2 * This software is part of the SBCL system. See the README file for
5 * This software is derived from the CMU CL system, which was
6 * written at Carnegie Mellon University and released into the
7 * public domain. The software is in the public domain and is
8 * provided with absolutely no warranty. See the COPYING and CREDITS
9 * files for more information.
17 #ifndef LISP_FEATURE_WIN32
23 #include <sys/types.h>
24 #ifndef LISP_FEATURE_WIN32
29 #include "validate.h" /* for CONTROL_STACK_SIZE etc */
33 #include "target-arch-os.h"
37 #include "genesis/cons.h"
38 #include "genesis/fdefn.h"
39 #include "interr.h" /* for lose() */
40 #include "gc-internal.h"
42 #ifdef LISP_FEATURE_WIN32
44 * Win32 doesn't have SIGSTKSZ, and we're not switching stacks anyway,
45 * so define it arbitrarily
50 #if defined(LISP_FEATURE_DARWIN) && defined(LISP_FEATURE_SB_THREAD)
51 #define QUEUE_FREEABLE_THREAD_STACKS
54 #ifdef LISP_FEATURE_FREEBSD
55 #define CREATE_CLEANUP_THREAD
56 #define LOCK_CREATE_THREAD
59 #define ALIEN_STACK_SIZE (1*1024*1024) /* 1Mb size chosen at random */
61 struct freeable_stack {
62 #ifdef QUEUE_FREEABLE_THREAD_STACKS
63 struct freeable_stack *next;
65 os_thread_t os_thread;
66 os_vm_address_t stack;
70 #ifdef QUEUE_FREEABLE_THREAD_STACKS
71 static struct freeable_stack * volatile freeable_stack_queue = 0;
72 static int freeable_stack_count = 0;
73 pthread_mutex_t freeable_stack_lock = PTHREAD_MUTEX_INITIALIZER;
75 static struct freeable_stack * volatile freeable_stack = 0;
78 int dynamic_values_bytes=4096*sizeof(lispobj); /* same for all threads */
79 struct thread * volatile all_threads;
80 extern struct interrupt_data * global_interrupt_data;
82 #ifdef LISP_FEATURE_SB_THREAD
83 pthread_mutex_t all_threads_lock = PTHREAD_MUTEX_INITIALIZER;
84 #ifdef LOCK_CREATE_THREAD
85 static pthread_mutex_t create_thread_lock = PTHREAD_MUTEX_INITIALIZER;
89 #if defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64)
90 extern lispobj call_into_lisp_first_time(lispobj fun, lispobj *args, int nargs);
94 link_thread(struct thread *th)
96 if (all_threads) all_threads->prev=th;
102 #ifdef LISP_FEATURE_SB_THREAD
104 unlink_thread(struct thread *th)
107 th->prev->next = th->next;
109 all_threads = th->next;
111 th->next->prev = th->prev;
116 initial_thread_trampoline(struct thread *th)
119 #if defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64)
120 lispobj *args = NULL;
122 function = th->no_tls_value_marker;
123 th->no_tls_value_marker = NO_TLS_VALUE_MARKER_WIDETAG;
124 if(arch_os_thread_init(th)==0) return 1;
126 th->os_thread=thread_self();
127 #ifndef LISP_FEATURE_WIN32
128 protect_control_stack_guard_page(1);
131 #if defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64)
132 return call_into_lisp_first_time(function,args,0);
134 return funcall0(function);
138 #define THREAD_STRUCT_SIZE (THREAD_CONTROL_STACK_SIZE + BINDING_STACK_SIZE + \
139 ALIEN_STACK_SIZE + dynamic_values_bytes + \
142 #ifdef LISP_FEATURE_SB_THREAD
144 #ifdef QUEUE_FREEABLE_THREAD_STACKS
146 queue_freeable_thread_stack(struct thread *thread_to_be_cleaned_up)
148 if (thread_to_be_cleaned_up) {
149 pthread_mutex_lock(&freeable_stack_lock);
150 if (freeable_stack_queue) {
151 struct freeable_stack *new_freeable_stack = 0, *next;
152 next = freeable_stack_queue;
156 new_freeable_stack = (struct freeable_stack *)
157 os_validate(0, sizeof(struct freeable_stack));
158 new_freeable_stack->next = NULL;
159 new_freeable_stack->os_thread = thread_to_be_cleaned_up->os_thread;
160 new_freeable_stack->stack = (os_vm_address_t)
161 thread_to_be_cleaned_up->control_stack_start;
162 next->next = new_freeable_stack;
163 freeable_stack_count++;
165 struct freeable_stack *new_freeable_stack = 0;
166 new_freeable_stack = (struct freeable_stack *)
167 os_validate(0, sizeof(struct freeable_stack));
168 new_freeable_stack->next = NULL;
169 new_freeable_stack->os_thread = thread_to_be_cleaned_up->os_thread;
170 new_freeable_stack->stack = (os_vm_address_t)
171 thread_to_be_cleaned_up->control_stack_start;
172 freeable_stack_queue = new_freeable_stack;
173 freeable_stack_count++;
175 pthread_mutex_unlock(&freeable_stack_lock);
179 #define FREEABLE_STACK_QUEUE_SIZE 4
182 free_freeable_stacks() {
183 if (freeable_stack_queue && (freeable_stack_count > FREEABLE_STACK_QUEUE_SIZE)) {
184 struct freeable_stack* old;
185 pthread_mutex_lock(&freeable_stack_lock);
186 old = freeable_stack_queue;
187 freeable_stack_queue = old->next;
188 freeable_stack_count--;
189 gc_assert(pthread_join(old->os_thread, NULL) == 0);
190 FSHOW((stderr, "freeing thread %x stack\n", old->os_thread));
191 os_invalidate(old->stack, THREAD_STRUCT_SIZE);
192 os_invalidate((os_vm_address_t)old, sizeof(struct freeable_stack));
193 pthread_mutex_unlock(&freeable_stack_lock);
197 #elif defined(CREATE_CLEANUP_THREAD)
199 cleanup_thread(void *arg)
201 struct freeable_stack *freeable = arg;
202 pthread_t self = pthread_self();
204 FSHOW((stderr, "/cleaner thread(%p): joining %p\n",
205 self, freeable->os_thread));
206 gc_assert(pthread_join(freeable->os_thread, NULL) == 0);
207 FSHOW((stderr, "/cleaner thread(%p): free stack %p\n",
208 self, freeable->stack));
209 os_invalidate(freeable->stack, THREAD_STRUCT_SIZE);
212 pthread_detach(self);
218 create_cleanup_thread(struct thread *thread_to_be_cleaned_up)
223 if (thread_to_be_cleaned_up) {
224 struct freeable_stack *freeable =
225 malloc(sizeof(struct freeable_stack));
226 gc_assert(freeable != NULL);
227 freeable->os_thread = thread_to_be_cleaned_up->os_thread;
229 (os_vm_address_t) thread_to_be_cleaned_up->control_stack_start;
230 result = pthread_create(&thread, NULL, cleanup_thread, freeable);
231 gc_assert(result == 0);
238 free_thread_stack_later(struct thread *thread_to_be_cleaned_up)
240 struct freeable_stack *new_freeable_stack = 0;
241 if (thread_to_be_cleaned_up) {
242 new_freeable_stack = (struct freeable_stack *)
243 os_validate(0, sizeof(struct freeable_stack));
244 new_freeable_stack->os_thread = thread_to_be_cleaned_up->os_thread;
245 new_freeable_stack->stack = (os_vm_address_t)
246 thread_to_be_cleaned_up->control_stack_start;
248 new_freeable_stack = (struct freeable_stack *)
249 swap_lispobjs((lispobj *)(void *)&freeable_stack,
250 (lispobj)new_freeable_stack);
251 if (new_freeable_stack) {
252 FSHOW((stderr,"/reaping %p\n", (void*) new_freeable_stack->os_thread));
253 /* Under NPTL pthread_join really waits until the thread
254 * exists and the stack can be safely freed. This is sadly not
255 * mandated by the pthread spec. */
256 gc_assert(pthread_join(new_freeable_stack->os_thread, NULL) == 0);
257 os_invalidate(new_freeable_stack->stack, THREAD_STRUCT_SIZE);
258 os_invalidate((os_vm_address_t) new_freeable_stack,
259 sizeof(struct freeable_stack));
264 /* this is the first thing that runs in the child (which is why the
265 * silly calling convention). Basically it calls the user's requested
266 * lisp function after doing arch_os_thread_init and whatever other
267 * bookkeeping needs to be done
270 new_thread_trampoline(struct thread *th)
273 int result, lock_ret;
275 FSHOW((stderr,"/creating thread %lu\n", thread_self()));
276 function = th->no_tls_value_marker;
277 th->no_tls_value_marker = NO_TLS_VALUE_MARKER_WIDETAG;
278 if(arch_os_thread_init(th)==0) {
279 /* FIXME: handle error */
280 lose("arch_os_thread_init failed\n");
283 th->os_thread=thread_self();
284 protect_control_stack_guard_page(1);
285 /* Since GC can only know about this thread from the all_threads
286 * list and we're just adding this thread to it there is no danger
287 * of deadlocking even with SIG_STOP_FOR_GC blocked (which it is
289 lock_ret = pthread_mutex_lock(&all_threads_lock);
290 gc_assert(lock_ret == 0);
292 lock_ret = pthread_mutex_unlock(&all_threads_lock);
293 gc_assert(lock_ret == 0);
295 result = funcall0(function);
298 block_blockable_signals();
299 th->state=STATE_DEAD;
301 /* SIG_STOP_FOR_GC is blocked and GC might be waiting for this
302 * thread, but since we are already dead it won't wait long. */
303 lock_ret = pthread_mutex_lock(&all_threads_lock);
304 gc_assert(lock_ret == 0);
306 gc_alloc_update_page_tables(0, &th->alloc_region);
308 pthread_mutex_unlock(&all_threads_lock);
309 gc_assert(lock_ret == 0);
311 if(th->tls_cookie>=0) arch_os_thread_cleanup(th);
312 os_invalidate((os_vm_address_t)th->interrupt_data,
313 (sizeof (struct interrupt_data)));
315 #ifdef QUEUE_FREEABLE_THREAD_STACKS
316 queue_freeable_thread_stack(th);
317 #elif defined(CREATE_CLEANUP_THREAD)
318 create_cleanup_thread(th);
320 free_thread_stack_later(th);
323 FSHOW((stderr,"/exiting thread %p\n", thread_self()));
327 #endif /* LISP_FEATURE_SB_THREAD */
330 free_thread_struct(struct thread *th)
332 if (th->interrupt_data)
333 os_invalidate((os_vm_address_t) th->interrupt_data,
334 (sizeof (struct interrupt_data)));
335 os_invalidate((os_vm_address_t) th->control_stack_start,
339 /* this is called from any other thread to create the new one, and
340 * initialize all parts of it that can be initialized from another
344 static struct thread *
345 create_thread_struct(lispobj initial_function) {
346 union per_thread_data *per_thread;
347 struct thread *th=0; /* subdue gcc */
349 #ifdef LISP_FEATURE_SB_THREAD
353 /* may as well allocate all the spaces at once: it saves us from
354 * having to decide what to do if only some of the allocations
356 spaces=os_validate(0, THREAD_STRUCT_SIZE);
359 per_thread=(union per_thread_data *)
361 THREAD_CONTROL_STACK_SIZE+
365 #ifdef LISP_FEATURE_SB_THREAD
366 for(i = 0; i < (dynamic_values_bytes / sizeof(lispobj)); i++)
367 per_thread->dynamic_values[i] = NO_TLS_VALUE_MARKER_WIDETAG;
368 if (all_threads == 0) {
369 if(SymbolValue(FREE_TLS_INDEX,0)==UNBOUND_MARKER_WIDETAG) {
372 /* FIXME: should be MAX_INTERRUPTS -1 ? */
373 make_fixnum(MAX_INTERRUPTS+
374 sizeof(struct thread)/sizeof(lispobj)),
376 SetSymbolValue(TLS_INDEX_LOCK,make_fixnum(0),0);
378 #define STATIC_TLS_INIT(sym,field) \
379 ((struct symbol *)(sym-OTHER_POINTER_LOWTAG))->tls_index= \
380 make_fixnum(THREAD_SLOT_OFFSET_WORDS(field))
382 STATIC_TLS_INIT(BINDING_STACK_START,binding_stack_start);
383 STATIC_TLS_INIT(BINDING_STACK_POINTER,binding_stack_pointer);
384 STATIC_TLS_INIT(CONTROL_STACK_START,control_stack_start);
385 STATIC_TLS_INIT(CONTROL_STACK_END,control_stack_end);
386 STATIC_TLS_INIT(ALIEN_STACK,alien_stack_pointer);
387 #if defined(LISP_FEATURE_X86) || defined (LISP_FEATURE_X86_64)
388 STATIC_TLS_INIT(PSEUDO_ATOMIC_BITS,pseudo_atomic_bits);
390 #undef STATIC_TLS_INIT
394 th=&per_thread->thread;
395 th->control_stack_start = spaces;
396 th->binding_stack_start=
397 (lispobj*)((void*)th->control_stack_start+THREAD_CONTROL_STACK_SIZE);
398 th->control_stack_end = th->binding_stack_start;
399 th->alien_stack_start=
400 (lispobj*)((void*)th->binding_stack_start+BINDING_STACK_SIZE);
401 th->binding_stack_pointer=th->binding_stack_start;
404 th->state=STATE_RUNNING;
405 #ifdef LISP_FEATURE_STACK_GROWS_DOWNWARD_NOT_UPWARD
406 th->alien_stack_pointer=((void *)th->alien_stack_start
407 + ALIEN_STACK_SIZE-N_WORD_BYTES);
409 th->alien_stack_pointer=((void *)th->alien_stack_start);
411 #if defined(LISP_FEATURE_X86) || defined (LISP_FEATURE_X86_64)
412 th->pseudo_atomic_bits=0;
414 #ifdef LISP_FEATURE_GENCGC
415 gc_set_region_empty(&th->alloc_region);
418 #ifndef LISP_FEATURE_SB_THREAD
419 /* the tls-points-into-struct-thread trick is only good for threaded
420 * sbcl, because unithread sbcl doesn't have tls. So, we copy the
421 * appropriate values from struct thread here, and make sure that
422 * we use the appropriate SymbolValue macros to access any of the
423 * variable quantities from the C runtime. It's not quite OAOOM,
424 * it just feels like it */
425 SetSymbolValue(BINDING_STACK_START,(lispobj)th->binding_stack_start,th);
426 SetSymbolValue(CONTROL_STACK_START,(lispobj)th->control_stack_start,th);
427 SetSymbolValue(CONTROL_STACK_END,(lispobj)th->control_stack_end,th);
428 #if defined(LISP_FEATURE_X86) || defined (LISP_FEATURE_X86_64)
429 SetSymbolValue(BINDING_STACK_POINTER,(lispobj)th->binding_stack_pointer,th);
430 SetSymbolValue(ALIEN_STACK,(lispobj)th->alien_stack_pointer,th);
431 SetSymbolValue(PSEUDO_ATOMIC_BITS,(lispobj)th->pseudo_atomic_bits,th);
433 current_binding_stack_pointer=th->binding_stack_pointer;
434 current_control_stack_pointer=th->control_stack_start;
437 bind_variable(CURRENT_CATCH_BLOCK,make_fixnum(0),th);
438 bind_variable(CURRENT_UNWIND_PROTECT_BLOCK,make_fixnum(0),th);
439 bind_variable(FREE_INTERRUPT_CONTEXT_INDEX,make_fixnum(0),th);
440 bind_variable(INTERRUPT_PENDING, NIL,th);
441 bind_variable(INTERRUPTS_ENABLED,T,th);
442 bind_variable(GC_PENDING,NIL,th);
443 #ifdef LISP_FEATURE_SB_THREAD
444 bind_variable(STOP_FOR_GC_PENDING,NIL,th);
447 th->interrupt_data = (struct interrupt_data *)
448 os_validate(0,(sizeof (struct interrupt_data)));
449 if (!th->interrupt_data) {
450 free_thread_struct(th);
453 th->interrupt_data->pending_handler = 0;
454 th->no_tls_value_marker=initial_function;
460 void create_initial_thread(lispobj initial_function) {
461 struct thread *th=create_thread_struct(initial_function);
463 initial_thread_trampoline(th); /* no return */
464 } else lose("can't create initial thread\n");
467 #ifdef LISP_FEATURE_SB_THREAD
469 #ifndef __USE_XOPEN2K
470 extern int pthread_attr_setstack (pthread_attr_t *__attr, void *__stackaddr,
474 boolean create_os_thread(struct thread *th,os_thread_t *kid_tid)
476 /* The new thread inherits the restrictive signal mask set here,
477 * and enables signals again when it is set up properly. */
479 sigset_t newset,oldset;
481 int retcode, initcode, sizecode, addrcode;
483 FSHOW_SIGNAL((stderr,"/create_os_thread: creating new thread\n"));
485 #ifdef LOCK_CREATE_THREAD
486 retcode = pthread_mutex_lock(&create_thread_lock);
487 gc_assert(retcode == 0);
488 FSHOW_SIGNAL((stderr,"/create_os_thread: got lock\n"));
490 sigemptyset(&newset);
491 /* Blocking deferrable signals is enough, no need to block
492 * SIG_STOP_FOR_GC because the child process is not linked onto
493 * all_threads until it's ready. */
494 sigaddset_deferrable(&newset);
495 thread_sigmask(SIG_BLOCK, &newset, &oldset);
497 #if defined(LISP_FEATURE_DARWIN)
498 #define CONTROL_STACK_ADJUST 8192 /* darwin wants page-aligned stacks */
500 #define CONTROL_STACK_ADJUST 16
503 if((initcode = pthread_attr_init(&attr)) ||
504 /* FIXME: why do we even have this in the first place? */
505 (pthread_attr_setstack(&attr,th->control_stack_start,
506 THREAD_CONTROL_STACK_SIZE-CONTROL_STACK_ADJUST)) ||
507 #undef CONTROL_STACK_ADJUST
508 (retcode = pthread_create
509 (kid_tid,&attr,(void *(*)(void *))new_thread_trampoline,th))) {
510 FSHOW_SIGNAL((stderr, "init, size, addr = %d, %d, %d\n", initcode, sizecode, addrcode));
511 FSHOW_SIGNAL((stderr, printf("pthread_create returned %d, errno %d\n", retcode, errno)));
512 FSHOW_SIGNAL((stderr, "wanted stack size %d, min stack size %d\n",
513 THREAD_CONTROL_STACK_SIZE-16, PTHREAD_STACK_MIN));
515 perror("create_os_thread");
519 #ifdef QUEUE_FREEABLE_THREAD_STACKS
520 free_freeable_stacks();
522 thread_sigmask(SIG_SETMASK,&oldset,0);
523 #ifdef LOCK_CREATE_THREAD
524 retcode = pthread_mutex_unlock(&create_thread_lock);
525 gc_assert(retcode == 0);
526 FSHOW_SIGNAL((stderr,"/create_os_thread: released lock\n"));
531 os_thread_t create_thread(lispobj initial_function) {
535 /* Assuming that a fresh thread struct has no lisp objects in it,
536 * linking it to all_threads can be left to the thread itself
537 * without fear of gc lossage. initial_function violates this
538 * assumption and must stay pinned until the child starts up. */
539 th = create_thread_struct(initial_function);
542 if (create_os_thread(th,&kid_tid)) {
545 free_thread_struct(th);
550 /* Send the signo to os_thread, retry if the rt signal queue is
553 kill_thread_safely(os_thread_t os_thread, int signo)
556 /* The man page does not mention EAGAIN as a valid return value
557 * for either pthread_kill or kill. But that's theory, this is
558 * practice. By waiting here we assume that the delivery of this
559 * signal is not necessary for the delivery of the signals in the
560 * queue. In other words, we _assume_ there are no deadlocks. */
561 while ((r=pthread_kill(os_thread,signo))==EAGAIN) {
562 /* wait a bit then try again in the hope of the rt signal
563 * queue not being full */
564 FSHOW_SIGNAL((stderr,"/rt signal queue full\n"));
565 /* FIXME: some kind of backoff (random, exponential) would be
572 int signal_interrupt_thread(os_thread_t os_thread)
574 int status = kill_thread_safely(os_thread, SIG_INTERRUPT_THREAD);
577 } else if (status == ESRCH) {
580 lose("cannot send SIG_INTERRUPT_THREAD to thread=%lu: %d, %s\n",
581 os_thread, status, strerror(status));
585 /* stopping the world is a two-stage process. From this thread we signal
586 * all the others with SIG_STOP_FOR_GC. The handler for this signal does
587 * the usual pseudo-atomic checks (we don't want to stop a thread while
588 * it's in the middle of allocation) then waits for another SIG_STOP_FOR_GC.
591 /* To avoid deadlocks when gc stops the world all clients of each
592 * mutex must enable or disable SIG_STOP_FOR_GC for the duration of
593 * holding the lock, but they must agree on which. */
594 void gc_stop_the_world()
596 struct thread *p,*th=arch_os_get_current_thread();
597 int status, lock_ret;
598 #ifdef LOCK_CREATE_THREAD
599 /* KLUDGE: Stopping the thread during pthread_create() causes deadlock
601 FSHOW_SIGNAL((stderr,"/gc_stop_the_world:waiting on create_thread_lock, thread=%lu\n",
603 lock_ret = pthread_mutex_lock(&create_thread_lock);
604 gc_assert(lock_ret == 0);
605 FSHOW_SIGNAL((stderr,"/gc_stop_the_world:got create_thread_lock, thread=%lu\n",
608 FSHOW_SIGNAL((stderr,"/gc_stop_the_world:waiting on lock, thread=%lu\n",
610 /* keep threads from starting while the world is stopped. */
611 lock_ret = pthread_mutex_lock(&all_threads_lock); \
612 gc_assert(lock_ret == 0);
614 FSHOW_SIGNAL((stderr,"/gc_stop_the_world:got lock, thread=%lu\n",
616 /* stop all other threads by sending them SIG_STOP_FOR_GC */
617 for(p=all_threads; p; p=p->next) {
618 gc_assert(p->os_thread != 0);
619 FSHOW_SIGNAL((stderr,"/gc_stop_the_world: p->state: %x\n", p->state));
620 if((p!=th) && ((p->state==STATE_RUNNING))) {
621 FSHOW_SIGNAL((stderr,"/gc_stop_the_world: suspending %x, os_thread %x\n",
623 status=kill_thread_safely(p->os_thread,SIG_STOP_FOR_GC);
625 /* This thread has exited. */
626 gc_assert(p->state==STATE_DEAD);
628 lose("cannot send suspend thread=%lu: %d, %s\n",
629 p->os_thread,status,strerror(status));
633 FSHOW_SIGNAL((stderr,"/gc_stop_the_world:signals sent\n"));
634 /* wait for the running threads to stop or finish */
635 for(p=all_threads;p;) {
636 FSHOW_SIGNAL((stderr,"/gc_stop_the_world: th: %p, p: %p\n", th, p));
637 if((p!=th) && (p->state==STATE_RUNNING)) {
643 FSHOW_SIGNAL((stderr,"/gc_stop_the_world:end\n"));
646 void gc_start_the_world()
648 struct thread *p,*th=arch_os_get_current_thread();
649 int status, lock_ret;
650 /* if a resumed thread creates a new thread before we're done with
651 * this loop, the new thread will get consed on the front of
652 * all_threads, but it won't have been stopped so won't need
654 FSHOW_SIGNAL((stderr,"/gc_start_the_world:begin\n"));
655 for(p=all_threads;p;p=p->next) {
656 gc_assert(p->os_thread!=0);
657 if((p!=th) && (p->state!=STATE_DEAD)) {
658 if(p->state!=STATE_SUSPENDED) {
659 lose("gc_start_the_world: wrong thread state is %d\n",
660 fixnum_value(p->state));
662 FSHOW_SIGNAL((stderr, "/gc_start_the_world: resuming %lu\n",
664 p->state=STATE_RUNNING;
666 #if defined(SIG_RESUME_FROM_GC)
667 status=kill_thread_safely(p->os_thread,SIG_RESUME_FROM_GC);
669 status=kill_thread_safely(p->os_thread,SIG_STOP_FOR_GC);
672 lose("cannot resume thread=%lu: %d, %s\n",
673 p->os_thread,status,strerror(status));
677 /* If we waited here until all threads leave STATE_SUSPENDED, then
678 * SIG_STOP_FOR_GC wouldn't need to be a rt signal. That has some
679 * performance implications, but does away with the 'rt signal
680 * queue full' problem. */
682 lock_ret = pthread_mutex_unlock(&all_threads_lock);
683 gc_assert(lock_ret == 0);
684 #ifdef LOCK_CREATE_THREAD
685 lock_ret = pthread_mutex_unlock(&create_thread_lock);
686 gc_assert(lock_ret == 0);
689 FSHOW_SIGNAL((stderr,"/gc_start_the_world:end\n"));