-#include "config.h"
+/*
+ * Copyright (c) 1994 by Xerox Corporation. All rights reserved.
+ * Copyright (c) 1996 by Silicon Graphics. All rights reserved.
+ * Copyright (c) 1998 by Fergus Henderson. All rights reserved.
+ * Copyright (c) 2000-2008 by Hewlett-Packard Development Company.
+ * All rights reserved.
+ *
+ * THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED
+ * OR IMPLIED. ANY USE IS AT YOUR OWN RISK.
+ *
+ * Permission is hereby granted to use or copy this program
+ * for any purpose, provided the above notices are retained on all copies.
+ * Permission to modify the code and to distribute modified code is granted,
+ * provided the above notices are retained, and a notice that the code was
+ * modified is included with the above copyright notice.
+ */
+
#include "private/gc_priv.h"
-#if defined(GC_WIN32_THREADS)
+#if defined(GC_WIN32_THREADS)
#include <windows.h>
-#ifdef CYGWIN32
+#ifdef THREAD_LOCAL_ALLOC
+# include "private/thread_local_alloc.h"
+#endif /* THREAD_LOCAL_ALLOC */
+
+/* Allocation lock declarations. */
+#if !defined(USE_PTHREAD_LOCKS)
+# if defined(GC_DLL)
+ __declspec(dllexport) CRITICAL_SECTION GC_allocate_ml;
+# else
+ CRITICAL_SECTION GC_allocate_ml;
+# endif
+ DWORD GC_lock_holder = NO_THREAD;
+ /* Thread id for current holder of allocation lock */
+#else
+ pthread_mutex_t GC_allocate_ml = PTHREAD_MUTEX_INITIALIZER;
+ unsigned long GC_lock_holder = NO_THREAD;
+#endif
+
+#ifdef GC_PTHREADS
# include <errno.h>
/* Cygwin-specific forward decls */
# undef pthread_detach
# undef dlopen
-# define DEBUG_CYGWIN_THREADS 0
+# ifdef DEBUG_THREADS
+# ifdef CYGWIN32
+# define DEBUG_CYGWIN_THREADS 1
+# define DEBUG_WIN32_PTHREADS 0
+# else
+# define DEBUG_WIN32_PTHREADS 1
+# define DEBUG_CYGWIN_THREADS 0
+# endif
+# else
+# define DEBUG_CYGWIN_THREADS 0
+# define DEBUG_WIN32_PTHREADS 0
+# endif
+
+ STATIC void * GC_pthread_start(void * arg);
+ STATIC void GC_thread_exit_proc(void *arg);
+
+# include <pthread.h>
+
+#else
+
+# ifdef DEBUG_THREADS
+# define DEBUG_WIN32_THREADS 1
+# else
+# define DEBUG_WIN32_THREADS 0
+# endif
+
+# undef CreateThread
+# undef ExitThread
+# undef _beginthreadex
+# undef _endthreadex
+# undef _beginthread
+# ifdef DEBUG_THREADS
+# define DEBUG_WIN32_THREADS 1
+# else
+# define DEBUG_WIN32_THREADS 0
+# endif
+
+# ifndef MSWINCE
+# include <process.h> /* For _beginthreadex, _endthreadex */
+# endif
- void * GC_start_routine(void * arg);
- void GC_thread_exit_proc(void *arg);
+#endif
+/* DllMain-based thread registration is currently incompatible */
+/* with thread-local allocation, pthreads and WinCE. */
+#if defined(GC_DLL) && !defined(MSWINCE) \
+ && !defined(THREAD_LOCAL_ALLOC) && !defined(GC_PTHREADS)
+ static GC_bool GC_win32_dll_threads = FALSE;
+ /* This code operates in two distinct modes, depending on */
+ /* the setting of GC_win32_dll_threads. If */
+ /* GC_win32_dll_threads is set, all threads in the process */
+ /* are implicitly registered with the GC by DllMain. */
+ /* No explicit registration is required, and attempts at */
+ /* explicit registration are ignored. This mode is */
+ /* very different from the Posix operation of the collector. */
+ /* In this mode access to the thread table is lock-free. */
+ /* Hence there is a static limit on the number of threads. */
+
+ /* If GC_win32_dll_threads is FALSE, or the collector is */
+ /* built without GC_DLL defined, things operate in a way */
+ /* that is very similar to Posix platforms, and new threads */
+ /* must be registered with the collector, e.g. by using */
+ /* preprocessor-based interception of the thread primitives. */
+ /* In this case, we use a real data structure for the thread */
+ /* table. Note that there is no equivalent of linker-based */
+ /* call interception, since we don't have ELF-like */
+ /* facilities. The Windows analog appears to be "API */
+ /* hooking", which really seems to be a standard way to */
+ /* do minor binary rewriting (?). I'd prefer not to have */
+ /* the basic collector rely on such facilities, but an */
+ /* optional package that intercepts thread calls this way */
+ /* would probably be nice. */
+
+ /* GC_win32_dll_threads must be set at initialization time, */
+ /* i.e. before any collector or thread calls. We make it a */
+ /* "dynamic" option only to avoid multiple library versions. */
+#else
+# define GC_win32_dll_threads FALSE
+# undef MAX_THREADS
+# define MAX_THREADS 1 /* dll_thread_table[] is always empty. */
#endif
+/* We have two versions of the thread table. Which one */
+/* we us depends on whether or not GC_win32_dll_threads */
+/* is set. Note that before initialization, we don't */
+/* add any entries to either table, even if DllMain is */
+/* called. The main thread will be added on */
+/* initialization. */
+
/* The type of the first argument to InterlockedExchange. */
/* Documented to be LONG volatile *, but at least gcc likes */
/* this better. */
typedef LONG * IE_t;
-#ifndef MAX_THREADS
-# define MAX_THREADS 256
- /* FIXME: */
- /* Things may get quite slow for large numbers of threads, */
- /* since we look them up with sequential search. */
-#endif
-
GC_bool GC_thr_initialized = FALSE;
-DWORD GC_main_thread = 0;
+GC_bool GC_need_to_lock = FALSE;
+
+static GC_bool parallel_initialized = FALSE;
+
+void GC_init_parallel(void);
+
+/* GC_use_DllMain() is currently incompatible with pthreads. */
+/* It might be possible to get GC_DLL and DllMain-based thread registration */
+/* to work with Cygwin, but if you try, you are on your own. */
+#if defined(GC_DLL) && !defined(GC_PTHREADS)
+ /* Turn on GC_win32_dll_threads */
+ GC_API void GC_CALL GC_use_DllMain(void)
+ {
+# ifdef THREAD_LOCAL_ALLOC
+ ABORT("Cannot use thread local allocation with DllMain-based "
+ "thread registration.");
+ /* Thread-local allocation really wants to lock at thread */
+ /* entry and exit. */
+# else
+ GC_ASSERT(!parallel_initialized);
+ GC_win32_dll_threads = TRUE;
+ GC_init_parallel();
+# endif
+ }
+#else
+ GC_API void GC_CALL GC_use_DllMain(void)
+ {
+ ABORT("GC not configured as DLL");
+ }
+#endif
-struct GC_thread_Rep {
- LONG in_use; /* Updated without lock. */
- /* We assert that unused */
- /* entries have invalid ids of */
- /* zero and zero stack fields. */
+STATIC DWORD GC_main_thread = 0;
+
+#define ADDR_LIMIT ((ptr_t)(word)-1)
+
+struct GC_Thread_Rep {
+ union {
+ AO_t tm_in_use; /* Updated without lock. */
+ /* We assert that unused */
+ /* entries have invalid ids of */
+ /* zero and zero stack fields. */
+ /* Used only with GC_win32_dll_threads. */
+ struct GC_Thread_Rep * tm_next;
+ /* Hash table link without */
+ /* GC_win32_dll_threads. */
+ /* More recently allocated threads */
+ /* with a given pthread id come */
+ /* first. (All but the first are */
+ /* guaranteed to be dead, but we may */
+ /* not yet have registered the join.) */
+ } table_management;
+# define in_use table_management.tm_in_use
+# define next table_management.tm_next
DWORD id;
HANDLE handle;
ptr_t stack_base; /* The cold end of the stack. */
/* 0 ==> entry not valid. */
/* !in_use ==> stack_base == 0 */
+ ptr_t last_stack_min; /* Last known minimum (hottest) address */
+ /* in stack or ADDR_LIMIT if unset */
+# ifdef IA64
+ ptr_t backing_store_end;
+ ptr_t backing_store_ptr;
+# endif
+
GC_bool suspended;
-# ifdef CYGWIN32
+# ifdef GC_PTHREADS
void *status; /* hold exit value until join in case it's a pointer */
pthread_t pthread_id;
short flags; /* Protected by GC lock. */
# define FINISHED 1 /* Thread has exited. */
# define DETACHED 2 /* Thread is intended to be detached. */
+# define KNOWN_FINISHED(t) (((t) -> flags) & FINISHED)
+# else
+# define KNOWN_FINISHED(t) 0
+# endif
+# ifdef THREAD_LOCAL_ALLOC
+ struct thread_local_freelists tlfs;
# endif
};
-typedef volatile struct GC_thread_Rep * GC_thread;
+typedef struct GC_Thread_Rep * GC_thread;
+typedef volatile struct GC_Thread_Rep * GC_vthread;
/*
- * We generally assume that volatile ==> memory ordering, at least among
- * volatiles.
+ * We assumed that volatile ==> memory ordering, at least among
+ * volatiles. This code should consistently use atomic_ops.
*/
volatile GC_bool GC_please_stop = FALSE;
-volatile struct GC_thread_Rep thread_table[MAX_THREADS];
+/*
+ * We track thread attachments while the world is supposed to be stopped.
+ * Unfortunately, we can't stop them from starting, since blocking in
+ * DllMain seems to cause the world to deadlock. Thus we have to recover
+ * If we notice this in the middle of marking.
+ */
+
+AO_t GC_attached_thread = FALSE;
+/* Return TRUE if an thread was attached since we last asked or */
+/* since GC_attached_thread was explicitly reset. */
+GC_bool GC_started_thread_while_stopped(void)
+{
+ AO_t result;
+
+ if (GC_win32_dll_threads) {
+ AO_nop_full(); /* Prior heap reads need to complete earlier. */
+ result = AO_load(&GC_attached_thread);
+ if (result) {
+ AO_store(&GC_attached_thread, FALSE);
+ }
+ return ((GC_bool)result);
+ } else {
+ return FALSE;
+ }
+}
-volatile LONG GC_max_thread_index = 0; /* Largest index in thread_table */
- /* that was ever used. */
+/* Thread table used if GC_win32_dll_threads is set. */
+/* This is a fixed size array. */
+/* Since we use runtime conditionals, both versions */
+/* are always defined. */
+# ifndef MAX_THREADS
+# define MAX_THREADS 512
+# endif
+ /* Things may get quite slow for large numbers of threads, */
+ /* since we look them up with sequential search. */
+
+ volatile struct GC_Thread_Rep dll_thread_table[MAX_THREADS];
+
+ volatile LONG GC_max_thread_index = 0;
+ /* Largest index in dll_thread_table */
+ /* that was ever used. */
+
+/* And now the version used if GC_win32_dll_threads is not set. */
+/* This is a chained hash table, with much of the code borrowed */
+/* From the Posix implementation. */
+#ifndef THREAD_TABLE_SZ
+# define THREAD_TABLE_SZ 256 /* Must be power of 2 */
+#endif
+ STATIC GC_thread GC_threads[THREAD_TABLE_SZ];
+
+ /* It may not be safe to allocate when we register the first thread. */
+ /* Thus we allocated one statically. */
+ static struct GC_Thread_Rep first_thread;
+ static GC_bool first_thread_used = FALSE;
+
+/* Add a thread to GC_threads. We assume it wasn't already there. */
+/* Caller holds allocation lock. */
+/* Unlike the pthreads version, the id field is set by the caller. */
+STATIC GC_thread GC_new_thread(DWORD id)
+{
+ word hv = ((word)id) % THREAD_TABLE_SZ;
+ GC_thread result;
+
+ GC_ASSERT(I_HOLD_LOCK());
+ if (!first_thread_used) {
+ result = &first_thread;
+ first_thread_used = TRUE;
+ } else {
+ GC_ASSERT(!GC_win32_dll_threads);
+ result = (struct GC_Thread_Rep *)
+ GC_INTERNAL_MALLOC(sizeof(struct GC_Thread_Rep), NORMAL);
+ /* result can be NULL */
+ if (result == 0) return(0);
+ }
+ /* result -> id = id; Done by caller. */
+ result -> next = GC_threads[hv];
+ GC_threads[hv] = result;
+# ifdef GC_PTHREADS
+ GC_ASSERT(result -> flags == 0 /* && result -> thread_blocked == 0 */);
+# endif
+ return(result);
+}
extern LONG WINAPI GC_write_fault_handler(struct _EXCEPTION_POINTERS *exc_info);
+#if defined(GWW_VDB) && defined(MPROTECT_VDB)
+ extern GC_bool GC_gww_dirty_init(void);
+ /* Defined in os_dep.c. Returns TRUE if GetWriteWatch is available. */
+ /* may be called repeatedly. */
+#endif
+
+GC_bool GC_in_thread_creation = FALSE; /* Protected by allocation lock. */
+
/*
* This may be called from DllMain, and hence operates under unusual
- * constraints.
+ * constraints. In particular, it must be lock-free if GC_win32_dll_threads
+ * is set. Always called from the thread being added.
+ * If GC_win32_dll_threads is not set, we already hold the allocation lock,
+ * except possibly during single-threaded start-up code.
*/
-static GC_thread GC_new_thread(void) {
- int i;
- /* It appears to be unsafe to acquire a lock here, since this */
- /* code is apparently not preeemptible on some systems. */
- /* (This is based on complaints, not on Microsoft's official */
- /* documentation, which says this should perform "only simple */
- /* initialization tasks".) */
- /* Hence we make do with nonblocking synchronization. */
-
- /* The following should be a noop according to the win32 */
+static GC_thread GC_register_my_thread_inner(struct GC_stack_base *sb,
+ DWORD thread_id)
+{
+ GC_vthread me;
+
+ /* The following should be a no-op according to the win32 */
/* documentation. There is empirical evidence that it */
/* isn't. - HB */
# if defined(MPROTECT_VDB)
- if (GC_incremental) SetUnhandledExceptionFilter(GC_write_fault_handler);
+# if defined(GWW_VDB)
+ if (GC_incremental && !GC_gww_dirty_init())
+ SetUnhandledExceptionFilter(GC_write_fault_handler);
+# else
+ if (GC_incremental) SetUnhandledExceptionFilter(GC_write_fault_handler);
+# endif
# endif
+
+ if (GC_win32_dll_threads) {
+ int i;
+ /* It appears to be unsafe to acquire a lock here, since this */
+ /* code is apparently not preemptible on some systems. */
+ /* (This is based on complaints, not on Microsoft's official */
+ /* documentation, which says this should perform "only simple */
+ /* initialization tasks".) */
+ /* Hence we make do with nonblocking synchronization. */
+ /* It has been claimed that DllMain is really only executed with */
+ /* a particular system lock held, and thus careful use of locking */
+ /* around code that doesn't call back into the system libraries */
+ /* might be OK. But this hasn't been tested across all win32 */
+ /* variants. */
/* cast away volatile qualifier */
- for (i = 0; InterlockedExchange((IE_t)&thread_table[i].in_use,1) != 0; i++) {
- /* Compare-and-swap would make this cleaner, but that's not */
- /* supported before Windows 98 and NT 4.0. In Windows 2000, */
- /* InterlockedExchange is supposed to be replaced by */
- /* InterlockedExchangePointer, but that's not really what I */
- /* want here. */
- if (i == MAX_THREADS - 1)
- ABORT("too many threads");
- }
- /* Update GC_max_thread_index if necessary. The following is safe, */
- /* and unlike CompareExchange-based solutions seems to work on all */
- /* Windows95 and later platforms. */
- /* Unfortunately, GC_max_thread_index may be temporarily out of */
- /* bounds, so readers have to compensate. */
- while (i > GC_max_thread_index) {
- InterlockedIncrement((IE_t)&GC_max_thread_index);
- }
- if (GC_max_thread_index >= MAX_THREADS) {
- /* We overshot due to simultaneous increments. */
- /* Setting it to MAX_THREADS-1 is always safe. */
- GC_max_thread_index = MAX_THREADS - 1;
+ for (i = 0; InterlockedExchange((void*)&dll_thread_table[i].in_use,1) != 0;
+ i++) {
+ /* Compare-and-swap would make this cleaner, but that's not */
+ /* supported before Windows 98 and NT 4.0. In Windows 2000, */
+ /* InterlockedExchange is supposed to be replaced by */
+ /* InterlockedExchangePointer, but that's not really what I */
+ /* want here. */
+ /* FIXME: We should eventually declare Win95 dead and use AO_ */
+ /* primitives here. */
+ if (i == MAX_THREADS - 1)
+ ABORT("too many threads");
+ }
+ /* Update GC_max_thread_index if necessary. The following is safe, */
+ /* and unlike CompareExchange-based solutions seems to work on all */
+ /* Windows95 and later platforms. */
+ /* Unfortunately, GC_max_thread_index may be temporarily out of */
+ /* bounds, so readers have to compensate. */
+ while (i > GC_max_thread_index) {
+ InterlockedIncrement((IE_t)&GC_max_thread_index);
+ }
+ if (GC_max_thread_index >= MAX_THREADS) {
+ /* We overshot due to simultaneous increments. */
+ /* Setting it to MAX_THREADS-1 is always safe. */
+ GC_max_thread_index = MAX_THREADS - 1;
+ }
+ me = dll_thread_table + i;
+ } else /* Not using DllMain */ {
+ GC_ASSERT(I_HOLD_LOCK());
+ GC_in_thread_creation = TRUE; /* OK to collect from unknown thread. */
+ me = GC_new_thread(thread_id);
+ GC_in_thread_creation = FALSE;
+ if (me == 0)
+ ABORT("Failed to allocate memory for thread registering.");
}
-
-# ifdef CYGWIN32
- thread_table[i].pthread_id = pthread_self();
+# ifdef GC_PTHREADS
+ /* me can be NULL -> segfault */
+ me -> pthread_id = pthread_self();
# endif
+
if (!DuplicateHandle(GetCurrentProcess(),
- GetCurrentThread(),
- GetCurrentProcess(),
- (HANDLE*)&thread_table[i].handle,
- 0,
- 0,
- DUPLICATE_SAME_ACCESS)) {
- DWORD last_error = GetLastError();
- GC_printf1("Last error code: %lx\n", last_error);
+ GetCurrentThread(),
+ GetCurrentProcess(),
+ (HANDLE*)&(me -> handle),
+ 0,
+ 0,
+ DUPLICATE_SAME_ACCESS)) {
+ GC_err_printf("Last error code: %d\n", (int)GetLastError());
ABORT("DuplicateHandle failed");
}
- thread_table[i].stack_base = GC_get_stack_base();
+ me -> last_stack_min = ADDR_LIMIT;
+ me -> stack_base = sb -> mem_base;
+# ifdef IA64
+ me -> backing_store_end = sb -> reg_base;
+# endif
/* Up until this point, GC_push_all_stacks considers this thread */
/* invalid. */
- if (thread_table[i].stack_base == NULL)
- ABORT("Failed to find stack base in GC_new_thread");
/* Up until this point, this entry is viewed as reserved but invalid */
/* by GC_delete_thread. */
- thread_table[i].id = GetCurrentThreadId();
- /* If this thread is being created while we are trying to stop */
- /* the world, wait here. Hopefully this can't happen on any */
- /* systems that don't allow us to block here. */
- while (GC_please_stop) Sleep(20);
- return thread_table + i;
+ me -> id = thread_id;
+# if defined(THREAD_LOCAL_ALLOC)
+ GC_init_thread_local((GC_tlfs)(&(me->tlfs)));
+# endif
+ if (me -> stack_base == NULL)
+ ABORT("Bad stack base in GC_register_my_thread_inner");
+ if (GC_win32_dll_threads) {
+ if (GC_please_stop) {
+ AO_store(&GC_attached_thread, TRUE);
+ AO_nop_full(); /* Later updates must become visible after this. */
+ }
+ /* We'd like to wait here, but can't, since waiting in DllMain */
+ /* provokes deadlocks. */
+ /* Thus we force marking to be restarted instead. */
+ } else {
+ GC_ASSERT(!GC_please_stop);
+ /* Otherwise both we and the thread stopping code would be */
+ /* holding the allocation lock. */
+ }
+ return (GC_thread)(me);
}
/*
#ifdef __GNUC__
__inline__
#endif
-LONG GC_get_max_thread_index()
+STATIC LONG GC_get_max_thread_index(void)
{
LONG my_max = GC_max_thread_index;
return my_max;
}
-/* This is intended to be lock-free, though that */
-/* assumes that the CloseHandle becomes visible before the */
-/* in_use assignment. */
-static void GC_delete_gc_thread(GC_thread thr)
+/* Return the GC_thread corresponding to a thread id. May be called */
+/* without a lock, but should be called in contexts in which the */
+/* requested thread cannot be asynchronously deleted, e.g. from the */
+/* thread itself. */
+/* This version assumes that either GC_win32_dll_threads is set, or */
+/* we hold the allocator lock. */
+/* Also used (for assertion checking only) from thread_local_alloc.c. */
+GC_thread GC_lookup_thread_inner(DWORD thread_id) {
+ if (GC_win32_dll_threads) {
+ int i;
+ LONG my_max = GC_get_max_thread_index();
+ for (i = 0;
+ i <= my_max &&
+ (!AO_load_acquire(&(dll_thread_table[i].in_use))
+ || dll_thread_table[i].id != thread_id);
+ /* Must still be in_use, since nobody else can store our thread_id. */
+ i++) {}
+ if (i > my_max) {
+ return 0;
+ } else {
+ return (GC_thread)(dll_thread_table + i);
+ }
+ } else {
+ word hv = ((word)thread_id) % THREAD_TABLE_SZ;
+ register GC_thread p = GC_threads[hv];
+
+ GC_ASSERT(I_HOLD_LOCK());
+ while (p != 0 && p -> id != thread_id) p = p -> next;
+ return(p);
+ }
+}
+
+/* Make sure thread descriptor t is not protected by the VDB */
+/* implementation. */
+/* Used to prevent write faults when the world is (partially) stopped, */
+/* since it may have been stopped with a system lock held, and that */
+/* lock may be required for fault handling. */
+# if defined(MPROTECT_VDB) && !defined(MSWINCE)
+# define UNPROTECT(t) \
+ if (GC_dirty_maintained && !GC_win32_dll_threads && \
+ t != &first_thread) { \
+ GC_ASSERT(SMALL_OBJ(GC_size(t))); \
+ GC_remove_protection(HBLKPTR(t), 1, FALSE); \
+ }
+# else
+# define UNPROTECT(p)
+# endif
+
+/* If a thread has been joined, but we have not yet */
+/* been notified, then there may be more than one thread */
+/* in the table with the same win32 id. */
+/* This is OK, but we need a way to delete a specific one. */
+/* Assumes we hold the allocation lock unless */
+/* GC_win32_dll_threads is set. */
+/* If GC_win32_dll_threads is set it should be called from the */
+/* thread being deleted. */
+STATIC void GC_delete_gc_thread(GC_vthread gc_id)
{
- CloseHandle(thr->handle);
- /* cast away volatile qualifier */
- thr->stack_base = 0;
- thr->id = 0;
+ CloseHandle(gc_id->handle);
+ if (GC_win32_dll_threads) {
+ /* This is intended to be lock-free. */
+ /* It is either called synchronously from the thread being deleted, */
+ /* or by the joining thread. */
+ /* In this branch asynchronous changes to *gc_id are possible. */
+ gc_id -> stack_base = 0;
+ gc_id -> id = 0;
# ifdef CYGWIN32
- thr->pthread_id = 0;
+ gc_id -> pthread_id = 0;
# endif /* CYGWIN32 */
- thr->in_use = FALSE;
+# ifdef GC_WIN32_PTHREADS
+ gc_id -> pthread_id.p = NULL;
+# endif /* GC_WIN32_PTHREADS */
+ AO_store_release(&(gc_id->in_use), FALSE);
+ } else {
+ /* Cast away volatile qualifier, since we have lock. */
+ GC_thread gc_nvid = (GC_thread)gc_id;
+ DWORD id = gc_nvid -> id;
+ word hv = ((word)id) % THREAD_TABLE_SZ;
+ register GC_thread p = GC_threads[hv];
+ register GC_thread prev = 0;
+
+ GC_ASSERT(I_HOLD_LOCK());
+ while (p != gc_nvid) {
+ prev = p;
+ p = p -> next;
+ }
+ if (prev == 0) {
+ GC_threads[hv] = p -> next;
+ } else {
+ prev -> next = p -> next;
+ }
+ GC_INTERNAL_FREE(p);
+ }
}
-static void GC_delete_thread(DWORD thread_id) {
- int i;
- LONG my_max = GC_get_max_thread_index();
+/* Delete a thread from GC_threads. We assume it is there. */
+/* (The code intentionally traps if it wasn't.) */
+/* Assumes we hold the allocation lock unless */
+/* GC_win32_dll_threads is set. */
+/* If GC_win32_dll_threads is set it should be called from the */
+/* thread being deleted. */
+STATIC void GC_delete_thread(DWORD id)
+{
+ if (GC_win32_dll_threads) {
+ GC_thread t = GC_lookup_thread_inner(id);
- for (i = 0;
- i <= my_max &&
- (!thread_table[i].in_use || thread_table[i].id != thread_id);
- /* Must still be in_use, since nobody else can store our thread_id. */
- i++) {}
- if (i > my_max) {
- WARN("Removing nonexistent thread %ld\n", (GC_word)thread_id);
+ if (0 == t) {
+ WARN("Removing nonexistent thread %ld\n", (long)id);
+ } else {
+ GC_delete_gc_thread(t);
+ }
} else {
- GC_delete_gc_thread(thread_table+i);
+ word hv = ((word)id) % THREAD_TABLE_SZ;
+ register GC_thread p = GC_threads[hv];
+ register GC_thread prev = 0;
+
+ GC_ASSERT(I_HOLD_LOCK());
+ while (p -> id != id) {
+ prev = p;
+ p = p -> next;
+ }
+ CloseHandle(p->handle);
+ if (prev == 0) {
+ GC_threads[hv] = p -> next;
+ } else {
+ prev -> next = p -> next;
+ }
+ GC_INTERNAL_FREE(p);
}
}
+GC_API void GC_CALL GC_allow_register_threads(void)
+{
+ /* Check GC is initialized and the current thread is registered. */
+ GC_ASSERT(GC_lookup_thread_inner(GetCurrentThreadId()) != 0);
+
+# if defined(GC_DLL) && !defined(PARALLEL_MARK) && !defined(THREAD_LOCAL_ALLOC)
+ /* GC_init_parallel() is not called from GC_init_inner(). */
+ parallel_initialized = TRUE;
+# endif
+ GC_need_to_lock = TRUE; /* We are multi-threaded now. */
+}
+
+GC_API int GC_CALL GC_register_my_thread(struct GC_stack_base *sb) {
+ DWORD t = GetCurrentThreadId();
+
+ if (GC_need_to_lock == FALSE)
+ ABORT("Threads explicit registering is not previously enabled");
+
+ /* We lock here, since we want to wait for an ongoing GC. */
+ LOCK();
+ if (0 == GC_lookup_thread_inner(t)) {
+ GC_register_my_thread_inner(sb, t);
+ UNLOCK();
+ return GC_SUCCESS;
+ } else {
+ UNLOCK();
+ return GC_DUPLICATE;
+ }
+}
-#ifdef CYGWIN32
+GC_API int GC_CALL GC_unregister_my_thread(void)
+{
+ DWORD t = GetCurrentThreadId();
+
+ if (GC_win32_dll_threads) {
+# if defined(THREAD_LOCAL_ALLOC)
+ /* Can't happen: see GC_use_DllMain(). */
+ GC_ASSERT(FALSE);
+# endif
+ /* FIXME: Should we just ignore this? */
+ GC_delete_thread(t);
+ } else {
+ LOCK();
+# if defined(THREAD_LOCAL_ALLOC)
+ {
+ GC_thread me = GC_lookup_thread_inner(t);
+ GC_destroy_thread_local(&(me->tlfs));
+ }
+# endif
+ GC_delete_thread(t);
+ UNLOCK();
+ }
+ return GC_SUCCESS;
+}
+
+
+#ifdef GC_PTHREADS
+
+/* A quick-and-dirty cache of the mapping between pthread_t */
+/* and win32 thread id. */
+#define PTHREAD_MAP_SIZE 512
+DWORD GC_pthread_map_cache[PTHREAD_MAP_SIZE];
+#define HASH(pthread_id) ((NUMERIC_THREAD_ID(pthread_id) >> 5) % PTHREAD_MAP_SIZE)
+ /* It appears pthread_t is really a pointer type ... */
+#define SET_PTHREAD_MAP_CACHE(pthread_id, win32_id) \
+ (GC_pthread_map_cache[HASH(pthread_id)] = (win32_id))
+#define GET_PTHREAD_MAP_CACHE(pthread_id) \
+ GC_pthread_map_cache[HASH(pthread_id)]
/* Return a GC_thread corresponding to a given pthread_t. */
/* Returns 0 if it's not there. */
/* We assume that this is only called for pthread ids that */
-/* have not yet terminated or are still joinable. */
-static GC_thread GC_lookup_thread(pthread_t id)
+/* have not yet terminated or are still joinable, and */
+/* cannot be concurrently terminated. */
+/* Assumes we do NOT hold the allocation lock. */
+static GC_thread GC_lookup_pthread(pthread_t id)
{
- int i;
- LONG my_max = GC_get_max_thread_index();
+ if (GC_win32_dll_threads) {
+ int i;
+ LONG my_max = GC_get_max_thread_index();
- for (i = 0;
- i <= my_max &&
- (!thread_table[i].in_use || thread_table[i].pthread_id != id
- || !thread_table[i].in_use);
+ for (i = 0;
+ i <= my_max &&
+ (!AO_load_acquire(&(dll_thread_table[i].in_use))
+ || THREAD_EQUAL(dll_thread_table[i].pthread_id, id));
/* Must still be in_use, since nobody else can store our thread_id. */
i++);
- if (i > my_max) return 0;
- return thread_table + i;
+ if (i > my_max) return 0;
+ return (GC_thread)(dll_thread_table + i);
+ } else {
+ /* We first try the cache. If that fails, we use a very slow */
+ /* approach. */
+ int hv_guess = GET_PTHREAD_MAP_CACHE(id) % THREAD_TABLE_SZ;
+ int hv;
+ GC_thread p;
+
+ LOCK();
+ for (p = GC_threads[hv_guess]; 0 != p; p = p -> next) {
+ if (THREAD_EQUAL(p -> pthread_id, id))
+ goto foundit;
+ }
+ for (hv = 0; hv < THREAD_TABLE_SZ; ++hv) {
+ for (p = GC_threads[hv]; 0 != p; p = p -> next) {
+ if (THREAD_EQUAL(p -> pthread_id, id))
+ goto foundit;
+ }
+ }
+ p = 0;
+ foundit:
+ UNLOCK();
+ return p;
+ }
}
-#endif /* CYGWIN32 */
+#endif /* GC_PTHREADS */
-void GC_push_thread_structures GC_PROTO((void))
+void GC_push_thread_structures(void)
{
+ GC_ASSERT(I_HOLD_LOCK());
+ if (GC_win32_dll_threads) {
/* Unlike the other threads implementations, the thread table here */
/* contains no pointers to the collectable heap. Thus we have */
/* no private structures we need to preserve. */
-# ifdef CYGWIN32
- { int i; /* pthreads may keep a pointer in the thread exit value */
- LONG my_max = GC_get_max_thread_index();
-
- for (i = 0; i <= my_max; i++)
- if (thread_table[i].in_use)
- GC_push_all((ptr_t)&(thread_table[i].status),
- (ptr_t)(&(thread_table[i].status)+1));
+# ifdef GC_PTHREADS
+ { int i; /* pthreads may keep a pointer in the thread exit value */
+ LONG my_max = GC_get_max_thread_index();
+
+ for (i = 0; i <= my_max; i++)
+ if (dll_thread_table[i].in_use)
+ GC_push_all((ptr_t)&(dll_thread_table[i].status),
+ (ptr_t)(&(dll_thread_table[i].status)+1));
+ }
+# endif
+ } else {
+ GC_push_all((ptr_t)(GC_threads), (ptr_t)(GC_threads)+sizeof(GC_threads));
}
+# if defined(THREAD_LOCAL_ALLOC)
+ GC_push_all((ptr_t)(&GC_thread_key),
+ (ptr_t)(&GC_thread_key)+sizeof(&GC_thread_key));
+ /* Just in case we ever use our own TLS implementation. */
+# endif
+}
+
+#if defined(MPROTECT_VDB) && !defined(MSWINCE)
+ extern volatile AO_TS_t GC_fault_handler_lock; /* from os_dep.c */
+#endif
+
+/* Suspend the given thread, if it's still active. */
+STATIC void GC_suspend(GC_thread t)
+{
+# ifdef MSWINCE
+ /* SuspendThread will fail if thread is running kernel code */
+ while (SuspendThread(t -> handle) == (DWORD)-1)
+ Sleep(10);
+# else
+ /* Apparently the Windows 95 GetOpenFileName call creates */
+ /* a thread that does not properly get cleaned up, and */
+ /* SuspendThread on its descriptor may provoke a crash. */
+ /* This reduces the probability of that event, though it still */
+ /* appears there's a race here. */
+ DWORD exitCode;
+
+ UNPROTECT(t);
+ if (GetExitCodeThread(t -> handle, &exitCode) &&
+ exitCode != STILL_ACTIVE) {
+# ifdef GC_PTHREADS
+ t -> stack_base = 0; /* prevent stack from being pushed */
+# else
+ /* this breaks pthread_join on Cygwin, which is guaranteed to */
+ /* only see user pthreads */
+ GC_ASSERT(GC_win32_dll_threads);
+ GC_delete_gc_thread(t);
+# endif
+ return;
+ }
+# if defined(MPROTECT_VDB) && !defined(MSWINCE)
+ /* Acquire the spin lock we use to update dirty bits. */
+ /* Threads shouldn't get stopped holding it. But we may */
+ /* acquire and release it in the UNPROTECT call. */
+ while (AO_test_and_set_acquire(&GC_fault_handler_lock) == AO_TS_SET) {}
+# endif
+
+ if (SuspendThread(t -> handle) == (DWORD)-1)
+ ABORT("SuspendThread failed");
# endif
+ t -> suspended = TRUE;
+# if defined(MPROTECT_VDB) && !defined(MSWINCE)
+ AO_CLEAR(&GC_fault_handler_lock);
+# endif
}
/* Defined in misc.c */
-extern CRITICAL_SECTION GC_write_cs;
+#ifndef CYGWIN32
+ extern CRITICAL_SECTION GC_write_cs;
+#endif
-void GC_stop_world()
+void GC_stop_world(void)
{
DWORD thread_id = GetCurrentThreadId();
int i;
+ int my_max;
if (!GC_thr_initialized) ABORT("GC_stop_world() called before GC_thr_init()");
+ GC_ASSERT(I_HOLD_LOCK());
+
+ /* This code is the same as in pthread_stop_world.c */
+# ifdef PARALLEL_MARK
+ if (GC_parallel) {
+ GC_acquire_mark_lock();
+ GC_ASSERT(GC_fl_builder_count == 0);
+ /* We should have previously waited for it to become zero. */
+ }
+# endif /* PARALLEL_MARK */
GC_please_stop = TRUE;
# ifndef CYGWIN32
EnterCriticalSection(&GC_write_cs);
-# endif /* !CYGWIN32 */
- for (i = 0; i <= GC_get_max_thread_index(); i++)
- if (thread_table[i].stack_base != 0
- && thread_table[i].id != thread_id) {
-# ifdef MSWINCE
- /* SuspendThread will fail if thread is running kernel code */
- while (SuspendThread(thread_table[i].handle) == (DWORD)-1)
- Sleep(10);
-# else
- /* Apparently the Windows 95 GetOpenFileName call creates */
- /* a thread that does not properly get cleaned up, and */
- /* SuspendThread on its descriptor may provoke a crash. */
- /* This reduces the probability of that event, though it still */
- /* appears there's a race here. */
- DWORD exitCode;
- if (GetExitCodeThread(thread_table[i].handle,&exitCode) &&
- exitCode != STILL_ACTIVE) {
- thread_table[i].stack_base = 0; /* prevent stack from being pushed */
-# ifndef CYGWIN32
- /* this breaks pthread_join on Cygwin, which is guaranteed to */
- /* only see user pthreads */
- thread_table[i].in_use = FALSE;
- CloseHandle(thread_table[i].handle);
-# endif
- continue;
- }
- if (SuspendThread(thread_table[i].handle) == (DWORD)-1)
- ABORT("SuspendThread failed");
-# endif
- thread_table[i].suspended = TRUE;
+# endif
+ if (GC_win32_dll_threads) {
+ /* Any threads being created during this loop will end up setting */
+ /* GC_attached_thread when they start. This will force marking to */
+ /* restart. */
+ /* This is not ideal, but hopefully correct. */
+ GC_attached_thread = FALSE;
+ my_max = (int)GC_get_max_thread_index();
+ for (i = 0; i <= my_max; i++) {
+ GC_vthread t = dll_thread_table + i;
+ if (t -> stack_base != 0
+ && t -> id != thread_id) {
+ GC_suspend((GC_thread)t);
+ }
}
+ } else {
+ GC_thread t;
+ int i;
+
+ for (i = 0; i < THREAD_TABLE_SZ; i++) {
+ for (t = GC_threads[i]; t != 0; t = t -> next) {
+ if (t -> stack_base != 0
+ && !KNOWN_FINISHED(t)
+ && t -> id != thread_id) {
+ GC_suspend(t);
+ }
+ }
+ }
+ }
# ifndef CYGWIN32
LeaveCriticalSection(&GC_write_cs);
-# endif /* !CYGWIN32 */
+# endif
+# ifdef PARALLEL_MARK
+ if (GC_parallel)
+ GC_release_mark_lock();
+# endif
}
-void GC_start_world()
+void GC_start_world(void)
{
DWORD thread_id = GetCurrentThreadId();
int i;
- LONG my_max = GC_get_max_thread_index();
- for (i = 0; i <= my_max; i++)
- if (thread_table[i].stack_base != 0 && thread_table[i].suspended
- && thread_table[i].id != thread_id) {
- if (ResumeThread(thread_table[i].handle) == (DWORD)-1)
- ABORT("ResumeThread failed");
- thread_table[i].suspended = FALSE;
+ GC_ASSERT(I_HOLD_LOCK());
+ if (GC_win32_dll_threads) {
+ LONG my_max = GC_get_max_thread_index();
+ for (i = 0; i <= my_max; i++) {
+ GC_thread t = (GC_thread)(dll_thread_table + i);
+ if (t -> stack_base != 0 && t -> suspended
+ && t -> id != thread_id) {
+ if (ResumeThread(t -> handle) == (DWORD)-1)
+ ABORT("ResumeThread failed");
+ t -> suspended = FALSE;
+ }
}
- GC_please_stop = FALSE;
-}
-
-# ifdef _MSC_VER
-# pragma warning(disable:4715)
-# endif
-ptr_t GC_current_stackbottom()
-{
- DWORD thread_id = GetCurrentThreadId();
- int i;
- LONG my_max = GC_get_max_thread_index();
+ } else {
+ GC_thread t;
+ int i;
- for (i = 0; i <= my_max; i++)
- if (thread_table[i].stack_base && thread_table[i].id == thread_id)
- return thread_table[i].stack_base;
- ABORT("no thread table entry for current thread");
+ for (i = 0; i < THREAD_TABLE_SZ; i++) {
+ for (t = GC_threads[i]; t != 0; t = t -> next) {
+ if (t -> stack_base != 0 && t -> suspended
+ && t -> id != thread_id) {
+ if (ResumeThread(t -> handle) == (DWORD)-1)
+ ABORT("ResumeThread failed");
+ UNPROTECT(t);
+ t -> suspended = FALSE;
+ }
+ }
+ }
+ }
+ GC_please_stop = FALSE;
}
-# ifdef _MSC_VER
-# pragma warning(default:4715)
-# endif
# ifdef MSWINCE
/* The VirtualQuery calls below won't work properly on WinCE, but */
# define GC_get_stack_min(s) \
((ptr_t)(((DWORD)(s) - 1) & 0xFFFF0000))
# else
+
+ /* A cache holding the results of the last VirtualQuery call. */
+ /* Protected by the allocation lock. */
+ static ptr_t last_address = 0;
+ static MEMORY_BASIC_INFORMATION last_info;
+
+ /* Probe stack memory region (starting at "s") to find out its */
+ /* lowest address (i.e. stack top). */
+ /* S must be a mapped address inside the region, NOT the first */
+ /* unmapped address. */
static ptr_t GC_get_stack_min(ptr_t s)
{
ptr_t bottom;
- MEMORY_BASIC_INFORMATION info;
- VirtualQuery(s, &info, sizeof(info));
+
+ GC_ASSERT(I_HOLD_LOCK());
+ if (s != last_address) {
+ VirtualQuery(s, &last_info, sizeof(last_info));
+ last_address = s;
+ }
do {
- bottom = info.BaseAddress;
- VirtualQuery(bottom - 1, &info, sizeof(info));
- } while ((info.Protect & PAGE_READWRITE)
- && !(info.Protect & PAGE_GUARD));
+ bottom = last_info.BaseAddress;
+ VirtualQuery(bottom - 1, &last_info, sizeof(last_info));
+ last_address = bottom - 1;
+ } while ((last_info.Protect & PAGE_READWRITE)
+ && !(last_info.Protect & PAGE_GUARD));
return(bottom);
}
+
+ /* Return true if the page at s has protections appropriate */
+ /* for a stack page. */
+ static GC_bool GC_may_be_in_stack(ptr_t s)
+ {
+ GC_ASSERT(I_HOLD_LOCK());
+ if (s != last_address) {
+ VirtualQuery(s, &last_info, sizeof(last_info));
+ last_address = s;
+ }
+ return (last_info.Protect & PAGE_READWRITE)
+ && !(last_info.Protect & PAGE_GUARD);
+ }
# endif
-void GC_push_all_stacks()
+STATIC void GC_push_stack_for(GC_thread thread)
{
- DWORD thread_id = GetCurrentThreadId();
- GC_bool found_me = FALSE;
- int i;
- int dummy;
- ptr_t sp, stack_min;
- GC_thread thread;
- LONG my_max = GC_get_max_thread_index();
-
- for (i = 0; i <= my_max; i++) {
- thread = thread_table + i;
- if (thread -> in_use && thread -> stack_base) {
- if (thread -> id == thread_id) {
+ int dummy;
+ ptr_t sp, stack_min;
+ DWORD me = GetCurrentThreadId();
+
+ if (thread -> stack_base) {
+ if (thread -> id == me) {
sp = (ptr_t) &dummy;
- found_me = TRUE;
} else {
CONTEXT context;
context.ContextFlags = CONTEXT_INTEGER|CONTEXT_CONTROL;
- if (!GetThreadContext(thread_table[i].handle, &context))
+ if (!GetThreadContext(thread -> handle, &context))
ABORT("GetThreadContext failed");
/* Push all registers that might point into the heap. Frame */
# if defined(I386)
PUSH4(Edi,Esi,Ebx,Edx), PUSH2(Ecx,Eax), PUSH1(Ebp);
sp = (ptr_t)context.Esp;
+# elif defined(X86_64)
+ PUSH4(Rax,Rcx,Rdx,Rbx); PUSH2(Rbp, Rsi); PUSH1(Rdi);
+ PUSH4(R8, R9, R10, R11); PUSH4(R12, R13, R14, R15);
+ sp = (ptr_t)context.Rsp;
# elif defined(ARM32)
PUSH4(R0,R1,R2,R3),PUSH4(R4,R5,R6,R7),PUSH4(R8,R9,R10,R11),PUSH1(R12);
sp = (ptr_t)context.Sp;
# else
# error "architecture is not supported"
# endif
+ } /* ! current thread */
+
+ /* Set stack_min to the lowest address in the thread stack, */
+ /* or to an address in the thread stack no larger than sp, */
+ /* taking advantage of the old value to avoid slow traversals */
+ /* of large stacks. */
+ if (thread -> last_stack_min == ADDR_LIMIT) {
+ stack_min = GC_get_stack_min(thread -> stack_base);
+ UNPROTECT(thread);
+ thread -> last_stack_min = stack_min;
+ } else {
+ if (sp < thread -> stack_base && sp >= thread -> last_stack_min) {
+ stack_min = sp;
+ } else {
+# ifdef MSWINCE
+ stack_min = GC_get_stack_min(thread -> stack_base);
+# else
+ if (GC_may_be_in_stack(thread -> last_stack_min)) {
+ stack_min = GC_get_stack_min(thread -> last_stack_min);
+ } else {
+ /* Stack shrunk? Is this possible? */
+ stack_min = GC_get_stack_min(thread -> stack_base);
+ }
+# endif
+ UNPROTECT(thread);
+ thread -> last_stack_min = stack_min;
+ }
}
-
- stack_min = GC_get_stack_min(thread->stack_base);
-
- if (sp >= stack_min && sp < thread->stack_base)
+ GC_ASSERT(stack_min == GC_get_stack_min(thread -> stack_base)
+ || (sp >= stack_min && stack_min < thread -> stack_base
+ && stack_min > GC_get_stack_min(thread -> stack_base)));
+
+ if (sp >= stack_min && sp < thread->stack_base) {
+# ifdef DEBUG_THREADS
+ GC_printf("Pushing stack for 0x%x from sp %p to %p from 0x%x\n",
+ (int)thread -> id, sp, thread -> stack_base, (int)me);
+# endif
GC_push_all_stack(sp, thread->stack_base);
- else {
- WARN("Thread stack pointer 0x%lx out of range, pushing everything\n",
- (unsigned long)sp);
+ } else {
+ /* If not current thread then it is possible for sp to point to */
+ /* the guarded (untouched yet) page just below the current */
+ /* stack_min of the thread. */
+ if (thread -> id == me || sp >= thread->stack_base
+ || sp + GC_page_size < stack_min)
+ WARN("Thread stack pointer %p out of range, pushing everything\n",
+ sp);
+# ifdef DEBUG_THREADS
+ GC_printf("Pushing stack for 0x%x from (min) %p to %p from 0x%x\n",
+ (int)thread -> id, stack_min,
+ thread -> stack_base, (int)me);
+# endif
GC_push_all_stack(stack_min, thread->stack_base);
}
+ } /* thread looks live */
+}
+
+void GC_push_all_stacks(void)
+{
+ DWORD me = GetCurrentThreadId();
+ GC_bool found_me = FALSE;
+# ifndef SMALL_CONFIG
+ unsigned nthreads = 0;
+# endif
+
+ if (GC_win32_dll_threads) {
+ int i;
+ LONG my_max = GC_get_max_thread_index();
+
+ for (i = 0; i <= my_max; i++) {
+ GC_thread t = (GC_thread)(dll_thread_table + i);
+ if (t -> in_use) {
+# ifndef SMALL_CONFIG
+ ++nthreads;
+# endif
+ GC_push_stack_for(t);
+ if (t -> id == me) found_me = TRUE;
+ }
+ }
+ } else {
+ GC_thread t;
+ int i;
+
+ for (i = 0; i < THREAD_TABLE_SZ; i++) {
+ for (t = GC_threads[i]; t != 0; t = t -> next) {
+# ifndef SMALL_CONFIG
+ ++nthreads;
+# endif
+ if (!KNOWN_FINISHED(t)) GC_push_stack_for(t);
+ if (t -> id == me) found_me = TRUE;
+ }
}
}
- if (!found_me) ABORT("Collecting from unknown thread.");
+# ifndef SMALL_CONFIG
+ if (GC_print_stats == VERBOSE) {
+ GC_log_printf("Pushed %d thread stacks%s\n", nthreads,
+ GC_win32_dll_threads ? " based on DllMain thread tracking" : "");
+ }
+# endif
+ if (!found_me && !GC_in_thread_creation)
+ ABORT("Collecting from unknown thread.");
}
-void GC_get_next_stack(char *start, char **lo, char **hi)
+#ifdef PARALLEL_MARK
+
+# ifndef MAX_MARKERS
+# define MAX_MARKERS 16
+# endif
+
+ extern long GC_markers; /* Number of mark threads we would */
+ /* like to have. Includes the */
+ /* initiating thread. */
+
+ STATIC ptr_t marker_sp[MAX_MARKERS - 1]; /* The cold end of the stack */
+ /* for markers. */
+# ifdef IA64
+ STATIC ptr_t marker_bsp[MAX_MARKERS - 1];
+# endif
+
+ STATIC ptr_t marker_last_stack_min[MAX_MARKERS - 1];
+ /* Last known minimum (hottest) address */
+ /* in stack (or ADDR_LIMIT if unset) */
+ /* for markers. */
+
+#endif
+
+/* Find stack with the lowest address which overlaps the */
+/* interval [start, limit). */
+/* Return stack bounds in *lo and *hi. If no such stack */
+/* is found, both *hi and *lo will be set to an address */
+/* higher than limit. */
+void GC_get_next_stack(char *start, char *limit,
+ char **lo, char **hi)
{
int i;
-# define ADDR_LIMIT (char *)(-1L)
- char * current_min = ADDR_LIMIT;
- LONG my_max = GC_get_max_thread_index();
+ char * current_min = ADDR_LIMIT; /* Least in-range stack base */
+ ptr_t *plast_stack_min = NULL; /* Address of last_stack_min */
+ /* field for thread corresponding */
+ /* to current_min. */
+ GC_thread thread = NULL; /* Either NULL or points to the */
+ /* thread's hash table entry */
+ /* containing *plast_stack_min. */
+
+ /* First set current_min, ignoring limit. */
+ if (GC_win32_dll_threads) {
+ LONG my_max = GC_get_max_thread_index();
- for (i = 0; i <= my_max; i++) {
- char * s = (char *)thread_table[i].stack_base;
+ for (i = 0; i <= my_max; i++) {
+ ptr_t s = (ptr_t)(dll_thread_table[i].stack_base);
- if (0 != s && s > start && s < current_min) {
+ if (s > start && s < current_min) {
+ /* Update address of last_stack_min. */
+ plast_stack_min = (ptr_t * /* no volatile */)
+ &dll_thread_table[i].last_stack_min;
current_min = s;
- }
- }
+ }
+ }
+ } else {
+ for (i = 0; i < THREAD_TABLE_SZ; i++) {
+ GC_thread t;
+
+ for (t = GC_threads[i]; t != 0; t = t -> next) {
+ ptr_t s = t -> stack_base;
+
+ if (s > start && s < current_min) {
+ /* Update address of last_stack_min. */
+ plast_stack_min = &t -> last_stack_min;
+ thread = t; /* Remember current thread to unprotect. */
+ current_min = s;
+ }
+ }
+ }
+# ifdef PARALLEL_MARK
+ for (i = 0; i < GC_markers - 1; ++i) {
+ ptr_t s = marker_sp[i];
+# ifdef IA64
+ /* FIXME: not implemented */
+# endif
+ if (s > start && s < current_min) {
+ GC_ASSERT(marker_last_stack_min[i] != NULL);
+ plast_stack_min = &marker_last_stack_min[i];
+ current_min = s;
+ thread = NULL; /* Not a thread's hash table entry. */
+ }
+ }
+# endif
+ }
+
*hi = current_min;
if (current_min == ADDR_LIMIT) {
*lo = ADDR_LIMIT;
return;
}
- *lo = GC_get_stack_min(current_min);
- if (*lo < start) *lo = start;
+
+ GC_ASSERT(current_min > start);
+
+# ifndef MSWINCE
+ if (current_min > limit && !GC_may_be_in_stack(limit)) {
+ /* Skip the rest since the memory region at limit address is */
+ /* not a stack (so the lowest address of the found stack would */
+ /* be above the limit value anyway). */
+ *lo = ADDR_LIMIT;
+ return;
+ }
+# endif
+
+ /* Get the minimum address of the found stack by probing its memory */
+ /* region starting from the last known minimum (if set). */
+ if (*plast_stack_min == ADDR_LIMIT
+# ifndef MSWINCE
+ || !GC_may_be_in_stack(*plast_stack_min)
+# endif
+ ) {
+ /* Unsafe to start from last value. */
+ *lo = GC_get_stack_min(current_min);
+ } else {
+ /* Use last value value to optimize search for min address */
+ *lo = GC_get_stack_min(*plast_stack_min);
+ }
+
+ /* Remember current stack_min value. */
+ if (thread != NULL) {
+ UNPROTECT(thread);
+ }
+ *plast_stack_min = *lo;
}
-#if !defined(CYGWIN32)
+#ifdef PARALLEL_MARK
-#if !defined(MSWINCE) && defined(GC_DLL)
+ /* GC_mark_thread() is the same as in pthread_support.c */
+#ifdef GC_PTHREADS
+ STATIC void * GC_mark_thread(void * id)
+#else
+ STATIC unsigned __stdcall GC_mark_thread(void * id)
+#endif
+{
+ word my_mark_no = 0;
-/* We register threads from DllMain */
+ marker_sp[(word)id] = GC_approx_sp();
+# ifdef IA64
+ marker_bsp[(word)id] = GC_save_regs_in_stack();
+# endif
-GC_API HANDLE WINAPI GC_CreateThread(
- LPSECURITY_ATTRIBUTES lpThreadAttributes,
- DWORD dwStackSize, LPTHREAD_START_ROUTINE lpStartAddress,
- LPVOID lpParameter, DWORD dwCreationFlags, LPDWORD lpThreadId )
+ if ((word)id == (word)-1) return 0; /* to make compiler happy */
+
+ for (;; ++my_mark_no) {
+ if (my_mark_no - GC_mark_no > (word)2) {
+ /* resynchronize if we get far off, e.g. because GC_mark_no */
+ /* wrapped. */
+ my_mark_no = GC_mark_no;
+ }
+# ifdef DEBUG_THREADS
+ GC_printf("Starting mark helper for mark number %lu\n",
+ (unsigned long)my_mark_no);
+# endif
+ GC_help_marker(my_mark_no);
+ }
+}
+
+#ifdef GC_ASSERTIONS
+ unsigned long GC_mark_lock_holder = NO_THREAD;
+#endif
+
+/* GC_mark_threads[] is unused here unlike that in pthread_support.c */
+
+#ifdef GC_PTHREADS
+
+/* start_mark_threads() is the same as in pthread_support.c except for: */
+/* - GC_markers value is adjusted already; */
+/* - thread stack is assumed to be large enough; and */
+/* - statistics about the number of marker threads is already printed. */
+
+STATIC void start_mark_threads(void)
{
- return CreateThread(lpThreadAttributes, dwStackSize, lpStartAddress,
- lpParameter, dwCreationFlags, lpThreadId);
+ unsigned i;
+ pthread_attr_t attr;
+ pthread_t new_thread;
+
+ if (0 != pthread_attr_init(&attr)) ABORT("pthread_attr_init failed");
+
+ if (0 != pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED))
+ ABORT("pthread_attr_setdetachstate failed");
+
+ for (i = 0; i < GC_markers - 1; ++i) {
+ marker_last_stack_min[i] = ADDR_LIMIT;
+ if (0 != pthread_create(&new_thread, &attr,
+ GC_mark_thread, (void *)(word)i)) {
+ WARN("Marker thread creation failed, errno = %ld.\n",
+ /* (word) */ errno);
+ }
+ }
+ pthread_attr_destroy(&attr);
}
-#else /* defined(MSWINCE) || !defined(GC_DLL)) */
+STATIC pthread_mutex_t mark_mutex = PTHREAD_MUTEX_INITIALIZER;
-/* We have no DllMain to take care of new threads. Thus we */
-/* must properly intercept thread creation. */
+STATIC pthread_cond_t builder_cv = PTHREAD_COND_INITIALIZER;
-typedef struct {
- LPTHREAD_START_ROUTINE start;
- LPVOID param;
-} thread_args;
+/* GC_acquire/release_mark_lock(), GC_wait_builder/marker(), */
+/* GC_wait_for_reclaim(), GC_notify_all_builder/marker() are the same */
+/* as in pthread_support.c except that GC_generic_lock() is not used. */
+
+#ifdef LOCK_STATS
+ AO_t GC_block_count = 0;
+#endif
-static DWORD WINAPI thread_start(LPVOID arg);
+void GC_acquire_mark_lock(void)
+{
+ if (pthread_mutex_lock(&mark_mutex) != 0) {
+ ABORT("pthread_mutex_lock failed");
+ }
+# ifdef LOCK_STATS
+ (void)AO_fetch_and_add1(&GC_block_count);
+# endif
+ /* GC_generic_lock(&mark_mutex); */
+# ifdef GC_ASSERTIONS
+ GC_mark_lock_holder = NUMERIC_THREAD_ID(pthread_self());
+# endif
+}
-GC_API HANDLE WINAPI GC_CreateThread(
- LPSECURITY_ATTRIBUTES lpThreadAttributes,
- DWORD dwStackSize, LPTHREAD_START_ROUTINE lpStartAddress,
- LPVOID lpParameter, DWORD dwCreationFlags, LPDWORD lpThreadId )
+void GC_release_mark_lock(void)
{
- HANDLE thread_h = NULL;
+ GC_ASSERT(GC_mark_lock_holder == NUMERIC_THREAD_ID(pthread_self()));
+# ifdef GC_ASSERTIONS
+ GC_mark_lock_holder = NO_THREAD;
+# endif
+ if (pthread_mutex_unlock(&mark_mutex) != 0) {
+ ABORT("pthread_mutex_unlock failed");
+ }
+}
- thread_args *args;
+/* Collector must wait for a freelist builders for 2 reasons: */
+/* 1) Mark bits may still be getting examined without lock. */
+/* 2) Partial free lists referenced only by locals may not be scanned */
+/* correctly, e.g. if they contain "pointer-free" objects, since the */
+/* free-list link may be ignored. */
+/* STATIC */ void GC_wait_builder(void)
+{
+ GC_ASSERT(GC_mark_lock_holder == NUMERIC_THREAD_ID(pthread_self()));
+# ifdef GC_ASSERTIONS
+ GC_mark_lock_holder = NO_THREAD;
+# endif
+ if (pthread_cond_wait(&builder_cv, &mark_mutex) != 0) {
+ ABORT("pthread_cond_wait failed");
+ }
+ GC_ASSERT(GC_mark_lock_holder == NO_THREAD);
+# ifdef GC_ASSERTIONS
+ GC_mark_lock_holder = NUMERIC_THREAD_ID(pthread_self());
+# endif
+}
- if (!GC_is_initialized) GC_init();
- /* make sure GC is initialized (i.e. main thread is attached) */
+void GC_wait_for_reclaim(void)
+{
+ GC_acquire_mark_lock();
+ while (GC_fl_builder_count > 0) {
+ GC_wait_builder();
+ }
+ GC_release_mark_lock();
+}
+
+void GC_notify_all_builder(void)
+{
+ GC_ASSERT(GC_mark_lock_holder == NUMERIC_THREAD_ID(pthread_self()));
+ if (pthread_cond_broadcast(&builder_cv) != 0) {
+ ABORT("pthread_cond_broadcast failed");
+ }
+}
+
+STATIC pthread_cond_t mark_cv = PTHREAD_COND_INITIALIZER;
+
+void GC_wait_marker(void)
+{
+ GC_ASSERT(GC_mark_lock_holder == NUMERIC_THREAD_ID(pthread_self()));
+# ifdef GC_ASSERTIONS
+ GC_mark_lock_holder = NO_THREAD;
+# endif
+ if (pthread_cond_wait(&mark_cv, &mark_mutex) != 0) {
+ ABORT("pthread_cond_wait failed");
+ }
+ GC_ASSERT(GC_mark_lock_holder == NO_THREAD);
+# ifdef GC_ASSERTIONS
+ GC_mark_lock_holder = NUMERIC_THREAD_ID(pthread_self());
+# endif
+}
+
+void GC_notify_all_marker(void)
+{
+ if (pthread_cond_broadcast(&mark_cv) != 0) {
+ ABORT("pthread_cond_broadcast failed");
+ }
+}
+
+#else /* ! GC_PTHREADS */
+
+STATIC void start_mark_threads(void)
+{
+ int i;
+ GC_uintptr_t handle;
+ unsigned thread_id;
+
+ for (i = 0; i < GC_markers - 1; ++i) {
+ marker_last_stack_min[i] = ADDR_LIMIT;
+ handle = _beginthreadex(NULL /* security_attr */, 0 /* stack_size */,
+ GC_mark_thread, (void *)(word)i, 0 /* flags */,
+ &thread_id);
+ if (!handle || handle == (GC_uintptr_t)-1L)
+ WARN("Marker thread creation failed\n", 0);
+ else { /* We may detach the thread (if handle is of HANDLE type) */
+ /* CloseHandle((HANDLE)handle); */
+ }
+ }
+}
+
+STATIC HANDLE mark_mutex_event = (HANDLE)0; /* Event with auto-reset. */
+volatile AO_t GC_mark_mutex_waitcnt = 0; /* Number of waiters + 1; */
+ /* 0 - unlocked. */
+
+STATIC HANDLE builder_cv = (HANDLE)0; /* Event with manual reset */
+
+/* mark_mutex_event, builder_cv, mark_cv are initialized in GC_thr_init(). */
+
+/* #define LOCK_STATS */
+#ifdef LOCK_STATS
+ AO_t GC_block_count = 0;
+ AO_t GC_unlocked_count = 0;
+#endif
+
+void GC_acquire_mark_lock(void)
+{
+ if (AO_fetch_and_add1_acquire(&GC_mark_mutex_waitcnt) != 0) {
+# ifdef LOCK_STATS
+ (void)AO_fetch_and_add1(&GC_block_count);
+# endif
+ if (WaitForSingleObject(mark_mutex_event, INFINITE) == WAIT_FAILED)
+ ABORT("WaitForSingleObject() failed");
+ }
+# ifdef LOCK_STATS
+ else {
+ (void)AO_fetch_and_add1(&GC_unlocked_count);
+ }
+# endif
+
+ GC_ASSERT(GC_mark_lock_holder == NO_THREAD);
+# ifdef GC_ASSERTIONS
+ GC_mark_lock_holder = (unsigned long)GetCurrentThreadId();
+# endif
+}
+
+void GC_release_mark_lock(void)
+{
+ GC_ASSERT(GC_mark_lock_holder == (unsigned long)GetCurrentThreadId());
+# ifdef GC_ASSERTIONS
+ GC_mark_lock_holder = NO_THREAD;
+# endif
+ GC_ASSERT(AO_load(&GC_mark_mutex_waitcnt) != 0);
+ if (AO_fetch_and_sub1_release(&GC_mark_mutex_waitcnt) > 1 &&
+ SetEvent(mark_mutex_event) == FALSE)
+ ABORT("SetEvent() failed");
+}
+
+/* In GC_wait_for_reclaim/GC_notify_all_builder() we emulate POSIX */
+/* cond_wait/cond_broadcast() primitives with WinAPI Event object */
+/* (working in "manual reset" mode). This works here because */
+/* GC_notify_all_builder() is always called holding lock on */
+/* mark_mutex and the checked condition (GC_fl_builder_count == 0) */
+/* is the only one for which broadcasting on builder_cv is performed. */
+
+void GC_wait_for_reclaim(void)
+{
+ GC_ASSERT(builder_cv != 0);
+ for (;;) {
+ GC_acquire_mark_lock();
+ if (GC_fl_builder_count == 0)
+ break;
+ if (ResetEvent(builder_cv) == FALSE)
+ ABORT("ResetEvent() failed");
+ GC_release_mark_lock();
+ if (WaitForSingleObject(builder_cv, INFINITE) == WAIT_FAILED)
+ ABORT("WaitForSingleObject() failed");
+ }
+ GC_release_mark_lock();
+}
+
+void GC_notify_all_builder(void)
+{
+ GC_ASSERT(GC_mark_lock_holder == (unsigned long)GetCurrentThreadId());
+ GC_ASSERT(builder_cv != 0);
+ GC_ASSERT(GC_fl_builder_count == 0);
+ if (SetEvent(builder_cv) == FALSE)
+ ABORT("SetEvent() failed");
+}
+
+/* For GC_wait_marker/GC_notify_all_marker() the above technique does */
+/* not work because they are used with different checked conditions in */
+/* different places (and, in addition, notifying is done after leaving */
+/* critical section) and this could result in a signal loosing between */
+/* checking for a particular condition and calling WaitForSingleObject. */
+/* So, we use PulseEvent() and NT SignalObjectAndWait() (which */
+/* atomically sets mutex event to signaled state and starts waiting on */
+/* condvar). A special case here is GC_mark_mutex_waitcnt == 1 (i.e. */
+/* nobody waits for mark lock at this moment) - we don't change it */
+/* (otherwise we may loose a signal sent between decrementing */
+/* GC_mark_mutex_waitcnt and calling WaitForSingleObject()). */
+
+STATIC HANDLE mark_cv = (HANDLE)0; /* Event with manual reset */
+
+typedef DWORD (WINAPI * SignalObjectAndWait_type)(
+ HANDLE, HANDLE, DWORD, BOOL);
+STATIC SignalObjectAndWait_type signalObjectAndWait_func = 0;
+
+void GC_wait_marker(void)
+{
+ /* Here we assume that GC_wait_marker() is always called */
+ /* from a while(check_cond) loop. */
+ AO_t waitcnt;
+ GC_ASSERT(mark_cv != 0);
+ GC_ASSERT(signalObjectAndWait_func != 0);
+
+ /* We inline GC_release_mark_lock() to have atomic */
+ /* unlock-and-wait action here. */
+ GC_ASSERT(GC_mark_lock_holder == (unsigned long)GetCurrentThreadId());
+# ifdef GC_ASSERTIONS
+ GC_mark_lock_holder = NO_THREAD;
+# endif
- args = GC_malloc_uncollectable(sizeof(thread_args));
- /* Handed off to and deallocated by child thread. */
- if (0 == args) {
- SetLastError(ERROR_NOT_ENOUGH_MEMORY);
- return NULL;
+ if ((waitcnt = AO_load(&GC_mark_mutex_waitcnt)) > 1) {
+ (void)AO_fetch_and_sub1_release(&GC_mark_mutex_waitcnt);
+ } else {
+ GC_ASSERT(AO_load(&GC_mark_mutex_waitcnt) != 0);
}
- /* set up thread arguments */
- args -> start = lpStartAddress;
- args -> param = lpParameter;
+ /* The state of mark_cv is non-signaled here. */
+ if ((*signalObjectAndWait_func)(mark_mutex_event /* hObjectToSignal */,
+ mark_cv /* hObjectToWaitOn */,
+ INFINITE /* timeout */,
+ FALSE /* isAlertable */) == WAIT_FAILED)
+ ABORT("SignalObjectAndWait() failed");
+ /* The state of mark_cv is non-signaled here again. */
- thread_h = CreateThread(lpThreadAttributes,
- dwStackSize, thread_start,
- args, dwCreationFlags,
- lpThreadId);
+ if (waitcnt > 1) {
+ GC_acquire_mark_lock();
+ } else {
+ GC_ASSERT(GC_mark_mutex_waitcnt != 0);
+ /* Acquire mark lock */
+ if (WaitForSingleObject(mark_mutex_event, INFINITE) == WAIT_FAILED)
+ ABORT("WaitForSingleObject() failed");
+ GC_ASSERT(GC_mark_lock_holder == NO_THREAD);
+# ifdef GC_ASSERTIONS
+ GC_mark_lock_holder = (unsigned long)GetCurrentThreadId();
+# endif
+ }
+}
- return thread_h;
+void GC_notify_all_marker(void)
+{
+ GC_ASSERT(mark_cv != 0);
+ if (PulseEvent(mark_cv) == FALSE)
+ ABORT("PulseEvent() failed");
}
-static DWORD WINAPI thread_start(LPVOID arg)
+/* Defined in os_dep.c */
+extern GC_bool GC_wnt;
+
+#endif /* ! GC_PTHREADS */
+
+#endif /* PARALLEL_MARK */
+
+#ifndef GC_PTHREADS
+
+/* We have no DllMain to take care of new threads. Thus we */
+/* must properly intercept thread creation. */
+
+typedef struct {
+ LPTHREAD_START_ROUTINE start;
+ LPVOID param;
+} thread_args;
+
+STATIC void * GC_CALLBACK GC_win32_start_inner(struct GC_stack_base *sb,
+ void *arg)
{
- DWORD ret = 0;
+ void * ret;
thread_args *args = (thread_args *)arg;
- GC_new_thread();
+ GC_register_my_thread(sb); /* This waits for an in-progress GC. */
+
+# if DEBUG_WIN32_THREADS
+ GC_printf("thread 0x%x starting...\n", (unsigned)GetCurrentThreadId());
+# endif
/* Clear the thread entry even if we exit with an exception. */
/* This is probably pointless, since an uncaught exception is */
#ifndef __GNUC__
__try {
#endif /* __GNUC__ */
- ret = args->start (args->param);
+ ret = (void *)(word)args->start (args->param);
#ifndef __GNUC__
} __finally {
#endif /* __GNUC__ */
+ GC_unregister_my_thread();
GC_free(args);
- GC_delete_thread(GetCurrentThreadId());
#ifndef __GNUC__
}
#endif /* __GNUC__ */
+# if DEBUG_WIN32_THREADS
+ GC_printf("thread 0x%x returned from start routine.\n",
+ (unsigned)GetCurrentThreadId());
+# endif
return ret;
}
-#endif /* !defined(MSWINCE) && !(defined(__MINGW32__) && !defined(_DLL)) */
-#endif /* !CYGWIN32 */
+DWORD WINAPI GC_win32_start(LPVOID arg)
+{
+ return (DWORD)(word)GC_call_with_stack_base(GC_win32_start_inner, arg);
+}
+
+GC_API HANDLE WINAPI GC_CreateThread(
+ LPSECURITY_ATTRIBUTES lpThreadAttributes,
+ DWORD dwStackSize, LPTHREAD_START_ROUTINE lpStartAddress,
+ LPVOID lpParameter, DWORD dwCreationFlags, LPDWORD lpThreadId )
+{
+ HANDLE thread_h;
+
+ thread_args *args;
+
+ if (!parallel_initialized) GC_init_parallel();
+ /* make sure GC is initialized (i.e. main thread is attached,
+ tls initialized) */
+
+# if DEBUG_WIN32_THREADS
+ GC_printf("About to create a thread from 0x%x\n",
+ (unsigned)GetCurrentThreadId());
+# endif
+ if (GC_win32_dll_threads) {
+ return CreateThread(lpThreadAttributes, dwStackSize, lpStartAddress,
+ lpParameter, dwCreationFlags, lpThreadId);
+ } else {
+ args = GC_malloc_uncollectable(sizeof(thread_args));
+ /* Handed off to and deallocated by child thread. */
+ if (0 == args) {
+ SetLastError(ERROR_NOT_ENOUGH_MEMORY);
+ return NULL;
+ }
+
+ /* set up thread arguments */
+ args -> start = lpStartAddress;
+ args -> param = lpParameter;
+
+ GC_need_to_lock = TRUE;
+ thread_h = CreateThread(lpThreadAttributes,
+ dwStackSize, GC_win32_start,
+ args, dwCreationFlags,
+ lpThreadId);
+ if( thread_h == 0 ) GC_free( args );
+ return thread_h;
+ }
+}
+
+GC_API void WINAPI GC_ExitThread(DWORD dwExitCode)
+{
+ GC_unregister_my_thread();
+ ExitThread(dwExitCode);
+}
+
+#ifndef MSWINCE
+
+GC_API GC_uintptr_t GC_CALL GC_beginthreadex(
+ void *security, unsigned stack_size,
+ unsigned ( __stdcall *start_address )( void * ),
+ void *arglist, unsigned initflag, unsigned *thrdaddr)
+{
+ GC_uintptr_t thread_h;
+
+ thread_args *args;
+
+ if (!parallel_initialized) GC_init_parallel();
+ /* make sure GC is initialized (i.e. main thread is attached,
+ tls initialized) */
+# if DEBUG_WIN32_THREADS
+ GC_printf("About to create a thread from 0x%x\n",
+ (unsigned)GetCurrentThreadId());
+# endif
+
+ if (GC_win32_dll_threads) {
+ return _beginthreadex(security, stack_size, start_address,
+ arglist, initflag, thrdaddr);
+ } else {
+ args = GC_malloc_uncollectable(sizeof(thread_args));
+ /* Handed off to and deallocated by child thread. */
+ if (0 == args) {
+ SetLastError(ERROR_NOT_ENOUGH_MEMORY);
+ return (GC_uintptr_t)(-1L);
+ }
+
+ /* set up thread arguments */
+ args -> start = (LPTHREAD_START_ROUTINE)start_address;
+ args -> param = arglist;
+
+ GC_need_to_lock = TRUE;
+ thread_h = _beginthreadex(security, stack_size,
+ (unsigned (__stdcall *) (void *))GC_win32_start,
+ args, initflag, thrdaddr);
+ if( thread_h == 0 ) GC_free( args );
+ return thread_h;
+ }
+}
+
+GC_API void GC_CALL GC_endthreadex(unsigned retval)
+{
+ GC_unregister_my_thread();
+ _endthreadex(retval);
+}
+
+#endif /* !MSWINCE */
+
+#endif /* !GC_PTHREADS */
#ifdef MSWINCE
# else /* !MSWINCE */
/* Called by GC_init() - we hold the allocation lock. */
-void GC_thr_init() {
+void GC_thr_init(void) {
+ struct GC_stack_base sb;
+# ifdef GC_ASSERTIONS
+ int sb_result;
+# endif
+
+ GC_ASSERT(I_HOLD_LOCK());
if (GC_thr_initialized) return;
GC_main_thread = GetCurrentThreadId();
GC_thr_initialized = TRUE;
/* Add the initial thread, so we can stop it. */
- GC_new_thread();
+# ifdef GC_ASSERTIONS
+ sb_result =
+# endif
+ GC_get_stack_base(&sb);
+ GC_ASSERT(sb_result == GC_SUCCESS);
+
+# ifdef PARALLEL_MARK
+ /* Set GC_markers. */
+ {
+ char * markers_string = GETENV("GC_MARKERS");
+ if (markers_string != NULL) {
+ GC_markers = atoi(markers_string);
+ if (GC_markers > MAX_MARKERS) {
+ WARN("Limiting number of mark threads\n", 0);
+ GC_markers = MAX_MARKERS;
+ }
+ } else {
+# ifdef _WIN64
+ DWORD_PTR procMask = 0;
+ DWORD_PTR sysMask;
+# else
+ DWORD procMask = 0;
+ DWORD sysMask;
+# endif
+ int ncpu = 0;
+ if (GetProcessAffinityMask(GetCurrentProcess(),
+ (void *)&procMask, (void *)&sysMask)
+ && procMask) {
+ do {
+ ncpu++;
+ } while ((procMask &= procMask - 1) != 0);
+ }
+ GC_markers = ncpu;
+ if (GC_markers >= MAX_MARKERS)
+ GC_markers = MAX_MARKERS; /* silently limit GC_markers value */
+ }
+ }
+
+ /* Set GC_parallel. */
+ {
+# ifndef GC_PTHREADS
+ HMODULE hK32;
+ /* SignalObjectAndWait() API call works only under NT. */
+# endif
+ if (GC_markers <= 1 || GC_win32_dll_threads
+# ifndef GC_PTHREADS
+ || GC_wnt == FALSE
+ || (hK32 = GetModuleHandleA("kernel32.dll")) == (HMODULE)0
+ || (signalObjectAndWait_func = (SignalObjectAndWait_type)
+ GetProcAddress(hK32, "SignalObjectAndWait")) == 0
+# endif
+ ) {
+ /* Disable parallel marking. */
+ GC_parallel = FALSE;
+ GC_markers = 1;
+ } else {
+# ifndef GC_PTHREADS
+ /* Initialize Win32 event objects for parallel marking. */
+ mark_mutex_event = CreateEventA(NULL /* attrs */,
+ FALSE /* isManualReset */,
+ FALSE /* initialState */, NULL /* name */);
+ builder_cv = CreateEventA(NULL /* attrs */,
+ TRUE /* isManualReset */,
+ FALSE /* initialState */, NULL /* name */);
+ mark_cv = CreateEventA(NULL /* attrs */, TRUE /* isManualReset */,
+ FALSE /* initialState */, NULL /* name */);
+ if (mark_mutex_event == (HANDLE)0 || builder_cv == (HANDLE)0
+ || mark_cv == (HANDLE)0)
+ ABORT("CreateEvent() failed");
+# endif
+ GC_parallel = TRUE;
+ /* Disable true incremental collection, but generational is OK. */
+ GC_time_limit = GC_TIME_UNLIMITED;
+ }
+ }
+
+ if (GC_print_stats) {
+ GC_log_printf("Number of marker threads = %ld\n", GC_markers);
+ }
+# endif /* PARALLEL_MARK */
+
+ GC_ASSERT(0 == GC_lookup_thread_inner(GC_main_thread));
+ GC_register_my_thread_inner(&sb, GC_main_thread);
+
+# ifdef PARALLEL_MARK
+ /* If we are using a parallel marker, actually start helper threads. */
+ if (GC_parallel) start_mark_threads();
+# endif
}
-#ifdef CYGWIN32
+#ifdef GC_PTHREADS
struct start_info {
void *(*start_routine)(void *);
int GC_pthread_join(pthread_t pthread_id, void **retval) {
int result;
- int i;
- GC_thread me;
+ GC_thread joinee;
# if DEBUG_CYGWIN_THREADS
- GC_printf3("thread 0x%x(0x%x) is joining thread 0x%x.\n",
- (int)pthread_self(), GetCurrentThreadId(), (int)pthread_id);
+ GC_printf("thread 0x%x(0x%x) is joining thread 0x%x.\n",
+ (int)pthread_self(), (int)GetCurrentThreadId(),
+ (int)pthread_id);
+# endif
+# if DEBUG_WIN32_PTHREADS
+ GC_printf("thread 0x%x(0x%x) is joining thread 0x%x.\n",
+ (int)(pthread_self()).p, (int)GetCurrentThreadId(),
+ pthread_id.p);
# endif
+ if (!parallel_initialized) GC_init_parallel();
/* Thread being joined might not have registered itself yet. */
/* After the join,thread id may have been recycled. */
/* FIXME: It would be better if this worked more like */
/* pthread_support.c. */
- while ((me = GC_lookup_thread(pthread_id)) == 0) Sleep(10);
+# ifndef GC_WIN32_PTHREADS
+ while ((joinee = GC_lookup_pthread(pthread_id)) == 0) Sleep(10);
+# endif
result = pthread_join(pthread_id, retval);
- GC_delete_gc_thread(me);
+# ifdef GC_WIN32_PTHREADS
+ /* win32_pthreads id are unique */
+ joinee = GC_lookup_pthread(pthread_id);
+# endif
+
+ if (!GC_win32_dll_threads) {
+ LOCK();
+ GC_delete_gc_thread(joinee);
+ UNLOCK();
+ } /* otherwise dllmain handles it. */
# if DEBUG_CYGWIN_THREADS
- GC_printf3("thread 0x%x(0x%x) completed join with thread 0x%x.\n",
- (int)pthread_self(), GetCurrentThreadId(), (int)pthread_id);
+ GC_printf("thread 0x%x(0x%x) completed join with thread 0x%x.\n",
+ (int)pthread_self(), (int)GetCurrentThreadId(),
+ (int)pthread_id);
+# endif
+# if DEBUG_WIN32_PTHREADS
+ GC_printf("thread 0x%x(0x%x) completed join with thread 0x%x.\n",
+ (int)(pthread_self()).p, (int)GetCurrentThreadId(),
+ pthread_id.p);
# endif
return result;
int result;
struct start_info * si;
- if (!GC_is_initialized) GC_init();
+ if (!parallel_initialized) GC_init_parallel();
/* make sure GC is initialized (i.e. main thread is attached) */
+ if (GC_win32_dll_threads) {
+ return pthread_create(new_thread, attr, start_routine, arg);
+ }
/* This is otherwise saved only in an area mmapped by the thread */
/* library, which isn't visible to the collector. */
}
# if DEBUG_CYGWIN_THREADS
- GC_printf2("About to create a thread from 0x%x(0x%x)\n",
- (int)pthread_self(), GetCurrentThreadId);
+ GC_printf("About to create a thread from 0x%x(0x%x)\n",
+ (int)pthread_self(), (int)GetCurrentThreadId);
# endif
- result = pthread_create(new_thread, attr, GC_start_routine, si);
+# if DEBUG_WIN32_PTHREADS
+ GC_printf("About to create a thread from 0x%x(0x%x)\n",
+ (int)(pthread_self()).p, (int)GetCurrentThreadId());
+# endif
+ GC_need_to_lock = TRUE;
+ result = pthread_create(new_thread, attr, GC_pthread_start, si);
if (result) { /* failure */
GC_free(si);
return(result);
}
-void * GC_start_routine(void * arg)
+STATIC void * GC_CALLBACK GC_pthread_start_inner(struct GC_stack_base *sb,
+ void * arg)
{
struct start_info * si = arg;
void * result;
void *(*start)(void *);
void *start_arg;
- pthread_t pthread_id;
+ DWORD thread_id = GetCurrentThreadId();
+ pthread_t pthread_id = pthread_self();
GC_thread me;
- GC_bool detached;
- int i;
# if DEBUG_CYGWIN_THREADS
- GC_printf2("thread 0x%x(0x%x) starting...\n",(int)pthread_self(),
- GetCurrentThreadId());
+ GC_printf("thread 0x%x(0x%x) starting...\n",(int)pthread_id,
+ (int)thread_id);
+# endif
+# if DEBUG_WIN32_PTHREADS
+ GC_printf("thread 0x%x(0x%x) starting...\n",(int) pthread_id.p,
+ (int)thread_id);
# endif
+ GC_ASSERT(!GC_win32_dll_threads);
/* If a GC occurs before the thread is registered, that GC will */
/* ignore this thread. That's fine, since it will block trying to */
/* acquire the allocation lock, and won't yet hold interesting */
LOCK();
/* We register the thread here instead of in the parent, so that */
/* we don't need to hold the allocation lock during pthread_create. */
- me = GC_new_thread();
+ me = GC_register_my_thread_inner(sb, thread_id);
+ SET_PTHREAD_MAP_CACHE(pthread_id, thread_id);
UNLOCK();
start = si -> start_routine;
start_arg = si -> arg;
if (si-> detached) me -> flags |= DETACHED;
- me -> pthread_id = pthread_id = pthread_self();
+ me -> pthread_id = pthread_id;
GC_free(si); /* was allocated uncollectable */
pthread_cleanup_push(GC_thread_exit_proc, (void *)me);
result = (*start)(start_arg);
me -> status = result;
- pthread_cleanup_pop(0);
+ pthread_cleanup_pop(1);
# if DEBUG_CYGWIN_THREADS
- GC_printf2("thread 0x%x(0x%x) returned from start routine.\n",
- (int)pthread_self(),GetCurrentThreadId());
+ GC_printf("thread 0x%x(0x%x) returned from start routine.\n",
+ (int)pthread_self(),(int)GetCurrentThreadId());
+# endif
+# if DEBUG_WIN32_PTHREADS
+ GC_printf("thread 0x%x(0x%x) returned from start routine.\n",
+ (int)(pthread_self()).p, (int)GetCurrentThreadId());
# endif
return(result);
}
-void GC_thread_exit_proc(void *arg)
+STATIC void * GC_pthread_start(void * arg)
+{
+ return GC_call_with_stack_base(GC_pthread_start_inner, arg);
+}
+
+STATIC void GC_thread_exit_proc(void *arg)
{
GC_thread me = (GC_thread)arg;
- int i;
+ GC_ASSERT(!GC_win32_dll_threads);
# if DEBUG_CYGWIN_THREADS
- GC_printf2("thread 0x%x(0x%x) called pthread_exit().\n",
- (int)pthread_self(),GetCurrentThreadId());
+ GC_printf("thread 0x%x(0x%x) called pthread_exit().\n",
+ (int)pthread_self(),(int)GetCurrentThreadId());
+# endif
+# if DEBUG_WIN32_PTHREADS
+ GC_printf("thread 0x%x(0x%x) called pthread_exit().\n",
+ (int)(pthread_self()).p,(int)GetCurrentThreadId());
# endif
LOCK();
+# if defined(THREAD_LOCAL_ALLOC)
+ GC_destroy_thread_local(&(me->tlfs));
+# endif
if (me -> flags & DETACHED) {
GC_delete_thread(GetCurrentThreadId());
} else {
UNLOCK();
}
+#ifndef GC_WIN32_PTHREADS
+/* win32 pthread does not support sigmask */
/* nothing required here... */
int GC_pthread_sigmask(int how, const sigset_t *set, sigset_t *oset) {
+ if (!parallel_initialized) GC_init_parallel();
return pthread_sigmask(how, set, oset);
}
+#endif
int GC_pthread_detach(pthread_t thread)
{
int result;
GC_thread thread_gc_id;
+ if (!parallel_initialized) GC_init_parallel();
LOCK();
- thread_gc_id = GC_lookup_thread(thread);
+ thread_gc_id = GC_lookup_pthread(thread);
UNLOCK();
result = pthread_detach(thread);
if (result == 0) {
return result;
}
-#else /* !CYGWIN32 */
+#else /* !GC_PTHREADS */
/*
- * We avoid acquiring locks here, since this doesn't seem to be preemptable.
- * Pontus Rydin suggests wrapping the thread start routine instead.
+ * We avoid acquiring locks here, since this doesn't seem to be preemptible.
+ * This may run with an uninitialized collector, in which case we don't do much.
+ * This implies that no threads other than the main one should be created
+ * with an uninitialized collector. (The alternative of initializing
+ * the collector here seems dangerous, since DllMain is limited in what it
+ * can do.)
*/
#ifdef GC_DLL
+/*ARGSUSED*/
BOOL WINAPI DllMain(HINSTANCE inst, ULONG reason, LPVOID reserved)
{
+ struct GC_stack_base sb;
+ DWORD thread_id;
+# ifdef GC_ASSERTIONS
+ int sb_result;
+# endif
+ static int entry_count = 0;
+
+ if (parallel_initialized && !GC_win32_dll_threads) return TRUE;
+
switch (reason) {
- case DLL_PROCESS_ATTACH:
- GC_init(); /* Force initialization before thread attach. */
- /* fall through */
- case DLL_THREAD_ATTACH:
- GC_ASSERT(GC_thr_initialized);
- if (GC_main_thread != GetCurrentThreadId()) {
- GC_new_thread();
+ case DLL_THREAD_ATTACH:
+# ifdef PARALLEL_MARK
+ /* Don't register marker threads. */
+ if (GC_parallel) {
+ /* We could reach here only if parallel_initialized == FALSE. */
+ break;
+ }
+# endif
+ GC_ASSERT(entry_count == 0 || parallel_initialized);
+ ++entry_count; /* and fall through: */
+ case DLL_PROCESS_ATTACH:
+ /* This may run with the collector uninitialized. */
+ thread_id = GetCurrentThreadId();
+ if (parallel_initialized && GC_main_thread != thread_id) {
+ /* Don't lock here. */
+# ifdef GC_ASSERTIONS
+ sb_result =
+# endif
+ GC_get_stack_base(&sb);
+ GC_ASSERT(sb_result == GC_SUCCESS);
+# if defined(THREAD_LOCAL_ALLOC) || defined(PARALLEL_MARK)
+ ABORT("Cannot initialize thread local cache from DllMain");
+# endif
+ GC_register_my_thread_inner(&sb, thread_id);
} /* o.w. we already did it during GC_thr_init(), called by GC_init() */
break;
- case DLL_THREAD_DETACH:
+ case DLL_THREAD_DETACH:
+ /* We are hopefully running in the context of the exiting thread. */
+ GC_ASSERT(parallel_initialized);
+ if (!GC_win32_dll_threads) return TRUE;
GC_delete_thread(GetCurrentThreadId());
break;
- case DLL_PROCESS_DETACH:
+ case DLL_PROCESS_DETACH:
{
int i;
+ int my_max;
- LOCK();
- for (i = 0; i <= GC_get_max_thread_index(); ++i)
+ if (!GC_win32_dll_threads) return TRUE;
+ my_max = (int)GC_get_max_thread_index();
+ for (i = 0; i <= my_max; ++i)
{
- if (thread_table[i].in_use)
- GC_delete_gc_thread(thread_table + i);
+ if (AO_load(&(dll_thread_table[i].in_use)))
+ GC_delete_gc_thread(dll_thread_table + i);
}
- UNLOCK();
GC_deinit();
DeleteCriticalSection(&GC_allocate_ml);
return TRUE;
}
#endif /* GC_DLL */
-#endif /* !CYGWIN32 */
+#endif /* !GC_PTHREADS */
# endif /* !MSWINCE */
+/* Perform all initializations, including those that */
+/* may require allocation. */
+/* Called without allocation lock. */
+/* Must be called before a second thread is created. */
+void GC_init_parallel(void)
+{
+ if (parallel_initialized) return;
+ parallel_initialized = TRUE;
+ /* GC_init() calls us back, so set flag first. */
+
+ if (!GC_is_initialized) GC_init();
+ if (GC_win32_dll_threads) {
+ GC_need_to_lock = TRUE;
+ /* Cannot intercept thread creation. Hence we don't know if */
+ /* other threads exist. However, client is not allowed to */
+ /* create other threads before collector initialization. */
+ /* Thus it's OK not to lock before this. */
+ }
+ /* Initialize thread local free lists if used. */
+# if defined(THREAD_LOCAL_ALLOC)
+ LOCK();
+ GC_init_thread_local(&GC_lookup_thread_inner(GetCurrentThreadId())->tlfs);
+ UNLOCK();
+# endif
+}
+
+#if defined(USE_PTHREAD_LOCKS)
+ /* Support for pthread locking code. */
+ /* Pthread_mutex_try_lock may not win here, */
+ /* due to builtin support for spinning first? */
+
+volatile GC_bool GC_collecting = 0;
+ /* A hint that we're in the collector and */
+ /* holding the allocation lock for an */
+ /* extended period. */
+
+void GC_lock(void)
+{
+ pthread_mutex_lock(&GC_allocate_ml);
+}
+#endif /* USE_PTHREAD ... */
+
+# if defined(THREAD_LOCAL_ALLOC)
+
+/* Add thread-local allocation support. Microsoft uses __declspec(thread) */
+
+/* We must explicitly mark ptrfree and gcj free lists, since the free */
+/* list links wouldn't otherwise be found. We also set them in the */
+/* normal free lists, since that involves touching less memory than if */
+/* we scanned them normally. */
+void GC_mark_thread_local_free_lists(void)
+{
+ int i;
+ GC_thread p;
+
+ for (i = 0; i < THREAD_TABLE_SZ; ++i) {
+ for (p = GC_threads[i]; 0 != p; p = p -> next) {
+# ifdef DEBUG_THREADS
+ GC_printf("Marking thread locals for 0x%x\n", p -> id);
+# endif
+ GC_mark_thread_local_fls_for(&(p->tlfs));
+ }
+ }
+}
+
+#if defined(GC_ASSERTIONS)
+ void GC_check_tls_for(GC_tlfs p);
+# if defined(USE_CUSTOM_SPECIFIC)
+ void GC_check_tsd_marks(tsd *key);
+# endif
+ /* Check that all thread-local free-lists are completely marked. */
+ /* also check that thread-specific-data structures are marked. */
+ void GC_check_tls(void) {
+ int i;
+ GC_thread p;
+
+ for (i = 0; i < THREAD_TABLE_SZ; ++i) {
+ for (p = GC_threads[i]; 0 != p; p = p -> next) {
+ GC_check_tls_for(&(p->tlfs));
+ }
+ }
+# if defined(USE_CUSTOM_SPECIFIC)
+ if (GC_thread_key != 0)
+ GC_check_tsd_marks(GC_thread_key);
+# endif
+ }
+#endif /* GC_ASSERTIONS */
+
+#endif /* THREAD_LOCAL_ALLOC ... */
+
#endif /* GC_WIN32_THREADS */
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