+ skip_size = safe_object_get_size ((MonoObject*)start);
+ skip_size += (ALLOC_ALIGN - 1);
+ skip_size &= ~(ALLOC_ALIGN - 1);
+ return start + skip_size;
+ case DESC_TYPE_COMPLEX:
+ OBJ_COMPLEX_FOREACH_PTR (vt, start);
+ /* this is a complex object */
+ skip_size = safe_object_get_size ((MonoObject*)start);
+ skip_size += (ALLOC_ALIGN - 1);
+ skip_size &= ~(ALLOC_ALIGN - 1);
+ return start + skip_size;
+ case DESC_TYPE_COMPLEX_ARR:
+ OBJ_COMPLEX_ARR_FOREACH_PTR (vt, start);
+ /* this is an array of complex structs */
+ skip_size = safe_object_get_size ((MonoObject*)start);
+ skip_size += (ALLOC_ALIGN - 1);
+ skip_size &= ~(ALLOC_ALIGN - 1);
+ return start + skip_size;
+ }
+ g_assert_not_reached ();
+ return NULL;
+}
+
/*
* ######################################################################
* ######## Other mono public interface functions.
int
mono_gc_get_generation (MonoObject *obj)
{
- if ((char*)obj >= nursery_start && (char*)obj < nursery_real_end)
+ if (ptr_in_nursery (obj))
return 0;
return 1;
}
mono_gc_make_descr_from_bitmap (gsize *bitmap, int numbits)
{
if (numbits < ((sizeof (*bitmap) * 8) - ROOT_DESC_TYPE_SHIFT)) {
- mword desc = ROOT_DESC_BITMAP | (bitmap [0] << ROOT_DESC_TYPE_SHIFT);
- return (void*)desc;
+ return (void*)MAKE_ROOT_DESC (ROOT_DESC_BITMAP, bitmap [0]);
+ } else {
+ mword complex = alloc_complex_descriptor (bitmap, numbits + 1);
+ return (void*)MAKE_ROOT_DESC (ROOT_DESC_COMPLEX, complex);
}
- /* conservative scanning */
- DEBUG (3, fprintf (gc_debug_file, "Conservative root descr for size: %d\n", numbits));
- return NULL;
+}
+
+void*
+mono_gc_make_root_descr_user (MonoGCMarkFunc marker)
+{
+ void *descr;
+
+ g_assert (user_descriptors_next < MAX_USER_DESCRIPTORS);
+ descr = (void*)MAKE_ROOT_DESC (ROOT_DESC_USER, (mword)user_descriptors_next);
+ user_descriptors [user_descriptors_next ++] = marker;
+
+ return descr;
}
void*
}
pagesize = mono_pagesize ();
gc_debug_file = stderr;
- /* format: MONO_GC_DEBUG=[l[:filename]|<option>]+ where l is a debug level 0-9 */
if ((env = getenv ("MONO_GC_DEBUG"))) {
opts = g_strsplit (env, ",", -1);
for (ptr = opts; ptr && *ptr; ptr ++) {
consistency_check_at_minor_collection = TRUE;
} else {
fprintf (stderr, "Invalid format for the MONO_GC_DEBUG env variable: '%s'\n", env);
+ fprintf (stderr, "The format is: MONO_GC_DEBUG=[l[:filename]|<option>]+ where l is a debug level 0-9.\n");
+ fprintf (stderr, "Valid options are: collect-before-allocs, check-at-minor-collections.\n");
exit (1);
}
}
mono_gc_register_thread (&sinfo);
}
+enum {
+ ATYPE_NORMAL,
+ ATYPE_NUM
+};
+
+/* FIXME: Do this in the JIT, where specialized allocation sequences can be created
+ * for each class. This is currently not easy to do, as it is hard to generate basic
+ * blocks + branches, but it is easy with the linear IL codebase.
+ */
+static MonoMethod*
+create_allocator (int atype)
+{
+ int tlab_next_addr_offset = -1;
+ int tlab_temp_end_offset = -1;
+ int p_var, size_var, tlab_next_addr_var, new_next_var;
+ guint32 slowpath_branch;
+ MonoMethodBuilder *mb;
+ MonoMethod *res;
+ MonoMethodSignature *csig;
+ static gboolean registered = FALSE;
+
+ MONO_THREAD_VAR_OFFSET (tlab_next_addr, tlab_next_addr_offset);
+ MONO_THREAD_VAR_OFFSET (tlab_temp_end, tlab_temp_end_offset);
+
+ g_assert (tlab_next_addr_offset != -1);
+ g_assert (tlab_temp_end_offset != -1);
+
+ g_assert (atype == ATYPE_NORMAL);
+
+ if (!registered) {
+ mono_register_jit_icall (mono_gc_alloc_obj, "mono_gc_alloc_obj", mono_create_icall_signature ("object ptr int"), FALSE);
+ registered = TRUE;
+ }
+
+ csig = mono_metadata_signature_alloc (mono_defaults.corlib, 1);
+ csig->ret = &mono_defaults.object_class->byval_arg;
+ csig->params [0] = &mono_defaults.int_class->byval_arg;
+
+ mb = mono_mb_new (mono_defaults.object_class, "Alloc", MONO_WRAPPER_ALLOC);
+ size_var = mono_mb_add_local (mb, &mono_defaults.int32_class->byval_arg);
+ /* size = vtable->klass->instance_size; */
+ mono_mb_emit_ldarg (mb, 0);
+ mono_mb_emit_icon (mb, G_STRUCT_OFFSET (MonoVTable, klass));
+ mono_mb_emit_byte (mb, CEE_ADD);
+ mono_mb_emit_byte (mb, CEE_LDIND_I);
+ mono_mb_emit_icon (mb, G_STRUCT_OFFSET (MonoClass, instance_size));
+ mono_mb_emit_byte (mb, CEE_ADD);
+ /* FIXME: assert instance_size stays a 4 byte integer */
+ mono_mb_emit_byte (mb, CEE_LDIND_U4);
+ mono_mb_emit_stloc (mb, size_var);
+
+ /* size += ALLOC_ALIGN - 1; */
+ mono_mb_emit_ldloc (mb, size_var);
+ mono_mb_emit_icon (mb, ALLOC_ALIGN - 1);
+ mono_mb_emit_byte (mb, CEE_ADD);
+ /* size &= ~(ALLOC_ALIGN - 1); */
+ mono_mb_emit_icon (mb, ~(ALLOC_ALIGN - 1));
+ mono_mb_emit_byte (mb, CEE_AND);
+ mono_mb_emit_stloc (mb, size_var);
+
+ /*
+ * We need to modify tlab_next, but the JIT only supports reading, so we read
+ * another tls var holding its address instead.
+ */
+
+ /* tlab_next_addr (local) = tlab_next_addr (TLS var) */
+ tlab_next_addr_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
+ mono_mb_emit_byte (mb, MONO_CUSTOM_PREFIX);
+ mono_mb_emit_byte (mb, CEE_MONO_TLS);
+ mono_mb_emit_i4 (mb, tlab_next_addr_offset);
+ mono_mb_emit_stloc (mb, tlab_next_addr_var);
+
+ /* p = (void**)tlab_next; */
+ p_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
+ mono_mb_emit_ldloc (mb, tlab_next_addr_var);
+ mono_mb_emit_byte (mb, CEE_LDIND_I);
+ mono_mb_emit_stloc (mb, p_var);
+
+ /* new_next = (char*)p + size; */
+ new_next_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
+ mono_mb_emit_ldloc (mb, p_var);
+ mono_mb_emit_ldloc (mb, size_var);
+ mono_mb_emit_byte (mb, CEE_CONV_I);
+ mono_mb_emit_byte (mb, CEE_ADD);
+ mono_mb_emit_stloc (mb, new_next_var);
+
+ /* tlab_next = new_next */
+ mono_mb_emit_ldloc (mb, tlab_next_addr_var);
+ mono_mb_emit_ldloc (mb, new_next_var);
+ mono_mb_emit_byte (mb, CEE_STIND_I);
+
+ /* if (G_LIKELY (new_next < tlab_temp_end)) */
+ mono_mb_emit_ldloc (mb, new_next_var);
+ mono_mb_emit_byte (mb, MONO_CUSTOM_PREFIX);
+ mono_mb_emit_byte (mb, CEE_MONO_TLS);
+ mono_mb_emit_i4 (mb, tlab_temp_end_offset);
+ slowpath_branch = mono_mb_emit_short_branch (mb, MONO_CEE_BLT_UN_S);
+
+ /* Slowpath */
+
+ mono_mb_emit_byte (mb, MONO_CUSTOM_PREFIX);
+ mono_mb_emit_byte (mb, CEE_MONO_NOT_TAKEN);
+
+ /* FIXME: mono_gc_alloc_obj takes a 'size_t' as an argument, not an int32 */
+ mono_mb_emit_ldarg (mb, 0);
+ mono_mb_emit_ldloc (mb, size_var);
+ mono_mb_emit_icall (mb, mono_gc_alloc_obj);
+ mono_mb_emit_byte (mb, CEE_RET);
+
+ /* Fastpath */
+ mono_mb_patch_short_branch (mb, slowpath_branch);
+
+ /* FIXME: Memory barrier */
+
+ /* *p = vtable; */
+ mono_mb_emit_ldloc (mb, p_var);
+ mono_mb_emit_ldarg (mb, 0);
+ mono_mb_emit_byte (mb, CEE_STIND_I);
+
+ /* return p */
+ mono_mb_emit_ldloc (mb, p_var);
+ mono_mb_emit_byte (mb, CEE_RET);
+
+ res = mono_mb_create_method (mb, csig, 8);
+ mono_mb_free (mb);
+ mono_method_get_header (res)->init_locals = FALSE;
+ return res;
+}
+
+static MonoMethod* alloc_method_cache [ATYPE_NUM];
+
+/*
+ * Generate an allocator method implementing the fast path of mono_gc_alloc_obj ().
+ * The signature of the called method is:
+ * object allocate (MonoVTable *vtable)
+ */
MonoMethod*
mono_gc_get_managed_allocator (MonoVTable *vtable, gboolean for_box)
{
- return NULL;
+ int tlab_next_offset = -1;
+ int tlab_temp_end_offset = -1;
+ MonoClass *klass = vtable->klass;
+ MONO_THREAD_VAR_OFFSET (tlab_next, tlab_next_offset);
+ MONO_THREAD_VAR_OFFSET (tlab_temp_end, tlab_temp_end_offset);
+
+ if (tlab_next_offset == -1 || tlab_temp_end_offset == -1)
+ return NULL;
+ if (klass->instance_size > tlab_size)
+ return NULL;
+ if (klass->has_finalize || klass->marshalbyref || (mono_profiler_get_events () & MONO_PROFILE_ALLOCATIONS))
+ return NULL;
+ if (klass->rank)
+ return NULL;
+ if (klass->byval_arg.type == MONO_TYPE_STRING)
+ return NULL;
+ if (collect_before_allocs)
+ return NULL;
+
+ return mono_gc_get_managed_allocator_by_type (0);
}
int
mono_gc_get_managed_allocator_type (MonoMethod *managed_alloc)
{
- return -1;
+ return 0;
}
MonoMethod*
mono_gc_get_managed_allocator_by_type (int atype)
{
- return NULL;
+ MonoMethod *res;
+
+ mono_loader_lock ();
+ res = alloc_method_cache [atype];
+ if (!res)
+ res = alloc_method_cache [atype] = create_allocator (atype);
+ mono_loader_unlock ();
+ return res;
+}
+
+guint32
+mono_gc_get_managed_allocator_types (void)
+{
+ return ATYPE_NUM;
+}
+
+static MonoMethod *write_barrier_method;
+
+MonoMethod*
+mono_gc_get_write_barrier (void)
+{
+ MonoMethod *res;
+ int remset_offset = -1;
+ int remset_var, next_var;
+ MonoMethodBuilder *mb;
+ MonoMethodSignature *sig;
+ int label1, label2;
+
+ MONO_THREAD_VAR_OFFSET (remembered_set, remset_offset);
+
+ // FIXME: Maybe create a separate version for ctors (the branch would be
+ // correctly predicted more times)
+ if (write_barrier_method)
+ return write_barrier_method;
+
+ /* Create the IL version of mono_gc_barrier_generic_store () */
+ sig = mono_metadata_signature_alloc (mono_defaults.corlib, 2);
+ sig->ret = &mono_defaults.void_class->byval_arg;
+ sig->params [0] = &mono_defaults.int_class->byval_arg;
+ sig->params [1] = &mono_defaults.object_class->byval_arg;
+
+ mb = mono_mb_new (mono_defaults.object_class, "wbarrier", MONO_WRAPPER_WRITE_BARRIER);
+
+ /* ptr_in_nursery () check */
+#ifdef ALIGN_NURSERY
+ /*
+ * Masking out the bits might be faster, but we would have to use 64 bit
+ * immediates, which might be slower.
+ */
+ mono_mb_emit_ldarg (mb, 0);
+ mono_mb_emit_icon (mb, DEFAULT_NURSERY_BITS);
+ mono_mb_emit_byte (mb, CEE_SHR_UN);
+ mono_mb_emit_icon (mb, (mword)nursery_start >> DEFAULT_NURSERY_BITS);
+ label1 = mono_mb_emit_branch (mb, CEE_BNE_UN);
+#else
+ // FIXME:
+ g_assert_not_reached ();
+#endif
+
+ /* Don't need write barrier case */
+ /* do the assignment */
+ mono_mb_emit_ldarg (mb, 0);
+ mono_mb_emit_ldarg (mb, 1);
+ /* Don't use STIND_REF, as it would cause infinite recursion */
+ mono_mb_emit_byte (mb, CEE_STIND_I);
+ mono_mb_emit_byte (mb, CEE_RET);
+
+ /* Need write barrier case */
+ mono_mb_patch_branch (mb, label1);
+
+ if (remset_offset == -1)
+ // FIXME:
+ g_assert_not_reached ();
+
+ // remset_var = remembered_set;
+ remset_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
+ mono_mb_emit_byte (mb, MONO_CUSTOM_PREFIX);
+ mono_mb_emit_byte (mb, CEE_MONO_TLS);
+ mono_mb_emit_i4 (mb, remset_offset);
+ mono_mb_emit_stloc (mb, remset_var);
+
+ // next_var = rs->store_next
+ next_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
+ mono_mb_emit_ldloc (mb, remset_var);
+ mono_mb_emit_ldflda (mb, G_STRUCT_OFFSET (RememberedSet, store_next));
+ mono_mb_emit_byte (mb, CEE_LDIND_I);
+ mono_mb_emit_stloc (mb, next_var);
+
+ // if (rs->store_next < rs->end_set) {
+ mono_mb_emit_ldloc (mb, next_var);
+ mono_mb_emit_ldloc (mb, remset_var);
+ mono_mb_emit_ldflda (mb, G_STRUCT_OFFSET (RememberedSet, end_set));
+ mono_mb_emit_byte (mb, CEE_LDIND_I);
+ label2 = mono_mb_emit_branch (mb, CEE_BGE);
+
+ /* write barrier fast path */
+ // *(rs->store_next++) = (mword)ptr;
+ mono_mb_emit_ldloc (mb, next_var);
+ mono_mb_emit_ldarg (mb, 0);
+ mono_mb_emit_byte (mb, CEE_STIND_I);
+
+ mono_mb_emit_ldloc (mb, next_var);
+ mono_mb_emit_icon (mb, sizeof (gpointer));
+ mono_mb_emit_byte (mb, CEE_ADD);
+ mono_mb_emit_stloc (mb, next_var);
+
+ mono_mb_emit_ldloc (mb, remset_var);
+ mono_mb_emit_ldflda (mb, G_STRUCT_OFFSET (RememberedSet, store_next));
+ mono_mb_emit_ldloc (mb, next_var);
+ mono_mb_emit_byte (mb, CEE_STIND_I);
+
+ // *(void**)ptr = value;
+ mono_mb_emit_ldarg (mb, 0);
+ mono_mb_emit_ldarg (mb, 1);
+ mono_mb_emit_byte (mb, CEE_STIND_I);
+ mono_mb_emit_byte (mb, CEE_RET);
+
+ /* write barrier slow path */
+ mono_mb_patch_branch (mb, label2);
+
+ mono_mb_emit_ldarg (mb, 0);
+ mono_mb_emit_ldarg (mb, 1);
+ mono_mb_emit_icall (mb, mono_gc_wbarrier_generic_store);
+ mono_mb_emit_byte (mb, CEE_RET);
+
+ res = mono_mb_create_method (mb, sig, 16);
+ mono_mb_free (mb);
+
+ mono_loader_lock ();
+ if (write_barrier_method) {
+ /* Already created */
+ mono_free_method (res);
+ } else {
+ /* double-checked locking */
+ mono_memory_barrier ();
+ write_barrier_method = res;
+ }
+ mono_loader_unlock ();
+
+ return write_barrier_method;
}
#endif /* HAVE_SGEN_GC */
projects / mono.git / blobdiff