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;
96 #if defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64)
97 extern lispobj call_into_lisp_first_time(lispobj fun, lispobj *args, int nargs);
101 link_thread(struct thread *th)
103 if (all_threads) all_threads->prev=th;
104 th->next=all_threads;
109 #ifdef LISP_FEATURE_SB_THREAD
111 unlink_thread(struct thread *th)
114 th->prev->next = th->next;
116 all_threads = th->next;
118 th->next->prev = th->prev;
123 initial_thread_trampoline(struct thread *th)
126 #if defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64)
127 lispobj *args = NULL;
129 function = th->no_tls_value_marker;
130 th->no_tls_value_marker = NO_TLS_VALUE_MARKER_WIDETAG;
131 if(arch_os_thread_init(th)==0) return 1;
133 th->os_thread=thread_self();
134 #ifndef LISP_FEATURE_WIN32
135 protect_control_stack_guard_page(1);
138 #if defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64)
139 return call_into_lisp_first_time(function,args,0);
141 return funcall0(function);
145 #define THREAD_STRUCT_SIZE (THREAD_CONTROL_STACK_SIZE + BINDING_STACK_SIZE + \
146 ALIEN_STACK_SIZE + dynamic_values_bytes + \
150 #ifdef LISP_FEATURE_SB_THREAD
152 #ifdef QUEUE_FREEABLE_THREAD_STACKS
155 queue_freeable_thread_stack(struct thread *thread_to_be_cleaned_up)
157 struct freeable_stack *new_freeable_stack = 0;
158 if (thread_to_be_cleaned_up) {
159 /* FIXME: os_validate is mmap -- for small things like these
160 * malloc would probably perform better. */
161 new_freeable_stack = (struct freeable_stack *)
162 os_validate(0, sizeof(struct freeable_stack));
163 new_freeable_stack->next = NULL;
164 new_freeable_stack->os_thread = thread_to_be_cleaned_up->os_thread;
165 new_freeable_stack->os_address = thread_to_be_cleaned_up->os_address;
166 pthread_mutex_lock(&freeable_stack_lock);
167 if (freeable_stack_queue) {
168 struct freeable_stack *next;
169 next = freeable_stack_queue;
173 next->next = new_freeable_stack;
175 freeable_stack_queue = new_freeable_stack;
177 freeable_stack_count++;
178 pthread_mutex_unlock(&freeable_stack_lock);
182 #define FREEABLE_STACK_QUEUE_SIZE 4
185 free_freeable_stacks() {
186 if (freeable_stack_queue && (freeable_stack_count > FREEABLE_STACK_QUEUE_SIZE)) {
187 struct freeable_stack* old;
188 pthread_mutex_lock(&freeable_stack_lock);
189 old = freeable_stack_queue;
190 freeable_stack_queue = old->next;
191 freeable_stack_count--;
192 gc_assert(pthread_join(old->os_thread, NULL) == 0);
193 FSHOW((stderr, "freeing thread %x stack\n", old->os_thread));
194 os_invalidate(old->os_address, THREAD_STRUCT_SIZE);
195 os_invalidate((os_vm_address_t)old, sizeof(struct freeable_stack));
196 pthread_mutex_unlock(&freeable_stack_lock);
200 #elif defined(CREATE_CLEANUP_THREAD)
202 cleanup_thread(void *arg)
204 struct freeable_stack *freeable = arg;
205 pthread_t self = pthread_self();
207 FSHOW((stderr, "/cleaner thread(%p): joining %p\n",
208 self, freeable->os_thread));
209 gc_assert(pthread_join(freeable->os_thread, NULL) == 0);
210 FSHOW((stderr, "/cleaner thread(%p): free stack %p\n",
211 self, freeable->stack));
212 os_invalidate(freeable->os_address, THREAD_STRUCT_SIZE);
215 pthread_detach(self);
221 create_cleanup_thread(struct thread *thread_to_be_cleaned_up)
226 if (thread_to_be_cleaned_up) {
227 struct freeable_stack *freeable =
228 malloc(sizeof(struct freeable_stack));
229 gc_assert(freeable != NULL);
230 freeable->os_thread = thread_to_be_cleaned_up->os_thread;
231 freeable->os_address =
232 (os_vm_address_t) thread_to_be_cleaned_up->os_address;
233 result = pthread_create(&thread, NULL, cleanup_thread, freeable);
234 gc_assert(result == 0);
241 free_thread_stack_later(struct thread *thread_to_be_cleaned_up)
243 struct freeable_stack *new_freeable_stack = 0;
244 if (thread_to_be_cleaned_up) {
245 new_freeable_stack = (struct freeable_stack *)
246 os_validate(0, sizeof(struct freeable_stack));
247 new_freeable_stack->os_thread = thread_to_be_cleaned_up->os_thread;
248 new_freeable_stack->os_address = (os_vm_address_t)
249 thread_to_be_cleaned_up->os_address;
251 new_freeable_stack = (struct freeable_stack *)
252 swap_lispobjs((lispobj *)(void *)&freeable_stack,
253 (lispobj)new_freeable_stack);
254 if (new_freeable_stack) {
255 FSHOW((stderr,"/reaping %p\n", (void*) new_freeable_stack->os_thread));
256 /* Under NPTL pthread_join really waits until the thread
257 * exists and the stack can be safely freed. This is sadly not
258 * mandated by the pthread spec. */
259 gc_assert(pthread_join(new_freeable_stack->os_thread, NULL) == 0);
260 os_invalidate(new_freeable_stack->os_address, THREAD_STRUCT_SIZE);
261 os_invalidate((os_vm_address_t) new_freeable_stack,
262 sizeof(struct freeable_stack));
267 /* this is the first thing that runs in the child (which is why the
268 * silly calling convention). Basically it calls the user's requested
269 * lisp function after doing arch_os_thread_init and whatever other
270 * bookkeeping needs to be done
273 new_thread_trampoline(struct thread *th)
276 int result, lock_ret;
278 FSHOW((stderr,"/creating thread %lu\n", thread_self()));
279 function = th->no_tls_value_marker;
280 th->no_tls_value_marker = NO_TLS_VALUE_MARKER_WIDETAG;
281 if(arch_os_thread_init(th)==0) {
282 /* FIXME: handle error */
283 lose("arch_os_thread_init failed\n");
286 th->os_thread=thread_self();
287 protect_control_stack_guard_page(1);
288 /* Since GC can only know about this thread from the all_threads
289 * list and we're just adding this thread to it there is no danger
290 * of deadlocking even with SIG_STOP_FOR_GC blocked (which it is
292 lock_ret = pthread_mutex_lock(&all_threads_lock);
293 gc_assert(lock_ret == 0);
295 lock_ret = pthread_mutex_unlock(&all_threads_lock);
296 gc_assert(lock_ret == 0);
298 result = funcall0(function);
301 block_blockable_signals();
302 th->state=STATE_DEAD;
304 /* SIG_STOP_FOR_GC is blocked and GC might be waiting for this
305 * thread, but since we are already dead it won't wait long. */
306 lock_ret = pthread_mutex_lock(&all_threads_lock);
307 gc_assert(lock_ret == 0);
309 gc_alloc_update_page_tables(0, &th->alloc_region);
311 pthread_mutex_unlock(&all_threads_lock);
312 gc_assert(lock_ret == 0);
314 if(th->tls_cookie>=0) arch_os_thread_cleanup(th);
315 os_invalidate((os_vm_address_t)th->interrupt_data,
316 (sizeof (struct interrupt_data)));
318 #ifdef LISP_FEATURE_MACH_EXCEPTION_HANDLER
319 FSHOW((stderr, "Deallocating mach port %x\n", THREAD_STRUCT_TO_EXCEPTION_PORT(th)));
320 mach_port_move_member(mach_task_self(),
321 THREAD_STRUCT_TO_EXCEPTION_PORT(th),
323 mach_port_deallocate(mach_task_self(),
324 THREAD_STRUCT_TO_EXCEPTION_PORT(th));
325 mach_port_destroy(mach_task_self(),
326 THREAD_STRUCT_TO_EXCEPTION_PORT(th));
329 #ifdef QUEUE_FREEABLE_THREAD_STACKS
330 queue_freeable_thread_stack(th);
331 #elif defined(CREATE_CLEANUP_THREAD)
332 create_cleanup_thread(th);
334 free_thread_stack_later(th);
337 FSHOW((stderr,"/exiting thread %p\n", thread_self()));
341 #endif /* LISP_FEATURE_SB_THREAD */
344 free_thread_struct(struct thread *th)
346 if (th->interrupt_data)
347 os_invalidate((os_vm_address_t) th->interrupt_data,
348 (sizeof (struct interrupt_data)));
349 os_invalidate((os_vm_address_t) th->os_address,
353 /* this is called from any other thread to create the new one, and
354 * initialize all parts of it that can be initialized from another
358 static struct thread *
359 create_thread_struct(lispobj initial_function) {
360 union per_thread_data *per_thread;
361 struct thread *th=0; /* subdue gcc */
363 void *aligned_spaces=0;
364 #ifdef LISP_FEATURE_SB_THREAD
368 #ifdef CREATE_CLEANUP_THREAD
369 /* Give a chance for cleanup threads to run. */
372 /* May as well allocate all the spaces at once: it saves us from
373 * having to decide what to do if only some of the allocations
374 * succeed. SPACES must be page-aligned, since the GC expects the
375 * control stack to start at a page boundary. We can't rely on the
376 * alignment passed from os_validate, since that might assume the
377 * current (e.g. 4k) pagesize, while we calculate with the biggest
378 * (e.g. 64k) pagesize allowed by the ABI. */
379 spaces=os_validate(0, THREAD_STRUCT_SIZE);
382 /* Aligning up is safe as THREAD_STRUCT_SIZE has BACKEND_PAGE_SIZE
384 aligned_spaces = (void *)((((unsigned long)(char *)spaces)
385 + BACKEND_PAGE_SIZE - 1)
386 & ~(unsigned long)(BACKEND_PAGE_SIZE - 1));
387 per_thread=(union per_thread_data *)
389 THREAD_CONTROL_STACK_SIZE+
393 #ifdef LISP_FEATURE_SB_THREAD
394 for(i = 0; i < (dynamic_values_bytes / sizeof(lispobj)); i++)
395 per_thread->dynamic_values[i] = NO_TLS_VALUE_MARKER_WIDETAG;
396 if (all_threads == 0) {
397 if(SymbolValue(FREE_TLS_INDEX,0)==UNBOUND_MARKER_WIDETAG) {
400 /* FIXME: should be MAX_INTERRUPTS -1 ? */
401 make_fixnum(MAX_INTERRUPTS+
402 sizeof(struct thread)/sizeof(lispobj)),
404 SetSymbolValue(TLS_INDEX_LOCK,make_fixnum(0),0);
406 #define STATIC_TLS_INIT(sym,field) \
407 ((struct symbol *)(sym-OTHER_POINTER_LOWTAG))->tls_index= \
408 make_fixnum(THREAD_SLOT_OFFSET_WORDS(field))
410 STATIC_TLS_INIT(BINDING_STACK_START,binding_stack_start);
411 STATIC_TLS_INIT(BINDING_STACK_POINTER,binding_stack_pointer);
412 STATIC_TLS_INIT(CONTROL_STACK_START,control_stack_start);
413 STATIC_TLS_INIT(CONTROL_STACK_END,control_stack_end);
414 STATIC_TLS_INIT(ALIEN_STACK,alien_stack_pointer);
415 #if defined(LISP_FEATURE_X86) || defined (LISP_FEATURE_X86_64)
416 STATIC_TLS_INIT(PSEUDO_ATOMIC_BITS,pseudo_atomic_bits);
418 #undef STATIC_TLS_INIT
422 th=&per_thread->thread;
423 th->os_address = spaces;
424 th->control_stack_start = aligned_spaces;
425 th->binding_stack_start=
426 (lispobj*)((void*)th->control_stack_start+THREAD_CONTROL_STACK_SIZE);
427 th->control_stack_end = th->binding_stack_start;
428 th->alien_stack_start=
429 (lispobj*)((void*)th->binding_stack_start+BINDING_STACK_SIZE);
430 th->binding_stack_pointer=th->binding_stack_start;
433 th->state=STATE_RUNNING;
434 #ifdef LISP_FEATURE_STACK_GROWS_DOWNWARD_NOT_UPWARD
435 th->alien_stack_pointer=((void *)th->alien_stack_start
436 + ALIEN_STACK_SIZE-N_WORD_BYTES);
438 th->alien_stack_pointer=((void *)th->alien_stack_start);
440 #if defined(LISP_FEATURE_X86) || defined (LISP_FEATURE_X86_64)
441 th->pseudo_atomic_bits=0;
443 #ifdef LISP_FEATURE_GENCGC
444 gc_set_region_empty(&th->alloc_region);
447 #ifndef LISP_FEATURE_SB_THREAD
448 /* the tls-points-into-struct-thread trick is only good for threaded
449 * sbcl, because unithread sbcl doesn't have tls. So, we copy the
450 * appropriate values from struct thread here, and make sure that
451 * we use the appropriate SymbolValue macros to access any of the
452 * variable quantities from the C runtime. It's not quite OAOOM,
453 * it just feels like it */
454 SetSymbolValue(BINDING_STACK_START,(lispobj)th->binding_stack_start,th);
455 SetSymbolValue(CONTROL_STACK_START,(lispobj)th->control_stack_start,th);
456 SetSymbolValue(CONTROL_STACK_END,(lispobj)th->control_stack_end,th);
457 #if defined(LISP_FEATURE_X86) || defined (LISP_FEATURE_X86_64)
458 SetSymbolValue(BINDING_STACK_POINTER,(lispobj)th->binding_stack_pointer,th);
459 SetSymbolValue(ALIEN_STACK,(lispobj)th->alien_stack_pointer,th);
460 SetSymbolValue(PSEUDO_ATOMIC_BITS,(lispobj)th->pseudo_atomic_bits,th);
462 current_binding_stack_pointer=th->binding_stack_pointer;
463 current_control_stack_pointer=th->control_stack_start;
466 bind_variable(CURRENT_CATCH_BLOCK,make_fixnum(0),th);
467 bind_variable(CURRENT_UNWIND_PROTECT_BLOCK,make_fixnum(0),th);
468 bind_variable(FREE_INTERRUPT_CONTEXT_INDEX,make_fixnum(0),th);
469 bind_variable(INTERRUPT_PENDING, NIL,th);
470 bind_variable(INTERRUPTS_ENABLED,T,th);
471 bind_variable(ALLOW_WITH_INTERRUPTS,T,th);
472 bind_variable(GC_PENDING,NIL,th);
473 #ifdef LISP_FEATURE_SB_THREAD
474 bind_variable(STOP_FOR_GC_PENDING,NIL,th);
477 th->interrupt_data = (struct interrupt_data *)
478 os_validate(0,(sizeof (struct interrupt_data)));
479 if (!th->interrupt_data) {
480 free_thread_struct(th);
483 th->interrupt_data->pending_handler = 0;
484 th->no_tls_value_marker=initial_function;
490 #ifdef LISP_FEATURE_MACH_EXCEPTION_HANDLER
491 mach_port_t setup_mach_exception_handling_thread();
492 kern_return_t mach_thread_init(mach_port_t thread_exception_port);
496 void create_initial_thread(lispobj initial_function) {
497 struct thread *th=create_thread_struct(initial_function);
499 #ifdef LISP_FEATURE_MACH_EXCEPTION_HANDLER
502 setup_mach_exception_handling_thread();
504 initial_thread_trampoline(th); /* no return */
505 } else lose("can't create initial thread\n");
508 #ifdef LISP_FEATURE_SB_THREAD
510 #ifndef __USE_XOPEN2K
511 extern int pthread_attr_setstack (pthread_attr_t *__attr, void *__stackaddr,
515 boolean create_os_thread(struct thread *th,os_thread_t *kid_tid)
517 /* The new thread inherits the restrictive signal mask set here,
518 * and enables signals again when it is set up properly. */
520 sigset_t newset,oldset;
522 int retcode, initcode, sizecode, addrcode;
524 FSHOW_SIGNAL((stderr,"/create_os_thread: creating new thread\n"));
526 #ifdef LOCK_CREATE_THREAD
527 retcode = pthread_mutex_lock(&create_thread_lock);
528 gc_assert(retcode == 0);
529 FSHOW_SIGNAL((stderr,"/create_os_thread: got lock\n"));
531 sigemptyset(&newset);
532 /* Blocking deferrable signals is enough, no need to block
533 * SIG_STOP_FOR_GC because the child process is not linked onto
534 * all_threads until it's ready. */
535 sigaddset_deferrable(&newset);
536 thread_sigmask(SIG_BLOCK, &newset, &oldset);
538 #if defined(LISP_FEATURE_DARWIN)
539 #define CONTROL_STACK_ADJUST 8192 /* darwin wants page-aligned stacks */
541 #define CONTROL_STACK_ADJUST 16
544 if((initcode = pthread_attr_init(&attr)) ||
545 /* FIXME: why do we even have this in the first place? */
546 (pthread_attr_setstack(&attr,th->control_stack_start,
547 THREAD_CONTROL_STACK_SIZE-CONTROL_STACK_ADJUST)) ||
548 #undef CONTROL_STACK_ADJUST
549 (retcode = pthread_create
550 (kid_tid,&attr,(void *(*)(void *))new_thread_trampoline,th))) {
551 FSHOW_SIGNAL((stderr, "init, size, addr = %d, %d, %d\n", initcode, sizecode, addrcode));
552 FSHOW_SIGNAL((stderr, printf("pthread_create returned %d, errno %d\n", retcode, errno)));
553 FSHOW_SIGNAL((stderr, "wanted stack size %d, min stack size %d\n",
554 THREAD_CONTROL_STACK_SIZE-16, PTHREAD_STACK_MIN));
556 perror("create_os_thread");
561 #ifdef QUEUE_FREEABLE_THREAD_STACKS
562 free_freeable_stacks();
564 thread_sigmask(SIG_SETMASK,&oldset,0);
565 #ifdef LOCK_CREATE_THREAD
566 retcode = pthread_mutex_unlock(&create_thread_lock);
567 gc_assert(retcode == 0);
568 FSHOW_SIGNAL((stderr,"/create_os_thread: released lock\n"));
573 os_thread_t create_thread(lispobj initial_function) {
577 /* Assuming that a fresh thread struct has no lisp objects in it,
578 * linking it to all_threads can be left to the thread itself
579 * without fear of gc lossage. initial_function violates this
580 * assumption and must stay pinned until the child starts up. */
581 th = create_thread_struct(initial_function);
584 if (create_os_thread(th,&kid_tid)) {
587 free_thread_struct(th);
592 /* Send the signo to os_thread, retry if the rt signal queue is
595 kill_thread_safely(os_thread_t os_thread, int signo)
598 /* The man page does not mention EAGAIN as a valid return value
599 * for either pthread_kill or kill. But that's theory, this is
600 * practice. By waiting here we assume that the delivery of this
601 * signal is not necessary for the delivery of the signals in the
602 * queue. In other words, we _assume_ there are no deadlocks. */
603 while ((r=pthread_kill(os_thread,signo))==EAGAIN) {
604 /* wait a bit then try again in the hope of the rt signal
605 * queue not being full */
606 FSHOW_SIGNAL((stderr,"/rt signal queue full\n"));
607 /* FIXME: some kind of backoff (random, exponential) would be
614 int signal_interrupt_thread(os_thread_t os_thread)
616 int status = kill_thread_safely(os_thread, SIG_INTERRUPT_THREAD);
619 } else if (status == ESRCH) {
622 lose("cannot send SIG_INTERRUPT_THREAD to thread=%lu: %d, %s\n",
623 os_thread, status, strerror(status));
627 /* stopping the world is a two-stage process. From this thread we signal
628 * all the others with SIG_STOP_FOR_GC. The handler for this signal does
629 * the usual pseudo-atomic checks (we don't want to stop a thread while
630 * it's in the middle of allocation) then waits for another SIG_STOP_FOR_GC.
633 /* To avoid deadlocks when gc stops the world all clients of each
634 * mutex must enable or disable SIG_STOP_FOR_GC for the duration of
635 * holding the lock, but they must agree on which. */
636 void gc_stop_the_world()
638 struct thread *p,*th=arch_os_get_current_thread();
639 int status, lock_ret;
640 #ifdef LOCK_CREATE_THREAD
641 /* KLUDGE: Stopping the thread during pthread_create() causes deadlock
643 FSHOW_SIGNAL((stderr,"/gc_stop_the_world:waiting on create_thread_lock, thread=%lu\n",
645 lock_ret = pthread_mutex_lock(&create_thread_lock);
646 gc_assert(lock_ret == 0);
647 FSHOW_SIGNAL((stderr,"/gc_stop_the_world:got create_thread_lock, thread=%lu\n",
650 FSHOW_SIGNAL((stderr,"/gc_stop_the_world:waiting on lock, thread=%lu\n",
652 /* keep threads from starting while the world is stopped. */
653 lock_ret = pthread_mutex_lock(&all_threads_lock); \
654 gc_assert(lock_ret == 0);
656 FSHOW_SIGNAL((stderr,"/gc_stop_the_world:got lock, thread=%lu\n",
658 /* stop all other threads by sending them SIG_STOP_FOR_GC */
659 for(p=all_threads; p; p=p->next) {
660 gc_assert(p->os_thread != 0);
661 FSHOW_SIGNAL((stderr,"/gc_stop_the_world: p->state: %x\n", p->state));
662 if((p!=th) && ((p->state==STATE_RUNNING))) {
663 FSHOW_SIGNAL((stderr,"/gc_stop_the_world: suspending %x, os_thread %x\n",
665 status=kill_thread_safely(p->os_thread,SIG_STOP_FOR_GC);
667 /* This thread has exited. */
668 gc_assert(p->state==STATE_DEAD);
670 lose("cannot send suspend thread=%lu: %d, %s\n",
671 p->os_thread,status,strerror(status));
675 FSHOW_SIGNAL((stderr,"/gc_stop_the_world:signals sent\n"));
676 /* wait for the running threads to stop or finish */
677 for(p=all_threads;p;) {
678 FSHOW_SIGNAL((stderr,"/gc_stop_the_world: th: %p, p: %p\n", th, p));
679 if((p!=th) && (p->state==STATE_RUNNING)) {
685 FSHOW_SIGNAL((stderr,"/gc_stop_the_world:end\n"));
688 void gc_start_the_world()
690 struct thread *p,*th=arch_os_get_current_thread();
691 int status, lock_ret;
692 /* if a resumed thread creates a new thread before we're done with
693 * this loop, the new thread will get consed on the front of
694 * all_threads, but it won't have been stopped so won't need
696 FSHOW_SIGNAL((stderr,"/gc_start_the_world:begin\n"));
697 for(p=all_threads;p;p=p->next) {
698 gc_assert(p->os_thread!=0);
699 if((p!=th) && (p->state!=STATE_DEAD)) {
700 if(p->state!=STATE_SUSPENDED) {
701 lose("gc_start_the_world: wrong thread state is %d\n",
702 fixnum_value(p->state));
704 FSHOW_SIGNAL((stderr, "/gc_start_the_world: resuming %lu\n",
706 p->state=STATE_RUNNING;
708 #if defined(SIG_RESUME_FROM_GC)
709 status=kill_thread_safely(p->os_thread,SIG_RESUME_FROM_GC);
711 status=kill_thread_safely(p->os_thread,SIG_STOP_FOR_GC);
714 lose("cannot resume thread=%lu: %d, %s\n",
715 p->os_thread,status,strerror(status));
719 /* If we waited here until all threads leave STATE_SUSPENDED, then
720 * SIG_STOP_FOR_GC wouldn't need to be a rt signal. That has some
721 * performance implications, but does away with the 'rt signal
722 * queue full' problem. */
724 lock_ret = pthread_mutex_unlock(&all_threads_lock);
725 gc_assert(lock_ret == 0);
726 #ifdef LOCK_CREATE_THREAD
727 lock_ret = pthread_mutex_unlock(&create_thread_lock);
728 gc_assert(lock_ret == 0);
731 FSHOW_SIGNAL((stderr,"/gc_start_the_world:end\n"));