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 BINDING_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 DELAY_THREAD_POST_MORTEM 5
58 #define LOCK_CREATE_THREAD
61 #ifdef LISP_FEATURE_FREEBSD
62 #define CREATE_CLEANUP_THREAD
63 #define LOCK_CREATE_THREAD
66 #ifdef LISP_FEATURE_SB_THREAD
67 struct thread_post_mortem {
68 #ifdef DELAY_THREAD_POST_MORTEM
69 struct thread_post_mortem *next;
71 os_thread_t os_thread;
72 pthread_attr_t *os_attr;
73 os_vm_address_t os_address;
76 #ifdef DELAY_THREAD_POST_MORTEM
77 static int pending_thread_post_mortem_count = 0;
78 pthread_mutex_t thread_post_mortem_lock = PTHREAD_MUTEX_INITIALIZER;
80 static struct thread_post_mortem * volatile pending_thread_post_mortem = 0;
83 int dynamic_values_bytes=TLS_SIZE*sizeof(lispobj); /* same for all threads */
84 struct thread *all_threads;
85 extern struct interrupt_data * global_interrupt_data;
87 #ifdef LISP_FEATURE_SB_THREAD
88 pthread_mutex_t all_threads_lock = PTHREAD_MUTEX_INITIALIZER;
89 #ifdef LOCK_CREATE_THREAD
90 static pthread_mutex_t create_thread_lock = PTHREAD_MUTEX_INITIALIZER;
92 #ifdef LISP_FEATURE_GCC_TLS
93 __thread struct thread *current_thread;
97 #if defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64)
98 extern lispobj call_into_lisp_first_time(lispobj fun, lispobj *args, int nargs);
102 link_thread(struct thread *th)
104 if (all_threads) all_threads->prev=th;
105 th->next=all_threads;
110 #ifdef LISP_FEATURE_SB_THREAD
112 unlink_thread(struct thread *th)
115 th->prev->next = th->next;
117 all_threads = th->next;
119 th->next->prev = th->prev;
124 initial_thread_trampoline(struct thread *th)
127 #if defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64)
128 lispobj *args = NULL;
130 function = th->no_tls_value_marker;
131 th->no_tls_value_marker = NO_TLS_VALUE_MARKER_WIDETAG;
132 if(arch_os_thread_init(th)==0) return 1;
134 th->os_thread=thread_self();
135 #ifndef LISP_FEATURE_WIN32
136 protect_control_stack_guard_page(1, NULL);
137 protect_binding_stack_guard_page(1, NULL);
138 protect_alien_stack_guard_page(1, NULL);
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 #ifdef LISP_FEATURE_SB_THREAD
149 #define THREAD_STATE_LOCK_SIZE \
150 (sizeof(pthread_mutex_t))+(sizeof(pthread_cond_t))
152 #define THREAD_STATE_LOCK_SIZE 0
155 #define THREAD_STRUCT_SIZE (thread_control_stack_size + BINDING_STACK_SIZE + \
157 THREAD_STATE_LOCK_SIZE + \
158 dynamic_values_bytes + \
160 THREAD_ALIGNMENT_BYTES)
162 #ifdef LISP_FEATURE_SB_THREAD
163 /* THREAD POST MORTEM CLEANUP
165 * Memory allocated for the thread stacks cannot be reclaimed while
166 * the thread is still alive, so we need a mechanism for post mortem
167 * cleanups. FIXME: We actually have three, for historical reasons as
168 * the saying goes. Do we really need three? Nikodemus guesses that
169 * not anymore, now that we properly call pthread_attr_destroy before
170 * freeing the stack. */
172 static struct thread_post_mortem *
173 plan_thread_post_mortem(struct thread *corpse)
176 struct thread_post_mortem *post_mortem = malloc(sizeof(struct thread_post_mortem));
177 gc_assert(post_mortem);
178 post_mortem->os_thread = corpse->os_thread;
179 post_mortem->os_attr = corpse->os_attr;
180 post_mortem->os_address = corpse->os_address;
181 #ifdef DELAY_THREAD_POST_MORTEM
182 post_mortem->next = NULL;
186 /* FIXME: When does this happen? */
192 perform_thread_post_mortem(struct thread_post_mortem *post_mortem)
194 #ifdef CREATE_POST_MORTEM_THREAD
195 pthread_detach(pthread_self());
198 gc_assert(!pthread_join(post_mortem->os_thread, NULL));
199 gc_assert(!pthread_attr_destroy(post_mortem->os_attr));
200 free(post_mortem->os_attr);
201 os_invalidate(post_mortem->os_address, THREAD_STRUCT_SIZE);
207 schedule_thread_post_mortem(struct thread *corpse)
209 struct thread_post_mortem *post_mortem = NULL;
211 post_mortem = plan_thread_post_mortem(corpse);
213 #ifdef DELAY_THREAD_POST_MORTEM
214 pthread_mutex_lock(&thread_post_mortem_lock);
215 /* First stick the new post mortem to the end of the queue. */
216 if (pending_thread_post_mortem) {
217 struct thread_post_mortem *next = pending_thread_post_mortem;
221 next->next = post_mortem;
223 pending_thread_post_mortem = post_mortem;
225 /* Then, if there are enough things in the queue, clean up one
226 * from the head -- or increment the count, and null out the
227 * post_mortem we have. */
228 if (pending_thread_post_mortem_count > DELAY_THREAD_POST_MORTEM) {
229 post_mortem = pending_thread_post_mortem;
230 pending_thread_post_mortem = post_mortem->next;
232 pending_thread_post_mortem_count++;
235 pthread_mutex_unlock(&thread_post_mortem_lock);
236 /* Finally run, the cleanup, if any. */
237 perform_thread_post_mortem(post_mortem);
238 #elif defined(CREATE_POST_MORTEM_THREAD)
239 gc_assert(!pthread_create(&thread, NULL, perform_thread_post_mortem, post_mortem));
241 post_mortem = (struct thread_post_mortem *)
242 swap_lispobjs((lispobj *)(void *)&pending_thread_post_mortem,
243 (lispobj)post_mortem);
244 perform_thread_post_mortem(post_mortem);
249 /* this is the first thing that runs in the child (which is why the
250 * silly calling convention). Basically it calls the user's requested
251 * lisp function after doing arch_os_thread_init and whatever other
252 * bookkeeping needs to be done
255 new_thread_trampoline(struct thread *th)
258 int result, lock_ret;
260 FSHOW((stderr,"/creating thread %lu\n", thread_self()));
261 check_deferrables_blocked_or_lose(0);
262 check_gc_signals_unblocked_or_lose(0);
263 function = th->no_tls_value_marker;
264 th->no_tls_value_marker = NO_TLS_VALUE_MARKER_WIDETAG;
265 if(arch_os_thread_init(th)==0) {
266 /* FIXME: handle error */
267 lose("arch_os_thread_init failed\n");
270 th->os_thread=thread_self();
271 protect_control_stack_guard_page(1, NULL);
272 protect_binding_stack_guard_page(1, NULL);
273 protect_alien_stack_guard_page(1, NULL);
274 /* Since GC can only know about this thread from the all_threads
275 * list and we're just adding this thread to it, there is no
276 * danger of deadlocking even with SIG_STOP_FOR_GC blocked (which
278 lock_ret = pthread_mutex_lock(&all_threads_lock);
279 gc_assert(lock_ret == 0);
281 lock_ret = pthread_mutex_unlock(&all_threads_lock);
282 gc_assert(lock_ret == 0);
284 result = funcall0(function);
287 block_blockable_signals(0, 0);
288 set_thread_state(th, STATE_DEAD);
290 /* SIG_STOP_FOR_GC is blocked and GC might be waiting for this
291 * thread, but since we are already dead it won't wait long. */
292 lock_ret = pthread_mutex_lock(&all_threads_lock);
293 gc_assert(lock_ret == 0);
295 gc_alloc_update_page_tables(BOXED_PAGE_FLAG, &th->alloc_region);
297 pthread_mutex_unlock(&all_threads_lock);
298 gc_assert(lock_ret == 0);
300 if(th->tls_cookie>=0) arch_os_thread_cleanup(th);
301 pthread_mutex_destroy(th->state_lock);
302 pthread_cond_destroy(th->state_cond);
304 os_invalidate((os_vm_address_t)th->interrupt_data,
305 (sizeof (struct interrupt_data)));
307 #ifdef LISP_FEATURE_MACH_EXCEPTION_HANDLER
308 FSHOW((stderr, "Deallocating mach port %x\n", THREAD_STRUCT_TO_EXCEPTION_PORT(th)));
309 mach_port_move_member(mach_task_self(),
310 THREAD_STRUCT_TO_EXCEPTION_PORT(th),
312 mach_port_deallocate(mach_task_self(),
313 THREAD_STRUCT_TO_EXCEPTION_PORT(th));
314 mach_port_destroy(mach_task_self(),
315 THREAD_STRUCT_TO_EXCEPTION_PORT(th));
318 schedule_thread_post_mortem(th);
319 FSHOW((stderr,"/exiting thread %lu\n", thread_self()));
323 #endif /* LISP_FEATURE_SB_THREAD */
326 free_thread_struct(struct thread *th)
328 if (th->interrupt_data)
329 os_invalidate((os_vm_address_t) th->interrupt_data,
330 (sizeof (struct interrupt_data)));
331 os_invalidate((os_vm_address_t) th->os_address,
335 /* this is called from any other thread to create the new one, and
336 * initialize all parts of it that can be initialized from another
340 static struct thread *
341 create_thread_struct(lispobj initial_function) {
342 union per_thread_data *per_thread;
343 struct thread *th=0; /* subdue gcc */
345 void *aligned_spaces=0;
346 #ifdef LISP_FEATURE_SB_THREAD
350 /* May as well allocate all the spaces at once: it saves us from
351 * having to decide what to do if only some of the allocations
352 * succeed. SPACES must be appropriately aligned, since the GC
353 * expects the control stack to start at a page boundary -- and
354 * the OS may have even more rigorous requirements. We can't rely
355 * on the alignment passed from os_validate, since that might
356 * assume the current (e.g. 4k) pagesize, while we calculate with
357 * the biggest (e.g. 64k) pagesize allowed by the ABI. */
358 spaces=os_validate(0, THREAD_STRUCT_SIZE);
361 /* Aligning up is safe as THREAD_STRUCT_SIZE has
362 * THREAD_ALIGNMENT_BYTES padding. */
363 aligned_spaces = (void *)((((unsigned long)(char *)spaces)
364 + THREAD_ALIGNMENT_BYTES-1)
365 &~(unsigned long)(THREAD_ALIGNMENT_BYTES-1));
366 per_thread=(union per_thread_data *)
368 thread_control_stack_size+
371 THREAD_STATE_LOCK_SIZE);
373 #ifdef LISP_FEATURE_SB_THREAD
374 for(i = 0; i < (dynamic_values_bytes / sizeof(lispobj)); i++)
375 per_thread->dynamic_values[i] = NO_TLS_VALUE_MARKER_WIDETAG;
376 if (all_threads == 0) {
377 if(SymbolValue(FREE_TLS_INDEX,0)==UNBOUND_MARKER_WIDETAG) {
380 /* FIXME: should be MAX_INTERRUPTS -1 ? */
381 make_fixnum(MAX_INTERRUPTS+
382 sizeof(struct thread)/sizeof(lispobj)),
384 SetSymbolValue(TLS_INDEX_LOCK,make_fixnum(0),0);
386 #define STATIC_TLS_INIT(sym,field) \
387 ((struct symbol *)(sym-OTHER_POINTER_LOWTAG))->tls_index= \
388 make_fixnum(THREAD_SLOT_OFFSET_WORDS(field))
390 STATIC_TLS_INIT(BINDING_STACK_START,binding_stack_start);
391 STATIC_TLS_INIT(BINDING_STACK_POINTER,binding_stack_pointer);
392 STATIC_TLS_INIT(CONTROL_STACK_START,control_stack_start);
393 STATIC_TLS_INIT(CONTROL_STACK_END,control_stack_end);
394 STATIC_TLS_INIT(ALIEN_STACK,alien_stack_pointer);
395 #if defined(LISP_FEATURE_X86) || defined (LISP_FEATURE_X86_64)
396 STATIC_TLS_INIT(PSEUDO_ATOMIC_BITS,pseudo_atomic_bits);
398 #undef STATIC_TLS_INIT
402 th=&per_thread->thread;
403 th->os_address = spaces;
404 th->control_stack_start = aligned_spaces;
405 th->binding_stack_start=
406 (lispobj*)((void*)th->control_stack_start+thread_control_stack_size);
407 th->control_stack_end = th->binding_stack_start;
408 th->alien_stack_start=
409 (lispobj*)((void*)th->binding_stack_start+BINDING_STACK_SIZE);
410 th->binding_stack_pointer=th->binding_stack_start;
413 #ifdef LISP_FEATURE_SB_THREAD
414 th->os_attr=malloc(sizeof(pthread_attr_t));
415 th->state_lock=(pthread_mutex_t *)((void *)th->alien_stack_start +
417 pthread_mutex_init(th->state_lock, NULL);
418 th->state_cond=(pthread_cond_t *)((void *)th->state_lock +
419 (sizeof(pthread_mutex_t)));
420 pthread_cond_init(th->state_cond, NULL);
422 th->state=STATE_RUNNING;
423 #ifdef LISP_FEATURE_STACK_GROWS_DOWNWARD_NOT_UPWARD
424 th->alien_stack_pointer=((void *)th->alien_stack_start
425 + ALIEN_STACK_SIZE-N_WORD_BYTES);
427 th->alien_stack_pointer=((void *)th->alien_stack_start);
429 #if defined(LISP_FEATURE_X86) || defined (LISP_FEATURE_X86_64)
430 th->pseudo_atomic_bits=0;
432 #ifdef LISP_FEATURE_GENCGC
433 gc_set_region_empty(&th->alloc_region);
436 #ifndef LISP_FEATURE_SB_THREAD
437 /* the tls-points-into-struct-thread trick is only good for threaded
438 * sbcl, because unithread sbcl doesn't have tls. So, we copy the
439 * appropriate values from struct thread here, and make sure that
440 * we use the appropriate SymbolValue macros to access any of the
441 * variable quantities from the C runtime. It's not quite OAOOM,
442 * it just feels like it */
443 SetSymbolValue(BINDING_STACK_START,(lispobj)th->binding_stack_start,th);
444 SetSymbolValue(CONTROL_STACK_START,(lispobj)th->control_stack_start,th);
445 SetSymbolValue(CONTROL_STACK_END,(lispobj)th->control_stack_end,th);
446 #if defined(LISP_FEATURE_X86) || defined (LISP_FEATURE_X86_64)
447 SetSymbolValue(BINDING_STACK_POINTER,(lispobj)th->binding_stack_pointer,th);
448 SetSymbolValue(ALIEN_STACK,(lispobj)th->alien_stack_pointer,th);
449 SetSymbolValue(PSEUDO_ATOMIC_BITS,(lispobj)th->pseudo_atomic_bits,th);
451 current_binding_stack_pointer=th->binding_stack_pointer;
452 current_control_stack_pointer=th->control_stack_start;
455 bind_variable(CURRENT_CATCH_BLOCK,make_fixnum(0),th);
456 bind_variable(CURRENT_UNWIND_PROTECT_BLOCK,make_fixnum(0),th);
457 bind_variable(FREE_INTERRUPT_CONTEXT_INDEX,make_fixnum(0),th);
458 bind_variable(INTERRUPT_PENDING, NIL,th);
459 bind_variable(INTERRUPTS_ENABLED,T,th);
460 bind_variable(ALLOW_WITH_INTERRUPTS,T,th);
461 bind_variable(GC_PENDING,NIL,th);
462 bind_variable(ALLOC_SIGNAL,NIL,th);
463 #ifdef LISP_FEATURE_SB_THREAD
464 bind_variable(STOP_FOR_GC_PENDING,NIL,th);
467 th->interrupt_data = (struct interrupt_data *)
468 os_validate(0,(sizeof (struct interrupt_data)));
469 if (!th->interrupt_data) {
470 free_thread_struct(th);
473 th->interrupt_data->pending_handler = 0;
474 th->interrupt_data->gc_blocked_deferrables = 0;
475 th->no_tls_value_marker=initial_function;
481 #ifdef LISP_FEATURE_MACH_EXCEPTION_HANDLER
482 mach_port_t setup_mach_exception_handling_thread();
483 kern_return_t mach_thread_init(mach_port_t thread_exception_port);
487 void create_initial_thread(lispobj initial_function) {
488 struct thread *th=create_thread_struct(initial_function);
490 #ifdef LISP_FEATURE_MACH_EXCEPTION_HANDLER
491 setup_mach_exception_handling_thread();
493 initial_thread_trampoline(th); /* no return */
494 } else lose("can't create initial thread\n");
497 #ifdef LISP_FEATURE_SB_THREAD
499 #ifndef __USE_XOPEN2K
500 extern int pthread_attr_setstack (pthread_attr_t *__attr, void *__stackaddr,
504 boolean create_os_thread(struct thread *th,os_thread_t *kid_tid)
506 /* The new thread inherits the restrictive signal mask set here,
507 * and enables signals again when it is set up properly. */
510 int retcode = 0, initcode;
512 FSHOW_SIGNAL((stderr,"/create_os_thread: creating new thread\n"));
514 /* Blocking deferrable signals is enough, no need to block
515 * SIG_STOP_FOR_GC because the child process is not linked onto
516 * all_threads until it's ready. */
517 block_deferrable_signals(0, &oldset);
519 #ifdef LOCK_CREATE_THREAD
520 retcode = pthread_mutex_lock(&create_thread_lock);
521 gc_assert(retcode == 0);
522 FSHOW_SIGNAL((stderr,"/create_os_thread: got lock\n"));
525 if((initcode = pthread_attr_init(th->os_attr)) ||
526 /* call_into_lisp_first_time switches the stack for the initial
527 * thread. For the others, we use this. */
528 (pthread_attr_setstack(th->os_attr,th->control_stack_start,
529 thread_control_stack_size)) ||
530 (retcode = pthread_create
531 (kid_tid,th->os_attr,(void *(*)(void *))new_thread_trampoline,th))) {
532 FSHOW_SIGNAL((stderr, "init = %d\n", initcode));
533 FSHOW_SIGNAL((stderr, "pthread_create returned %d, errno %d\n",
536 perror("create_os_thread");
541 #ifdef LOCK_CREATE_THREAD
542 retcode = pthread_mutex_unlock(&create_thread_lock);
543 gc_assert(retcode == 0);
544 FSHOW_SIGNAL((stderr,"/create_os_thread: released lock\n"));
546 thread_sigmask(SIG_SETMASK,&oldset,0);
550 os_thread_t create_thread(lispobj initial_function) {
551 struct thread *th, *thread = arch_os_get_current_thread();
552 os_thread_t kid_tid = 0;
554 /* Must defend against async unwinds. */
555 if (SymbolValue(INTERRUPTS_ENABLED, thread) != NIL)
556 lose("create_thread is not safe when interrupts are enabled.\n");
558 /* Assuming that a fresh thread struct has no lisp objects in it,
559 * linking it to all_threads can be left to the thread itself
560 * without fear of gc lossage. initial_function violates this
561 * assumption and must stay pinned until the child starts up. */
562 th = create_thread_struct(initial_function);
563 if (th && !create_os_thread(th,&kid_tid)) {
564 free_thread_struct(th);
570 /* stopping the world is a two-stage process. From this thread we signal
571 * all the others with SIG_STOP_FOR_GC. The handler for this signal does
572 * the usual pseudo-atomic checks (we don't want to stop a thread while
573 * it's in the middle of allocation) then waits for another SIG_STOP_FOR_GC.
576 /* To avoid deadlocks when gc stops the world all clients of each
577 * mutex must enable or disable SIG_STOP_FOR_GC for the duration of
578 * holding the lock, but they must agree on which. */
579 void gc_stop_the_world()
581 struct thread *p,*th=arch_os_get_current_thread();
582 int status, lock_ret;
583 #ifdef LOCK_CREATE_THREAD
584 /* KLUDGE: Stopping the thread during pthread_create() causes deadlock
586 FSHOW_SIGNAL((stderr,"/gc_stop_the_world:waiting on create_thread_lock\n"));
587 lock_ret = pthread_mutex_lock(&create_thread_lock);
588 gc_assert(lock_ret == 0);
589 FSHOW_SIGNAL((stderr,"/gc_stop_the_world:got create_thread_lock\n"));
591 FSHOW_SIGNAL((stderr,"/gc_stop_the_world:waiting on lock\n"));
592 /* keep threads from starting while the world is stopped. */
593 lock_ret = pthread_mutex_lock(&all_threads_lock); \
594 gc_assert(lock_ret == 0);
596 FSHOW_SIGNAL((stderr,"/gc_stop_the_world:got lock\n"));
597 /* stop all other threads by sending them SIG_STOP_FOR_GC */
598 for(p=all_threads; p; p=p->next) {
599 gc_assert(p->os_thread != 0);
600 FSHOW_SIGNAL((stderr,"/gc_stop_the_world: thread=%lu, state=%x\n",
601 p->os_thread, thread_state(p)));
602 if((p!=th) && ((thread_state(p)==STATE_RUNNING))) {
603 FSHOW_SIGNAL((stderr,"/gc_stop_the_world: suspending thread %lu\n",
605 /* We already hold all_thread_lock, P can become DEAD but
606 * cannot exit, ergo it's safe to use pthread_kill. */
607 status=pthread_kill(p->os_thread,SIG_STOP_FOR_GC);
609 /* This thread has exited. */
610 gc_assert(thread_state(p)==STATE_DEAD);
612 lose("cannot send suspend thread=%lu: %d, %s\n",
613 p->os_thread,status,strerror(status));
617 FSHOW_SIGNAL((stderr,"/gc_stop_the_world:signals sent\n"));
618 for(p=all_threads;p;p=p->next) {
622 "/gc_stop_the_world: waiting for thread=%lu: state=%x\n",
623 p->os_thread, thread_state(p)));
624 wait_for_thread_state_change(p, STATE_RUNNING);
625 if (p->state == STATE_RUNNING)
626 lose("/gc_stop_the_world: unexpected state");
629 FSHOW_SIGNAL((stderr,"/gc_stop_the_world:end\n"));
632 void gc_start_the_world()
634 struct thread *p,*th=arch_os_get_current_thread();
636 /* if a resumed thread creates a new thread before we're done with
637 * this loop, the new thread will get consed on the front of
638 * all_threads, but it won't have been stopped so won't need
640 FSHOW_SIGNAL((stderr,"/gc_start_the_world:begin\n"));
641 for(p=all_threads;p;p=p->next) {
642 gc_assert(p->os_thread!=0);
644 lispobj state = thread_state(p);
645 if (state != STATE_DEAD) {
646 if(state != STATE_SUSPENDED) {
647 lose("gc_start_the_world: wrong thread state is %d\n",
648 fixnum_value(state));
650 FSHOW_SIGNAL((stderr, "/gc_start_the_world: resuming %lu\n",
652 set_thread_state(p, STATE_RUNNING);
657 lock_ret = pthread_mutex_unlock(&all_threads_lock);
658 gc_assert(lock_ret == 0);
659 #ifdef LOCK_CREATE_THREAD
660 lock_ret = pthread_mutex_unlock(&create_thread_lock);
661 gc_assert(lock_ret == 0);
664 FSHOW_SIGNAL((stderr,"/gc_start_the_world:end\n"));
671 #ifdef LISP_FEATURE_SB_THREAD
672 return sched_yield();
678 /* If the thread id given does not belong to a running thread (it has
679 * exited or never even existed) pthread_kill _may_ fail with ESRCH,
680 * but it is also allowed to just segfault, see
681 * <http://udrepper.livejournal.com/16844.html>.
683 * Relying on thread ids can easily backfire since ids are recycled
684 * (NPTL recycles them extremely fast) so a signal can be sent to
685 * another process if the one it was sent to exited.
687 * We send signals in two places: signal_interrupt_thread sends a
688 * signal that's harmless if delivered to another thread, but
689 * SIG_STOP_FOR_GC is fatal.
691 * For these reasons, we must make sure that the thread is still alive
692 * when the pthread_kill is called and return if the thread is
695 kill_safely(os_thread_t os_thread, int signal)
697 FSHOW_SIGNAL((stderr,"/kill_safely: %lu, %d\n", os_thread, signal));
699 #ifdef LISP_FEATURE_SB_THREAD
701 struct thread *thread;
702 /* pthread_kill is not async signal safe and we don't want to be
703 * interrupted while holding the lock. */
704 block_deferrable_signals(0, &oldset);
705 pthread_mutex_lock(&all_threads_lock);
706 for (thread = all_threads; thread; thread = thread->next) {
707 if (thread->os_thread == os_thread) {
708 int status = pthread_kill(os_thread, signal);
710 lose("kill_safely: pthread_kill failed with %d\n", status);
714 pthread_mutex_unlock(&all_threads_lock);
715 thread_sigmask(SIG_SETMASK,&oldset,0);
723 lose("kill_safely: who do you want to kill? %d?\n", os_thread);
724 /* Dubious (as in don't know why it works) workaround for the
725 * signal sometimes not being generated on darwin. */
726 #ifdef LISP_FEATURE_DARWIN
729 sigprocmask(SIG_BLOCK, &deferrable_sigset, &oldset);
730 status = raise(signal);
731 sigprocmask(SIG_SETMASK,&oldset,0);
734 status = raise(signal);
739 lose("cannot raise signal %d, %d %s\n",
740 signal, status, strerror(errno));