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
28 #ifdef LISP_FEATURE_MACH_EXCEPTION_HANDLER
29 #include <mach/mach.h>
30 #include <mach/mach_error.h>
31 #include <mach/mach_types.h>
35 #include "validate.h" /* for CONTROL_STACK_SIZE etc */
39 #include "target-arch-os.h"
43 #include "genesis/cons.h"
44 #include "genesis/fdefn.h"
45 #include "interr.h" /* for lose() */
46 #include "gc-internal.h"
48 #ifdef LISP_FEATURE_WIN32
50 * Win32 doesn't have SIGSTKSZ, and we're not switching stacks anyway,
51 * so define it arbitrarily
56 #if defined(LISP_FEATURE_DARWIN) && defined(LISP_FEATURE_SB_THREAD)
57 #define QUEUE_FREEABLE_THREAD_STACKS
58 #define LOCK_CREATE_THREAD
61 #ifdef LISP_FEATURE_FREEBSD
62 #define CREATE_CLEANUP_THREAD
63 #define LOCK_CREATE_THREAD
66 #define ALIEN_STACK_SIZE (1*1024*1024) /* 1Mb size chosen at random */
68 struct freeable_stack {
69 #ifdef QUEUE_FREEABLE_THREAD_STACKS
70 struct freeable_stack *next;
72 os_thread_t os_thread;
73 os_vm_address_t os_address;
77 #ifdef QUEUE_FREEABLE_THREAD_STACKS
78 static struct freeable_stack * volatile freeable_stack_queue = 0;
79 static int freeable_stack_count = 0;
80 pthread_mutex_t freeable_stack_lock = PTHREAD_MUTEX_INITIALIZER;
82 static struct freeable_stack * volatile freeable_stack = 0;
85 int dynamic_values_bytes=4096*sizeof(lispobj); /* same for all threads */
86 struct thread * volatile all_threads;
87 extern struct interrupt_data * global_interrupt_data;
89 #ifdef LISP_FEATURE_SB_THREAD
90 pthread_mutex_t all_threads_lock = PTHREAD_MUTEX_INITIALIZER;
91 #ifdef LOCK_CREATE_THREAD
92 static pthread_mutex_t create_thread_lock = PTHREAD_MUTEX_INITIALIZER;
94 #ifdef LISP_FEATURE_GCC_TLS
95 __thread struct thread *current_thread;
99 #if defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64)
100 extern lispobj call_into_lisp_first_time(lispobj fun, lispobj *args, int nargs);
104 link_thread(struct thread *th)
106 if (all_threads) all_threads->prev=th;
107 th->next=all_threads;
112 #ifdef LISP_FEATURE_SB_THREAD
114 unlink_thread(struct thread *th)
117 th->prev->next = th->next;
119 all_threads = th->next;
121 th->next->prev = th->prev;
126 initial_thread_trampoline(struct thread *th)
129 #if defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64)
130 lispobj *args = NULL;
132 function = th->no_tls_value_marker;
133 th->no_tls_value_marker = NO_TLS_VALUE_MARKER_WIDETAG;
134 if(arch_os_thread_init(th)==0) return 1;
136 th->os_thread=thread_self();
137 #ifndef LISP_FEATURE_WIN32
138 protect_control_stack_guard_page(1);
141 #if defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64)
142 return call_into_lisp_first_time(function,args,0);
144 return funcall0(function);
148 #define THREAD_STRUCT_SIZE (THREAD_CONTROL_STACK_SIZE + BINDING_STACK_SIZE + \
149 ALIEN_STACK_SIZE + dynamic_values_bytes + \
153 #ifdef LISP_FEATURE_SB_THREAD
155 #ifdef QUEUE_FREEABLE_THREAD_STACKS
158 queue_freeable_thread_stack(struct thread *thread_to_be_cleaned_up)
160 struct freeable_stack *new_freeable_stack = 0;
161 if (thread_to_be_cleaned_up) {
162 /* FIXME: os_validate is mmap -- for small things like these
163 * malloc would probably perform better. */
164 new_freeable_stack = (struct freeable_stack *)
165 os_validate(0, sizeof(struct freeable_stack));
166 new_freeable_stack->next = NULL;
167 new_freeable_stack->os_thread = thread_to_be_cleaned_up->os_thread;
168 new_freeable_stack->os_address = thread_to_be_cleaned_up->os_address;
169 pthread_mutex_lock(&freeable_stack_lock);
170 if (freeable_stack_queue) {
171 struct freeable_stack *next;
172 next = freeable_stack_queue;
176 next->next = new_freeable_stack;
178 freeable_stack_queue = new_freeable_stack;
180 freeable_stack_count++;
181 pthread_mutex_unlock(&freeable_stack_lock);
185 #define FREEABLE_STACK_QUEUE_SIZE 4
188 free_freeable_stacks() {
189 if (freeable_stack_queue && (freeable_stack_count > FREEABLE_STACK_QUEUE_SIZE)) {
190 struct freeable_stack* old;
191 pthread_mutex_lock(&freeable_stack_lock);
192 old = freeable_stack_queue;
193 freeable_stack_queue = old->next;
194 freeable_stack_count--;
195 gc_assert(pthread_join(old->os_thread, NULL) == 0);
196 FSHOW((stderr, "freeing thread %x stack\n", old->os_thread));
197 os_invalidate(old->os_address, THREAD_STRUCT_SIZE);
198 os_invalidate((os_vm_address_t)old, sizeof(struct freeable_stack));
199 pthread_mutex_unlock(&freeable_stack_lock);
203 #elif defined(CREATE_CLEANUP_THREAD)
205 cleanup_thread(void *arg)
207 struct freeable_stack *freeable = arg;
208 pthread_t self = pthread_self();
210 FSHOW((stderr, "/cleaner thread(%p): joining %p\n",
211 self, freeable->os_thread));
212 gc_assert(pthread_join(freeable->os_thread, NULL) == 0);
213 FSHOW((stderr, "/cleaner thread(%p): free stack %p\n",
214 self, freeable->stack));
215 os_invalidate(freeable->os_address, THREAD_STRUCT_SIZE);
218 pthread_detach(self);
224 create_cleanup_thread(struct thread *thread_to_be_cleaned_up)
229 if (thread_to_be_cleaned_up) {
230 struct freeable_stack *freeable =
231 malloc(sizeof(struct freeable_stack));
232 gc_assert(freeable != NULL);
233 freeable->os_thread = thread_to_be_cleaned_up->os_thread;
234 freeable->os_address =
235 (os_vm_address_t) thread_to_be_cleaned_up->os_address;
236 result = pthread_create(&thread, NULL, cleanup_thread, freeable);
237 gc_assert(result == 0);
244 free_thread_stack_later(struct thread *thread_to_be_cleaned_up)
246 struct freeable_stack *new_freeable_stack = 0;
247 if (thread_to_be_cleaned_up) {
248 new_freeable_stack = (struct freeable_stack *)
249 os_validate(0, sizeof(struct freeable_stack));
250 new_freeable_stack->os_thread = thread_to_be_cleaned_up->os_thread;
251 new_freeable_stack->os_address = (os_vm_address_t)
252 thread_to_be_cleaned_up->os_address;
254 new_freeable_stack = (struct freeable_stack *)
255 swap_lispobjs((lispobj *)(void *)&freeable_stack,
256 (lispobj)new_freeable_stack);
257 if (new_freeable_stack) {
258 FSHOW((stderr,"/reaping %p\n", (void*) new_freeable_stack->os_thread));
259 /* Under NPTL pthread_join really waits until the thread
260 * exists and the stack can be safely freed. This is sadly not
261 * mandated by the pthread spec. */
262 gc_assert(pthread_join(new_freeable_stack->os_thread, NULL) == 0);
263 os_invalidate(new_freeable_stack->os_address, THREAD_STRUCT_SIZE);
264 os_invalidate((os_vm_address_t) new_freeable_stack,
265 sizeof(struct freeable_stack));
270 /* this is the first thing that runs in the child (which is why the
271 * silly calling convention). Basically it calls the user's requested
272 * lisp function after doing arch_os_thread_init and whatever other
273 * bookkeeping needs to be done
276 new_thread_trampoline(struct thread *th)
279 int result, lock_ret;
281 FSHOW((stderr,"/creating thread %lu\n", thread_self()));
282 function = th->no_tls_value_marker;
283 th->no_tls_value_marker = NO_TLS_VALUE_MARKER_WIDETAG;
284 if(arch_os_thread_init(th)==0) {
285 /* FIXME: handle error */
286 lose("arch_os_thread_init failed\n");
289 th->os_thread=thread_self();
290 protect_control_stack_guard_page(1);
291 /* Since GC can only know about this thread from the all_threads
292 * list and we're just adding this thread to it there is no danger
293 * of deadlocking even with SIG_STOP_FOR_GC blocked (which it is
295 lock_ret = pthread_mutex_lock(&all_threads_lock);
296 gc_assert(lock_ret == 0);
298 lock_ret = pthread_mutex_unlock(&all_threads_lock);
299 gc_assert(lock_ret == 0);
301 result = funcall0(function);
304 block_blockable_signals();
305 th->state=STATE_DEAD;
307 /* SIG_STOP_FOR_GC is blocked and GC might be waiting for this
308 * thread, but since we are already dead it won't wait long. */
309 lock_ret = pthread_mutex_lock(&all_threads_lock);
310 gc_assert(lock_ret == 0);
312 gc_alloc_update_page_tables(0, &th->alloc_region);
314 pthread_mutex_unlock(&all_threads_lock);
315 gc_assert(lock_ret == 0);
317 if(th->tls_cookie>=0) arch_os_thread_cleanup(th);
318 os_invalidate((os_vm_address_t)th->interrupt_data,
319 (sizeof (struct interrupt_data)));
321 #ifdef LISP_FEATURE_MACH_EXCEPTION_HANDLER
322 FSHOW((stderr, "Deallocating mach port %x\n", THREAD_STRUCT_TO_EXCEPTION_PORT(th)));
323 mach_port_move_member(mach_task_self(),
324 THREAD_STRUCT_TO_EXCEPTION_PORT(th),
326 mach_port_deallocate(mach_task_self(),
327 THREAD_STRUCT_TO_EXCEPTION_PORT(th));
328 mach_port_destroy(mach_task_self(),
329 THREAD_STRUCT_TO_EXCEPTION_PORT(th));
332 #ifdef QUEUE_FREEABLE_THREAD_STACKS
333 queue_freeable_thread_stack(th);
334 #elif defined(CREATE_CLEANUP_THREAD)
335 create_cleanup_thread(th);
337 free_thread_stack_later(th);
340 FSHOW((stderr,"/exiting thread %p\n", thread_self()));
344 #endif /* LISP_FEATURE_SB_THREAD */
347 free_thread_struct(struct thread *th)
349 if (th->interrupt_data)
350 os_invalidate((os_vm_address_t) th->interrupt_data,
351 (sizeof (struct interrupt_data)));
352 os_invalidate((os_vm_address_t) th->os_address,
356 /* this is called from any other thread to create the new one, and
357 * initialize all parts of it that can be initialized from another
361 static struct thread *
362 create_thread_struct(lispobj initial_function) {
363 union per_thread_data *per_thread;
364 struct thread *th=0; /* subdue gcc */
366 void *aligned_spaces=0;
367 #ifdef LISP_FEATURE_SB_THREAD
371 #ifdef CREATE_CLEANUP_THREAD
372 /* Give a chance for cleanup threads to run. */
375 /* May as well allocate all the spaces at once: it saves us from
376 * having to decide what to do if only some of the allocations
377 * succeed. SPACES must be page-aligned, since the GC expects the
378 * control stack to start at a page boundary. We can't rely on the
379 * alignment passed from os_validate, since that might assume the
380 * current (e.g. 4k) pagesize, while we calculate with the biggest
381 * (e.g. 64k) pagesize allowed by the ABI. */
382 spaces=os_validate(0, THREAD_STRUCT_SIZE);
385 /* Aligning up is safe as THREAD_STRUCT_SIZE has BACKEND_PAGE_SIZE
387 aligned_spaces = (void *)((((unsigned long)(char *)spaces)
388 + BACKEND_PAGE_SIZE - 1)
389 & ~(unsigned long)(BACKEND_PAGE_SIZE - 1));
390 per_thread=(union per_thread_data *)
392 THREAD_CONTROL_STACK_SIZE+
396 #ifdef LISP_FEATURE_SB_THREAD
397 for(i = 0; i < (dynamic_values_bytes / sizeof(lispobj)); i++)
398 per_thread->dynamic_values[i] = NO_TLS_VALUE_MARKER_WIDETAG;
399 if (all_threads == 0) {
400 if(SymbolValue(FREE_TLS_INDEX,0)==UNBOUND_MARKER_WIDETAG) {
403 /* FIXME: should be MAX_INTERRUPTS -1 ? */
404 make_fixnum(MAX_INTERRUPTS+
405 sizeof(struct thread)/sizeof(lispobj)),
407 SetSymbolValue(TLS_INDEX_LOCK,make_fixnum(0),0);
409 #define STATIC_TLS_INIT(sym,field) \
410 ((struct symbol *)(sym-OTHER_POINTER_LOWTAG))->tls_index= \
411 make_fixnum(THREAD_SLOT_OFFSET_WORDS(field))
413 STATIC_TLS_INIT(BINDING_STACK_START,binding_stack_start);
414 STATIC_TLS_INIT(BINDING_STACK_POINTER,binding_stack_pointer);
415 STATIC_TLS_INIT(CONTROL_STACK_START,control_stack_start);
416 STATIC_TLS_INIT(CONTROL_STACK_END,control_stack_end);
417 STATIC_TLS_INIT(ALIEN_STACK,alien_stack_pointer);
418 #if defined(LISP_FEATURE_X86) || defined (LISP_FEATURE_X86_64)
419 STATIC_TLS_INIT(PSEUDO_ATOMIC_BITS,pseudo_atomic_bits);
421 #undef STATIC_TLS_INIT
425 th=&per_thread->thread;
426 th->os_address = spaces;
427 th->control_stack_start = aligned_spaces;
428 th->binding_stack_start=
429 (lispobj*)((void*)th->control_stack_start+THREAD_CONTROL_STACK_SIZE);
430 th->control_stack_end = th->binding_stack_start;
431 th->alien_stack_start=
432 (lispobj*)((void*)th->binding_stack_start+BINDING_STACK_SIZE);
433 th->binding_stack_pointer=th->binding_stack_start;
436 th->state=STATE_RUNNING;
437 #ifdef LISP_FEATURE_STACK_GROWS_DOWNWARD_NOT_UPWARD
438 th->alien_stack_pointer=((void *)th->alien_stack_start
439 + ALIEN_STACK_SIZE-N_WORD_BYTES);
441 th->alien_stack_pointer=((void *)th->alien_stack_start);
443 #if defined(LISP_FEATURE_X86) || defined (LISP_FEATURE_X86_64)
444 th->pseudo_atomic_bits=0;
446 #ifdef LISP_FEATURE_GENCGC
447 gc_set_region_empty(&th->alloc_region);
450 #ifndef LISP_FEATURE_SB_THREAD
451 /* the tls-points-into-struct-thread trick is only good for threaded
452 * sbcl, because unithread sbcl doesn't have tls. So, we copy the
453 * appropriate values from struct thread here, and make sure that
454 * we use the appropriate SymbolValue macros to access any of the
455 * variable quantities from the C runtime. It's not quite OAOOM,
456 * it just feels like it */
457 SetSymbolValue(BINDING_STACK_START,(lispobj)th->binding_stack_start,th);
458 SetSymbolValue(CONTROL_STACK_START,(lispobj)th->control_stack_start,th);
459 SetSymbolValue(CONTROL_STACK_END,(lispobj)th->control_stack_end,th);
460 #if defined(LISP_FEATURE_X86) || defined (LISP_FEATURE_X86_64)
461 SetSymbolValue(BINDING_STACK_POINTER,(lispobj)th->binding_stack_pointer,th);
462 SetSymbolValue(ALIEN_STACK,(lispobj)th->alien_stack_pointer,th);
463 SetSymbolValue(PSEUDO_ATOMIC_BITS,(lispobj)th->pseudo_atomic_bits,th);
465 current_binding_stack_pointer=th->binding_stack_pointer;
466 current_control_stack_pointer=th->control_stack_start;
469 bind_variable(CURRENT_CATCH_BLOCK,make_fixnum(0),th);
470 bind_variable(CURRENT_UNWIND_PROTECT_BLOCK,make_fixnum(0),th);
471 bind_variable(FREE_INTERRUPT_CONTEXT_INDEX,make_fixnum(0),th);
472 bind_variable(INTERRUPT_PENDING, NIL,th);
473 bind_variable(INTERRUPTS_ENABLED,T,th);
474 bind_variable(ALLOW_WITH_INTERRUPTS,T,th);
475 bind_variable(GC_PENDING,NIL,th);
476 #ifdef LISP_FEATURE_SB_THREAD
477 bind_variable(STOP_FOR_GC_PENDING,NIL,th);
480 th->interrupt_data = (struct interrupt_data *)
481 os_validate(0,(sizeof (struct interrupt_data)));
482 if (!th->interrupt_data) {
483 free_thread_struct(th);
486 th->interrupt_data->pending_handler = 0;
487 th->no_tls_value_marker=initial_function;
493 #ifdef LISP_FEATURE_MACH_EXCEPTION_HANDLER
494 mach_port_t setup_mach_exception_handling_thread();
495 kern_return_t mach_thread_init(mach_port_t thread_exception_port);
499 void create_initial_thread(lispobj initial_function) {
500 struct thread *th=create_thread_struct(initial_function);
502 #ifdef LISP_FEATURE_MACH_EXCEPTION_HANDLER
505 setup_mach_exception_handling_thread();
507 initial_thread_trampoline(th); /* no return */
508 } else lose("can't create initial thread\n");
511 #ifdef LISP_FEATURE_SB_THREAD
513 #ifndef __USE_XOPEN2K
514 extern int pthread_attr_setstack (pthread_attr_t *__attr, void *__stackaddr,
518 boolean create_os_thread(struct thread *th,os_thread_t *kid_tid)
520 /* The new thread inherits the restrictive signal mask set here,
521 * and enables signals again when it is set up properly. */
523 sigset_t newset,oldset;
525 int retcode = 0, initcode;
527 FSHOW_SIGNAL((stderr,"/create_os_thread: creating new thread\n"));
529 #ifdef LOCK_CREATE_THREAD
530 retcode = pthread_mutex_lock(&create_thread_lock);
531 gc_assert(retcode == 0);
532 FSHOW_SIGNAL((stderr,"/create_os_thread: got lock\n"));
534 sigemptyset(&newset);
535 /* Blocking deferrable signals is enough, no need to block
536 * SIG_STOP_FOR_GC because the child process is not linked onto
537 * all_threads until it's ready. */
538 sigaddset_deferrable(&newset);
539 thread_sigmask(SIG_BLOCK, &newset, &oldset);
541 #if defined(LISP_FEATURE_DARWIN)
542 #define CONTROL_STACK_ADJUST 8192 /* darwin wants page-aligned stacks */
544 #define CONTROL_STACK_ADJUST 16
547 if((initcode = pthread_attr_init(&attr)) ||
548 /* FIXME: why do we even have this in the first place? */
549 (pthread_attr_setstack(&attr,th->control_stack_start,
550 THREAD_CONTROL_STACK_SIZE-CONTROL_STACK_ADJUST)) ||
551 #undef CONTROL_STACK_ADJUST
552 (retcode = pthread_create
553 (kid_tid,&attr,(void *(*)(void *))new_thread_trampoline,th))) {
554 FSHOW_SIGNAL((stderr, "init = %d\n", initcode));
555 FSHOW_SIGNAL((stderr, printf("pthread_create returned %d, errno %d\n", retcode, errno)));
556 FSHOW_SIGNAL((stderr, "wanted stack size %d, min stack size %d\n",
557 THREAD_CONTROL_STACK_SIZE-16, PTHREAD_STACK_MIN));
559 perror("create_os_thread");
564 #ifdef QUEUE_FREEABLE_THREAD_STACKS
565 free_freeable_stacks();
567 thread_sigmask(SIG_SETMASK,&oldset,0);
568 #ifdef LOCK_CREATE_THREAD
569 retcode = pthread_mutex_unlock(&create_thread_lock);
570 gc_assert(retcode == 0);
571 FSHOW_SIGNAL((stderr,"/create_os_thread: released lock\n"));
576 os_thread_t create_thread(lispobj initial_function) {
580 /* Assuming that a fresh thread struct has no lisp objects in it,
581 * linking it to all_threads can be left to the thread itself
582 * without fear of gc lossage. initial_function violates this
583 * assumption and must stay pinned until the child starts up. */
584 th = create_thread_struct(initial_function);
587 if (create_os_thread(th,&kid_tid)) {
590 free_thread_struct(th);
595 /* Send the signo to os_thread, retry if the rt signal queue is
598 kill_thread_safely(os_thread_t os_thread, int signo)
601 /* The man page does not mention EAGAIN as a valid return value
602 * for either pthread_kill or kill. But that's theory, this is
603 * practice. By waiting here we assume that the delivery of this
604 * signal is not necessary for the delivery of the signals in the
605 * queue. In other words, we _assume_ there are no deadlocks. */
606 while ((r=pthread_kill(os_thread,signo))==EAGAIN) {
607 /* wait a bit then try again in the hope of the rt signal
608 * queue not being full */
609 FSHOW_SIGNAL((stderr,"/rt signal queue full\n"));
610 /* FIXME: some kind of backoff (random, exponential) would be
617 int signal_interrupt_thread(os_thread_t os_thread)
619 int status = kill_thread_safely(os_thread, SIG_INTERRUPT_THREAD);
622 } else if (status == ESRCH) {
625 lose("cannot send SIG_INTERRUPT_THREAD to thread=%lu: %d, %s\n",
626 os_thread, status, strerror(status));
630 /* stopping the world is a two-stage process. From this thread we signal
631 * all the others with SIG_STOP_FOR_GC. The handler for this signal does
632 * the usual pseudo-atomic checks (we don't want to stop a thread while
633 * it's in the middle of allocation) then waits for another SIG_STOP_FOR_GC.
636 /* To avoid deadlocks when gc stops the world all clients of each
637 * mutex must enable or disable SIG_STOP_FOR_GC for the duration of
638 * holding the lock, but they must agree on which. */
639 void gc_stop_the_world()
641 struct thread *p,*th=arch_os_get_current_thread();
642 int status, lock_ret;
643 #ifdef LOCK_CREATE_THREAD
644 /* KLUDGE: Stopping the thread during pthread_create() causes deadlock
646 FSHOW_SIGNAL((stderr,"/gc_stop_the_world:waiting on create_thread_lock, thread=%lu\n",
648 lock_ret = pthread_mutex_lock(&create_thread_lock);
649 gc_assert(lock_ret == 0);
650 FSHOW_SIGNAL((stderr,"/gc_stop_the_world:got create_thread_lock, thread=%lu\n",
653 FSHOW_SIGNAL((stderr,"/gc_stop_the_world:waiting on lock, thread=%lu\n",
655 /* keep threads from starting while the world is stopped. */
656 lock_ret = pthread_mutex_lock(&all_threads_lock); \
657 gc_assert(lock_ret == 0);
659 FSHOW_SIGNAL((stderr,"/gc_stop_the_world:got lock, thread=%lu\n",
661 /* stop all other threads by sending them SIG_STOP_FOR_GC */
662 for(p=all_threads; p; p=p->next) {
663 gc_assert(p->os_thread != 0);
664 FSHOW_SIGNAL((stderr,"/gc_stop_the_world: p->state: %x\n", p->state));
665 if((p!=th) && ((p->state==STATE_RUNNING))) {
666 FSHOW_SIGNAL((stderr,"/gc_stop_the_world: suspending %x, os_thread %x\n",
668 status=kill_thread_safely(p->os_thread,SIG_STOP_FOR_GC);
670 /* This thread has exited. */
671 gc_assert(p->state==STATE_DEAD);
673 lose("cannot send suspend thread=%lu: %d, %s\n",
674 p->os_thread,status,strerror(status));
678 FSHOW_SIGNAL((stderr,"/gc_stop_the_world:signals sent\n"));
679 /* wait for the running threads to stop or finish */
680 for(p=all_threads;p;) {
681 FSHOW_SIGNAL((stderr,"/gc_stop_the_world: th: %p, p: %p\n", th, p));
682 if((p!=th) && (p->state==STATE_RUNNING)) {
688 FSHOW_SIGNAL((stderr,"/gc_stop_the_world:end\n"));
691 void gc_start_the_world()
693 struct thread *p,*th=arch_os_get_current_thread();
694 int status, lock_ret;
695 /* if a resumed thread creates a new thread before we're done with
696 * this loop, the new thread will get consed on the front of
697 * all_threads, but it won't have been stopped so won't need
699 FSHOW_SIGNAL((stderr,"/gc_start_the_world:begin\n"));
700 for(p=all_threads;p;p=p->next) {
701 gc_assert(p->os_thread!=0);
702 if((p!=th) && (p->state!=STATE_DEAD)) {
703 if(p->state!=STATE_SUSPENDED) {
704 lose("gc_start_the_world: wrong thread state is %d\n",
705 fixnum_value(p->state));
707 FSHOW_SIGNAL((stderr, "/gc_start_the_world: resuming %lu\n",
709 p->state=STATE_RUNNING;
711 #if defined(SIG_RESUME_FROM_GC)
712 status=kill_thread_safely(p->os_thread,SIG_RESUME_FROM_GC);
714 status=kill_thread_safely(p->os_thread,SIG_STOP_FOR_GC);
717 lose("cannot resume thread=%lu: %d, %s\n",
718 p->os_thread,status,strerror(status));
722 /* If we waited here until all threads leave STATE_SUSPENDED, then
723 * SIG_STOP_FOR_GC wouldn't need to be a rt signal. That has some
724 * performance implications, but does away with the 'rt signal
725 * queue full' problem. */
727 lock_ret = pthread_mutex_unlock(&all_threads_lock);
728 gc_assert(lock_ret == 0);
729 #ifdef LOCK_CREATE_THREAD
730 lock_ret = pthread_mutex_unlock(&create_thread_lock);
731 gc_assert(lock_ret == 0);
734 FSHOW_SIGNAL((stderr,"/gc_start_the_world:end\n"));