2 * Copyright (c) 1994 by Xerox Corporation. All rights reserved.
3 * Copyright (c) 1996 by Silicon Graphics. All rights reserved.
4 * Copyright (c) 1998 by Fergus Henderson. All rights reserved.
5 * Copyright (c) 2000-2001 by Hewlett-Packard Company. All rights reserved.
7 * THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED
8 * OR IMPLIED. ANY USE IS AT YOUR OWN RISK.
10 * Permission is hereby granted to use or copy this program
11 * for any purpose, provided the above notices are retained on all copies.
12 * Permission to modify the code and to distribute modified code is granted,
13 * provided the above notices are retained, and a notice that the code was
14 * modified is included with the above copyright notice.
17 * Support code for LinuxThreads, the clone()-based kernel
18 * thread package for Linux which is included in libc6.
20 * This code relies on implementation details of LinuxThreads,
21 * (i.e. properties not guaranteed by the Pthread standard),
22 * though this version now does less of that than the other Pthreads
25 * Note that there is a lot of code duplication between linux_threads.c
26 * and thread support for some of the other Posix platforms; any changes
27 * made here may need to be reflected there too.
29 /* DG/UX ix86 support <takis@xfree86.org> */
31 * Linux_threads.c now also includes some code to support HPUX and
32 * OSF1 (Compaq Tru64 Unix, really). The OSF1 support is based on Eric Benson's
35 * Eric also suggested an alternate basis for a lock implementation in
37 * + #elif defined(OSF1)
38 * + unsigned long GC_allocate_lock = 0;
39 * + msemaphore GC_allocate_semaphore;
40 * + # define GC_TRY_LOCK() \
41 * + ((msem_lock(&GC_allocate_semaphore, MSEM_IF_NOWAIT) == 0) \
42 * + ? (GC_allocate_lock = 1) \
44 * + # define GC_LOCK_TAKEN GC_allocate_lock
47 /*#define DEBUG_THREADS 1*/
48 /*#define GC_ASSERTIONS*/
50 # include "private/pthread_support.h"
52 # if defined(GC_PTHREADS) && !defined(GC_SOLARIS_THREADS) \
53 && !defined(GC_IRIX_THREADS) && !defined(GC_WIN32_THREADS) \
54 && !defined(GC_AIX_THREADS)
56 # if defined(GC_HPUX_THREADS) && !defined(USE_PTHREAD_SPECIFIC) \
57 && !defined(USE_COMPILER_TLS)
59 # define USE_PTHREAD_SPECIFIC
60 /* Empirically, as of gcc 3.3, USE_COMPILER_TLS doesn't work. */
62 # define USE_COMPILER_TLS
66 # if defined USE_HPUX_TLS
67 --> Macro replaced by USE_COMPILER_TLS
70 # if (defined(GC_DGUX386_THREADS) || defined(GC_OSF1_THREADS) || \
71 defined(GC_DARWIN_THREADS)) && !defined(USE_PTHREAD_SPECIFIC)
72 # define USE_PTHREAD_SPECIFIC
75 # if defined(GC_DGUX386_THREADS) && !defined(_POSIX4A_DRAFT10_SOURCE)
76 # define _POSIX4A_DRAFT10_SOURCE 1
79 # if defined(GC_DGUX386_THREADS) && !defined(_USING_POSIX4A_DRAFT10)
80 # define _USING_POSIX4A_DRAFT10 1
83 # ifdef THREAD_LOCAL_ALLOC
84 # if !defined(USE_PTHREAD_SPECIFIC) && !defined(USE_COMPILER_TLS)
85 # include "private/specific.h"
87 # if defined(USE_PTHREAD_SPECIFIC)
88 # define GC_getspecific pthread_getspecific
89 # define GC_setspecific pthread_setspecific
90 # define GC_key_create pthread_key_create
91 typedef pthread_key_t GC_key_t;
93 # if defined(USE_COMPILER_TLS)
94 # define GC_getspecific(x) (x)
95 # define GC_setspecific(key, v) ((key) = (v), 0)
96 # define GC_key_create(key, d) 0
97 typedef void * GC_key_t;
101 # include <pthread.h>
106 # include <sys/mman.h>
107 # include <sys/time.h>
108 # include <sys/types.h>
109 # include <sys/stat.h>
113 #if defined(GC_DARWIN_THREADS)
114 # include "private/darwin_semaphore.h"
116 # include <semaphore.h>
117 #endif /* !GC_DARWIN_THREADS */
119 #if defined(GC_DARWIN_THREADS)
120 # include <sys/sysctl.h>
121 #endif /* GC_DARWIN_THREADS */
125 #if defined(GC_DGUX386_THREADS)
126 # include <sys/dg_sys_info.h>
127 # include <sys/_int_psem.h>
128 /* sem_t is an uint in DG/UX */
129 typedef unsigned int sem_t;
130 #endif /* GC_DGUX386_THREADS */
136 #ifdef GC_USE_LD_WRAP
137 # define WRAP_FUNC(f) __wrap_##f
138 # define REAL_FUNC(f) __real_##f
140 # define WRAP_FUNC(f) GC_##f
141 # if !defined(GC_DGUX386_THREADS)
142 # define REAL_FUNC(f) f
143 # else /* GC_DGUX386_THREADS */
144 # define REAL_FUNC(f) __d10_##f
145 # endif /* GC_DGUX386_THREADS */
146 # undef pthread_create
147 # if !defined(GC_DARWIN_THREADS)
148 # undef pthread_sigmask
151 # undef pthread_detach
152 # if defined(GC_OSF1_THREADS) && defined(_PTHREAD_USE_MANGLED_NAMES_) \
153 && !defined(_PTHREAD_USE_PTDNAM_)
154 /* Restore the original mangled names on Tru64 UNIX. */
155 # define pthread_create __pthread_create
156 # define pthread_join __pthread_join
157 # define pthread_detach __pthread_detach
163 static GC_bool parallel_initialized = FALSE;
165 void GC_init_parallel();
167 # if defined(THREAD_LOCAL_ALLOC) && !defined(DBG_HDRS_ALL)
169 /* We don't really support thread-local allocation with DBG_HDRS_ALL */
171 #ifdef USE_COMPILER_TLS
174 GC_key_t GC_thread_key;
176 static GC_bool keys_initialized;
178 /* Recover the contents of the freelist array fl into the global one gfl.*/
179 /* Note that the indexing scheme differs, in that gfl has finer size */
180 /* resolution, even if not all entries are used. */
181 /* We hold the allocator lock. */
182 static void return_freelists(ptr_t *fl, ptr_t *gfl)
188 for (i = 1; i < NFREELISTS; ++i) {
189 nwords = i * (GRANULARITY/sizeof(word));
192 if ((word)q >= HBLKSIZE) {
193 if (gfl[nwords] == 0) {
197 for (; (word)q >= HBLKSIZE; qptr = &(obj_link(q)), q = *qptr);
203 /* Clear fl[i], since the thread structure may hang around. */
204 /* Do it in a way that is likely to trap if we access it. */
205 fl[i] = (ptr_t)HBLKSIZE;
209 /* We statically allocate a single "size 0" object. It is linked to */
210 /* itself, and is thus repeatedly reused for all size 0 allocation */
211 /* requests. (Size 0 gcj allocation requests are incorrect, and */
212 /* we arrange for those to fault asap.) */
213 static ptr_t size_zero_object = (ptr_t)(&size_zero_object);
215 /* Each thread structure must be initialized. */
216 /* This call must be made from the new thread. */
217 /* Caller holds allocation lock. */
218 void GC_init_thread_local(GC_thread p)
222 if (!keys_initialized) {
223 if (0 != GC_key_create(&GC_thread_key, 0)) {
224 ABORT("Failed to create key for local allocator");
226 keys_initialized = TRUE;
228 if (0 != GC_setspecific(GC_thread_key, p)) {
229 ABORT("Failed to set thread specific allocation pointers");
231 for (i = 1; i < NFREELISTS; ++i) {
232 p -> ptrfree_freelists[i] = (ptr_t)1;
233 p -> normal_freelists[i] = (ptr_t)1;
234 # ifdef GC_GCJ_SUPPORT
235 p -> gcj_freelists[i] = (ptr_t)1;
238 /* Set up the size 0 free lists. */
239 p -> ptrfree_freelists[0] = (ptr_t)(&size_zero_object);
240 p -> normal_freelists[0] = (ptr_t)(&size_zero_object);
241 # ifdef GC_GCJ_SUPPORT
242 p -> gcj_freelists[0] = (ptr_t)(-1);
246 #ifdef GC_GCJ_SUPPORT
247 extern ptr_t * GC_gcjobjfreelist;
250 /* We hold the allocator lock. */
251 void GC_destroy_thread_local(GC_thread p)
253 /* We currently only do this from the thread itself or from */
254 /* the fork handler for a child process. */
256 GC_ASSERT(GC_getspecific(GC_thread_key) == (void *)p);
258 return_freelists(p -> ptrfree_freelists, GC_aobjfreelist);
259 return_freelists(p -> normal_freelists, GC_objfreelist);
260 # ifdef GC_GCJ_SUPPORT
261 return_freelists(p -> gcj_freelists, GC_gcjobjfreelist);
265 extern GC_PTR GC_generic_malloc_many();
267 GC_PTR GC_local_malloc(size_t bytes)
269 if (EXPECT(!SMALL_ENOUGH(bytes),0)) {
270 return(GC_malloc(bytes));
272 int index = INDEX_FROM_BYTES(bytes);
275 # if defined(REDIRECT_MALLOC) && !defined(USE_PTHREAD_SPECIFIC)
276 GC_key_t k = GC_thread_key;
280 # if defined(REDIRECT_MALLOC) && !defined(USE_PTHREAD_SPECIFIC)
281 if (EXPECT(0 == k, 0)) {
282 /* This can happen if we get called when the world is */
283 /* being initialized. Whether we can actually complete */
284 /* the initialization then is unclear. */
289 tsd = GC_getspecific(GC_thread_key);
290 # ifdef GC_ASSERTIONS
292 GC_ASSERT(tsd == (void *)GC_lookup_thread(pthread_self()));
295 my_fl = ((GC_thread)tsd) -> normal_freelists + index;
297 if (EXPECT((word)my_entry >= HBLKSIZE, 1)) {
298 ptr_t next = obj_link(my_entry);
299 GC_PTR result = (GC_PTR)my_entry;
301 obj_link(my_entry) = 0;
302 PREFETCH_FOR_WRITE(next);
304 } else if ((word)my_entry - 1 < DIRECT_GRANULES) {
305 *my_fl = my_entry + index + 1;
306 return GC_malloc(bytes);
308 GC_generic_malloc_many(BYTES_FROM_INDEX(index), NORMAL, my_fl);
309 if (*my_fl == 0) return GC_oom_fn(bytes);
310 return GC_local_malloc(bytes);
315 GC_PTR GC_local_malloc_atomic(size_t bytes)
317 if (EXPECT(!SMALL_ENOUGH(bytes), 0)) {
318 return(GC_malloc_atomic(bytes));
320 int index = INDEX_FROM_BYTES(bytes);
321 ptr_t * my_fl = ((GC_thread)GC_getspecific(GC_thread_key))
322 -> ptrfree_freelists + index;
323 ptr_t my_entry = *my_fl;
325 if (EXPECT((word)my_entry >= HBLKSIZE, 1)) {
326 GC_PTR result = (GC_PTR)my_entry;
327 *my_fl = obj_link(my_entry);
329 } else if ((word)my_entry - 1 < DIRECT_GRANULES) {
330 *my_fl = my_entry + index + 1;
331 return GC_malloc_atomic(bytes);
333 GC_generic_malloc_many(BYTES_FROM_INDEX(index), PTRFREE, my_fl);
334 /* *my_fl is updated while the collector is excluded; */
335 /* the free list is always visible to the collector as */
337 if (*my_fl == 0) return GC_oom_fn(bytes);
338 return GC_local_malloc_atomic(bytes);
343 #ifdef GC_GCJ_SUPPORT
345 #include "include/gc_gcj.h"
348 extern GC_bool GC_gcj_malloc_initialized;
351 extern int GC_gcj_kind;
353 GC_PTR GC_local_gcj_malloc(size_t bytes,
354 void * ptr_to_struct_containing_descr)
356 GC_ASSERT(GC_gcj_malloc_initialized);
357 if (EXPECT(!SMALL_ENOUGH(bytes), 0)) {
358 return GC_gcj_malloc(bytes, ptr_to_struct_containing_descr);
360 int index = INDEX_FROM_BYTES(bytes);
361 ptr_t * my_fl = ((GC_thread)GC_getspecific(GC_thread_key))
362 -> gcj_freelists + index;
363 ptr_t my_entry = *my_fl;
364 if (EXPECT((word)my_entry >= HBLKSIZE, 1)) {
365 GC_PTR result = (GC_PTR)my_entry;
366 GC_ASSERT(!GC_incremental);
367 /* We assert that any concurrent marker will stop us. */
368 /* Thus it is impossible for a mark procedure to see the */
369 /* allocation of the next object, but to see this object */
370 /* still containing a free list pointer. Otherwise the */
371 /* marker might find a random "mark descriptor". */
372 *(volatile ptr_t *)my_fl = obj_link(my_entry);
373 /* We must update the freelist before we store the pointer. */
374 /* Otherwise a GC at this point would see a corrupted */
376 /* A memory barrier is probably never needed, since the */
377 /* action of stopping this thread will cause prior writes */
379 GC_ASSERT(((void * volatile *)result)[1] == 0);
380 *(void * volatile *)result = ptr_to_struct_containing_descr;
382 } else if ((word)my_entry - 1 < DIRECT_GRANULES) {
383 if (!GC_incremental) *my_fl = my_entry + index + 1;
384 /* In the incremental case, we always have to take this */
385 /* path. Thus we leave the counter alone. */
386 return GC_gcj_malloc(bytes, ptr_to_struct_containing_descr);
388 GC_generic_malloc_many(BYTES_FROM_INDEX(index), GC_gcj_kind, my_fl);
389 if (*my_fl == 0) return GC_oom_fn(bytes);
390 return GC_local_gcj_malloc(bytes, ptr_to_struct_containing_descr);
395 #endif /* GC_GCJ_SUPPORT */
397 # else /* !THREAD_LOCAL_ALLOC && !DBG_HDRS_ALL */
399 # define GC_destroy_thread_local(t)
401 # endif /* !THREAD_LOCAL_ALLOC */
405 To make sure that we're using LinuxThreads and not some other thread
406 package, we generate a dummy reference to `pthread_kill_other_threads_np'
407 (was `__pthread_initial_thread_bos' but that disappeared),
408 which is a symbol defined in LinuxThreads, but (hopefully) not in other
411 We no longer do this, since this code is now portable enough that it might
412 actually work for something else.
414 void (*dummy_var_to_force_linux_threads)() = pthread_kill_other_threads_np;
417 long GC_nprocs = 1; /* Number of processors. We may not have */
418 /* access to all of them, but this is as good */
419 /* a guess as any ... */
424 # define MAX_MARKERS 16
427 static ptr_t marker_sp[MAX_MARKERS] = {0};
429 void * GC_mark_thread(void * id)
433 marker_sp[(word)id] = GC_approx_sp();
434 for (;; ++my_mark_no) {
435 /* GC_mark_no is passed only to allow GC_help_marker to terminate */
436 /* promptly. This is important if it were called from the signal */
437 /* handler or from the GC lock acquisition code. Under Linux, it's */
438 /* not safe to call it from a signal handler, since it uses mutexes */
439 /* and condition variables. Since it is called only here, the */
440 /* argument is unnecessary. */
441 if (my_mark_no < GC_mark_no || my_mark_no > GC_mark_no + 2) {
442 /* resynchronize if we get far off, e.g. because GC_mark_no */
444 my_mark_no = GC_mark_no;
446 # ifdef DEBUG_THREADS
447 GC_printf1("Starting mark helper for mark number %ld\n", my_mark_no);
449 GC_help_marker(my_mark_no);
453 extern long GC_markers; /* Number of mark threads we would */
454 /* like to have. Includes the */
455 /* initiating thread. */
457 pthread_t GC_mark_threads[MAX_MARKERS];
459 #define PTHREAD_CREATE REAL_FUNC(pthread_create)
461 static void start_mark_threads()
466 if (GC_markers > MAX_MARKERS) {
467 WARN("Limiting number of mark threads\n", 0);
468 GC_markers = MAX_MARKERS;
470 if (0 != pthread_attr_init(&attr)) ABORT("pthread_attr_init failed");
472 if (0 != pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED))
473 ABORT("pthread_attr_setdetachstate failed");
475 # if defined(HPUX) || defined(GC_DGUX386_THREADS)
476 /* Default stack size is usually too small: fix it. */
477 /* Otherwise marker threads or GC may run out of */
479 # define MIN_STACK_SIZE (8*HBLKSIZE*sizeof(word))
484 if (pthread_attr_getstacksize(&attr, &old_size) != 0)
485 ABORT("pthread_attr_getstacksize failed\n");
486 if (old_size < MIN_STACK_SIZE) {
487 if (pthread_attr_setstacksize(&attr, MIN_STACK_SIZE) != 0)
488 ABORT("pthread_attr_setstacksize failed\n");
491 # endif /* HPUX || GC_DGUX386_THREADS */
493 if (GC_print_stats) {
494 GC_printf1("Starting %ld marker threads\n", GC_markers - 1);
497 for (i = 0; i < GC_markers - 1; ++i) {
498 if (0 != PTHREAD_CREATE(GC_mark_threads + i, &attr,
499 GC_mark_thread, (void *)(word)i)) {
500 WARN("Marker thread creation failed, errno = %ld.\n", errno);
505 #else /* !PARALLEL_MARK */
507 static __inline__ void start_mark_threads()
511 #endif /* !PARALLEL_MARK */
513 GC_bool GC_thr_initialized = FALSE;
515 volatile GC_thread GC_threads[THREAD_TABLE_SZ];
517 void GC_push_thread_structures GC_PROTO((void))
519 GC_push_all((ptr_t)(GC_threads), (ptr_t)(GC_threads)+sizeof(GC_threads));
520 # if defined(THREAD_LOCAL_ALLOC) && !defined(DBG_HDRS_ALL)
521 GC_push_all((ptr_t)(&GC_thread_key),
522 (ptr_t)(&GC_thread_key)+sizeof(&GC_thread_key));
526 #ifdef THREAD_LOCAL_ALLOC
527 /* We must explicitly mark ptrfree and gcj free lists, since the free */
528 /* list links wouldn't otherwise be found. We also set them in the */
529 /* normal free lists, since that involves touching less memory than if */
530 /* we scanned them normally. */
531 void GC_mark_thread_local_free_lists(void)
537 for (i = 0; i < THREAD_TABLE_SZ; ++i) {
538 for (p = GC_threads[i]; 0 != p; p = p -> next) {
539 for (j = 1; j < NFREELISTS; ++j) {
540 q = p -> ptrfree_freelists[j];
541 if ((word)q > HBLKSIZE) GC_set_fl_marks(q);
542 q = p -> normal_freelists[j];
543 if ((word)q > HBLKSIZE) GC_set_fl_marks(q);
544 # ifdef GC_GCJ_SUPPORT
545 q = p -> gcj_freelists[j];
546 if ((word)q > HBLKSIZE) GC_set_fl_marks(q);
547 # endif /* GC_GCJ_SUPPORT */
552 #endif /* THREAD_LOCAL_ALLOC */
554 static struct GC_Thread_Rep first_thread;
556 /* Add a thread to GC_threads. We assume it wasn't already there. */
557 /* Caller holds allocation lock. */
558 GC_thread GC_new_thread(pthread_t id)
560 int hv = ((word)id) % THREAD_TABLE_SZ;
562 static GC_bool first_thread_used = FALSE;
564 if (!first_thread_used) {
565 result = &first_thread;
566 first_thread_used = TRUE;
568 result = (struct GC_Thread_Rep *)
569 GC_INTERNAL_MALLOC(sizeof(struct GC_Thread_Rep), NORMAL);
571 if (result == 0) return(0);
573 result -> next = GC_threads[hv];
574 GC_threads[hv] = result;
575 GC_ASSERT(result -> flags == 0 && result -> thread_blocked == 0);
579 /* Delete a thread from GC_threads. We assume it is there. */
580 /* (The code intentionally traps if it wasn't.) */
581 /* Caller holds allocation lock. */
582 void GC_delete_thread(pthread_t id)
584 int hv = ((word)id) % THREAD_TABLE_SZ;
585 register GC_thread p = GC_threads[hv];
586 register GC_thread prev = 0;
588 while (!pthread_equal(p -> id, id)) {
593 GC_threads[hv] = p -> next;
595 prev -> next = p -> next;
600 /* If a thread has been joined, but we have not yet */
601 /* been notified, then there may be more than one thread */
602 /* in the table with the same pthread id. */
603 /* This is OK, but we need a way to delete a specific one. */
604 void GC_delete_gc_thread(pthread_t id, GC_thread gc_id)
606 int hv = ((word)id) % THREAD_TABLE_SZ;
607 register GC_thread p = GC_threads[hv];
608 register GC_thread prev = 0;
615 GC_threads[hv] = p -> next;
617 prev -> next = p -> next;
622 /* Return a GC_thread corresponding to a given pthread_t. */
623 /* Returns 0 if it's not there. */
624 /* Caller holds allocation lock or otherwise inhibits */
626 /* If there is more than one thread with the given id we */
627 /* return the most recent one. */
628 GC_thread GC_lookup_thread(pthread_t id)
630 int hv = ((word)id) % THREAD_TABLE_SZ;
631 register GC_thread p = GC_threads[hv];
633 while (p != 0 && !pthread_equal(p -> id, id)) p = p -> next;
638 /* Remove all entries from the GC_threads table, except the */
639 /* one for the current thread. We need to do this in the child */
640 /* process after a fork(), since only the current thread */
641 /* survives in the child. */
642 void GC_remove_all_threads_but_me(void)
644 pthread_t self = pthread_self();
646 GC_thread p, next, me;
648 for (hv = 0; hv < THREAD_TABLE_SZ; ++hv) {
650 for (p = GC_threads[hv]; 0 != p; p = next) {
652 if (p -> id == self) {
656 # ifdef THREAD_LOCAL_ALLOC
657 if (!(p -> flags & FINISHED)) {
658 GC_destroy_thread_local(p);
660 # endif /* THREAD_LOCAL_ALLOC */
661 if (p != &first_thread) GC_INTERNAL_FREE(p);
667 #endif /* HANDLE_FORK */
669 #ifdef USE_PROC_FOR_LIBRARIES
670 int GC_segment_is_thread_stack(ptr_t lo, ptr_t hi)
675 # ifdef PARALLEL_MARK
676 for (i = 0; i < GC_markers; ++i) {
677 if (marker_sp[i] > lo & marker_sp[i] < hi) return 1;
680 for (i = 0; i < THREAD_TABLE_SZ; i++) {
681 for (p = GC_threads[i]; p != 0; p = p -> next) {
682 if (0 != p -> stack_end) {
683 # ifdef STACK_GROWS_UP
684 if (p -> stack_end >= lo && p -> stack_end < hi) return 1;
685 # else /* STACK_GROWS_DOWN */
686 if (p -> stack_end > lo && p -> stack_end <= hi) return 1;
693 #endif /* USE_PROC_FOR_LIBRARIES */
695 #ifdef GC_LINUX_THREADS
696 /* Return the number of processors, or i<= 0 if it can't be determined. */
699 /* Should be "return sysconf(_SC_NPROCESSORS_ONLN);" but that */
700 /* appears to be buggy in many cases. */
701 /* We look for lines "cpu<n>" in /proc/stat. */
702 # define STAT_BUF_SIZE 4096
703 # define STAT_READ read
704 /* If read is wrapped, this may need to be redefined to call */
706 char stat_buf[STAT_BUF_SIZE];
709 /* Some old kernels only have a single "cpu nnnn ..." */
710 /* entry in /proc/stat. We identify those as */
714 f = open("/proc/stat", O_RDONLY);
715 if (f < 0 || (len = STAT_READ(f, stat_buf, STAT_BUF_SIZE)) < 100) {
716 WARN("Couldn't read /proc/stat\n", 0);
719 for (i = 0; i < len - 100; ++i) {
720 if (stat_buf[i] == '\n' && stat_buf[i+1] == 'c'
721 && stat_buf[i+2] == 'p' && stat_buf[i+3] == 'u') {
722 int cpu_no = atoi(stat_buf + i + 4);
723 if (cpu_no >= result) result = cpu_no + 1;
729 #endif /* GC_LINUX_THREADS */
731 /* We hold the GC lock. Wait until an in-progress GC has finished. */
732 /* Repeatedly RELEASES GC LOCK in order to wait. */
733 /* If wait_for_all is true, then we exit with the GC lock held and no */
734 /* collection in progress; otherwise we just wait for the current GC */
736 extern GC_bool GC_collection_in_progress();
737 void GC_wait_for_gc_completion(GC_bool wait_for_all)
739 if (GC_incremental && GC_collection_in_progress()) {
740 int old_gc_no = GC_gc_no;
742 /* Make sure that no part of our stack is still on the mark stack, */
743 /* since it's about to be unmapped. */
744 while (GC_incremental && GC_collection_in_progress()
745 && (wait_for_all || old_gc_no == GC_gc_no)) {
747 GC_in_thread_creation = TRUE;
748 GC_collect_a_little_inner(1);
749 GC_in_thread_creation = FALSE;
759 /* Procedures called before and after a fork. The goal here is to make */
760 /* it safe to call GC_malloc() in a forked child. It's unclear that is */
761 /* attainable, since the single UNIX spec seems to imply that one */
762 /* should only call async-signal-safe functions, and we probably can't */
763 /* quite guarantee that. But we give it our best shot. (That same */
764 /* spec also implies that it's not safe to call the system malloc */
765 /* between fork() and exec(). Thus we're doing no worse than it. */
767 /* Called before a fork() */
768 void GC_fork_prepare_proc(void)
770 /* Acquire all relevant locks, so that after releasing the locks */
771 /* the child will see a consistent state in which monitor */
772 /* invariants hold. Unfortunately, we can't acquire libc locks */
773 /* we might need, and there seems to be no guarantee that libc */
774 /* must install a suitable fork handler. */
775 /* Wait for an ongoing GC to finish, since we can't finish it in */
776 /* the (one remaining thread in) the child. */
778 # if defined(PARALLEL_MARK) || defined(THREAD_LOCAL_ALLOC)
779 GC_wait_for_reclaim();
781 GC_wait_for_gc_completion(TRUE);
782 # if defined(PARALLEL_MARK) || defined(THREAD_LOCAL_ALLOC)
783 GC_acquire_mark_lock();
787 /* Called in parent after a fork() */
788 void GC_fork_parent_proc(void)
790 # if defined(PARALLEL_MARK) || defined(THREAD_LOCAL_ALLOC)
791 GC_release_mark_lock();
796 /* Called in child after a fork() */
797 void GC_fork_child_proc(void)
799 /* Clean up the thread table, so that just our thread is left. */
800 # if defined(PARALLEL_MARK) || defined(THREAD_LOCAL_ALLOC)
801 GC_release_mark_lock();
803 GC_remove_all_threads_but_me();
804 # ifdef PARALLEL_MARK
805 /* Turn off parallel marking in the child, since we are probably */
806 /* just going to exec, and we would have to restart mark threads. */
809 # endif /* PARALLEL_MARK */
812 #endif /* HANDLE_FORK */
814 #if defined(GC_DGUX386_THREADS)
815 /* Return the number of processors, or i<= 0 if it can't be determined. */
818 /* <takis@XFree86.Org> */
820 struct dg_sys_info_pm_info pm_sysinfo;
823 status = dg_sys_info((long int *) &pm_sysinfo,
824 DG_SYS_INFO_PM_INFO_TYPE, DG_SYS_INFO_PM_CURRENT_VERSION);
826 /* set -1 for error */
830 numCpus = pm_sysinfo.idle_vp_count;
832 # ifdef DEBUG_THREADS
833 GC_printf1("Number of active CPUs in this system: %d\n", numCpus);
837 #endif /* GC_DGUX386_THREADS */
839 /* We hold the allocation lock. */
842 # ifndef GC_DARWIN_THREADS
847 if (GC_thr_initialized) return;
848 GC_thr_initialized = TRUE;
851 /* Prepare for a possible fork. */
852 pthread_atfork(GC_fork_prepare_proc, GC_fork_parent_proc,
854 # endif /* HANDLE_FORK */
855 /* Add the initial thread, so we can stop it. */
856 t = GC_new_thread(pthread_self());
857 # ifdef GC_DARWIN_THREADS
858 t -> stop_info.mach_thread = mach_thread_self();
860 t -> stop_info.stack_ptr = (ptr_t)(&dummy);
862 t -> flags = DETACHED | MAIN_THREAD;
868 char * nprocs_string = GETENV("GC_NPROCS");
870 if (nprocs_string != NULL) GC_nprocs = atoi(nprocs_string);
872 if (GC_nprocs <= 0) {
873 # if defined(GC_HPUX_THREADS)
874 GC_nprocs = pthread_num_processors_np();
876 # if defined(GC_OSF1_THREADS)
877 GC_nprocs = sysconf(_SC_NPROCESSORS_ONLN);
878 if (GC_nprocs <= 0) GC_nprocs = 1;
880 # if defined(GC_FREEBSD_THREADS)
883 # if defined(GC_DARWIN_THREADS)
885 size_t len = sizeof(ncpus);
886 sysctl((int[2]) {CTL_HW, HW_NCPU}, 2, &ncpus, &len, NULL, 0);
889 # if defined(GC_LINUX_THREADS) || defined(GC_DGUX386_THREADS)
890 GC_nprocs = GC_get_nprocs();
893 if (GC_nprocs <= 0) {
894 WARN("GC_get_nprocs() returned %ld\n", GC_nprocs);
896 # ifdef PARALLEL_MARK
900 # ifdef PARALLEL_MARK
902 char * markers_string = GETENV("GC_MARKERS");
903 if (markers_string != NULL) {
904 GC_markers = atoi(markers_string);
906 GC_markers = GC_nprocs;
911 # ifdef PARALLEL_MARK
913 if (GC_print_stats) {
914 GC_printf2("Number of processors = %ld, "
915 "number of marker threads = %ld\n", GC_nprocs, GC_markers);
918 if (GC_markers == 1) {
921 if (GC_print_stats) {
922 GC_printf0("Single marker thread, turning off parallel marking\n");
927 /* Disable true incremental collection, but generational is OK. */
928 GC_time_limit = GC_TIME_UNLIMITED;
934 /* Perform all initializations, including those that */
935 /* may require allocation. */
936 /* Called without allocation lock. */
937 /* Must be called before a second thread is created. */
938 /* Called without allocation lock. */
939 void GC_init_parallel()
941 if (parallel_initialized) return;
942 parallel_initialized = TRUE;
944 /* GC_init() calls us back, so set flag first. */
945 if (!GC_is_initialized) GC_init();
946 /* If we are using a parallel marker, start the helper threads. */
947 # ifdef PARALLEL_MARK
948 if (GC_parallel) start_mark_threads();
950 /* Initialize thread local free lists if used. */
951 # if defined(THREAD_LOCAL_ALLOC) && !defined(DBG_HDRS_ALL)
953 GC_init_thread_local(GC_lookup_thread(pthread_self()));
959 #if !defined(GC_DARWIN_THREADS)
960 int WRAP_FUNC(pthread_sigmask)(int how, const sigset_t *set, sigset_t *oset)
964 if (set != NULL && (how == SIG_BLOCK || how == SIG_SETMASK)) {
966 sigdelset(&fudged_set, SIG_SUSPEND);
969 return(REAL_FUNC(pthread_sigmask)(how, set, oset));
971 #endif /* !GC_DARWIN_THREADS */
973 /* Wrappers for functions that are likely to block for an appreciable */
974 /* length of time. Must be called in pairs, if at all. */
975 /* Nothing much beyond the system call itself should be executed */
978 void GC_start_blocking(void) {
982 me = GC_lookup_thread(pthread_self());
983 GC_ASSERT(!(me -> thread_blocked));
985 me -> stop_info.stack_ptr = (ptr_t)GC_save_regs_in_stack();
987 # ifndef GC_DARWIN_THREADS
988 me -> stop_info.stack_ptr = (ptr_t)GC_approx_sp();
992 me -> backing_store_ptr = (ptr_t)GC_save_regs_in_stack() + SP_SLOP;
994 /* Add some slop to the stack pointer, since the wrapped call may */
995 /* end up pushing more callee-save registers. */
996 # ifndef GC_DARWIN_THREADS
997 # ifdef STACK_GROWS_UP
998 me -> stop_info.stack_ptr += SP_SLOP;
1000 me -> stop_info.stack_ptr -= SP_SLOP;
1003 me -> thread_blocked = TRUE;
1007 void GC_end_blocking(void) {
1009 LOCK(); /* This will block if the world is stopped. */
1010 me = GC_lookup_thread(pthread_self());
1011 GC_ASSERT(me -> thread_blocked);
1012 me -> thread_blocked = FALSE;
1016 #if defined(GC_DGUX386_THREADS)
1017 #define __d10_sleep sleep
1018 #endif /* GC_DGUX386_THREADS */
1020 /* A wrapper for the standard C sleep function */
1021 int WRAP_FUNC(sleep) (unsigned int seconds)
1025 GC_start_blocking();
1026 result = REAL_FUNC(sleep)(seconds);
1032 void *(*start_routine)(void *);
1035 sem_t registered; /* 1 ==> in our thread table, but */
1036 /* parent hasn't yet noticed. */
1039 /* Called at thread exit. */
1040 /* Never called for main thread. That's OK, since it */
1041 /* results in at most a tiny one-time leak. And */
1042 /* linuxthreads doesn't reclaim the main threads */
1043 /* resources or id anyway. */
1044 void GC_thread_exit_proc(void *arg)
1049 me = GC_lookup_thread(pthread_self());
1050 GC_destroy_thread_local(me);
1051 if (me -> flags & DETACHED) {
1052 GC_delete_thread(pthread_self());
1054 me -> flags |= FINISHED;
1056 # if defined(THREAD_LOCAL_ALLOC) && !defined(USE_PTHREAD_SPECIFIC) \
1057 && !defined(USE_COMPILER_TLS) && !defined(DBG_HDRS_ALL)
1058 GC_remove_specific(GC_thread_key);
1060 /* The following may run the GC from "nonexistent" thread. */
1061 GC_wait_for_gc_completion(FALSE);
1065 int WRAP_FUNC(pthread_join)(pthread_t thread, void **retval)
1068 GC_thread thread_gc_id;
1071 thread_gc_id = GC_lookup_thread(thread);
1072 /* This is guaranteed to be the intended one, since the thread id */
1073 /* cant have been recycled by pthreads. */
1075 result = REAL_FUNC(pthread_join)(thread, retval);
1076 # if defined (GC_FREEBSD_THREADS)
1077 /* On FreeBSD, the wrapped pthread_join() sometimes returns (what
1078 appears to be) a spurious EINTR which caused the test and real code
1079 to gratuitously fail. Having looked at system pthread library source
1080 code, I see how this return code may be generated. In one path of
1081 code, pthread_join() just returns the errno setting of the thread
1082 being joined. This does not match the POSIX specification or the
1083 local man pages thus I have taken the liberty to catch this one
1084 spurious return value properly conditionalized on GC_FREEBSD_THREADS. */
1085 if (result == EINTR) result = 0;
1089 /* Here the pthread thread id may have been recycled. */
1090 GC_delete_gc_thread(thread, thread_gc_id);
1097 WRAP_FUNC(pthread_detach)(pthread_t thread)
1100 GC_thread thread_gc_id;
1103 thread_gc_id = GC_lookup_thread(thread);
1105 result = REAL_FUNC(pthread_detach)(thread);
1108 thread_gc_id -> flags |= DETACHED;
1109 /* Here the pthread thread id may have been recycled. */
1110 if (thread_gc_id -> flags & FINISHED) {
1111 GC_delete_gc_thread(thread, thread_gc_id);
1118 GC_bool GC_in_thread_creation = FALSE;
1120 void * GC_start_routine(void * arg)
1123 struct start_info * si = arg;
1126 pthread_t my_pthread;
1127 void *(*start)(void *);
1130 my_pthread = pthread_self();
1131 # ifdef DEBUG_THREADS
1132 GC_printf1("Starting thread 0x%lx\n", my_pthread);
1133 GC_printf1("pid = %ld\n", (long) getpid());
1134 GC_printf1("sp = 0x%lx\n", (long) &arg);
1137 GC_in_thread_creation = TRUE;
1138 me = GC_new_thread(my_pthread);
1139 GC_in_thread_creation = FALSE;
1140 #ifdef GC_DARWIN_THREADS
1141 me -> stop_info.mach_thread = mach_thread_self();
1143 me -> stop_info.stack_ptr = 0;
1145 me -> flags = si -> flags;
1146 /* me -> stack_end = GC_linux_stack_base(); -- currently (11/99) */
1147 /* doesn't work because the stack base in /proc/self/stat is the */
1148 /* one for the main thread. There is a strong argument that that's */
1149 /* a kernel bug, but a pervasive one. */
1150 # ifdef STACK_GROWS_DOWN
1151 me -> stack_end = (ptr_t)(((word)(&dummy) + (GC_page_size - 1))
1152 & ~(GC_page_size - 1));
1153 # ifndef GC_DARWIN_THREADS
1154 me -> stop_info.stack_ptr = me -> stack_end - 0x10;
1156 /* Needs to be plausible, since an asynchronous stack mark */
1157 /* should not crash. */
1159 me -> stack_end = (ptr_t)((word)(&dummy) & ~(GC_page_size - 1));
1160 me -> stop_info.stack_ptr = me -> stack_end + 0x10;
1162 /* This is dubious, since we may be more than a page into the stack, */
1163 /* and hence skip some of it, though it's not clear that matters. */
1165 me -> backing_store_end = (ptr_t)
1166 (GC_save_regs_in_stack() & ~(GC_page_size - 1));
1167 /* This is also < 100% convincing. We should also read this */
1168 /* from /proc, but the hook to do so isn't there yet. */
1171 start = si -> start_routine;
1172 # ifdef DEBUG_THREADS
1173 GC_printf1("start_routine = 0x%lx\n", start);
1175 start_arg = si -> arg;
1176 sem_post(&(si -> registered)); /* Last action on si. */
1177 /* OK to deallocate. */
1178 pthread_cleanup_push(GC_thread_exit_proc, 0);
1179 # if defined(THREAD_LOCAL_ALLOC) && !defined(DBG_HDRS_ALL)
1181 GC_init_thread_local(me);
1184 result = (*start)(start_arg);
1186 GC_printf1("Finishing thread 0x%x\n", pthread_self());
1188 me -> status = result;
1189 pthread_cleanup_pop(1);
1190 /* Cleanup acquires lock, ensuring that we can't exit */
1191 /* while a collection that thinks we're alive is trying to stop */
1197 WRAP_FUNC(pthread_create)(pthread_t *new_thread,
1198 const pthread_attr_t *attr,
1199 void *(*start_routine)(void *), void *arg)
1204 struct start_info * si;
1205 /* This is otherwise saved only in an area mmapped by the thread */
1206 /* library, which isn't visible to the collector. */
1208 /* We resist the temptation to muck with the stack size here, */
1209 /* even if the default is unreasonably small. That's the client's */
1210 /* responsibility. */
1213 si = (struct start_info *)GC_INTERNAL_MALLOC(sizeof(struct start_info),
1216 if (!parallel_initialized) GC_init_parallel();
1217 if (0 == si) return(ENOMEM);
1218 sem_init(&(si -> registered), 0, 0);
1219 si -> start_routine = start_routine;
1222 if (!GC_thr_initialized) GC_thr_init();
1223 # ifdef GC_ASSERTIONS
1227 pthread_attr_t my_attr;
1228 pthread_attr_init(&my_attr);
1229 pthread_attr_getstacksize(&my_attr, &stack_size);
1231 pthread_attr_getstacksize(attr, &stack_size);
1233 GC_ASSERT(stack_size >= (8*HBLKSIZE*sizeof(word)));
1234 /* Our threads may need to do some work for the GC. */
1235 /* Ridiculously small threads won't work, and they */
1236 /* probably wouldn't work anyway. */
1240 detachstate = PTHREAD_CREATE_JOINABLE;
1242 pthread_attr_getdetachstate(attr, &detachstate);
1244 if (PTHREAD_CREATE_DETACHED == detachstate) my_flags |= DETACHED;
1245 si -> flags = my_flags;
1247 # ifdef DEBUG_THREADS
1248 GC_printf1("About to start new thread from thread 0x%X\n",
1252 result = REAL_FUNC(pthread_create)(new_thread, attr, GC_start_routine, si);
1254 # ifdef DEBUG_THREADS
1255 GC_printf1("Started thread 0x%X\n", *new_thread);
1257 /* Wait until child has been added to the thread table. */
1258 /* This also ensures that we hold onto si until the child is done */
1259 /* with it. Thus it doesn't matter whether it is otherwise */
1260 /* visible to the collector. */
1262 while (0 != sem_wait(&(si -> registered))) {
1263 if (EINTR != errno) ABORT("sem_wait failed");
1266 sem_destroy(&(si -> registered));
1268 GC_INTERNAL_FREE(si);
1274 #ifdef GENERIC_COMPARE_AND_SWAP
1275 pthread_mutex_t GC_compare_and_swap_lock = PTHREAD_MUTEX_INITIALIZER;
1277 GC_bool GC_compare_and_exchange(volatile GC_word *addr,
1278 GC_word old, GC_word new_val)
1281 pthread_mutex_lock(&GC_compare_and_swap_lock);
1288 pthread_mutex_unlock(&GC_compare_and_swap_lock);
1292 GC_word GC_atomic_add(volatile GC_word *addr, GC_word how_much)
1295 pthread_mutex_lock(&GC_compare_and_swap_lock);
1297 *addr = old + how_much;
1298 pthread_mutex_unlock(&GC_compare_and_swap_lock);
1302 #endif /* GENERIC_COMPARE_AND_SWAP */
1303 /* Spend a few cycles in a way that can't introduce contention with */
1304 /* othre threads. */
1308 # if !defined(__GNUC__) || defined(__INTEL_COMPILER)
1309 volatile word dummy = 0;
1312 for (i = 0; i < 10; ++i) {
1313 # if defined(__GNUC__) && !defined(__INTEL_COMPILER)
1314 __asm__ __volatile__ (" " : : : "memory");
1316 /* Something that's unlikely to be optimized away. */
1322 #define SPIN_MAX 128 /* Maximum number of calls to GC_pause before */
1325 VOLATILE GC_bool GC_collecting = 0;
1326 /* A hint that we're in the collector and */
1327 /* holding the allocation lock for an */
1328 /* extended period. */
1330 #if !defined(USE_SPIN_LOCK) || defined(PARALLEL_MARK)
1331 /* If we don't want to use the below spinlock implementation, either */
1332 /* because we don't have a GC_test_and_set implementation, or because */
1333 /* we don't want to risk sleeping, we can still try spinning on */
1334 /* pthread_mutex_trylock for a while. This appears to be very */
1335 /* beneficial in many cases. */
1336 /* I suspect that under high contention this is nearly always better */
1337 /* than the spin lock. But it's a bit slower on a uniprocessor. */
1338 /* Hence we still default to the spin lock. */
1339 /* This is also used to acquire the mark lock for the parallel */
1342 /* Here we use a strict exponential backoff scheme. I don't know */
1343 /* whether that's better or worse than the above. We eventually */
1344 /* yield by calling pthread_mutex_lock(); it never makes sense to */
1345 /* explicitly sleep. */
1349 unsigned long GC_spin_count = 0;
1350 unsigned long GC_block_count = 0;
1351 unsigned long GC_unlocked_count = 0;
1354 void GC_generic_lock(pthread_mutex_t * lock)
1356 #ifndef NO_PTHREAD_TRYLOCK
1357 unsigned pause_length = 1;
1360 if (0 == pthread_mutex_trylock(lock)) {
1362 ++GC_unlocked_count;
1366 for (; pause_length <= SPIN_MAX; pause_length <<= 1) {
1367 for (i = 0; i < pause_length; ++i) {
1370 switch(pthread_mutex_trylock(lock)) {
1379 ABORT("Unexpected error from pthread_mutex_trylock");
1382 #endif /* !NO_PTHREAD_TRYLOCK */
1386 pthread_mutex_lock(lock);
1389 #endif /* !USE_SPIN_LOCK || PARALLEL_MARK */
1391 #if defined(USE_SPIN_LOCK)
1393 /* Reasonably fast spin locks. Basically the same implementation */
1394 /* as STL alloc.h. This isn't really the right way to do this. */
1395 /* but until the POSIX scheduling mess gets straightened out ... */
1397 volatile unsigned int GC_allocate_lock = 0;
1402 # define low_spin_max 30 /* spin cycles if we suspect uniprocessor */
1403 # define high_spin_max SPIN_MAX /* spin cycles for multiprocessor */
1404 static unsigned spin_max = low_spin_max;
1405 unsigned my_spin_max;
1406 static unsigned last_spins = 0;
1407 unsigned my_last_spins;
1410 if (!GC_test_and_set(&GC_allocate_lock)) {
1413 my_spin_max = spin_max;
1414 my_last_spins = last_spins;
1415 for (i = 0; i < my_spin_max; i++) {
1416 if (GC_collecting || GC_nprocs == 1) goto yield;
1417 if (i < my_last_spins/2 || GC_allocate_lock) {
1421 if (!GC_test_and_set(&GC_allocate_lock)) {
1424 * Spinning worked. Thus we're probably not being scheduled
1425 * against the other process with which we were contending.
1426 * Thus it makes sense to spin longer the next time.
1429 spin_max = high_spin_max;
1433 /* We are probably being scheduled against the other process. Sleep. */
1434 spin_max = low_spin_max;
1437 if (!GC_test_and_set(&GC_allocate_lock)) {
1440 # define SLEEP_THRESHOLD 12
1441 /* Under Linux very short sleeps tend to wait until */
1442 /* the current time quantum expires. On old Linux */
1443 /* kernels nanosleep(<= 2ms) just spins under Linux. */
1444 /* (Under 2.4, this happens only for real-time */
1445 /* processes.) We want to minimize both behaviors */
1447 if (i < SLEEP_THRESHOLD) {
1453 /* Don't wait for more than about 15msecs, even */
1454 /* under extreme contention. */
1456 ts.tv_nsec = 1 << i;
1462 #else /* !USE_SPINLOCK */
1465 #ifndef NO_PTHREAD_TRYLOCK
1466 if (1 == GC_nprocs || GC_collecting) {
1467 pthread_mutex_lock(&GC_allocate_ml);
1469 GC_generic_lock(&GC_allocate_ml);
1471 #else /* !NO_PTHREAD_TRYLOCK */
1472 pthread_mutex_lock(&GC_allocate_ml);
1473 #endif /* !NO_PTHREAD_TRYLOCK */
1476 #endif /* !USE_SPINLOCK */
1478 #if defined(PARALLEL_MARK) || defined(THREAD_LOCAL_ALLOC)
1480 #ifdef GC_ASSERTIONS
1481 pthread_t GC_mark_lock_holder = NO_THREAD;
1485 /* Ugly workaround for a linux threads bug in the final versions */
1486 /* of glibc2.1. Pthread_mutex_trylock sets the mutex owner */
1487 /* field even when it fails to acquire the mutex. This causes */
1488 /* pthread_cond_wait to die. Remove for glibc2.2. */
1489 /* According to the man page, we should use */
1490 /* PTHREAD_ERRORCHECK_MUTEX_INITIALIZER_NP, but that isn't actually */
1492 static pthread_mutex_t mark_mutex =
1493 {0, 0, 0, PTHREAD_MUTEX_ERRORCHECK_NP, {0, 0}};
1495 static pthread_mutex_t mark_mutex = PTHREAD_MUTEX_INITIALIZER;
1498 static pthread_cond_t builder_cv = PTHREAD_COND_INITIALIZER;
1500 void GC_acquire_mark_lock()
1503 if (pthread_mutex_lock(&mark_mutex) != 0) {
1504 ABORT("pthread_mutex_lock failed");
1507 GC_generic_lock(&mark_mutex);
1508 # ifdef GC_ASSERTIONS
1509 GC_mark_lock_holder = pthread_self();
1513 void GC_release_mark_lock()
1515 GC_ASSERT(GC_mark_lock_holder == pthread_self());
1516 # ifdef GC_ASSERTIONS
1517 GC_mark_lock_holder = NO_THREAD;
1519 if (pthread_mutex_unlock(&mark_mutex) != 0) {
1520 ABORT("pthread_mutex_unlock failed");
1524 /* Collector must wait for a freelist builders for 2 reasons: */
1525 /* 1) Mark bits may still be getting examined without lock. */
1526 /* 2) Partial free lists referenced only by locals may not be scanned */
1527 /* correctly, e.g. if they contain "pointer-free" objects, since the */
1528 /* free-list link may be ignored. */
1529 void GC_wait_builder()
1531 GC_ASSERT(GC_mark_lock_holder == pthread_self());
1532 # ifdef GC_ASSERTIONS
1533 GC_mark_lock_holder = NO_THREAD;
1535 if (pthread_cond_wait(&builder_cv, &mark_mutex) != 0) {
1536 ABORT("pthread_cond_wait failed");
1538 GC_ASSERT(GC_mark_lock_holder == NO_THREAD);
1539 # ifdef GC_ASSERTIONS
1540 GC_mark_lock_holder = pthread_self();
1544 void GC_wait_for_reclaim()
1546 GC_acquire_mark_lock();
1547 while (GC_fl_builder_count > 0) {
1550 GC_release_mark_lock();
1553 void GC_notify_all_builder()
1555 GC_ASSERT(GC_mark_lock_holder == pthread_self());
1556 if (pthread_cond_broadcast(&builder_cv) != 0) {
1557 ABORT("pthread_cond_broadcast failed");
1561 #endif /* PARALLEL_MARK || THREAD_LOCAL_ALLOC */
1563 #ifdef PARALLEL_MARK
1565 static pthread_cond_t mark_cv = PTHREAD_COND_INITIALIZER;
1567 void GC_wait_marker()
1569 GC_ASSERT(GC_mark_lock_holder == pthread_self());
1570 # ifdef GC_ASSERTIONS
1571 GC_mark_lock_holder = NO_THREAD;
1573 if (pthread_cond_wait(&mark_cv, &mark_mutex) != 0) {
1574 ABORT("pthread_cond_wait failed");
1576 GC_ASSERT(GC_mark_lock_holder == NO_THREAD);
1577 # ifdef GC_ASSERTIONS
1578 GC_mark_lock_holder = pthread_self();
1582 void GC_notify_all_marker()
1584 if (pthread_cond_broadcast(&mark_cv) != 0) {
1585 ABORT("pthread_cond_broadcast failed");
1589 #endif /* PARALLEL_MARK */
1591 # endif /* GC_LINUX_THREADS and friends */