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) 2000-2004 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
49 /*#define DEBUG_THREADS 1*/
50 /*#define GC_ASSERTIONS*/
52 # include "private/pthread_support.h"
54 # if defined(GC_PTHREADS) && !defined(GC_SOLARIS_THREADS) \
55 && !defined(GC_WIN32_THREADS)
57 # if defined(GC_HPUX_THREADS) && !defined(USE_PTHREAD_SPECIFIC) \
58 && !defined(USE_COMPILER_TLS)
60 # define USE_PTHREAD_SPECIFIC
61 /* Empirically, as of gcc 3.3, USE_COMPILER_TLS doesn't work. */
63 # define USE_COMPILER_TLS
67 # if defined USE_HPUX_TLS
68 --> Macro replaced by USE_COMPILER_TLS
71 # if (defined(GC_DGUX386_THREADS) || defined(GC_OSF1_THREADS) || \
72 defined(GC_DARWIN_THREADS) || defined(GC_AIX_THREADS)) \
73 && !defined(USE_PTHREAD_SPECIFIC)
74 # define USE_PTHREAD_SPECIFIC
77 # if defined(GC_DGUX386_THREADS) && !defined(_POSIX4A_DRAFT10_SOURCE)
78 # define _POSIX4A_DRAFT10_SOURCE 1
81 # if defined(GC_DGUX386_THREADS) && !defined(_USING_POSIX4A_DRAFT10)
82 # define _USING_POSIX4A_DRAFT10 1
85 # ifdef THREAD_LOCAL_ALLOC
86 # if !defined(USE_PTHREAD_SPECIFIC) && !defined(USE_COMPILER_TLS)
87 # include "private/specific.h"
89 # if defined(USE_PTHREAD_SPECIFIC)
90 # define GC_getspecific pthread_getspecific
91 # define GC_setspecific pthread_setspecific
92 # define GC_key_create pthread_key_create
93 typedef pthread_key_t GC_key_t;
95 # if defined(USE_COMPILER_TLS)
96 # define GC_getspecific(x) (x)
97 # define GC_setspecific(key, v) ((key) = (v), 0)
98 # define GC_key_create(key, d) 0
99 typedef void * GC_key_t;
103 # include <pthread.h>
108 # include <sys/mman.h>
109 # include <sys/time.h>
110 # include <sys/types.h>
111 # include <sys/stat.h>
115 #if defined(GC_DARWIN_THREADS)
116 # include "private/darwin_semaphore.h"
118 # include <semaphore.h>
119 #endif /* !GC_DARWIN_THREADS */
121 #if defined(GC_DARWIN_THREADS) || defined(GC_FREEBSD_THREADS)
122 # include <sys/sysctl.h>
123 #endif /* GC_DARWIN_THREADS */
127 #if defined(GC_DGUX386_THREADS)
128 # include <sys/dg_sys_info.h>
129 # include <sys/_int_psem.h>
130 /* sem_t is an uint in DG/UX */
131 typedef unsigned int sem_t;
132 #endif /* GC_DGUX386_THREADS */
138 #ifdef GC_USE_LD_WRAP
139 # define WRAP_FUNC(f) __wrap_##f
140 # define REAL_FUNC(f) __real_##f
142 # define WRAP_FUNC(f) GC_##f
143 # if !defined(GC_DGUX386_THREADS)
144 # define REAL_FUNC(f) f
145 # else /* GC_DGUX386_THREADS */
146 # define REAL_FUNC(f) __d10_##f
147 # endif /* GC_DGUX386_THREADS */
148 # undef pthread_create
149 # if !defined(GC_DARWIN_THREADS)
150 # undef pthread_sigmask
153 # undef pthread_detach
154 # if defined(GC_OSF1_THREADS) && defined(_PTHREAD_USE_MANGLED_NAMES_) \
155 && !defined(_PTHREAD_USE_PTDNAM_)
156 /* Restore the original mangled names on Tru64 UNIX. */
157 # define pthread_create __pthread_create
158 # define pthread_join __pthread_join
159 # define pthread_detach __pthread_detach
165 static GC_bool parallel_initialized = FALSE;
167 void GC_init_parallel();
169 # if defined(THREAD_LOCAL_ALLOC) && !defined(DBG_HDRS_ALL)
171 /* We don't really support thread-local allocation with DBG_HDRS_ALL */
173 #ifdef USE_COMPILER_TLS
176 GC_key_t GC_thread_key;
178 static GC_bool keys_initialized;
180 /* Recover the contents of the freelist array fl into the global one gfl.*/
181 /* Note that the indexing scheme differs, in that gfl has finer size */
182 /* resolution, even if not all entries are used. */
183 /* We hold the allocator lock. */
184 static void return_freelists(ptr_t *fl, ptr_t *gfl)
190 for (i = 1; i < NFREELISTS; ++i) {
191 nwords = i * (GRANULARITY/sizeof(word));
194 if ((word)q >= HBLKSIZE) {
195 if (gfl[nwords] == 0) {
199 for (; (word)q >= HBLKSIZE; qptr = &(obj_link(q)), q = *qptr);
205 /* Clear fl[i], since the thread structure may hang around. */
206 /* Do it in a way that is likely to trap if we access it. */
207 fl[i] = (ptr_t)HBLKSIZE;
211 /* We statically allocate a single "size 0" object. It is linked to */
212 /* itself, and is thus repeatedly reused for all size 0 allocation */
213 /* requests. (Size 0 gcj allocation requests are incorrect, and */
214 /* we arrange for those to fault asap.) */
215 static ptr_t size_zero_object = (ptr_t)(&size_zero_object);
217 /* Each thread structure must be initialized. */
218 /* This call must be made from the new thread. */
219 /* Caller holds allocation lock. */
220 void GC_init_thread_local(GC_thread p)
224 if (!keys_initialized) {
225 if (0 != GC_key_create(&GC_thread_key, 0)) {
226 ABORT("Failed to create key for local allocator");
228 keys_initialized = TRUE;
230 if (0 != GC_setspecific(GC_thread_key, p)) {
231 ABORT("Failed to set thread specific allocation pointers");
233 for (i = 1; i < NFREELISTS; ++i) {
234 p -> ptrfree_freelists[i] = (ptr_t)1;
235 p -> normal_freelists[i] = (ptr_t)1;
236 # ifdef GC_GCJ_SUPPORT
237 p -> gcj_freelists[i] = (ptr_t)1;
240 /* Set up the size 0 free lists. */
241 p -> ptrfree_freelists[0] = (ptr_t)(&size_zero_object);
242 p -> normal_freelists[0] = (ptr_t)(&size_zero_object);
243 # ifdef GC_GCJ_SUPPORT
244 p -> gcj_freelists[0] = (ptr_t)(-1);
248 #ifdef GC_GCJ_SUPPORT
249 extern ptr_t * GC_gcjobjfreelist;
252 /* We hold the allocator lock. */
253 void GC_destroy_thread_local(GC_thread p)
255 /* We currently only do this from the thread itself or from */
256 /* the fork handler for a child process. */
258 GC_ASSERT(GC_getspecific(GC_thread_key) == (void *)p);
260 return_freelists(p -> ptrfree_freelists, GC_aobjfreelist);
261 return_freelists(p -> normal_freelists, GC_objfreelist);
262 # ifdef GC_GCJ_SUPPORT
263 return_freelists(p -> gcj_freelists, GC_gcjobjfreelist);
267 extern GC_PTR GC_generic_malloc_many();
269 GC_PTR GC_local_malloc(size_t bytes)
271 if (EXPECT(!SMALL_ENOUGH(bytes),0)) {
272 return(GC_malloc(bytes));
274 int index = INDEX_FROM_BYTES(bytes);
277 # if defined(REDIRECT_MALLOC) && !defined(USE_PTHREAD_SPECIFIC)
278 GC_key_t k = GC_thread_key;
282 # if defined(REDIRECT_MALLOC) && !defined(USE_PTHREAD_SPECIFIC)
283 if (EXPECT(0 == k, 0)) {
284 /* This can happen if we get called when the world is */
285 /* being initialized. Whether we can actually complete */
286 /* the initialization then is unclear. */
291 tsd = GC_getspecific(GC_thread_key);
292 # ifdef GC_ASSERTIONS
294 GC_ASSERT(tsd == (void *)GC_lookup_thread(pthread_self()));
297 my_fl = ((GC_thread)tsd) -> normal_freelists + index;
299 if (EXPECT((word)my_entry >= HBLKSIZE, 1)) {
300 ptr_t next = obj_link(my_entry);
301 GC_PTR result = (GC_PTR)my_entry;
303 obj_link(my_entry) = 0;
304 PREFETCH_FOR_WRITE(next);
306 } else if ((word)my_entry - 1 < DIRECT_GRANULES) {
307 *my_fl = my_entry + index + 1;
308 return GC_malloc(bytes);
310 GC_generic_malloc_many(BYTES_FROM_INDEX(index), NORMAL, my_fl);
311 if (*my_fl == 0) return GC_oom_fn(bytes);
312 return GC_local_malloc(bytes);
317 GC_PTR GC_local_malloc_atomic(size_t bytes)
319 if (EXPECT(!SMALL_ENOUGH(bytes), 0)) {
320 return(GC_malloc_atomic(bytes));
322 int index = INDEX_FROM_BYTES(bytes);
323 ptr_t * my_fl = ((GC_thread)GC_getspecific(GC_thread_key))
324 -> ptrfree_freelists + index;
325 ptr_t my_entry = *my_fl;
327 if (EXPECT((word)my_entry >= HBLKSIZE, 1)) {
328 GC_PTR result = (GC_PTR)my_entry;
329 *my_fl = obj_link(my_entry);
331 } else if ((word)my_entry - 1 < DIRECT_GRANULES) {
332 *my_fl = my_entry + index + 1;
333 return GC_malloc_atomic(bytes);
335 GC_generic_malloc_many(BYTES_FROM_INDEX(index), PTRFREE, my_fl);
336 /* *my_fl is updated while the collector is excluded; */
337 /* the free list is always visible to the collector as */
339 if (*my_fl == 0) return GC_oom_fn(bytes);
340 return GC_local_malloc_atomic(bytes);
345 #ifdef GC_GCJ_SUPPORT
347 #include "include/gc_gcj.h"
350 extern GC_bool GC_gcj_malloc_initialized;
353 extern int GC_gcj_kind;
355 GC_PTR GC_local_gcj_malloc(size_t bytes,
356 void * ptr_to_struct_containing_descr)
358 GC_ASSERT(GC_gcj_malloc_initialized);
359 if (EXPECT(!SMALL_ENOUGH(bytes), 0)) {
360 return GC_gcj_malloc(bytes, ptr_to_struct_containing_descr);
362 int index = INDEX_FROM_BYTES(bytes);
363 ptr_t * my_fl = ((GC_thread)GC_getspecific(GC_thread_key))
364 -> gcj_freelists + index;
365 ptr_t my_entry = *my_fl;
366 if (EXPECT((word)my_entry >= HBLKSIZE, 1)) {
367 GC_PTR result = (GC_PTR)my_entry;
368 GC_ASSERT(!GC_incremental);
369 /* We assert that any concurrent marker will stop us. */
370 /* Thus it is impossible for a mark procedure to see the */
371 /* allocation of the next object, but to see this object */
372 /* still containing a free list pointer. Otherwise the */
373 /* marker might find a random "mark descriptor". */
374 *(volatile ptr_t *)my_fl = obj_link(my_entry);
375 /* We must update the freelist before we store the pointer. */
376 /* Otherwise a GC at this point would see a corrupted */
378 /* A memory barrier is probably never needed, since the */
379 /* action of stopping this thread will cause prior writes */
381 GC_ASSERT(((void * volatile *)result)[1] == 0);
382 *(void * volatile *)result = ptr_to_struct_containing_descr;
384 } else if ((word)my_entry - 1 < DIRECT_GRANULES) {
385 if (!GC_incremental) *my_fl = my_entry + index + 1;
386 /* In the incremental case, we always have to take this */
387 /* path. Thus we leave the counter alone. */
388 return GC_gcj_malloc(bytes, ptr_to_struct_containing_descr);
390 GC_generic_malloc_many(BYTES_FROM_INDEX(index), GC_gcj_kind, my_fl);
391 if (*my_fl == 0) return GC_oom_fn(bytes);
392 return GC_local_gcj_malloc(bytes, ptr_to_struct_containing_descr);
397 #endif /* GC_GCJ_SUPPORT */
399 # else /* !THREAD_LOCAL_ALLOC && !DBG_HDRS_ALL */
401 # define GC_destroy_thread_local(t)
403 # endif /* !THREAD_LOCAL_ALLOC */
407 To make sure that we're using LinuxThreads and not some other thread
408 package, we generate a dummy reference to `pthread_kill_other_threads_np'
409 (was `__pthread_initial_thread_bos' but that disappeared),
410 which is a symbol defined in LinuxThreads, but (hopefully) not in other
413 We no longer do this, since this code is now portable enough that it might
414 actually work for something else.
416 void (*dummy_var_to_force_linux_threads)() = pthread_kill_other_threads_np;
419 long GC_nprocs = 1; /* Number of processors. We may not have */
420 /* access to all of them, but this is as good */
421 /* a guess as any ... */
426 # define MAX_MARKERS 16
429 static ptr_t marker_sp[MAX_MARKERS] = {0};
431 void * GC_mark_thread(void * id)
435 marker_sp[(word)id] = GC_approx_sp();
436 for (;; ++my_mark_no) {
437 /* GC_mark_no is passed only to allow GC_help_marker to terminate */
438 /* promptly. This is important if it were called from the signal */
439 /* handler or from the GC lock acquisition code. Under Linux, it's */
440 /* not safe to call it from a signal handler, since it uses mutexes */
441 /* and condition variables. Since it is called only here, the */
442 /* argument is unnecessary. */
443 if (my_mark_no < GC_mark_no || my_mark_no > GC_mark_no + 2) {
444 /* resynchronize if we get far off, e.g. because GC_mark_no */
446 my_mark_no = GC_mark_no;
448 # ifdef DEBUG_THREADS
449 GC_printf1("Starting mark helper for mark number %ld\n", my_mark_no);
451 GC_help_marker(my_mark_no);
455 extern long GC_markers; /* Number of mark threads we would */
456 /* like to have. Includes the */
457 /* initiating thread. */
459 pthread_t GC_mark_threads[MAX_MARKERS];
461 #define PTHREAD_CREATE REAL_FUNC(pthread_create)
463 static void start_mark_threads()
468 if (GC_markers > MAX_MARKERS) {
469 WARN("Limiting number of mark threads\n", 0);
470 GC_markers = MAX_MARKERS;
472 if (0 != pthread_attr_init(&attr)) ABORT("pthread_attr_init failed");
474 if (0 != pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED))
475 ABORT("pthread_attr_setdetachstate failed");
477 # if defined(HPUX) || defined(GC_DGUX386_THREADS)
478 /* Default stack size is usually too small: fix it. */
479 /* Otherwise marker threads or GC may run out of */
481 # define MIN_STACK_SIZE (8*HBLKSIZE*sizeof(word))
486 if (pthread_attr_getstacksize(&attr, &old_size) != 0)
487 ABORT("pthread_attr_getstacksize failed\n");
488 if (old_size < MIN_STACK_SIZE) {
489 if (pthread_attr_setstacksize(&attr, MIN_STACK_SIZE) != 0)
490 ABORT("pthread_attr_setstacksize failed\n");
493 # endif /* HPUX || GC_DGUX386_THREADS */
495 if (GC_print_stats) {
496 GC_printf1("Starting %ld marker threads\n", GC_markers - 1);
499 for (i = 0; i < GC_markers - 1; ++i) {
500 if (0 != PTHREAD_CREATE(GC_mark_threads + i, &attr,
501 GC_mark_thread, (void *)(word)i)) {
502 WARN("Marker thread creation failed, errno = %ld.\n", errno);
507 #else /* !PARALLEL_MARK */
509 static __inline__ void start_mark_threads()
513 #endif /* !PARALLEL_MARK */
515 GC_bool GC_thr_initialized = FALSE;
517 volatile GC_thread GC_threads[THREAD_TABLE_SZ];
519 void GC_push_thread_structures GC_PROTO((void))
521 GC_push_all((ptr_t)(GC_threads), (ptr_t)(GC_threads)+sizeof(GC_threads));
522 # if defined(THREAD_LOCAL_ALLOC) && !defined(DBG_HDRS_ALL)
523 GC_push_all((ptr_t)(&GC_thread_key),
524 (ptr_t)(&GC_thread_key)+sizeof(&GC_thread_key));
528 #ifdef THREAD_LOCAL_ALLOC
529 /* We must explicitly mark ptrfree and gcj free lists, since the free */
530 /* list links wouldn't otherwise be found. We also set them in the */
531 /* normal free lists, since that involves touching less memory than if */
532 /* we scanned them normally. */
533 void GC_mark_thread_local_free_lists(void)
539 for (i = 0; i < THREAD_TABLE_SZ; ++i) {
540 for (p = GC_threads[i]; 0 != p; p = p -> next) {
541 for (j = 1; j < NFREELISTS; ++j) {
542 q = p -> ptrfree_freelists[j];
543 if ((word)q > HBLKSIZE) GC_set_fl_marks(q);
544 q = p -> normal_freelists[j];
545 if ((word)q > HBLKSIZE) GC_set_fl_marks(q);
546 # ifdef GC_GCJ_SUPPORT
547 q = p -> gcj_freelists[j];
548 if ((word)q > HBLKSIZE) GC_set_fl_marks(q);
549 # endif /* GC_GCJ_SUPPORT */
554 #endif /* THREAD_LOCAL_ALLOC */
556 static struct GC_Thread_Rep first_thread;
558 /* Add a thread to GC_threads. We assume it wasn't already there. */
559 /* Caller holds allocation lock. */
560 GC_thread GC_new_thread(pthread_t id)
562 int hv = ((word)id) % THREAD_TABLE_SZ;
564 static GC_bool first_thread_used = FALSE;
566 if (!first_thread_used) {
567 result = &first_thread;
568 first_thread_used = TRUE;
570 result = (struct GC_Thread_Rep *)
571 GC_INTERNAL_MALLOC(sizeof(struct GC_Thread_Rep), NORMAL);
573 if (result == 0) return(0);
575 result -> next = GC_threads[hv];
576 GC_threads[hv] = result;
577 GC_ASSERT(result -> flags == 0 && result -> thread_blocked == 0);
581 /* Delete a thread from GC_threads. We assume it is there. */
582 /* (The code intentionally traps if it wasn't.) */
583 /* Caller holds allocation lock. */
584 void GC_delete_thread(pthread_t id)
586 int hv = ((word)id) % THREAD_TABLE_SZ;
587 register GC_thread p = GC_threads[hv];
588 register GC_thread prev = 0;
590 while (!pthread_equal(p -> id, id)) {
595 GC_threads[hv] = p -> next;
597 prev -> next = p -> next;
602 /* If a thread has been joined, but we have not yet */
603 /* been notified, then there may be more than one thread */
604 /* in the table with the same pthread id. */
605 /* This is OK, but we need a way to delete a specific one. */
606 void GC_delete_gc_thread(pthread_t id, GC_thread gc_id)
608 int hv = ((word)id) % THREAD_TABLE_SZ;
609 register GC_thread p = GC_threads[hv];
610 register GC_thread prev = 0;
617 GC_threads[hv] = p -> next;
619 prev -> next = p -> next;
624 /* Return a GC_thread corresponding to a given pthread_t. */
625 /* Returns 0 if it's not there. */
626 /* Caller holds allocation lock or otherwise inhibits */
628 /* If there is more than one thread with the given id we */
629 /* return the most recent one. */
630 GC_thread GC_lookup_thread(pthread_t id)
632 int hv = ((word)id) % THREAD_TABLE_SZ;
633 register GC_thread p = GC_threads[hv];
635 while (p != 0 && !pthread_equal(p -> id, id)) p = p -> next;
640 /* Remove all entries from the GC_threads table, except the */
641 /* one for the current thread. We need to do this in the child */
642 /* process after a fork(), since only the current thread */
643 /* survives in the child. */
644 void GC_remove_all_threads_but_me(void)
646 pthread_t self = pthread_self();
648 GC_thread p, next, me;
650 for (hv = 0; hv < THREAD_TABLE_SZ; ++hv) {
652 for (p = GC_threads[hv]; 0 != p; p = next) {
654 if (p -> id == self) {
658 # ifdef THREAD_LOCAL_ALLOC
659 if (!(p -> flags & FINISHED)) {
660 GC_destroy_thread_local(p);
662 # endif /* THREAD_LOCAL_ALLOC */
663 if (p != &first_thread) GC_INTERNAL_FREE(p);
669 #endif /* HANDLE_FORK */
671 #ifdef USE_PROC_FOR_LIBRARIES
672 int GC_segment_is_thread_stack(ptr_t lo, ptr_t hi)
677 # ifdef PARALLEL_MARK
678 for (i = 0; i < GC_markers; ++i) {
679 if (marker_sp[i] > lo & marker_sp[i] < hi) return 1;
682 for (i = 0; i < THREAD_TABLE_SZ; i++) {
683 for (p = GC_threads[i]; p != 0; p = p -> next) {
684 if (0 != p -> stack_end) {
685 # ifdef STACK_GROWS_UP
686 if (p -> stack_end >= lo && p -> stack_end < hi) return 1;
687 # else /* STACK_GROWS_DOWN */
688 if (p -> stack_end > lo && p -> stack_end <= hi) return 1;
695 #endif /* USE_PROC_FOR_LIBRARIES */
697 #ifdef GC_LINUX_THREADS
698 /* Return the number of processors, or i<= 0 if it can't be determined. */
701 /* Should be "return sysconf(_SC_NPROCESSORS_ONLN);" but that */
702 /* appears to be buggy in many cases. */
703 /* We look for lines "cpu<n>" in /proc/stat. */
704 # define STAT_BUF_SIZE 4096
705 # define STAT_READ read
706 /* If read is wrapped, this may need to be redefined to call */
708 char stat_buf[STAT_BUF_SIZE];
711 /* Some old kernels only have a single "cpu nnnn ..." */
712 /* entry in /proc/stat. We identify those as */
716 f = open("/proc/stat", O_RDONLY);
717 if (f < 0 || (len = STAT_READ(f, stat_buf, STAT_BUF_SIZE)) < 100) {
718 WARN("Couldn't read /proc/stat\n", 0);
721 for (i = 0; i < len - 100; ++i) {
722 if (stat_buf[i] == '\n' && stat_buf[i+1] == 'c'
723 && stat_buf[i+2] == 'p' && stat_buf[i+3] == 'u') {
724 int cpu_no = atoi(stat_buf + i + 4);
725 if (cpu_no >= result) result = cpu_no + 1;
731 #endif /* GC_LINUX_THREADS */
733 /* We hold the GC lock. Wait until an in-progress GC has finished. */
734 /* Repeatedly RELEASES GC LOCK in order to wait. */
735 /* If wait_for_all is true, then we exit with the GC lock held and no */
736 /* collection in progress; otherwise we just wait for the current GC */
738 extern GC_bool GC_collection_in_progress();
739 void GC_wait_for_gc_completion(GC_bool wait_for_all)
741 if (GC_incremental && GC_collection_in_progress()) {
742 int old_gc_no = GC_gc_no;
744 /* Make sure that no part of our stack is still on the mark stack, */
745 /* since it's about to be unmapped. */
746 while (GC_incremental && GC_collection_in_progress()
747 && (wait_for_all || old_gc_no == GC_gc_no)) {
749 GC_in_thread_creation = TRUE;
750 GC_collect_a_little_inner(1);
751 GC_in_thread_creation = FALSE;
761 /* Procedures called before and after a fork. The goal here is to make */
762 /* it safe to call GC_malloc() in a forked child. It's unclear that is */
763 /* attainable, since the single UNIX spec seems to imply that one */
764 /* should only call async-signal-safe functions, and we probably can't */
765 /* quite guarantee that. But we give it our best shot. (That same */
766 /* spec also implies that it's not safe to call the system malloc */
767 /* between fork() and exec(). Thus we're doing no worse than it. */
769 /* Called before a fork() */
770 void GC_fork_prepare_proc(void)
772 /* Acquire all relevant locks, so that after releasing the locks */
773 /* the child will see a consistent state in which monitor */
774 /* invariants hold. Unfortunately, we can't acquire libc locks */
775 /* we might need, and there seems to be no guarantee that libc */
776 /* must install a suitable fork handler. */
777 /* Wait for an ongoing GC to finish, since we can't finish it in */
778 /* the (one remaining thread in) the child. */
780 # if defined(PARALLEL_MARK) || defined(THREAD_LOCAL_ALLOC)
781 GC_wait_for_reclaim();
783 GC_wait_for_gc_completion(TRUE);
784 # if defined(PARALLEL_MARK) || defined(THREAD_LOCAL_ALLOC)
785 GC_acquire_mark_lock();
789 /* Called in parent after a fork() */
790 void GC_fork_parent_proc(void)
792 # if defined(PARALLEL_MARK) || defined(THREAD_LOCAL_ALLOC)
793 GC_release_mark_lock();
798 /* Called in child after a fork() */
799 void GC_fork_child_proc(void)
801 /* Clean up the thread table, so that just our thread is left. */
802 # if defined(PARALLEL_MARK) || defined(THREAD_LOCAL_ALLOC)
803 GC_release_mark_lock();
805 GC_remove_all_threads_but_me();
806 # ifdef PARALLEL_MARK
807 /* Turn off parallel marking in the child, since we are probably */
808 /* just going to exec, and we would have to restart mark threads. */
811 # endif /* PARALLEL_MARK */
814 #endif /* HANDLE_FORK */
816 #if defined(GC_DGUX386_THREADS)
817 /* Return the number of processors, or i<= 0 if it can't be determined. */
820 /* <takis@XFree86.Org> */
822 struct dg_sys_info_pm_info pm_sysinfo;
825 status = dg_sys_info((long int *) &pm_sysinfo,
826 DG_SYS_INFO_PM_INFO_TYPE, DG_SYS_INFO_PM_CURRENT_VERSION);
828 /* set -1 for error */
832 numCpus = pm_sysinfo.idle_vp_count;
834 # ifdef DEBUG_THREADS
835 GC_printf1("Number of active CPUs in this system: %d\n", numCpus);
839 #endif /* GC_DGUX386_THREADS */
841 /* We hold the allocation lock. */
844 # ifndef GC_DARWIN_THREADS
849 if (GC_thr_initialized) return;
850 GC_thr_initialized = TRUE;
853 /* Prepare for a possible fork. */
854 pthread_atfork(GC_fork_prepare_proc, GC_fork_parent_proc,
856 # endif /* HANDLE_FORK */
857 /* Add the initial thread, so we can stop it. */
858 t = GC_new_thread(pthread_self());
859 # ifdef GC_DARWIN_THREADS
860 t -> stop_info.mach_thread = mach_thread_self();
862 t -> stop_info.stack_ptr = (ptr_t)(&dummy);
864 t -> flags = DETACHED | MAIN_THREAD;
870 char * nprocs_string = GETENV("GC_NPROCS");
872 if (nprocs_string != NULL) GC_nprocs = atoi(nprocs_string);
874 if (GC_nprocs <= 0) {
875 # if defined(GC_HPUX_THREADS)
876 GC_nprocs = pthread_num_processors_np();
878 # if defined(GC_OSF1_THREADS) || defined(GC_AIX_THREADS)
879 GC_nprocs = sysconf(_SC_NPROCESSORS_ONLN);
880 if (GC_nprocs <= 0) GC_nprocs = 1;
882 # if defined(GC_IRIX_THREADS)
883 GC_nprocs = sysconf(_SC_NPROC_ONLN);
884 if (GC_nprocs <= 0) GC_nprocs = 1;
886 # if defined(GC_DARWIN_THREADS) || defined(GC_FREEBSD_THREADS)
888 size_t len = sizeof(ncpus);
889 sysctl((int[2]) {CTL_HW, HW_NCPU}, 2, &ncpus, &len, NULL, 0);
892 # if defined(GC_LINUX_THREADS) || defined(GC_DGUX386_THREADS)
893 GC_nprocs = GC_get_nprocs();
896 if (GC_nprocs <= 0) {
897 WARN("GC_get_nprocs() returned %ld\n", GC_nprocs);
899 # ifdef PARALLEL_MARK
903 # ifdef PARALLEL_MARK
905 char * markers_string = GETENV("GC_MARKERS");
906 if (markers_string != NULL) {
907 GC_markers = atoi(markers_string);
909 GC_markers = GC_nprocs;
914 # ifdef PARALLEL_MARK
916 if (GC_print_stats) {
917 GC_printf2("Number of processors = %ld, "
918 "number of marker threads = %ld\n", GC_nprocs, GC_markers);
921 if (GC_markers == 1) {
924 if (GC_print_stats) {
925 GC_printf0("Single marker thread, turning off parallel marking\n");
930 /* Disable true incremental collection, but generational is OK. */
931 GC_time_limit = GC_TIME_UNLIMITED;
933 /* If we are using a parallel marker, actually start helper threads. */
934 if (GC_parallel) start_mark_threads();
939 /* Perform all initializations, including those that */
940 /* may require allocation. */
941 /* Called without allocation lock. */
942 /* Must be called before a second thread is created. */
943 /* Called without allocation lock. */
944 void GC_init_parallel()
946 if (parallel_initialized) return;
947 parallel_initialized = TRUE;
949 /* GC_init() calls us back, so set flag first. */
950 if (!GC_is_initialized) GC_init();
951 /* Initialize thread local free lists if used. */
952 # if defined(THREAD_LOCAL_ALLOC) && !defined(DBG_HDRS_ALL)
954 GC_init_thread_local(GC_lookup_thread(pthread_self()));
960 #if !defined(GC_DARWIN_THREADS)
961 int WRAP_FUNC(pthread_sigmask)(int how, const sigset_t *set, sigset_t *oset)
965 if (set != NULL && (how == SIG_BLOCK || how == SIG_SETMASK)) {
967 sigdelset(&fudged_set, SIG_SUSPEND);
970 return(REAL_FUNC(pthread_sigmask)(how, set, oset));
972 #endif /* !GC_DARWIN_THREADS */
974 /* Wrappers for functions that are likely to block for an appreciable */
975 /* length of time. Must be called in pairs, if at all. */
976 /* Nothing much beyond the system call itself should be executed */
979 void GC_start_blocking(void) {
983 me = GC_lookup_thread(pthread_self());
984 GC_ASSERT(!(me -> thread_blocked));
986 me -> stop_info.stack_ptr = (ptr_t)GC_save_regs_in_stack();
988 # ifndef GC_DARWIN_THREADS
989 me -> stop_info.stack_ptr = (ptr_t)GC_approx_sp();
993 me -> backing_store_ptr = (ptr_t)GC_save_regs_in_stack() + SP_SLOP;
995 /* Add some slop to the stack pointer, since the wrapped call may */
996 /* end up pushing more callee-save registers. */
997 # ifndef GC_DARWIN_THREADS
998 # ifdef STACK_GROWS_UP
999 me -> stop_info.stack_ptr += SP_SLOP;
1001 me -> stop_info.stack_ptr -= SP_SLOP;
1004 me -> thread_blocked = TRUE;
1008 void GC_end_blocking(void) {
1010 LOCK(); /* This will block if the world is stopped. */
1011 me = GC_lookup_thread(pthread_self());
1012 GC_ASSERT(me -> thread_blocked);
1013 me -> thread_blocked = FALSE;
1017 #if defined(GC_DGUX386_THREADS)
1018 #define __d10_sleep sleep
1019 #endif /* GC_DGUX386_THREADS */
1021 /* A wrapper for the standard C sleep function */
1022 int WRAP_FUNC(sleep) (unsigned int seconds)
1026 GC_start_blocking();
1027 result = REAL_FUNC(sleep)(seconds);
1033 void *(*start_routine)(void *);
1036 sem_t registered; /* 1 ==> in our thread table, but */
1037 /* parent hasn't yet noticed. */
1040 /* Called at thread exit. */
1041 /* Never called for main thread. That's OK, since it */
1042 /* results in at most a tiny one-time leak. And */
1043 /* linuxthreads doesn't reclaim the main threads */
1044 /* resources or id anyway. */
1045 void GC_thread_exit_proc(void *arg)
1050 me = GC_lookup_thread(pthread_self());
1051 GC_destroy_thread_local(me);
1052 if (me -> flags & DETACHED) {
1053 GC_delete_thread(pthread_self());
1055 me -> flags |= FINISHED;
1057 # if defined(THREAD_LOCAL_ALLOC) && !defined(USE_PTHREAD_SPECIFIC) \
1058 && !defined(USE_COMPILER_TLS) && !defined(DBG_HDRS_ALL)
1059 GC_remove_specific(GC_thread_key);
1061 /* The following may run the GC from "nonexistent" thread. */
1062 GC_wait_for_gc_completion(FALSE);
1066 int WRAP_FUNC(pthread_join)(pthread_t thread, void **retval)
1069 GC_thread thread_gc_id;
1072 thread_gc_id = GC_lookup_thread(thread);
1073 /* This is guaranteed to be the intended one, since the thread id */
1074 /* cant have been recycled by pthreads. */
1076 result = REAL_FUNC(pthread_join)(thread, retval);
1077 # if defined (GC_FREEBSD_THREADS)
1078 /* On FreeBSD, the wrapped pthread_join() sometimes returns (what
1079 appears to be) a spurious EINTR which caused the test and real code
1080 to gratuitously fail. Having looked at system pthread library source
1081 code, I see how this return code may be generated. In one path of
1082 code, pthread_join() just returns the errno setting of the thread
1083 being joined. This does not match the POSIX specification or the
1084 local man pages thus I have taken the liberty to catch this one
1085 spurious return value properly conditionalized on GC_FREEBSD_THREADS. */
1086 if (result == EINTR) result = 0;
1090 /* Here the pthread thread id may have been recycled. */
1091 GC_delete_gc_thread(thread, thread_gc_id);
1098 WRAP_FUNC(pthread_detach)(pthread_t thread)
1101 GC_thread thread_gc_id;
1104 thread_gc_id = GC_lookup_thread(thread);
1106 result = REAL_FUNC(pthread_detach)(thread);
1109 thread_gc_id -> flags |= DETACHED;
1110 /* Here the pthread thread id may have been recycled. */
1111 if (thread_gc_id -> flags & FINISHED) {
1112 GC_delete_gc_thread(thread, thread_gc_id);
1119 GC_bool GC_in_thread_creation = FALSE;
1121 void * GC_start_routine(void * arg)
1124 struct start_info * si = arg;
1127 pthread_t my_pthread;
1128 void *(*start)(void *);
1131 my_pthread = pthread_self();
1132 # ifdef DEBUG_THREADS
1133 GC_printf1("Starting thread 0x%lx\n", my_pthread);
1134 GC_printf1("pid = %ld\n", (long) getpid());
1135 GC_printf1("sp = 0x%lx\n", (long) &arg);
1138 GC_in_thread_creation = TRUE;
1139 me = GC_new_thread(my_pthread);
1140 GC_in_thread_creation = FALSE;
1141 #ifdef GC_DARWIN_THREADS
1142 me -> stop_info.mach_thread = mach_thread_self();
1144 me -> stop_info.stack_ptr = 0;
1146 me -> flags = si -> flags;
1147 /* me -> stack_end = GC_linux_stack_base(); -- currently (11/99) */
1148 /* doesn't work because the stack base in /proc/self/stat is the */
1149 /* one for the main thread. There is a strong argument that that's */
1150 /* a kernel bug, but a pervasive one. */
1151 # ifdef STACK_GROWS_DOWN
1152 me -> stack_end = (ptr_t)(((word)(&dummy) + (GC_page_size - 1))
1153 & ~(GC_page_size - 1));
1154 # ifndef GC_DARWIN_THREADS
1155 me -> stop_info.stack_ptr = me -> stack_end - 0x10;
1157 /* Needs to be plausible, since an asynchronous stack mark */
1158 /* should not crash. */
1160 me -> stack_end = (ptr_t)((word)(&dummy) & ~(GC_page_size - 1));
1161 me -> stop_info.stack_ptr = me -> stack_end + 0x10;
1163 /* This is dubious, since we may be more than a page into the stack, */
1164 /* and hence skip some of it, though it's not clear that matters. */
1166 me -> backing_store_end = (ptr_t)
1167 (GC_save_regs_in_stack() & ~(GC_page_size - 1));
1168 /* This is also < 100% convincing. We should also read this */
1169 /* from /proc, but the hook to do so isn't there yet. */
1172 start = si -> start_routine;
1173 # ifdef DEBUG_THREADS
1174 GC_printf1("start_routine = 0x%lx\n", start);
1176 start_arg = si -> arg;
1177 sem_post(&(si -> registered)); /* Last action on si. */
1178 /* OK to deallocate. */
1179 pthread_cleanup_push(GC_thread_exit_proc, 0);
1180 # if defined(THREAD_LOCAL_ALLOC) && !defined(DBG_HDRS_ALL)
1182 GC_init_thread_local(me);
1185 result = (*start)(start_arg);
1187 GC_printf1("Finishing thread 0x%x\n", pthread_self());
1189 me -> status = result;
1190 pthread_cleanup_pop(1);
1191 /* Cleanup acquires lock, ensuring that we can't exit */
1192 /* while a collection that thinks we're alive is trying to stop */
1198 WRAP_FUNC(pthread_create)(pthread_t *new_thread,
1199 const pthread_attr_t *attr,
1200 void *(*start_routine)(void *), void *arg)
1205 struct start_info * si;
1206 /* This is otherwise saved only in an area mmapped by the thread */
1207 /* library, which isn't visible to the collector. */
1209 /* We resist the temptation to muck with the stack size here, */
1210 /* even if the default is unreasonably small. That's the client's */
1211 /* responsibility. */
1214 si = (struct start_info *)GC_INTERNAL_MALLOC(sizeof(struct start_info),
1217 if (!parallel_initialized) GC_init_parallel();
1218 if (0 == si) return(ENOMEM);
1219 sem_init(&(si -> registered), 0, 0);
1220 si -> start_routine = start_routine;
1223 if (!GC_thr_initialized) GC_thr_init();
1224 # ifdef GC_ASSERTIONS
1228 pthread_attr_t my_attr;
1229 pthread_attr_init(&my_attr);
1230 pthread_attr_getstacksize(&my_attr, &stack_size);
1232 pthread_attr_getstacksize(attr, &stack_size);
1234 # ifdef PARALLEL_MARK
1235 GC_ASSERT(stack_size >= (8*HBLKSIZE*sizeof(word)));
1237 /* FreeBSD-5.3/Alpha: default pthread stack is 64K, */
1238 /* HBLKSIZE=8192, sizeof(word)=8 */
1239 GC_ASSERT(stack_size >= 65536);
1241 /* Our threads may need to do some work for the GC. */
1242 /* Ridiculously small threads won't work, and they */
1243 /* probably wouldn't work anyway. */
1247 detachstate = PTHREAD_CREATE_JOINABLE;
1249 pthread_attr_getdetachstate(attr, &detachstate);
1251 if (PTHREAD_CREATE_DETACHED == detachstate) my_flags |= DETACHED;
1252 si -> flags = my_flags;
1254 # ifdef DEBUG_THREADS
1255 GC_printf1("About to start new thread from thread 0x%X\n",
1259 result = REAL_FUNC(pthread_create)(new_thread, attr, GC_start_routine, si);
1261 # ifdef DEBUG_THREADS
1262 GC_printf1("Started thread 0x%X\n", *new_thread);
1264 /* Wait until child has been added to the thread table. */
1265 /* This also ensures that we hold onto si until the child is done */
1266 /* with it. Thus it doesn't matter whether it is otherwise */
1267 /* visible to the collector. */
1269 while (0 != sem_wait(&(si -> registered))) {
1270 if (EINTR != errno) ABORT("sem_wait failed");
1273 sem_destroy(&(si -> registered));
1275 GC_INTERNAL_FREE(si);
1281 #ifdef GENERIC_COMPARE_AND_SWAP
1282 pthread_mutex_t GC_compare_and_swap_lock = PTHREAD_MUTEX_INITIALIZER;
1284 GC_bool GC_compare_and_exchange(volatile GC_word *addr,
1285 GC_word old, GC_word new_val)
1288 pthread_mutex_lock(&GC_compare_and_swap_lock);
1295 pthread_mutex_unlock(&GC_compare_and_swap_lock);
1299 GC_word GC_atomic_add(volatile GC_word *addr, GC_word how_much)
1302 pthread_mutex_lock(&GC_compare_and_swap_lock);
1304 *addr = old + how_much;
1305 pthread_mutex_unlock(&GC_compare_and_swap_lock);
1309 #endif /* GENERIC_COMPARE_AND_SWAP */
1310 /* Spend a few cycles in a way that can't introduce contention with */
1311 /* othre threads. */
1315 # if !defined(__GNUC__) || defined(__INTEL_COMPILER)
1316 volatile word dummy = 0;
1319 for (i = 0; i < 10; ++i) {
1320 # if defined(__GNUC__) && !defined(__INTEL_COMPILER)
1321 __asm__ __volatile__ (" " : : : "memory");
1323 /* Something that's unlikely to be optimized away. */
1329 #define SPIN_MAX 128 /* Maximum number of calls to GC_pause before */
1332 VOLATILE GC_bool GC_collecting = 0;
1333 /* A hint that we're in the collector and */
1334 /* holding the allocation lock for an */
1335 /* extended period. */
1337 #if !defined(USE_SPIN_LOCK) || defined(PARALLEL_MARK)
1338 /* If we don't want to use the below spinlock implementation, either */
1339 /* because we don't have a GC_test_and_set implementation, or because */
1340 /* we don't want to risk sleeping, we can still try spinning on */
1341 /* pthread_mutex_trylock for a while. This appears to be very */
1342 /* beneficial in many cases. */
1343 /* I suspect that under high contention this is nearly always better */
1344 /* than the spin lock. But it's a bit slower on a uniprocessor. */
1345 /* Hence we still default to the spin lock. */
1346 /* This is also used to acquire the mark lock for the parallel */
1349 /* Here we use a strict exponential backoff scheme. I don't know */
1350 /* whether that's better or worse than the above. We eventually */
1351 /* yield by calling pthread_mutex_lock(); it never makes sense to */
1352 /* explicitly sleep. */
1356 unsigned long GC_spin_count = 0;
1357 unsigned long GC_block_count = 0;
1358 unsigned long GC_unlocked_count = 0;
1361 void GC_generic_lock(pthread_mutex_t * lock)
1363 #ifndef NO_PTHREAD_TRYLOCK
1364 unsigned pause_length = 1;
1367 if (0 == pthread_mutex_trylock(lock)) {
1369 ++GC_unlocked_count;
1373 for (; pause_length <= SPIN_MAX; pause_length <<= 1) {
1374 for (i = 0; i < pause_length; ++i) {
1377 switch(pthread_mutex_trylock(lock)) {
1386 ABORT("Unexpected error from pthread_mutex_trylock");
1389 #endif /* !NO_PTHREAD_TRYLOCK */
1393 pthread_mutex_lock(lock);
1396 #endif /* !USE_SPIN_LOCK || PARALLEL_MARK */
1398 #if defined(USE_SPIN_LOCK)
1400 /* Reasonably fast spin locks. Basically the same implementation */
1401 /* as STL alloc.h. This isn't really the right way to do this. */
1402 /* but until the POSIX scheduling mess gets straightened out ... */
1404 volatile unsigned int GC_allocate_lock = 0;
1409 # define low_spin_max 30 /* spin cycles if we suspect uniprocessor */
1410 # define high_spin_max SPIN_MAX /* spin cycles for multiprocessor */
1411 static unsigned spin_max = low_spin_max;
1412 unsigned my_spin_max;
1413 static unsigned last_spins = 0;
1414 unsigned my_last_spins;
1417 if (!GC_test_and_set(&GC_allocate_lock)) {
1420 my_spin_max = spin_max;
1421 my_last_spins = last_spins;
1422 for (i = 0; i < my_spin_max; i++) {
1423 if (GC_collecting || GC_nprocs == 1) goto yield;
1424 if (i < my_last_spins/2 || GC_allocate_lock) {
1428 if (!GC_test_and_set(&GC_allocate_lock)) {
1431 * Spinning worked. Thus we're probably not being scheduled
1432 * against the other process with which we were contending.
1433 * Thus it makes sense to spin longer the next time.
1436 spin_max = high_spin_max;
1440 /* We are probably being scheduled against the other process. Sleep. */
1441 spin_max = low_spin_max;
1444 if (!GC_test_and_set(&GC_allocate_lock)) {
1447 # define SLEEP_THRESHOLD 12
1448 /* Under Linux very short sleeps tend to wait until */
1449 /* the current time quantum expires. On old Linux */
1450 /* kernels nanosleep(<= 2ms) just spins under Linux. */
1451 /* (Under 2.4, this happens only for real-time */
1452 /* processes.) We want to minimize both behaviors */
1454 if (i < SLEEP_THRESHOLD) {
1460 /* Don't wait for more than about 15msecs, even */
1461 /* under extreme contention. */
1463 ts.tv_nsec = 1 << i;
1469 #else /* !USE_SPINLOCK */
1472 #ifndef NO_PTHREAD_TRYLOCK
1473 if (1 == GC_nprocs || GC_collecting) {
1474 pthread_mutex_lock(&GC_allocate_ml);
1476 GC_generic_lock(&GC_allocate_ml);
1478 #else /* !NO_PTHREAD_TRYLOCK */
1479 pthread_mutex_lock(&GC_allocate_ml);
1480 #endif /* !NO_PTHREAD_TRYLOCK */
1483 #endif /* !USE_SPINLOCK */
1485 #if defined(PARALLEL_MARK) || defined(THREAD_LOCAL_ALLOC)
1487 #ifdef GC_ASSERTIONS
1488 pthread_t GC_mark_lock_holder = NO_THREAD;
1492 /* Ugly workaround for a linux threads bug in the final versions */
1493 /* of glibc2.1. Pthread_mutex_trylock sets the mutex owner */
1494 /* field even when it fails to acquire the mutex. This causes */
1495 /* pthread_cond_wait to die. Remove for glibc2.2. */
1496 /* According to the man page, we should use */
1497 /* PTHREAD_ERRORCHECK_MUTEX_INITIALIZER_NP, but that isn't actually */
1499 static pthread_mutex_t mark_mutex =
1500 {0, 0, 0, PTHREAD_MUTEX_ERRORCHECK_NP, {0, 0}};
1502 static pthread_mutex_t mark_mutex = PTHREAD_MUTEX_INITIALIZER;
1505 static pthread_cond_t builder_cv = PTHREAD_COND_INITIALIZER;
1507 void GC_acquire_mark_lock()
1510 if (pthread_mutex_lock(&mark_mutex) != 0) {
1511 ABORT("pthread_mutex_lock failed");
1514 GC_generic_lock(&mark_mutex);
1515 # ifdef GC_ASSERTIONS
1516 GC_mark_lock_holder = pthread_self();
1520 void GC_release_mark_lock()
1522 GC_ASSERT(GC_mark_lock_holder == pthread_self());
1523 # ifdef GC_ASSERTIONS
1524 GC_mark_lock_holder = NO_THREAD;
1526 if (pthread_mutex_unlock(&mark_mutex) != 0) {
1527 ABORT("pthread_mutex_unlock failed");
1531 /* Collector must wait for a freelist builders for 2 reasons: */
1532 /* 1) Mark bits may still be getting examined without lock. */
1533 /* 2) Partial free lists referenced only by locals may not be scanned */
1534 /* correctly, e.g. if they contain "pointer-free" objects, since the */
1535 /* free-list link may be ignored. */
1536 void GC_wait_builder()
1538 GC_ASSERT(GC_mark_lock_holder == pthread_self());
1539 # ifdef GC_ASSERTIONS
1540 GC_mark_lock_holder = NO_THREAD;
1542 if (pthread_cond_wait(&builder_cv, &mark_mutex) != 0) {
1543 ABORT("pthread_cond_wait failed");
1545 GC_ASSERT(GC_mark_lock_holder == NO_THREAD);
1546 # ifdef GC_ASSERTIONS
1547 GC_mark_lock_holder = pthread_self();
1551 void GC_wait_for_reclaim()
1553 GC_acquire_mark_lock();
1554 while (GC_fl_builder_count > 0) {
1557 GC_release_mark_lock();
1560 void GC_notify_all_builder()
1562 GC_ASSERT(GC_mark_lock_holder == pthread_self());
1563 if (pthread_cond_broadcast(&builder_cv) != 0) {
1564 ABORT("pthread_cond_broadcast failed");
1568 #endif /* PARALLEL_MARK || THREAD_LOCAL_ALLOC */
1570 #ifdef PARALLEL_MARK
1572 static pthread_cond_t mark_cv = PTHREAD_COND_INITIALIZER;
1574 void GC_wait_marker()
1576 GC_ASSERT(GC_mark_lock_holder == pthread_self());
1577 # ifdef GC_ASSERTIONS
1578 GC_mark_lock_holder = NO_THREAD;
1580 if (pthread_cond_wait(&mark_cv, &mark_mutex) != 0) {
1581 ABORT("pthread_cond_wait failed");
1583 GC_ASSERT(GC_mark_lock_holder == NO_THREAD);
1584 # ifdef GC_ASSERTIONS
1585 GC_mark_lock_holder = pthread_self();
1589 void GC_notify_all_marker()
1591 if (pthread_cond_broadcast(&mark_cv) != 0) {
1592 ABORT("pthread_cond_broadcast failed");
1596 #endif /* PARALLEL_MARK */
1598 # endif /* GC_LINUX_THREADS and friends */