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 */
38 #include "target-arch-os.h"
42 #include "genesis/cons.h"
43 #include "genesis/fdefn.h"
44 #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;
95 pthread_key_t lisp_thread = 0;
98 #if defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64)
99 extern lispobj call_into_lisp_first_time(lispobj fun, lispobj *args, int nargs);
103 link_thread(struct thread *th)
105 if (all_threads) all_threads->prev=th;
106 th->next=all_threads;
111 #ifdef LISP_FEATURE_SB_THREAD
113 unlink_thread(struct thread *th)
116 th->prev->next = th->next;
118 all_threads = th->next;
120 th->next->prev = th->prev;
125 initial_thread_trampoline(struct thread *th)
128 #if defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64)
129 lispobj *args = NULL;
131 #ifdef LISP_FEATURE_SB_THREAD
132 pthread_setspecific(lisp_thread, (void *)1);
134 function = th->no_tls_value_marker;
135 th->no_tls_value_marker = NO_TLS_VALUE_MARKER_WIDETAG;
136 if(arch_os_thread_init(th)==0) return 1;
138 th->os_thread=thread_self();
139 #ifndef LISP_FEATURE_WIN32
140 protect_control_stack_hard_guard_page(1, NULL);
141 protect_binding_stack_hard_guard_page(1, NULL);
142 protect_alien_stack_hard_guard_page(1, NULL);
143 protect_control_stack_guard_page(1, NULL);
144 protect_binding_stack_guard_page(1, NULL);
145 protect_alien_stack_guard_page(1, NULL);
148 #if defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64)
149 return call_into_lisp_first_time(function,args,0);
151 return funcall0(function);
155 #ifdef LISP_FEATURE_SB_THREAD
156 #define THREAD_STATE_LOCK_SIZE \
157 (sizeof(pthread_mutex_t))+(sizeof(pthread_cond_t))
159 #define THREAD_STATE_LOCK_SIZE 0
162 #define THREAD_STRUCT_SIZE (thread_control_stack_size + BINDING_STACK_SIZE + \
164 THREAD_STATE_LOCK_SIZE + \
165 dynamic_values_bytes + \
167 THREAD_ALIGNMENT_BYTES)
169 #ifdef LISP_FEATURE_SB_THREAD
170 /* THREAD POST MORTEM CLEANUP
172 * Memory allocated for the thread stacks cannot be reclaimed while
173 * the thread is still alive, so we need a mechanism for post mortem
174 * cleanups. FIXME: We actually have three, for historical reasons as
175 * the saying goes. Do we really need three? Nikodemus guesses that
176 * not anymore, now that we properly call pthread_attr_destroy before
177 * freeing the stack. */
179 static struct thread_post_mortem *
180 plan_thread_post_mortem(struct thread *corpse)
183 struct thread_post_mortem *post_mortem = malloc(sizeof(struct thread_post_mortem));
184 gc_assert(post_mortem);
185 post_mortem->os_thread = corpse->os_thread;
186 post_mortem->os_attr = corpse->os_attr;
187 post_mortem->os_address = corpse->os_address;
188 #ifdef DELAY_THREAD_POST_MORTEM
189 post_mortem->next = NULL;
193 /* FIXME: When does this happen? */
199 perform_thread_post_mortem(struct thread_post_mortem *post_mortem)
201 #ifdef CREATE_POST_MORTEM_THREAD
202 pthread_detach(pthread_self());
205 gc_assert(!pthread_join(post_mortem->os_thread, NULL));
206 gc_assert(!pthread_attr_destroy(post_mortem->os_attr));
207 free(post_mortem->os_attr);
208 os_invalidate(post_mortem->os_address, THREAD_STRUCT_SIZE);
214 schedule_thread_post_mortem(struct thread *corpse)
216 struct thread_post_mortem *post_mortem = NULL;
218 post_mortem = plan_thread_post_mortem(corpse);
220 #ifdef DELAY_THREAD_POST_MORTEM
221 pthread_mutex_lock(&thread_post_mortem_lock);
222 /* First stick the new post mortem to the end of the queue. */
223 if (pending_thread_post_mortem) {
224 struct thread_post_mortem *next = pending_thread_post_mortem;
228 next->next = post_mortem;
230 pending_thread_post_mortem = post_mortem;
232 /* Then, if there are enough things in the queue, clean up one
233 * from the head -- or increment the count, and null out the
234 * post_mortem we have. */
235 if (pending_thread_post_mortem_count > DELAY_THREAD_POST_MORTEM) {
236 post_mortem = pending_thread_post_mortem;
237 pending_thread_post_mortem = post_mortem->next;
239 pending_thread_post_mortem_count++;
242 pthread_mutex_unlock(&thread_post_mortem_lock);
243 /* Finally run, the cleanup, if any. */
244 perform_thread_post_mortem(post_mortem);
245 #elif defined(CREATE_POST_MORTEM_THREAD)
246 gc_assert(!pthread_create(&thread, NULL, perform_thread_post_mortem, post_mortem));
248 post_mortem = (struct thread_post_mortem *)
249 swap_lispobjs((lispobj *)(void *)&pending_thread_post_mortem,
250 (lispobj)post_mortem);
251 perform_thread_post_mortem(post_mortem);
256 /* this is the first thing that runs in the child (which is why the
257 * silly calling convention). Basically it calls the user's requested
258 * lisp function after doing arch_os_thread_init and whatever other
259 * bookkeeping needs to be done
262 new_thread_trampoline(struct thread *th)
265 int result, lock_ret;
267 FSHOW((stderr,"/creating thread %lu\n", thread_self()));
268 check_deferrables_blocked_or_lose(0);
269 check_gc_signals_unblocked_or_lose(0);
270 pthread_setspecific(lisp_thread, (void *)1);
271 function = th->no_tls_value_marker;
272 th->no_tls_value_marker = NO_TLS_VALUE_MARKER_WIDETAG;
273 if(arch_os_thread_init(th)==0) {
274 /* FIXME: handle error */
275 lose("arch_os_thread_init failed\n");
278 th->os_thread=thread_self();
279 protect_control_stack_guard_page(1, NULL);
280 protect_binding_stack_guard_page(1, NULL);
281 protect_alien_stack_guard_page(1, NULL);
282 /* Since GC can only know about this thread from the all_threads
283 * list and we're just adding this thread to it, there is no
284 * danger of deadlocking even with SIG_STOP_FOR_GC blocked (which
286 lock_ret = pthread_mutex_lock(&all_threads_lock);
287 gc_assert(lock_ret == 0);
289 lock_ret = pthread_mutex_unlock(&all_threads_lock);
290 gc_assert(lock_ret == 0);
292 result = funcall0(function);
295 block_blockable_signals(0, 0);
296 set_thread_state(th, STATE_DEAD);
298 /* SIG_STOP_FOR_GC is blocked and GC might be waiting for this
299 * thread, but since we are already dead it won't wait long. */
300 lock_ret = pthread_mutex_lock(&all_threads_lock);
301 gc_assert(lock_ret == 0);
303 gc_alloc_update_page_tables(BOXED_PAGE_FLAG, &th->alloc_region);
305 pthread_mutex_unlock(&all_threads_lock);
306 gc_assert(lock_ret == 0);
308 if(th->tls_cookie>=0) arch_os_thread_cleanup(th);
309 pthread_mutex_destroy(th->state_lock);
310 pthread_cond_destroy(th->state_cond);
312 os_invalidate((os_vm_address_t)th->interrupt_data,
313 (sizeof (struct interrupt_data)));
315 #ifdef LISP_FEATURE_MACH_EXCEPTION_HANDLER
316 FSHOW((stderr, "Deallocating mach port %x\n", THREAD_STRUCT_TO_EXCEPTION_PORT(th)));
317 mach_port_move_member(mach_task_self(),
318 THREAD_STRUCT_TO_EXCEPTION_PORT(th),
320 mach_port_deallocate(mach_task_self(),
321 THREAD_STRUCT_TO_EXCEPTION_PORT(th));
322 mach_port_destroy(mach_task_self(),
323 THREAD_STRUCT_TO_EXCEPTION_PORT(th));
326 schedule_thread_post_mortem(th);
327 FSHOW((stderr,"/exiting thread %lu\n", thread_self()));
331 #endif /* LISP_FEATURE_SB_THREAD */
334 free_thread_struct(struct thread *th)
336 if (th->interrupt_data)
337 os_invalidate((os_vm_address_t) th->interrupt_data,
338 (sizeof (struct interrupt_data)));
339 os_invalidate((os_vm_address_t) th->os_address,
343 /* this is called from any other thread to create the new one, and
344 * initialize all parts of it that can be initialized from another
348 static struct thread *
349 create_thread_struct(lispobj initial_function) {
350 union per_thread_data *per_thread;
351 struct thread *th=0; /* subdue gcc */
353 void *aligned_spaces=0;
354 #ifdef LISP_FEATURE_SB_THREAD
358 /* May as well allocate all the spaces at once: it saves us from
359 * having to decide what to do if only some of the allocations
360 * succeed. SPACES must be appropriately aligned, since the GC
361 * expects the control stack to start at a page boundary -- and
362 * the OS may have even more rigorous requirements. We can't rely
363 * on the alignment passed from os_validate, since that might
364 * assume the current (e.g. 4k) pagesize, while we calculate with
365 * the biggest (e.g. 64k) pagesize allowed by the ABI. */
366 spaces=os_validate(0, THREAD_STRUCT_SIZE);
369 /* Aligning up is safe as THREAD_STRUCT_SIZE has
370 * THREAD_ALIGNMENT_BYTES padding. */
371 aligned_spaces = (void *)((((unsigned long)(char *)spaces)
372 + THREAD_ALIGNMENT_BYTES-1)
373 &~(unsigned long)(THREAD_ALIGNMENT_BYTES-1));
374 per_thread=(union per_thread_data *)
376 thread_control_stack_size+
379 THREAD_STATE_LOCK_SIZE);
381 #ifdef LISP_FEATURE_SB_THREAD
382 for(i = 0; i < (dynamic_values_bytes / sizeof(lispobj)); i++)
383 per_thread->dynamic_values[i] = NO_TLS_VALUE_MARKER_WIDETAG;
384 if (all_threads == 0) {
385 if(SymbolValue(FREE_TLS_INDEX,0)==UNBOUND_MARKER_WIDETAG) {
388 /* FIXME: should be MAX_INTERRUPTS -1 ? */
389 make_fixnum(MAX_INTERRUPTS+
390 sizeof(struct thread)/sizeof(lispobj)),
392 SetSymbolValue(TLS_INDEX_LOCK,make_fixnum(0),0);
394 #define STATIC_TLS_INIT(sym,field) \
395 ((struct symbol *)(sym-OTHER_POINTER_LOWTAG))->tls_index= \
396 make_fixnum(THREAD_SLOT_OFFSET_WORDS(field))
398 STATIC_TLS_INIT(BINDING_STACK_START,binding_stack_start);
399 STATIC_TLS_INIT(BINDING_STACK_POINTER,binding_stack_pointer);
400 STATIC_TLS_INIT(CONTROL_STACK_START,control_stack_start);
401 STATIC_TLS_INIT(CONTROL_STACK_END,control_stack_end);
402 STATIC_TLS_INIT(ALIEN_STACK,alien_stack_pointer);
403 #if defined(LISP_FEATURE_X86) || defined (LISP_FEATURE_X86_64)
404 STATIC_TLS_INIT(PSEUDO_ATOMIC_BITS,pseudo_atomic_bits);
406 #undef STATIC_TLS_INIT
410 th=&per_thread->thread;
411 th->os_address = spaces;
412 th->control_stack_start = aligned_spaces;
413 th->binding_stack_start=
414 (lispobj*)((void*)th->control_stack_start+thread_control_stack_size);
415 th->control_stack_end = th->binding_stack_start;
416 th->control_stack_guard_page_protected = T;
417 th->alien_stack_start=
418 (lispobj*)((void*)th->binding_stack_start+BINDING_STACK_SIZE);
419 th->binding_stack_pointer=th->binding_stack_start;
422 #ifdef LISP_FEATURE_SB_THREAD
423 th->os_attr=malloc(sizeof(pthread_attr_t));
424 th->state_lock=(pthread_mutex_t *)((void *)th->alien_stack_start +
426 pthread_mutex_init(th->state_lock, NULL);
427 th->state_cond=(pthread_cond_t *)((void *)th->state_lock +
428 (sizeof(pthread_mutex_t)));
429 pthread_cond_init(th->state_cond, NULL);
431 th->state=STATE_RUNNING;
432 #ifdef LISP_FEATURE_STACK_GROWS_DOWNWARD_NOT_UPWARD
433 th->alien_stack_pointer=((void *)th->alien_stack_start
434 + ALIEN_STACK_SIZE-N_WORD_BYTES);
436 th->alien_stack_pointer=((void *)th->alien_stack_start);
438 #if defined(LISP_FEATURE_X86) || defined (LISP_FEATURE_X86_64)
439 th->pseudo_atomic_bits=0;
441 #ifdef LISP_FEATURE_GENCGC
442 gc_set_region_empty(&th->alloc_region);
445 #ifndef LISP_FEATURE_SB_THREAD
446 /* the tls-points-into-struct-thread trick is only good for threaded
447 * sbcl, because unithread sbcl doesn't have tls. So, we copy the
448 * appropriate values from struct thread here, and make sure that
449 * we use the appropriate SymbolValue macros to access any of the
450 * variable quantities from the C runtime. It's not quite OAOOM,
451 * it just feels like it */
452 SetSymbolValue(BINDING_STACK_START,(lispobj)th->binding_stack_start,th);
453 SetSymbolValue(CONTROL_STACK_START,(lispobj)th->control_stack_start,th);
454 SetSymbolValue(CONTROL_STACK_END,(lispobj)th->control_stack_end,th);
455 #if defined(LISP_FEATURE_X86) || defined (LISP_FEATURE_X86_64)
456 SetSymbolValue(BINDING_STACK_POINTER,(lispobj)th->binding_stack_pointer,th);
457 SetSymbolValue(ALIEN_STACK,(lispobj)th->alien_stack_pointer,th);
458 SetSymbolValue(PSEUDO_ATOMIC_BITS,(lispobj)th->pseudo_atomic_bits,th);
460 current_binding_stack_pointer=th->binding_stack_pointer;
461 current_control_stack_pointer=th->control_stack_start;
464 bind_variable(CURRENT_CATCH_BLOCK,make_fixnum(0),th);
465 bind_variable(CURRENT_UNWIND_PROTECT_BLOCK,make_fixnum(0),th);
466 bind_variable(FREE_INTERRUPT_CONTEXT_INDEX,make_fixnum(0),th);
467 bind_variable(INTERRUPT_PENDING, NIL,th);
468 bind_variable(INTERRUPTS_ENABLED,T,th);
469 bind_variable(ALLOW_WITH_INTERRUPTS,T,th);
470 bind_variable(GC_PENDING,NIL,th);
471 bind_variable(ALLOC_SIGNAL,NIL,th);
472 #ifdef LISP_FEATURE_SB_THREAD
473 bind_variable(STOP_FOR_GC_PENDING,NIL,th);
476 th->interrupt_data = (struct interrupt_data *)
477 os_validate(0,(sizeof (struct interrupt_data)));
478 if (!th->interrupt_data) {
479 free_thread_struct(th);
482 th->interrupt_data->pending_handler = 0;
483 th->interrupt_data->gc_blocked_deferrables = 0;
484 #ifdef LISP_FEATURE_PPC
485 th->interrupt_data->allocation_trap_context = 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);
501 #ifdef LISP_FEATURE_SB_THREAD
502 pthread_key_create(&lisp_thread, 0);
505 #ifdef LISP_FEATURE_MACH_EXCEPTION_HANDLER
506 setup_mach_exception_handling_thread();
508 initial_thread_trampoline(th); /* no return */
509 } else lose("can't create initial thread\n");
512 #ifdef LISP_FEATURE_SB_THREAD
514 #ifndef __USE_XOPEN2K
515 extern int pthread_attr_setstack (pthread_attr_t *__attr, void *__stackaddr,
519 boolean create_os_thread(struct thread *th,os_thread_t *kid_tid)
521 /* The new thread inherits the restrictive signal mask set here,
522 * and enables signals again when it is set up properly. */
525 int retcode = 0, initcode;
527 FSHOW_SIGNAL((stderr,"/create_os_thread: creating new thread\n"));
529 /* Blocking deferrable signals is enough, no need to block
530 * SIG_STOP_FOR_GC because the child process is not linked onto
531 * all_threads until it's ready. */
532 block_deferrable_signals(0, &oldset);
534 #ifdef LOCK_CREATE_THREAD
535 retcode = pthread_mutex_lock(&create_thread_lock);
536 gc_assert(retcode == 0);
537 FSHOW_SIGNAL((stderr,"/create_os_thread: got lock\n"));
540 if((initcode = pthread_attr_init(th->os_attr)) ||
541 /* call_into_lisp_first_time switches the stack for the initial
542 * thread. For the others, we use this. */
543 (pthread_attr_setstack(th->os_attr,th->control_stack_start,
544 thread_control_stack_size)) ||
545 (retcode = pthread_create
546 (kid_tid,th->os_attr,(void *(*)(void *))new_thread_trampoline,th))) {
547 FSHOW_SIGNAL((stderr, "init = %d\n", initcode));
548 FSHOW_SIGNAL((stderr, "pthread_create returned %d, errno %d\n",
551 perror("create_os_thread");
556 #ifdef LOCK_CREATE_THREAD
557 retcode = pthread_mutex_unlock(&create_thread_lock);
558 gc_assert(retcode == 0);
559 FSHOW_SIGNAL((stderr,"/create_os_thread: released lock\n"));
561 thread_sigmask(SIG_SETMASK,&oldset,0);
565 os_thread_t create_thread(lispobj initial_function) {
566 struct thread *th, *thread = arch_os_get_current_thread();
567 os_thread_t kid_tid = 0;
569 /* Must defend against async unwinds. */
570 if (SymbolValue(INTERRUPTS_ENABLED, thread) != NIL)
571 lose("create_thread is not safe when interrupts are enabled.\n");
573 /* Assuming that a fresh thread struct has no lisp objects in it,
574 * linking it to all_threads can be left to the thread itself
575 * without fear of gc lossage. initial_function violates this
576 * assumption and must stay pinned until the child starts up. */
577 th = create_thread_struct(initial_function);
578 if (th && !create_os_thread(th,&kid_tid)) {
579 free_thread_struct(th);
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\n"));
602 lock_ret = pthread_mutex_lock(&create_thread_lock);
603 gc_assert(lock_ret == 0);
604 FSHOW_SIGNAL((stderr,"/gc_stop_the_world:got create_thread_lock\n"));
606 FSHOW_SIGNAL((stderr,"/gc_stop_the_world:waiting on lock\n"));
607 /* keep threads from starting while the world is stopped. */
608 lock_ret = pthread_mutex_lock(&all_threads_lock); \
609 gc_assert(lock_ret == 0);
611 FSHOW_SIGNAL((stderr,"/gc_stop_the_world:got lock\n"));
612 /* stop all other threads by sending them SIG_STOP_FOR_GC */
613 for(p=all_threads; p; p=p->next) {
614 gc_assert(p->os_thread != 0);
615 FSHOW_SIGNAL((stderr,"/gc_stop_the_world: thread=%lu, state=%x\n",
616 p->os_thread, thread_state(p)));
617 if((p!=th) && ((thread_state(p)==STATE_RUNNING))) {
618 FSHOW_SIGNAL((stderr,"/gc_stop_the_world: suspending thread %lu\n",
620 /* We already hold all_thread_lock, P can become DEAD but
621 * cannot exit, ergo it's safe to use pthread_kill. */
622 status=pthread_kill(p->os_thread,SIG_STOP_FOR_GC);
624 /* This thread has exited. */
625 gc_assert(thread_state(p)==STATE_DEAD);
627 lose("cannot send suspend thread=%lu: %d, %s\n",
628 p->os_thread,status,strerror(status));
632 FSHOW_SIGNAL((stderr,"/gc_stop_the_world:signals sent\n"));
633 for(p=all_threads;p;p=p->next) {
637 "/gc_stop_the_world: waiting for thread=%lu: state=%x\n",
638 p->os_thread, thread_state(p)));
639 wait_for_thread_state_change(p, STATE_RUNNING);
640 if (p->state == STATE_RUNNING)
641 lose("/gc_stop_the_world: unexpected state");
644 FSHOW_SIGNAL((stderr,"/gc_stop_the_world:end\n"));
647 void gc_start_the_world()
649 struct thread *p,*th=arch_os_get_current_thread();
651 /* if a resumed thread creates a new thread before we're done with
652 * this loop, the new thread will get consed on the front of
653 * all_threads, but it won't have been stopped so won't need
655 FSHOW_SIGNAL((stderr,"/gc_start_the_world:begin\n"));
656 for(p=all_threads;p;p=p->next) {
657 gc_assert(p->os_thread!=0);
659 lispobj state = thread_state(p);
660 if (state != STATE_DEAD) {
661 if(state != STATE_SUSPENDED) {
662 lose("gc_start_the_world: wrong thread state is %d\n",
663 fixnum_value(state));
665 FSHOW_SIGNAL((stderr, "/gc_start_the_world: resuming %lu\n",
667 set_thread_state(p, STATE_RUNNING);
672 lock_ret = pthread_mutex_unlock(&all_threads_lock);
673 gc_assert(lock_ret == 0);
674 #ifdef LOCK_CREATE_THREAD
675 lock_ret = pthread_mutex_unlock(&create_thread_lock);
676 gc_assert(lock_ret == 0);
679 FSHOW_SIGNAL((stderr,"/gc_start_the_world:end\n"));
686 #ifdef LISP_FEATURE_SB_THREAD
687 return sched_yield();
693 /* If the thread id given does not belong to a running thread (it has
694 * exited or never even existed) pthread_kill _may_ fail with ESRCH,
695 * but it is also allowed to just segfault, see
696 * <http://udrepper.livejournal.com/16844.html>.
698 * Relying on thread ids can easily backfire since ids are recycled
699 * (NPTL recycles them extremely fast) so a signal can be sent to
700 * another process if the one it was sent to exited.
702 * We send signals in two places: signal_interrupt_thread sends a
703 * signal that's harmless if delivered to another thread, but
704 * SIG_STOP_FOR_GC is fatal.
706 * For these reasons, we must make sure that the thread is still alive
707 * when the pthread_kill is called and return if the thread is
710 kill_safely(os_thread_t os_thread, int signal)
712 FSHOW_SIGNAL((stderr,"/kill_safely: %lu, %d\n", os_thread, signal));
714 #ifdef LISP_FEATURE_SB_THREAD
716 struct thread *thread;
717 /* pthread_kill is not async signal safe and we don't want to be
718 * interrupted while holding the lock. */
719 block_deferrable_signals(0, &oldset);
720 pthread_mutex_lock(&all_threads_lock);
721 for (thread = all_threads; thread; thread = thread->next) {
722 if (thread->os_thread == os_thread) {
723 int status = pthread_kill(os_thread, signal);
725 lose("kill_safely: pthread_kill failed with %d\n", status);
729 pthread_mutex_unlock(&all_threads_lock);
730 thread_sigmask(SIG_SETMASK,&oldset,0);
738 lose("kill_safely: who do you want to kill? %d?\n", os_thread);
739 /* Dubious (as in don't know why it works) workaround for the
740 * signal sometimes not being generated on darwin. */
741 #ifdef LISP_FEATURE_DARWIN
744 sigprocmask(SIG_BLOCK, &deferrable_sigset, &oldset);
745 status = raise(signal);
746 sigprocmask(SIG_SETMASK,&oldset,0);
749 status = raise(signal);
754 lose("cannot raise signal %d, %d %s\n",
755 signal, status, strerror(errno));