13 #include "validate.h" /* for CONTROL_STACK_SIZE etc */
17 #include "target-arch-os.h"
21 #include "genesis/cons.h"
22 #include "genesis/fdefn.h"
23 #include "interr.h" /* for lose() */
24 #include "gc-internal.h"
26 #define ALIEN_STACK_SIZE (1*1024*1024) /* 1Mb size chosen at random */
28 struct freeable_stack
{
29 os_thread_t os_thread
;
30 os_vm_address_t stack
;
33 static struct freeable_stack
* volatile freeable_stack
= 0;
35 int dynamic_values_bytes
=4096*sizeof(lispobj
); /* same for all threads */
36 struct thread
* volatile all_threads
;
37 extern struct interrupt_data
* global_interrupt_data
;
38 extern int linux_no_threads_p
;
40 #ifdef LISP_FEATURE_SB_THREAD
42 pthread_mutex_t all_threads_lock
= PTHREAD_MUTEX_INITIALIZER
;
44 /* When trying to get all_threads_lock one should make sure that
45 * SIG_STOP_FOR_GC is not blocked. Else there would be a possible
46 * deadlock: gc locks it, other thread blocks signals, gc sends stop
47 * request to other thread and waits, other thread blocks on lock. */
48 void check_sig_stop_for_gc_can_arrive_or_lose()
50 /* Get the current sigmask, by blocking the empty set. */
51 sigset_t empty
,current
;
53 thread_sigmask(SIG_BLOCK
, &empty
, ¤t
);
54 if (sigismember(¤t
,SIG_STOP_FOR_GC
))
55 lose("SIG_STOP_FOR_GC cannot arrive: it is blocked\n");
56 if (SymbolValue(GC_INHIBIT
,arch_os_get_current_thread()) != NIL
)
57 lose("SIG_STOP_FOR_GC cannot arrive: gc is inhibited\n");
58 if (arch_pseudo_atomic_atomic(NULL
))
59 lose("SIG_STOP_FOR_GC cannot arrive: in pseudo atomic\n");
62 #define GET_ALL_THREADS_LOCK(name) \
64 sigset_t _newset,_oldset; \
65 sigemptyset(&_newset); \
66 sigaddset_deferrable(&_newset); \
67 thread_sigmask(SIG_BLOCK, &_newset, &_oldset); \
68 check_sig_stop_for_gc_can_arrive_or_lose(); \
69 FSHOW_SIGNAL((stderr,"/%s:waiting on lock=%ld, thread=%lu\n",name, \
70 all_threads_lock,arch_os_get_current_thread()->os_thread)); \
71 pthread_mutex_lock(&all_threads_lock); \
72 FSHOW_SIGNAL((stderr,"/%s:got lock, thread=%lu\n", \
73 name,arch_os_get_current_thread()->os_thread));
75 #define RELEASE_ALL_THREADS_LOCK(name) \
76 FSHOW_SIGNAL((stderr,"/%s:released lock\n",name)); \
77 pthread_mutex_unlock(&all_threads_lock); \
78 thread_sigmask(SIG_SETMASK,&_oldset,0); \
81 #if defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64)
82 extern lispobj
call_into_lisp_first_time(lispobj fun
, lispobj
*args
, int nargs
);
88 link_thread(struct thread
*th
)
90 if (all_threads
) all_threads
->prev
=th
;
96 #ifdef LISP_FEATURE_SB_THREAD
98 unlink_thread(struct thread
*th
)
101 th
->prev
->next
= th
->next
;
103 all_threads
= th
->next
;
105 th
->next
->prev
= th
->prev
;
110 initial_thread_trampoline(struct thread
*th
)
113 #if defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64)
114 lispobj
*args
= NULL
;
116 function
= th
->no_tls_value_marker
;
117 th
->no_tls_value_marker
= NO_TLS_VALUE_MARKER_WIDETAG
;
118 if(arch_os_thread_init(th
)==0) return 1;
120 th
->os_thread
=thread_self();
121 protect_control_stack_guard_page(1);
122 th
->state
= STATE_RUNNING
;
124 #if defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64)
125 return call_into_lisp_first_time(function
,args
,0);
127 return funcall0(function
);
131 #define THREAD_STRUCT_SIZE (THREAD_CONTROL_STACK_SIZE + BINDING_STACK_SIZE + \
132 ALIEN_STACK_SIZE + dynamic_values_bytes + \
135 #ifdef LISP_FEATURE_SB_THREAD
138 free_thread_stack_later(struct thread
*thread_to_be_cleaned_up
)
140 struct freeable_stack
*new_freeable_stack
= 0;
141 if (thread_to_be_cleaned_up
) {
142 new_freeable_stack
= (struct freeable_stack
*)
143 os_validate(0, sizeof(struct freeable_stack
));
144 new_freeable_stack
->os_thread
= thread_to_be_cleaned_up
->os_thread
;
145 new_freeable_stack
->stack
= (os_vm_address_t
)
146 thread_to_be_cleaned_up
->control_stack_start
;
148 new_freeable_stack
= (struct freeable_stack
*)
149 swap_lispobjs((lispobj
*)(void *)&freeable_stack
,
150 (lispobj
)new_freeable_stack
);
151 if (new_freeable_stack
) {
152 FSHOW((stderr
,"/reaping %lu\n", new_freeable_stack
->os_thread
));
153 /* Under NPTL pthread_join really waits until the thread
154 * exists and the stack can be safely freed. This is sadly not
155 * mandated by the pthread spec. */
156 gc_assert(pthread_join(new_freeable_stack
->os_thread
, NULL
) == 0);
157 os_invalidate(new_freeable_stack
->stack
, THREAD_STRUCT_SIZE
);
158 os_invalidate((os_vm_address_t
) new_freeable_stack
,
159 sizeof(struct freeable_stack
));
163 /* this is the first thing that runs in the child (which is why the
164 * silly calling convention). Basically it calls the user's requested
165 * lisp function after doing arch_os_thread_init and whatever other
166 * bookkeeping needs to be done
169 new_thread_trampoline(struct thread
*th
)
173 FSHOW((stderr
,"/creating thread %lu\n", thread_self()));
174 function
= th
->no_tls_value_marker
;
175 th
->no_tls_value_marker
= NO_TLS_VALUE_MARKER_WIDETAG
;
176 if(arch_os_thread_init(th
)==0) {
177 /* FIXME: handle error */
178 lose("arch_os_thread_init failed\n");
181 th
->os_thread
=thread_self();
182 protect_control_stack_guard_page(1);
183 /* This thread is in STATE_STARTING so the GC is not sending it
184 * SIG_STOP_FOR_GC => no danger of deadlocking even with
185 * SIG_STOP_FOR_GC blocked. The lock is acquired in order not to
186 * enter running state with the gc running. */
187 pthread_mutex_lock(&all_threads_lock
);
188 th
->state
= STATE_RUNNING
;
189 pthread_mutex_unlock(&all_threads_lock
);
190 /* Now that we entered STATE_RUNNING let the gc suspend this
194 sigemptyset(&sigset
);
195 sigaddset(&sigset
, SIG_STOP_FOR_GC
);
196 thread_sigmask(SIG_UNBLOCK
, &sigset
, 0);
199 result
= funcall0(function
);
200 th
->state
=STATE_DEAD
;
202 /* SIG_STOP_FOR_GC is blocked and GC might be waiting for this
203 * thread, but since we are already dead it won't wait long. */
204 pthread_mutex_lock(&all_threads_lock
);
206 pthread_mutex_unlock(&all_threads_lock
);
208 gc_alloc_update_page_tables(0, &th
->alloc_region
);
209 if(th
->tls_cookie
>=0) arch_os_thread_cleanup(th
);
210 os_invalidate((os_vm_address_t
)th
->interrupt_data
,
211 (sizeof (struct interrupt_data
)));
212 free_thread_stack_later(th
);
213 FSHOW((stderr
,"/exiting thread %lu\n", thread_self()));
217 #endif /* LISP_FEATURE_SB_THREAD */
220 free_thread_struct(struct thread
*th
)
222 if (th
->interrupt_data
)
223 os_invalidate((os_vm_address_t
) th
->interrupt_data
,
224 (sizeof (struct interrupt_data
)));
225 os_invalidate((os_vm_address_t
) th
->control_stack_start
,
229 /* this is called from any other thread to create the new one, and
230 * initialize all parts of it that can be initialized from another
234 static struct thread
*
235 create_thread_struct(lispobj initial_function
) {
236 union per_thread_data
*per_thread
;
237 struct thread
*th
=0; /* subdue gcc */
240 /* may as well allocate all the spaces at once: it saves us from
241 * having to decide what to do if only some of the allocations
243 spaces
=os_validate(0, THREAD_STRUCT_SIZE
);
246 per_thread
=(union per_thread_data
*)
248 THREAD_CONTROL_STACK_SIZE
+
253 memcpy(per_thread
,arch_os_get_current_thread(),
254 dynamic_values_bytes
);
256 #ifdef LISP_FEATURE_SB_THREAD
258 for(i
=0;i
<(dynamic_values_bytes
/sizeof(lispobj
));i
++)
259 per_thread
->dynamic_values
[i
]=NO_TLS_VALUE_MARKER_WIDETAG
;
260 if(SymbolValue(FREE_TLS_INDEX
,0)==UNBOUND_MARKER_WIDETAG
) {
263 make_fixnum(MAX_INTERRUPTS
+
264 sizeof(struct thread
)/sizeof(lispobj
)),
266 SetSymbolValue(TLS_INDEX_LOCK
,make_fixnum(0),0);
268 #define STATIC_TLS_INIT(sym,field) \
269 ((struct symbol *)(sym-OTHER_POINTER_LOWTAG))->tls_index= \
270 make_fixnum(THREAD_SLOT_OFFSET_WORDS(field))
272 STATIC_TLS_INIT(BINDING_STACK_START
,binding_stack_start
);
273 STATIC_TLS_INIT(BINDING_STACK_POINTER
,binding_stack_pointer
);
274 STATIC_TLS_INIT(CONTROL_STACK_START
,control_stack_start
);
275 STATIC_TLS_INIT(CONTROL_STACK_END
,control_stack_end
);
276 STATIC_TLS_INIT(ALIEN_STACK
,alien_stack_pointer
);
277 #if defined(LISP_FEATURE_X86) || defined (LISP_FEATURE_X86_64)
278 STATIC_TLS_INIT(PSEUDO_ATOMIC_ATOMIC
,pseudo_atomic_atomic
);
279 STATIC_TLS_INIT(PSEUDO_ATOMIC_INTERRUPTED
,pseudo_atomic_interrupted
);
281 #undef STATIC_TLS_INIT
285 th
=&per_thread
->thread
;
286 th
->control_stack_start
= spaces
;
287 th
->binding_stack_start
=
288 (lispobj
*)((void*)th
->control_stack_start
+THREAD_CONTROL_STACK_SIZE
);
289 th
->control_stack_end
= th
->binding_stack_start
;
290 th
->alien_stack_start
=
291 (lispobj
*)((void*)th
->binding_stack_start
+BINDING_STACK_SIZE
);
292 th
->binding_stack_pointer
=th
->binding_stack_start
;
295 th
->state
=STATE_STARTING
;
296 #ifdef LISP_FEATURE_STACK_GROWS_DOWNWARD_NOT_UPWARD
297 th
->alien_stack_pointer
=((void *)th
->alien_stack_start
298 + ALIEN_STACK_SIZE
-N_WORD_BYTES
);
300 th
->alien_stack_pointer
=((void *)th
->alien_stack_start
);
302 #if defined(LISP_FEATURE_X86) || defined (LISP_FEATURE_X86_64)
303 th
->pseudo_atomic_interrupted
=0;
304 th
->pseudo_atomic_atomic
=0;
306 #ifdef LISP_FEATURE_GENCGC
307 gc_set_region_empty(&th
->alloc_region
);
310 #ifndef LISP_FEATURE_SB_THREAD
311 /* the tls-points-into-struct-thread trick is only good for threaded
312 * sbcl, because unithread sbcl doesn't have tls. So, we copy the
313 * appropriate values from struct thread here, and make sure that
314 * we use the appropriate SymbolValue macros to access any of the
315 * variable quantities from the C runtime. It's not quite OAOOM,
316 * it just feels like it */
317 SetSymbolValue(BINDING_STACK_START
,(lispobj
)th
->binding_stack_start
,th
);
318 SetSymbolValue(CONTROL_STACK_START
,(lispobj
)th
->control_stack_start
,th
);
319 SetSymbolValue(CONTROL_STACK_END
,(lispobj
)th
->control_stack_end
,th
);
320 #if defined(LISP_FEATURE_X86) || defined (LISP_FEATURE_X86_64)
321 SetSymbolValue(BINDING_STACK_POINTER
,(lispobj
)th
->binding_stack_pointer
,th
);
322 SetSymbolValue(ALIEN_STACK
,(lispobj
)th
->alien_stack_pointer
,th
);
323 SetSymbolValue(PSEUDO_ATOMIC_ATOMIC
,(lispobj
)th
->pseudo_atomic_atomic
,th
);
324 SetSymbolValue(PSEUDO_ATOMIC_INTERRUPTED
,th
->pseudo_atomic_interrupted
,th
);
326 current_binding_stack_pointer
=th
->binding_stack_pointer
;
327 current_control_stack_pointer
=th
->control_stack_start
;
330 bind_variable(CURRENT_CATCH_BLOCK
,make_fixnum(0),th
);
331 bind_variable(CURRENT_UNWIND_PROTECT_BLOCK
,make_fixnum(0),th
);
332 bind_variable(FREE_INTERRUPT_CONTEXT_INDEX
,make_fixnum(0),th
);
333 bind_variable(INTERRUPT_PENDING
, NIL
,th
);
334 bind_variable(INTERRUPTS_ENABLED
,T
,th
);
335 bind_variable(GC_PENDING
,NIL
,th
);
336 #ifdef LISP_FEATURE_SB_THREAD
337 bind_variable(STOP_FOR_GC_PENDING
,NIL
,th
);
340 th
->interrupt_data
= (struct interrupt_data
*)
341 os_validate(0,(sizeof (struct interrupt_data
)));
342 if (!th
->interrupt_data
) {
343 free_thread_struct(th
);
346 th
->interrupt_data
->pending_handler
= 0;
347 th
->no_tls_value_marker
=initial_function
;
351 void create_initial_thread(lispobj initial_function
) {
352 struct thread
*th
=create_thread_struct(initial_function
);
354 initial_thread_trampoline(th
); /* no return */
355 } else lose("can't create initial thread");
358 #ifdef LISP_FEATURE_SB_THREAD
360 #ifndef __USE_XOPEN2K
361 extern int pthread_attr_setstack (pthread_attr_t
*__attr
, void *__stackaddr
,
365 boolean
create_os_thread(struct thread
*th
,os_thread_t
*kid_tid
)
367 /* The new thread inherits the restrictive signal mask set here,
368 * and enables signals again when it is set up properly. */
370 sigset_t newset
,oldset
;
372 sigemptyset(&newset
);
373 sigaddset_blockable(&newset
);
374 thread_sigmask(SIG_BLOCK
, &newset
, &oldset
);
376 if((pthread_attr_init(&attr
)) ||
377 (pthread_attr_setstack(&attr
,th
->control_stack_start
,
378 THREAD_CONTROL_STACK_SIZE
-16)) ||
380 (kid_tid
,&attr
,(void *(*)(void *))new_thread_trampoline
,th
)))
382 thread_sigmask(SIG_SETMASK
,&oldset
,0);
386 os_thread_t
create_thread(lispobj initial_function
) {
390 if(linux_no_threads_p
) return 0;
392 /* The new thread must be linked immediately onto all_threads for
394 GET_ALL_THREADS_LOCK("create_thread")
395 /* If it is too slow most of the allocation/initialization can
396 * be done without the lock. */
397 th
= create_thread_struct(initial_function
);
400 RELEASE_ALL_THREADS_LOCK("create_thread")
403 if (create_os_thread(th
,&kid_tid
)) {
406 GET_ALL_THREADS_LOCK("create_thread")
408 RELEASE_ALL_THREADS_LOCK("create_thread")
409 free_thread_struct(th
);
414 /* Send the signo to os_thread, retry if the rt signal queue is
416 static int kill_thread_safely(os_thread_t os_thread
, int signo
)
419 /* The man page does not mention EAGAIN as a valid return value
420 * for either pthread_kill or kill. But that's theory, this is
421 * practice. By waiting here we assume that the delivery of this
422 * signal is not necessary for the delivery of the signals in the
423 * queue. In other words, we _assume_ there are no deadlocks. */
424 while ((r
=pthread_kill(os_thread
,signo
))==EAGAIN
) {
425 /* wait a bit then try again in the hope of the rt signal
426 * queue not being full */
427 FSHOW_SIGNAL((stderr
,"/rt signal queue full\n"));
428 /* FIXME: some kind of backoff (random, exponential) would be
435 int signal_interrupt_thread(os_thread_t os_thread
)
437 int status
= kill_thread_safely(os_thread
, SIG_INTERRUPT_THREAD
);
440 } else if (status
== ESRCH
) {
443 lose("cannot send SIG_INTERRUPT_THREAD to thread=%lu: %d, %s",
444 os_thread
, status
, strerror(status
));
448 /* stopping the world is a two-stage process. From this thread we signal
449 * all the others with SIG_STOP_FOR_GC. The handler for this signal does
450 * the usual pseudo-atomic checks (we don't want to stop a thread while
451 * it's in the middle of allocation) then waits for another SIG_STOP_FOR_GC.
454 /* To avoid deadlocks when gc stops the world all clients of each
455 * mutex must enable or disable SIG_STOP_FOR_GC for the duration of
456 * holding the lock, but they must agree on which. */
457 void gc_stop_the_world()
459 struct thread
*p
,*th
=arch_os_get_current_thread();
461 FSHOW_SIGNAL((stderr
,"/gc_stop_the_world:waiting on lock, thread=%lu\n",
463 /* keep threads from starting while the world is stopped. */
464 pthread_mutex_lock(&all_threads_lock
); \
465 FSHOW_SIGNAL((stderr
,"/gc_stop_the_world:got lock, thread=%lu\n",
467 /* stop all other threads by sending them SIG_STOP_FOR_GC */
468 for(p
=all_threads
; p
; p
=p
->next
) {
469 if((p
!=th
) && ((p
->state
==STATE_RUNNING
))) {
470 FSHOW_SIGNAL((stderr
,"/gc_stop_the_world: suspending %lu\n",
472 status
=kill_thread_safely(p
->os_thread
,SIG_STOP_FOR_GC
);
474 /* This thread has exited. */
475 gc_assert(p
->state
==STATE_DEAD
);
477 lose("cannot send suspend thread=%lu: %d, %s",
478 p
->os_thread
,status
,strerror(status
));
482 FSHOW_SIGNAL((stderr
,"/gc_stop_the_world:signals sent\n"));
483 /* wait for the running threads to stop or finish */
484 for(p
=all_threads
;p
;) {
485 if((p
!=th
) && (p
->state
==STATE_RUNNING
)) {
486 gc_assert(p
->os_thread
!=0);
492 FSHOW_SIGNAL((stderr
,"/gc_stop_the_world:end\n"));
495 void gc_start_the_world()
497 struct thread
*p
,*th
=arch_os_get_current_thread();
499 /* if a resumed thread creates a new thread before we're done with
500 * this loop, the new thread will get consed on the front of
501 * all_threads, but it won't have been stopped so won't need
503 FSHOW_SIGNAL((stderr
,"/gc_start_the_world:begin\n"));
504 for(p
=all_threads
;p
;p
=p
->next
) {
505 if((p
!=th
) && (p
->state
!=STATE_STARTING
) && (p
->state
!=STATE_DEAD
)) {
506 gc_assert(p
->os_thread
!=0);
507 if(p
->state
!=STATE_SUSPENDED
) {
508 lose("gc_start_the_world: wrong thread state is %d\n",
509 fixnum_value(p
->state
));
511 FSHOW_SIGNAL((stderr
, "/gc_start_the_world: resuming %lu\n",
513 p
->state
=STATE_RUNNING
;
514 status
=kill_thread_safely(p
->os_thread
,SIG_STOP_FOR_GC
);
516 lose("cannot resume thread=%lu: %d, %s",
517 p
->os_thread
,status
,strerror(status
));
521 /* If we waited here until all threads leave STATE_SUSPENDED, then
522 * SIG_STOP_FOR_GC wouldn't need to be a rt signal. That has some
523 * performance implications, but does away with the 'rt signal
524 * queue full' problem. */
525 pthread_mutex_unlock(&all_threads_lock
); \
526 FSHOW_SIGNAL((stderr
,"/gc_start_the_world:end\n"));