1 #include "private/gc_priv.h"
3 #if defined(GC_WIN32_THREADS)
7 #ifdef THREAD_LOCAL_ALLOC
8 # include "private/thread_local_alloc.h"
9 #endif /* THREAD_LOCAL_ALLOC */
11 /* Allocation lock declarations. */
12 #if !defined(USE_PTHREAD_LOCKS)
14 __declspec(dllexport) CRITICAL_SECTION GC_allocate_ml;
16 CRITICAL_SECTION GC_allocate_ml;
18 DWORD GC_lock_holder = NO_THREAD;
19 /* Thread id for current holder of allocation lock */
21 pthread_mutex_t GC_allocate_ml = PTHREAD_MUTEX_INITIALIZER;
22 unsigned long GC_lock_holder = NO_THREAD;
28 /* GC_DLL should not normally be defined, especially since we often do turn */
29 /* on THREAD_LOCAL_ALLOC, which is currently incompatible. */
30 /* It might be possible to get GC_DLL and DllMain-based thread registration */
31 /* to work with Cygwin, but if you try you are on your own. */
33 # error GC_DLL untested with Cygwin
36 /* Cygwin-specific forward decls */
37 # undef pthread_create
38 # undef pthread_sigmask
40 # undef pthread_detach
45 # define DEBUG_CYGWIN_THREADS 1
46 # define DEBUG_WIN32_PTHREADS 0
48 # define DEBUG_WIN32_PTHREADS 1
49 # define DEBUG_CYGWIN_THREADS 0
52 # define DEBUG_CYGWIN_THREADS 0
53 # define DEBUG_WIN32_PTHREADS 0
56 void * GC_pthread_start(void * arg);
57 void GC_thread_exit_proc(void *arg);
64 # define DEBUG_WIN32_THREADS 1
66 # define DEBUG_WIN32_THREADS 0
71 # undef _beginthreadex
75 # define DEBUG_WIN32_THREADS 1
77 # define DEBUG_WIN32_THREADS 0
80 # include <process.h> /* For _beginthreadex, _endthreadex */
84 #if defined(GC_DLL) && !defined(MSWINCE)
85 static GC_bool GC_win32_dll_threads = FALSE;
86 /* This code operates in two distinct modes, depending on */
87 /* the setting of GC_win32_dll_threads. If */
88 /* GC_win32_dll_threads is set, all threads in the process */
89 /* are implicitly registered with the GC by DllMain. */
90 /* No explicit registration is required, and attempts at */
91 /* explicit registration are ignored. This mode is */
92 /* very different from the Posix operation of the collector. */
93 /* In this mode access to the thread table is lock-free. */
94 /* Hence there is a static limit on the number of threads. */
96 /* If GC_win32_dll_threads is FALSE, or the collector is */
97 /* built without GC_DLL defined, things operate in a way */
98 /* that is very similar to Posix platforms, and new threads */
99 /* must be registered with the collector, e.g. by using */
100 /* preprocessor-based interception of the thread primitives. */
101 /* In this case, we use a real data structure for the thread */
102 /* table. Note that there is no equivalent of linker-based */
103 /* call interception, since we don't have ELF-like */
104 /* facilities. The Windows analog appears to be "API */
105 /* hooking", which really seems to be a standard way to */
106 /* do minor binary rewriting (?). I'd prefer not to have */
107 /* the basic collector rely on such facilities, but an */
108 /* optional package that intercepts thread calls this way */
109 /* would probably be nice. */
111 /* GC_win32_dll_threads must be set at initialization time, */
112 /* i.e. before any collector or thread calls. We make it a */
113 /* "dynamic" option only to avoid multiple library versions. */
115 # define GC_win32_dll_threads FALSE
118 /* We have two versions of the thread table. Which one */
119 /* we us depends on whether or not GC_win32_dll_threads */
120 /* is set. Note that before initialization, we don't */
121 /* add any entries to either table, even if DllMain is */
122 /* called. The main thread will be added on */
123 /* initialization. */
125 /* The type of the first argument to InterlockedExchange. */
126 /* Documented to be LONG volatile *, but at least gcc likes */
130 GC_bool GC_thr_initialized = FALSE;
132 GC_bool GC_need_to_lock = FALSE;
134 static GC_bool parallel_initialized = FALSE;
136 void GC_init_parallel(void);
139 /* Turn on GC_win32_dll_threads */
140 GC_API void GC_use_DllMain(void)
142 # ifdef THREAD_LOCAL_ALLOC
143 ABORT("Cannot use thread local allocation with DllMain-based "
144 "thread registration.");
145 /* Thread-local allocation really wants to lock at thread */
146 /* entry and exit. */
148 GC_ASSERT(!parallel_initialized);
149 GC_win32_dll_threads = TRUE;
153 GC_API void GC_use_DllMain(void)
155 ABORT("GC not configured as DLL");
159 DWORD GC_main_thread = 0;
161 struct GC_Thread_Rep {
163 AO_t tm_in_use; /* Updated without lock. */
164 /* We assert that unused */
165 /* entries have invalid ids of */
166 /* zero and zero stack fields. */
167 /* Used only with GC_win32_dll_threads. */
168 struct GC_Thread_Rep * tm_next;
169 /* Hash table link without */
170 /* GC_win32_dll_threads. */
171 /* More recently allocated threads */
172 /* with a given pthread id come */
173 /* first. (All but the first are */
174 /* guaranteed to be dead, but we may */
175 /* not yet have registered the join.) */
177 # define in_use table_management.tm_in_use
178 # define next table_management.tm_next
181 ptr_t stack_base; /* The cold end of the stack. */
182 /* 0 ==> entry not valid. */
183 /* !in_use ==> stack_base == 0 */
187 void *status; /* hold exit value until join in case it's a pointer */
188 pthread_t pthread_id;
189 short flags; /* Protected by GC lock. */
190 # define FINISHED 1 /* Thread has exited. */
191 # define DETACHED 2 /* Thread is intended to be detached. */
192 # define KNOWN_FINISHED(t) (((t) -> flags) & FINISHED)
194 # define KNOWN_FINISHED(t) 0
196 # ifdef THREAD_LOCAL_ALLOC
197 struct thread_local_freelists tlfs;
201 typedef struct GC_Thread_Rep * GC_thread;
202 typedef volatile struct GC_Thread_Rep * GC_vthread;
205 * We assumed that volatile ==> memory ordering, at least among
206 * volatiles. This code should consistently use atomic_ops.
209 volatile GC_bool GC_please_stop = FALSE;
212 * We track thread attachments while the world is supposed to be stopped.
213 * Unfortunately, we can't stop them from starting, since blocking in
214 * DllMain seems to cause the world to deadlock. Thus we have to recover
215 * If we notice this in the middle of marking.
218 AO_t GC_attached_thread = FALSE;
219 /* Return TRUE if an thread was attached since we last asked or */
220 /* since GC_attached_thread was explicitly reset. */
221 GC_bool GC_started_thread_while_stopped(void)
225 if (GC_win32_dll_threads) {
226 AO_nop_full(); /* Prior heap reads need to complete earlier. */
227 result = AO_load(&GC_attached_thread);
229 AO_store(&GC_attached_thread, FALSE);
231 return ((GC_bool)result);
237 /* Thread table used if GC_win32_dll_threads is set. */
238 /* This is a fixed size array. */
239 /* Since we use runtime conditionals, both versions */
240 /* are always defined. */
242 # define MAX_THREADS 512
244 /* Things may get quite slow for large numbers of threads, */
245 /* since we look them up with sequential search. */
247 volatile struct GC_Thread_Rep dll_thread_table[MAX_THREADS];
249 volatile LONG GC_max_thread_index = 0;
250 /* Largest index in dll_thread_table */
251 /* that was ever used. */
253 /* And now the version used if GC_win32_dll_threads is not set. */
254 /* This is a chained hash table, with much of the code borrowed */
255 /* From the Posix implementation. */
256 # define THREAD_TABLE_SZ 256 /* Must be power of 2 */
257 GC_thread GC_threads[THREAD_TABLE_SZ];
260 /* Add a thread to GC_threads. We assume it wasn't already there. */
261 /* Caller holds allocation lock. */
262 /* Unlike the pthreads version, the id field is set by the caller. */
263 GC_thread GC_new_thread(DWORD id)
265 word hv = ((word)id) % THREAD_TABLE_SZ;
267 /* It may not be safe to allocate when we register the first thread. */
268 static struct GC_Thread_Rep first_thread;
269 static GC_bool first_thread_used = FALSE;
271 GC_ASSERT(I_HOLD_LOCK());
272 if (!first_thread_used) {
273 result = &first_thread;
274 first_thread_used = TRUE;
276 GC_ASSERT(!GC_win32_dll_threads);
277 result = (struct GC_Thread_Rep *)
278 GC_INTERNAL_MALLOC(sizeof(struct GC_Thread_Rep), NORMAL);
280 /* result can be NULL -> segfault */
281 GC_ASSERT(result -> flags == 0);
284 if (result == 0) return(0);
285 /* result -> id = id; Done by caller. */
286 result -> next = GC_threads[hv];
287 GC_threads[hv] = result;
289 GC_ASSERT(result -> flags == 0 /* && result -> thread_blocked == 0 */);
294 extern LONG WINAPI GC_write_fault_handler(struct _EXCEPTION_POINTERS *exc_info);
296 #if defined(GWW_VDB) && defined(MPROTECT_VDB)
297 extern GC_bool GC_gww_dirty_init(void);
298 /* Defined in os_dep.c. Returns TRUE if GetWriteWatch is available. */
299 /* may be called repeatedly. */
302 GC_bool GC_in_thread_creation = FALSE; /* Protected by allocation lock. */
305 * This may be called from DllMain, and hence operates under unusual
306 * constraints. In particular, it must be lock-free if GC_win32_dll_threads
307 * is set. Always called from the thread being added.
308 * If GC_win32_dll_threads is not set, we already hold the allocation lock,
309 * except possibly during single-threaded start-up code.
311 static GC_thread GC_register_my_thread_inner(struct GC_stack_base *sb,
316 /* The following should be a noop according to the win32 */
317 /* documentation. There is empirical evidence that it */
319 # if defined(MPROTECT_VDB)
320 # if defined(GWW_VDB)
321 if (GC_incremental && !GC_gww_dirty_init())
322 SetUnhandledExceptionFilter(GC_write_fault_handler);
324 if (GC_incremental) SetUnhandledExceptionFilter(GC_write_fault_handler);
328 if (GC_win32_dll_threads) {
330 /* It appears to be unsafe to acquire a lock here, since this */
331 /* code is apparently not preeemptible on some systems. */
332 /* (This is based on complaints, not on Microsoft's official */
333 /* documentation, which says this should perform "only simple */
334 /* initialization tasks".) */
335 /* Hence we make do with nonblocking synchronization. */
336 /* It has been claimed that DllMain is really only executed with */
337 /* a particular system lock held, and thus careful use of locking */
338 /* around code that doesn't call back into the system libraries */
339 /* might be OK. But this hasn't been tested across all win32 */
341 /* cast away volatile qualifier */
342 for (i = 0; InterlockedExchange((IE_t)&dll_thread_table[i].in_use,1) != 0;
344 /* Compare-and-swap would make this cleaner, but that's not */
345 /* supported before Windows 98 and NT 4.0. In Windows 2000, */
346 /* InterlockedExchange is supposed to be replaced by */
347 /* InterlockedExchangePointer, but that's not really what I */
349 /* FIXME: We should eventually declare Win95 dead and use AO_ */
350 /* primitives here. */
351 if (i == MAX_THREADS - 1)
352 ABORT("too many threads");
354 /* Update GC_max_thread_index if necessary. The following is safe, */
355 /* and unlike CompareExchange-based solutions seems to work on all */
356 /* Windows95 and later platforms. */
357 /* Unfortunately, GC_max_thread_index may be temporarily out of */
358 /* bounds, so readers have to compensate. */
359 while (i > GC_max_thread_index) {
360 InterlockedIncrement((IE_t)&GC_max_thread_index);
362 if (GC_max_thread_index >= MAX_THREADS) {
363 /* We overshot due to simultaneous increments. */
364 /* Setting it to MAX_THREADS-1 is always safe. */
365 GC_max_thread_index = MAX_THREADS - 1;
367 me = dll_thread_table + i;
368 } else /* Not using DllMain */ {
369 GC_ASSERT(I_HOLD_LOCK());
370 GC_in_thread_creation = TRUE; /* OK to collect from unknown thread. */
371 me = GC_new_thread(thread_id);
372 GC_in_thread_creation = FALSE;
375 /* me can be NULL -> segfault */
376 me -> pthread_id = pthread_self();
379 if (!DuplicateHandle(GetCurrentProcess(),
382 (HANDLE*)&(me -> handle),
385 DUPLICATE_SAME_ACCESS)) {
386 DWORD last_error = GetLastError();
387 GC_err_printf("Last error code: %d\n", last_error);
388 ABORT("DuplicateHandle failed");
390 me -> stack_base = sb -> mem_base;
391 /* Up until this point, GC_push_all_stacks considers this thread */
393 /* Up until this point, this entry is viewed as reserved but invalid */
394 /* by GC_delete_thread. */
395 me -> id = thread_id;
396 # if defined(THREAD_LOCAL_ALLOC)
397 GC_init_thread_local((GC_tlfs)(&(me->tlfs)));
399 if (me -> stack_base == NULL)
400 ABORT("Bad stack base in GC_register_my_thread_inner");
401 if (GC_win32_dll_threads) {
402 if (GC_please_stop) {
403 AO_store(&GC_attached_thread, TRUE);
404 AO_nop_full(); // Later updates must become visible after this.
406 /* We'd like to wait here, but can't, since waiting in DllMain */
407 /* provokes deadlocks. */
408 /* Thus we force marking to be restarted instead. */
410 GC_ASSERT(!GC_please_stop);
411 /* Otherwise both we and the thread stopping code would be */
412 /* holding the allocation lock. */
414 return (GC_thread)(me);
418 * GC_max_thread_index may temporarily be larger than MAX_THREADS.
419 * To avoid subscript errors, we check on access.
424 LONG GC_get_max_thread_index()
426 LONG my_max = GC_max_thread_index;
428 if (my_max >= MAX_THREADS) return MAX_THREADS-1;
432 /* Return the GC_thread corresponding to a thread id. May be called */
433 /* without a lock, but should be called in contexts in which the */
434 /* requested thread cannot be asynchronously deleted, e.g. from the */
436 /* This version assumes that either GC_win32_dll_threads is set, or */
437 /* we hold the allocator lock. */
438 /* Also used (for assertion checking only) from thread_local_alloc.c. */
439 GC_thread GC_lookup_thread_inner(DWORD thread_id) {
440 if (GC_win32_dll_threads) {
442 LONG my_max = GC_get_max_thread_index();
445 (!AO_load_acquire(&(dll_thread_table[i].in_use))
446 || dll_thread_table[i].id != thread_id);
447 /* Must still be in_use, since nobody else can store our thread_id. */
452 return (GC_thread)(dll_thread_table + i);
455 word hv = ((word)thread_id) % THREAD_TABLE_SZ;
456 register GC_thread p = GC_threads[hv];
458 GC_ASSERT(I_HOLD_LOCK());
459 while (p != 0 && p -> id != thread_id) p = p -> next;
464 /* A version of the above that acquires the lock if necessary. Note */
465 /* that the identically named function for pthreads is different, and */
466 /* just assumes we hold the lock. */
467 /* Also used (for assertion checking only) from thread_local_alloc.c. */
468 static GC_thread GC_lookup_thread(DWORD thread_id)
470 if (GC_win32_dll_threads) {
471 return GC_lookup_thread_inner(thread_id);
475 result = GC_lookup_thread_inner(thread_id);
481 /* If a thread has been joined, but we have not yet */
482 /* been notified, then there may be more than one thread */
483 /* in the table with the same win32 id. */
484 /* This is OK, but we need a way to delete a specific one. */
485 /* Assumes we hold the allocation lock unless */
486 /* GC_win32_dll_threads is set. */
487 /* If GC_win32_dll_threads is set it should be called from the */
488 /* thread being deleted. */
489 void GC_delete_gc_thread(GC_vthread gc_id)
491 CloseHandle(gc_id->handle);
492 if (GC_win32_dll_threads) {
493 /* This is intended to be lock-free. */
494 /* It is either called synchronously from the thread being deleted, */
495 /* or by the joining thread. */
496 /* In this branch asynchronosu changes to *gc_id are possible. */
497 gc_id -> stack_base = 0;
500 gc_id -> pthread_id = 0;
501 # endif /* CYGWIN32 */
502 # ifdef GC_WIN32_PTHREADS
503 gc_id -> pthread_id.p = NULL;
504 # endif /* GC_WIN32_PTHREADS */
505 AO_store_release(&(gc_id->in_use), FALSE);
507 /* Cast away volatile qualifier, since we have lock. */
508 GC_thread gc_nvid = (GC_thread)gc_id;
509 DWORD id = gc_nvid -> id;
510 word hv = ((word)id) % THREAD_TABLE_SZ;
511 register GC_thread p = GC_threads[hv];
512 register GC_thread prev = 0;
514 GC_ASSERT(I_HOLD_LOCK());
515 while (p != gc_nvid) {
520 GC_threads[hv] = p -> next;
522 prev -> next = p -> next;
528 /* Delete a thread from GC_threads. We assume it is there. */
529 /* (The code intentionally traps if it wasn't.) */
530 /* Assumes we hold the allocation lock unless */
531 /* GC_win32_dll_threads is set. */
532 /* If GC_win32_dll_threads is set it should be called from the */
533 /* thread being deleted. */
534 void GC_delete_thread(DWORD id)
536 if (GC_win32_dll_threads) {
537 GC_thread t = GC_lookup_thread_inner(id);
540 WARN("Removing nonexistent thread %ld\n", (GC_word)id);
542 GC_delete_gc_thread(t);
545 word hv = ((word)id) % THREAD_TABLE_SZ;
546 register GC_thread p = GC_threads[hv];
547 register GC_thread prev = 0;
549 GC_ASSERT(I_HOLD_LOCK());
550 while (p -> id != id) {
554 CloseHandle(p->handle);
556 GC_threads[hv] = p -> next;
558 prev -> next = p -> next;
564 GC_API int GC_register_my_thread(struct GC_stack_base *sb) {
565 DWORD t = GetCurrentThreadId();
567 if (0 == GC_lookup_thread(t)) {
568 /* We lock here, since we want to wait for an ongoing GC. */
570 GC_register_my_thread_inner(sb, t);
578 GC_API int GC_unregister_my_thread(void)
580 DWORD t = GetCurrentThreadId();
582 # if defined(THREAD_LOCAL_ALLOC)
585 GC_thread me = GC_lookup_thread_inner(t);
586 GC_destroy_thread_local(&(me->tlfs));
590 if (GC_win32_dll_threads) {
591 /* Should we just ignore this? */
604 /* A quick-and-dirty cache of the mapping between pthread_t */
605 /* and win32 thread id. */
606 #define PTHREAD_MAP_SIZE 512
607 DWORD GC_pthread_map_cache[PTHREAD_MAP_SIZE];
608 #define HASH(pthread_id) ((NUMERIC_THREAD_ID(pthread_id) >> 5) % PTHREAD_MAP_SIZE)
609 /* It appears pthread_t is really a pointer type ... */
610 #define SET_PTHREAD_MAP_CACHE(pthread_id, win32_id) \
611 GC_pthread_map_cache[HASH(pthread_id)] = (win32_id);
612 #define GET_PTHREAD_MAP_CACHE(pthread_id) \
613 GC_pthread_map_cache[HASH(pthread_id)]
615 /* Return a GC_thread corresponding to a given pthread_t. */
616 /* Returns 0 if it's not there. */
617 /* We assume that this is only called for pthread ids that */
618 /* have not yet terminated or are still joinable, and */
619 /* cannot be concurrently terminated. */
620 /* Assumes we do NOT hold the allocation lock. */
621 static GC_thread GC_lookup_pthread(pthread_t id)
623 if (GC_win32_dll_threads) {
625 LONG my_max = GC_get_max_thread_index();
629 (!AO_load_acquire(&(dll_thread_table[i].in_use))
630 || THREAD_EQUAL(dll_thread_table[i].pthread_id, id));
631 /* Must still be in_use, since nobody else can store our thread_id. */
633 if (i > my_max) return 0;
634 return (GC_thread)(dll_thread_table + i);
636 /* We first try the cache. If that fails, we use a very slow */
638 int hv_guess = GET_PTHREAD_MAP_CACHE(id) % THREAD_TABLE_SZ;
643 for (p = GC_threads[hv_guess]; 0 != p; p = p -> next) {
644 if (THREAD_EQUAL(p -> pthread_id, id))
647 for (hv = 0; hv < THREAD_TABLE_SZ; ++hv) {
648 for (p = GC_threads[hv]; 0 != p; p = p -> next) {
649 if (THREAD_EQUAL(p -> pthread_id, id))
660 #endif /* GC_PTHREADS */
662 void GC_push_thread_structures(void)
664 GC_ASSERT(I_HOLD_LOCK());
665 if (GC_win32_dll_threads) {
666 /* Unlike the other threads implementations, the thread table here */
667 /* contains no pointers to the collectable heap. Thus we have */
668 /* no private structures we need to preserve. */
670 { int i; /* pthreads may keep a pointer in the thread exit value */
671 LONG my_max = GC_get_max_thread_index();
673 for (i = 0; i <= my_max; i++)
674 if (dll_thread_table[i].in_use)
675 GC_push_all((ptr_t)&(dll_thread_table[i].status),
676 (ptr_t)(&(dll_thread_table[i].status)+1));
680 GC_push_all((ptr_t)(GC_threads), (ptr_t)(GC_threads)+sizeof(GC_threads));
682 # if defined(THREAD_LOCAL_ALLOC)
683 GC_push_all((ptr_t)(&GC_thread_key),
684 (ptr_t)(&GC_thread_key)+sizeof(&GC_thread_key));
685 /* Just in case we ever use our own TLS implementation. */
689 /* Suspend the given thread, if it's still active. */
690 void GC_suspend(GC_thread t)
693 /* SuspendThread will fail if thread is running kernel code */
694 while (SuspendThread(t -> handle) == (DWORD)-1)
697 /* Apparently the Windows 95 GetOpenFileName call creates */
698 /* a thread that does not properly get cleaned up, and */
699 /* SuspendThread on its descriptor may provoke a crash. */
700 /* This reduces the probability of that event, though it still */
701 /* appears there's a race here. */
703 if (GetExitCodeThread(t -> handle, &exitCode) &&
704 exitCode != STILL_ACTIVE) {
705 t -> stack_base = 0; /* prevent stack from being pushed */
707 /* this breaks pthread_join on Cygwin, which is guaranteed to */
708 /* only see user pthreads */
709 GC_ASSERT(GC_win32_dll_threads);
710 GC_delete_gc_thread(t);
714 if (SuspendThread(t -> handle) == (DWORD)-1)
715 ABORT("SuspendThread failed");
717 t -> suspended = TRUE;
720 /* Defined in misc.c */
722 extern CRITICAL_SECTION GC_write_cs;
725 void GC_stop_world(void)
727 DWORD thread_id = GetCurrentThreadId();
730 if (!GC_thr_initialized) ABORT("GC_stop_world() called before GC_thr_init()");
731 GC_ASSERT(I_HOLD_LOCK());
733 GC_please_stop = TRUE;
735 EnterCriticalSection(&GC_write_cs);
737 if (GC_win32_dll_threads) {
738 /* Any threads being created during this loop will end up setting */
739 /* GC_attached_thread when they start. This will force marking to */
741 /* This is not ideal, but hopefully correct. */
742 GC_attached_thread = FALSE;
743 for (i = 0; i <= GC_get_max_thread_index(); i++) {
744 GC_vthread t = dll_thread_table + i;
745 if (t -> stack_base != 0
746 && t -> id != thread_id) {
747 GC_suspend((GC_thread)t);
754 for (i = 0; i < THREAD_TABLE_SZ; i++) {
755 for (t = GC_threads[i]; t != 0; t = t -> next) {
756 if (t -> stack_base != 0
757 && !KNOWN_FINISHED(t)
758 && t -> id != thread_id) {
765 LeaveCriticalSection(&GC_write_cs);
769 void GC_start_world(void)
771 DWORD thread_id = GetCurrentThreadId();
773 LONG my_max = GC_get_max_thread_index();
775 GC_ASSERT(I_HOLD_LOCK());
776 if (GC_win32_dll_threads) {
777 for (i = 0; i <= my_max; i++) {
778 GC_thread t = (GC_thread)(dll_thread_table + i);
779 if (t -> stack_base != 0 && t -> suspended
780 && t -> id != thread_id) {
781 if (ResumeThread(t -> handle) == (DWORD)-1)
782 ABORT("ResumeThread failed");
783 t -> suspended = FALSE;
790 for (i = 0; i < THREAD_TABLE_SZ; i++) {
791 for (t = GC_threads[i]; t != 0; t = t -> next) {
792 if (t -> stack_base != 0 && t -> suspended
793 && t -> id != thread_id) {
794 if (ResumeThread(t -> handle) == (DWORD)-1)
795 ABORT("ResumeThread failed");
796 t -> suspended = FALSE;
801 GC_please_stop = FALSE;
805 /* The VirtualQuery calls below won't work properly on WinCE, but */
806 /* since each stack is restricted to an aligned 64K region of */
807 /* virtual memory we can just take the next lowest multiple of 64K. */
808 # define GC_get_stack_min(s) \
809 ((ptr_t)(((DWORD)(s) - 1) & 0xFFFF0000))
811 static ptr_t GC_get_stack_min(ptr_t s)
814 MEMORY_BASIC_INFORMATION info;
815 VirtualQuery(s, &info, sizeof(info));
817 bottom = info.BaseAddress;
818 VirtualQuery(bottom - 1, &info, sizeof(info));
819 } while ((info.Protect & PAGE_READWRITE)
820 && !(info.Protect & PAGE_GUARD));
825 void GC_push_stack_for(GC_thread thread)
829 DWORD me = GetCurrentThreadId();
831 if (thread -> stack_base) {
832 if (thread -> id == me) {
836 context.ContextFlags = CONTEXT_INTEGER|CONTEXT_CONTROL;
837 if (!GetThreadContext(thread -> handle, &context))
838 ABORT("GetThreadContext failed");
840 /* Push all registers that might point into the heap. Frame */
841 /* pointer registers are included in case client code was */
842 /* compiled with the 'omit frame pointer' optimisation. */
843 # define PUSH1(reg) GC_push_one((word)context.reg)
844 # define PUSH2(r1,r2) PUSH1(r1), PUSH1(r2)
845 # define PUSH4(r1,r2,r3,r4) PUSH2(r1,r2), PUSH2(r3,r4)
847 PUSH4(Edi,Esi,Ebx,Edx), PUSH2(Ecx,Eax), PUSH1(Ebp);
848 sp = (ptr_t)context.Esp;
849 # elif defined(X86_64)
850 PUSH4(Rax,Rcx,Rdx,Rbx); PUSH2(Rbp, Rsi); PUSH1(Rdi);
851 PUSH4(R8, R9, R10, R11); PUSH4(R12, R13, R14, R15);
852 sp = (ptr_t)context.Rsp;
853 # elif defined(ARM32)
854 PUSH4(R0,R1,R2,R3),PUSH4(R4,R5,R6,R7),PUSH4(R8,R9,R10,R11),PUSH1(R12);
855 sp = (ptr_t)context.Sp;
857 PUSH4(R0,R1,R2,R3), PUSH4(R4,R5,R6,R7), PUSH4(R8,R9,R10,R11);
858 PUSH2(R12,R13), PUSH1(R14);
859 sp = (ptr_t)context.R15;
861 PUSH4(IntAt,IntV0,IntV1,IntA0), PUSH4(IntA1,IntA2,IntA3,IntT0);
862 PUSH4(IntT1,IntT2,IntT3,IntT4), PUSH4(IntT5,IntT6,IntT7,IntS0);
863 PUSH4(IntS1,IntS2,IntS3,IntS4), PUSH4(IntS5,IntS6,IntS7,IntT8);
864 PUSH4(IntT9,IntK0,IntK1,IntS8);
865 sp = (ptr_t)context.IntSp;
867 PUSH4(Gpr0, Gpr3, Gpr4, Gpr5), PUSH4(Gpr6, Gpr7, Gpr8, Gpr9);
868 PUSH4(Gpr10,Gpr11,Gpr12,Gpr14), PUSH4(Gpr15,Gpr16,Gpr17,Gpr18);
869 PUSH4(Gpr19,Gpr20,Gpr21,Gpr22), PUSH4(Gpr23,Gpr24,Gpr25,Gpr26);
870 PUSH4(Gpr27,Gpr28,Gpr29,Gpr30), PUSH1(Gpr31);
871 sp = (ptr_t)context.Gpr1;
872 # elif defined(ALPHA)
873 PUSH4(IntV0,IntT0,IntT1,IntT2), PUSH4(IntT3,IntT4,IntT5,IntT6);
874 PUSH4(IntT7,IntS0,IntS1,IntS2), PUSH4(IntS3,IntS4,IntS5,IntFp);
875 PUSH4(IntA0,IntA1,IntA2,IntA3), PUSH4(IntA4,IntA5,IntT8,IntT9);
876 PUSH4(IntT10,IntT11,IntT12,IntAt);
877 sp = (ptr_t)context.IntSp;
879 # error "architecture is not supported"
881 } /* ! current thread */
883 stack_min = GC_get_stack_min(thread->stack_base);
885 if (sp >= stack_min && sp < thread->stack_base) {
886 # if DEBUG_WIN32_PTHREADS || DEBUG_WIN32_THREADS \
887 || DEBUG_CYGWIN_THREADS
888 GC_printf("Pushing thread from %p to %p for 0x%x from 0x%x\n",
889 sp, thread -> stack_base, thread -> id, me);
891 GC_push_all_stack(sp, thread->stack_base);
893 WARN("Thread stack pointer 0x%lx out of range, pushing everything\n",
894 (unsigned long)(size_t)sp);
895 GC_push_all_stack(stack_min, thread->stack_base);
897 } /* thread looks live */
900 void GC_push_all_stacks(void)
902 DWORD me = GetCurrentThreadId();
903 GC_bool found_me = FALSE;
906 if (GC_win32_dll_threads) {
908 LONG my_max = GC_get_max_thread_index();
910 for (i = 0; i <= my_max; i++) {
911 GC_thread t = (GC_thread)(dll_thread_table + i);
914 GC_push_stack_for(t);
915 if (t -> id == me) found_me = TRUE;
922 for (i = 0; i < THREAD_TABLE_SZ; i++) {
923 for (t = GC_threads[i]; t != 0; t = t -> next) {
925 if (!KNOWN_FINISHED(t)) GC_push_stack_for(t);
926 if (t -> id == me) found_me = TRUE;
930 if (GC_print_stats == VERBOSE) {
931 GC_log_printf("Pushed %d thread stacks ", nthreads);
932 if (GC_win32_dll_threads) {
933 GC_log_printf("based on DllMain thread tracking\n");
938 if (!found_me && !GC_in_thread_creation)
939 ABORT("Collecting from unknown thread.");
942 void GC_get_next_stack(char *start, char **lo, char **hi)
945 # define ADDR_LIMIT (char *)(-1L)
946 char * current_min = ADDR_LIMIT;
948 if (GC_win32_dll_threads) {
949 LONG my_max = GC_get_max_thread_index();
951 for (i = 0; i <= my_max; i++) {
952 ptr_t s = (ptr_t)(dll_thread_table[i].stack_base);
954 if (0 != s && s > start && s < current_min) {
959 for (i = 0; i < THREAD_TABLE_SZ; i++) {
962 for (t = GC_threads[i]; t != 0; t = t -> next) {
963 ptr_t s = (ptr_t)(t -> stack_base);
965 if (0 != s && s > start && s < current_min) {
972 if (current_min == ADDR_LIMIT) {
976 *lo = GC_get_stack_min(current_min);
977 if (*lo < start) *lo = start;
982 /* We have no DllMain to take care of new threads. Thus we */
983 /* must properly intercept thread creation. */
986 LPTHREAD_START_ROUTINE start;
990 static DWORD WINAPI thread_start(LPVOID arg);
992 void * GC_win32_start_inner(struct GC_stack_base *sb, LPVOID arg)
995 thread_args *args = (thread_args *)arg;
997 # if DEBUG_WIN32_THREADS
998 GC_printf("thread 0x%x starting...\n", GetCurrentThreadId());
1001 GC_register_my_thread(sb); /* This waits for an in-progress GC. */
1003 /* Clear the thread entry even if we exit with an exception. */
1004 /* This is probably pointless, since an uncaught exception is */
1005 /* supposed to result in the process being killed. */
1008 #endif /* __GNUC__ */
1009 ret = (void *)(size_t)args->start (args->param);
1012 #endif /* __GNUC__ */
1013 GC_unregister_my_thread();
1017 #endif /* __GNUC__ */
1019 # if DEBUG_WIN32_THREADS
1020 GC_printf("thread 0x%x returned from start routine.\n",
1021 GetCurrentThreadId());
1026 DWORD WINAPI GC_win32_start(LPVOID arg)
1028 return (DWORD)(size_t)GC_call_with_stack_base(GC_win32_start_inner, arg);
1031 GC_API HANDLE WINAPI GC_CreateThread(
1032 LPSECURITY_ATTRIBUTES lpThreadAttributes,
1033 DWORD dwStackSize, LPTHREAD_START_ROUTINE lpStartAddress,
1034 LPVOID lpParameter, DWORD dwCreationFlags, LPDWORD lpThreadId )
1036 HANDLE thread_h = NULL;
1040 if (!parallel_initialized) GC_init_parallel();
1041 /* make sure GC is initialized (i.e. main thread is attached,
1044 # if DEBUG_WIN32_THREADS
1045 GC_printf("About to create a thread from 0x%x\n", GetCurrentThreadId());
1047 if (GC_win32_dll_threads) {
1048 return CreateThread(lpThreadAttributes, dwStackSize, lpStartAddress,
1049 lpParameter, dwCreationFlags, lpThreadId);
1051 args = GC_malloc_uncollectable(sizeof(thread_args));
1052 /* Handed off to and deallocated by child thread. */
1054 SetLastError(ERROR_NOT_ENOUGH_MEMORY);
1058 /* set up thread arguments */
1059 args -> start = lpStartAddress;
1060 args -> param = lpParameter;
1062 GC_need_to_lock = TRUE;
1063 thread_h = CreateThread(lpThreadAttributes,
1064 dwStackSize, GC_win32_start,
1065 args, dwCreationFlags,
1067 if( thread_h == 0 ) GC_free( args );
1072 void WINAPI GC_ExitThread(DWORD dwExitCode)
1074 GC_unregister_my_thread();
1075 ExitThread(dwExitCode);
1078 uintptr_t GC_beginthreadex(
1079 void *security, unsigned stack_size,
1080 unsigned ( __stdcall *start_address )( void * ),
1081 void *arglist, unsigned initflag, unsigned *thrdaddr)
1087 if (!parallel_initialized) GC_init_parallel();
1088 /* make sure GC is initialized (i.e. main thread is attached,
1090 # if DEBUG_WIN32_THREADS
1091 GC_printf("About to create a thread from 0x%x\n", GetCurrentThreadId());
1094 if (GC_win32_dll_threads) {
1095 return _beginthreadex(security, stack_size, start_address,
1096 arglist, initflag, thrdaddr);
1098 args = GC_malloc_uncollectable(sizeof(thread_args));
1099 /* Handed off to and deallocated by child thread. */
1101 SetLastError(ERROR_NOT_ENOUGH_MEMORY);
1102 return (uintptr_t)(-1L);
1105 /* set up thread arguments */
1106 args -> start = (LPTHREAD_START_ROUTINE)start_address;
1107 args -> param = arglist;
1109 GC_need_to_lock = TRUE;
1110 thread_h = _beginthreadex(security, stack_size,
1111 (unsigned (__stdcall *) (void *))GC_win32_start,
1112 args, initflag, thrdaddr);
1113 if( thread_h == 0 ) GC_free( args );
1118 void GC_endthreadex(unsigned retval)
1120 GC_unregister_my_thread();
1121 _endthreadex(retval);
1124 #endif /* !GC_PTHREADS */
1129 HINSTANCE hInstance;
1130 HINSTANCE hPrevInstance;
1135 DWORD WINAPI main_thread_start(LPVOID arg);
1137 int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance,
1138 LPWSTR lpCmdLine, int nShowCmd)
1140 DWORD exit_code = 1;
1142 main_thread_args args = {
1143 hInstance, hPrevInstance, lpCmdLine, nShowCmd
1148 /* initialize everything */
1151 /* start the main thread */
1152 thread_h = GC_CreateThread(
1153 NULL, 0, main_thread_start, &args, 0, &thread_id);
1155 if (thread_h != NULL)
1157 WaitForSingleObject (thread_h, INFINITE);
1158 GetExitCodeThread (thread_h, &exit_code);
1159 CloseHandle (thread_h);
1163 DeleteCriticalSection(&GC_allocate_ml);
1165 return (int) exit_code;
1168 DWORD WINAPI main_thread_start(LPVOID arg)
1170 main_thread_args * args = (main_thread_args *) arg;
1172 return (DWORD) GC_WinMain (args->hInstance, args->hPrevInstance,
1173 args->lpCmdLine, args->nShowCmd);
1176 # else /* !MSWINCE */
1178 /* Called by GC_init() - we hold the allocation lock. */
1179 void GC_thr_init(void) {
1180 struct GC_stack_base sb;
1183 GC_ASSERT(I_HOLD_LOCK());
1184 if (GC_thr_initialized) return;
1185 GC_main_thread = GetCurrentThreadId();
1186 GC_thr_initialized = TRUE;
1188 /* Add the initial thread, so we can stop it. */
1189 sb_result = GC_get_stack_base(&sb);
1190 GC_ASSERT(sb_result == GC_SUCCESS);
1191 GC_register_my_thread(&sb);
1197 void *(*start_routine)(void *);
1202 int GC_pthread_join(pthread_t pthread_id, void **retval) {
1207 # if DEBUG_CYGWIN_THREADS
1208 GC_printf("thread 0x%x(0x%x) is joining thread 0x%x.\n",
1209 (int)pthread_self(), GetCurrentThreadId(), (int)pthread_id);
1211 # if DEBUG_WIN32_PTHREADS
1212 GC_printf("thread 0x%x(0x%x) is joining thread 0x%x.\n",
1213 (int)(pthread_self()).p, GetCurrentThreadId(), pthread_id.p);
1216 if (!parallel_initialized) GC_init_parallel();
1217 /* Thread being joined might not have registered itself yet. */
1218 /* After the join,thread id may have been recycled. */
1219 /* FIXME: It would be better if this worked more like */
1220 /* pthread_support.c. */
1222 #ifndef GC_WIN32_PTHREADS
1223 while ((joinee = GC_lookup_pthread(pthread_id)) == 0) Sleep(10);
1226 result = pthread_join(pthread_id, retval);
1228 #ifdef GC_WIN32_PTHREADS
1229 /* win32_pthreads id are unique */
1230 joinee = GC_lookup_pthread(pthread_id);
1233 if (!GC_win32_dll_threads) {
1235 GC_delete_gc_thread(joinee);
1237 } /* otherwise dllmain handles it. */
1239 # if DEBUG_CYGWIN_THREADS
1240 GC_printf("thread 0x%x(0x%x) completed join with thread 0x%x.\n",
1241 (int)pthread_self(), GetCurrentThreadId(), (int)pthread_id);
1243 # if DEBUG_WIN32_PTHREADS
1244 GC_printf("thread 0x%x(0x%x) completed join with thread 0x%x.\n",
1245 (int)(pthread_self()).p, GetCurrentThreadId(), pthread_id.p);
1251 /* Cygwin-pthreads calls CreateThread internally, but it's not
1252 * easily interceptible by us..
1253 * so intercept pthread_create instead
1256 GC_pthread_create(pthread_t *new_thread,
1257 const pthread_attr_t *attr,
1258 void *(*start_routine)(void *), void *arg) {
1260 struct start_info * si;
1262 if (!parallel_initialized) GC_init_parallel();
1263 /* make sure GC is initialized (i.e. main thread is attached) */
1264 if (GC_win32_dll_threads) {
1265 return pthread_create(new_thread, attr, start_routine, arg);
1268 /* This is otherwise saved only in an area mmapped by the thread */
1269 /* library, which isn't visible to the collector. */
1270 si = GC_malloc_uncollectable(sizeof(struct start_info));
1271 if (0 == si) return(EAGAIN);
1273 si -> start_routine = start_routine;
1276 pthread_attr_getdetachstate(attr, &si->detached)
1277 == PTHREAD_CREATE_DETACHED) {
1278 si->detached = TRUE;
1281 # if DEBUG_CYGWIN_THREADS
1282 GC_printf("About to create a thread from 0x%x(0x%x)\n",
1283 (int)pthread_self(), GetCurrentThreadId);
1285 # if DEBUG_WIN32_PTHREADS
1286 GC_printf("About to create a thread from 0x%x(0x%x)\n",
1287 (int)(pthread_self()).p, GetCurrentThreadId());
1289 GC_need_to_lock = TRUE;
1290 result = pthread_create(new_thread, attr, GC_pthread_start, si);
1292 if (result) { /* failure */
1299 void * GC_pthread_start_inner(struct GC_stack_base *sb, void * arg)
1301 struct start_info * si = arg;
1303 void *(*start)(void *);
1305 DWORD thread_id = GetCurrentThreadId();
1306 pthread_t pthread_id = pthread_self();
1311 # if DEBUG_CYGWIN_THREADS
1312 GC_printf("thread 0x%x(0x%x) starting...\n",(int)pthread_id,
1315 # if DEBUG_WIN32_PTHREADS
1316 GC_printf("thread 0x%x(0x%x) starting...\n",(int) pthread_id.p,
1320 GC_ASSERT(!GC_win32_dll_threads);
1321 /* If a GC occurs before the thread is registered, that GC will */
1322 /* ignore this thread. That's fine, since it will block trying to */
1323 /* acquire the allocation lock, and won't yet hold interesting */
1326 /* We register the thread here instead of in the parent, so that */
1327 /* we don't need to hold the allocation lock during pthread_create. */
1328 me = GC_register_my_thread_inner(sb, thread_id);
1329 SET_PTHREAD_MAP_CACHE(pthread_id, thread_id);
1332 start = si -> start_routine;
1333 start_arg = si -> arg;
1334 if (si-> detached) me -> flags |= DETACHED;
1335 me -> pthread_id = pthread_id;
1337 GC_free(si); /* was allocated uncollectable */
1339 pthread_cleanup_push(GC_thread_exit_proc, (void *)me);
1340 result = (*start)(start_arg);
1341 me -> status = result;
1342 pthread_cleanup_pop(1);
1344 # if DEBUG_CYGWIN_THREADS
1345 GC_printf("thread 0x%x(0x%x) returned from start routine.\n",
1346 (int)pthread_self(),GetCurrentThreadId());
1348 # if DEBUG_WIN32_PTHREADS
1349 GC_printf("thread 0x%x(0x%x) returned from start routine.\n",
1350 (int)(pthread_self()).p, GetCurrentThreadId());
1356 void * GC_pthread_start(void * arg)
1358 return GC_call_with_stack_base(GC_pthread_start_inner, arg);
1361 void GC_thread_exit_proc(void *arg)
1363 GC_thread me = (GC_thread)arg;
1366 GC_ASSERT(!GC_win32_dll_threads);
1367 # if DEBUG_CYGWIN_THREADS
1368 GC_printf("thread 0x%x(0x%x) called pthread_exit().\n",
1369 (int)pthread_self(),GetCurrentThreadId());
1371 # if DEBUG_WIN32_PTHREADS
1372 GC_printf("thread 0x%x(0x%x) called pthread_exit().\n",
1373 (int)(pthread_self()).p,GetCurrentThreadId());
1377 # if defined(THREAD_LOCAL_ALLOC)
1378 GC_destroy_thread_local(&(me->tlfs));
1380 if (me -> flags & DETACHED) {
1381 GC_delete_thread(GetCurrentThreadId());
1383 /* deallocate it as part of join */
1384 me -> flags |= FINISHED;
1389 #ifndef GC_WIN32_PTHREADS
1390 /* win32 pthread does not support sigmask */
1391 /* nothing required here... */
1392 int GC_pthread_sigmask(int how, const sigset_t *set, sigset_t *oset) {
1393 if (!parallel_initialized) GC_init_parallel();
1394 return pthread_sigmask(how, set, oset);
1398 int GC_pthread_detach(pthread_t thread)
1401 GC_thread thread_gc_id;
1403 if (!parallel_initialized) GC_init_parallel();
1405 thread_gc_id = GC_lookup_pthread(thread);
1407 result = pthread_detach(thread);
1410 thread_gc_id -> flags |= DETACHED;
1411 /* Here the pthread thread id may have been recycled. */
1412 if (thread_gc_id -> flags & FINISHED) {
1413 GC_delete_gc_thread(thread_gc_id);
1420 #else /* !GC_PTHREADS */
1423 * We avoid acquiring locks here, since this doesn't seem to be preemptable.
1424 * This may run with an uninitialized collector, in which case we don't do much.
1425 * This implies that no threads other than the main one should be created
1426 * with an uninitialized collector. (The alternative of initializing
1427 * the collector here seems dangerous, since DllMain is limited in what it
1431 GC_API BOOL WINAPI DllMain(HINSTANCE inst, ULONG reason, LPVOID reserved)
1433 struct GC_stack_base sb;
1436 static int entry_count = 0;
1438 if (parallel_initialized && !GC_win32_dll_threads) return TRUE;
1441 case DLL_THREAD_ATTACH:
1442 GC_ASSERT(entry_count == 0 || parallel_initialized);
1443 ++entry_count; /* and fall through: */
1444 case DLL_PROCESS_ATTACH:
1445 /* This may run with the collector uninitialized. */
1446 thread_id = GetCurrentThreadId();
1447 if (parallel_initialized && GC_main_thread != thread_id) {
1448 /* Don't lock here. */
1449 sb_result = GC_get_stack_base(&sb);
1450 GC_ASSERT(sb_result == GC_SUCCESS);
1451 # ifdef THREAD_LOCAL_ALLOC
1452 ABORT("Cannot initialize thread local cache from DllMain");
1454 GC_register_my_thread_inner(&sb, thread_id);
1455 } /* o.w. we already did it during GC_thr_init(), called by GC_init() */
1458 case DLL_THREAD_DETACH:
1459 /* We are hopefully running in the context of the exiting thread. */
1460 GC_ASSERT(parallel_initialized);
1461 if (!GC_win32_dll_threads) return TRUE;
1462 GC_delete_thread(GetCurrentThreadId());
1465 case DLL_PROCESS_DETACH:
1469 if (!GC_win32_dll_threads) return TRUE;
1470 for (i = 0; i <= GC_get_max_thread_index(); ++i)
1472 if (AO_load(&(dll_thread_table[i].in_use)))
1473 GC_delete_gc_thread(dll_thread_table + i);
1477 DeleteCriticalSection(&GC_allocate_ml);
1485 #endif /* !GC_PTHREADS */
1487 # endif /* !MSWINCE */
1489 /* Perform all initializations, including those that */
1490 /* may require allocation. */
1491 /* Called without allocation lock. */
1492 /* Must be called before a second thread is created. */
1493 void GC_init_parallel(void)
1495 if (parallel_initialized) return;
1496 parallel_initialized = TRUE;
1497 /* GC_init() calls us back, so set flag first. */
1499 if (!GC_is_initialized) GC_init();
1500 if (GC_win32_dll_threads) {
1501 GC_need_to_lock = TRUE;
1502 /* Cannot intercept thread creation. Hence we don't know if */
1503 /* other threads exist. However, client is not allowed to */
1504 /* create other threads before collector initialization. */
1505 /* Thus it's OK not to lock before this. */
1507 /* Initialize thread local free lists if used. */
1508 # if defined(THREAD_LOCAL_ALLOC)
1510 GC_init_thread_local(&(GC_lookup_thread(GetCurrentThreadId())->tlfs));
1515 #if defined(USE_PTHREAD_LOCKS)
1516 /* Support for pthread locking code. */
1517 /* Pthread_mutex_try_lock may not win here, */
1518 /* due to builtinsupport for spinning first? */
1520 volatile GC_bool GC_collecting = 0;
1521 /* A hint that we're in the collector and */
1522 /* holding the allocation lock for an */
1523 /* extended period. */
1527 pthread_mutex_lock(&GC_allocate_ml);
1529 #endif /* USE_PTHREAD ... */
1531 # if defined(THREAD_LOCAL_ALLOC)
1533 /* Add thread-local allocation support. Microsoft uses __declspec(thread) */
1535 /* We must explicitly mark ptrfree and gcj free lists, since the free */
1536 /* list links wouldn't otherwise be found. We also set them in the */
1537 /* normal free lists, since that involves touching less memory than if */
1538 /* we scanned them normally. */
1539 void GC_mark_thread_local_free_lists(void)
1544 for (i = 0; i < THREAD_TABLE_SZ; ++i) {
1545 for (p = GC_threads[i]; 0 != p; p = p -> next) {
1546 GC_mark_thread_local_fls_for(&(p->tlfs));
1551 #if defined(GC_ASSERTIONS)
1552 /* Check that all thread-local free-lists are completely marked. */
1553 /* also check that thread-specific-data structures are marked. */
1554 void GC_check_tls(void) {
1558 for (i = 0; i < THREAD_TABLE_SZ; ++i) {
1559 for (p = GC_threads[i]; 0 != p; p = p -> next) {
1560 GC_check_tls_for(&(p->tlfs));
1563 # if defined(USE_CUSTOM_SPECIFIC)
1564 if (GC_thread_key != 0)
1565 GC_check_tsd_marks(GC_thread_key);
1568 #endif /* GC_ASSERTIONS */
1570 #endif /* THREAD_LOCAL_ALLOC ... */
1572 #endif /* GC_WIN32_THREADS */