src/runtime/thread.c

   1 /*
   2  * This software is part of the SBCL system. See the README file for
   3  * more information.
   4  *
   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.
  10  */
  11
  12 #include "sbcl.h"
  13
  14 #include <stdlib.h>
  15 #include <stdio.h>
  16 #include <string.h>
  17 #ifndef LISP_FEATURE_WIN32
  18 #include <sched.h>
  19 #endif
  20 #include "runtime.h"
  21 #include <stddef.h>
  22 #include <errno.h>
  23 #include <sys/types.h>
  24 #ifndef LISP_FEATURE_WIN32
  25 #include <sys/wait.h>
  26 #endif
  27
  28 #ifdef LISP_FEATURE_MACH_EXCEPTION_HANDLER
  29 #include <mach/mach.h>
  30 #include <mach/mach_error.h>
  31 #include <mach/mach_types.h>
  32 #endif
  33
  34 #include "runtime.h"
  35 #include "validate.h"           /* for BINDING_STACK_SIZE etc */
  36 #include "thread.h"
  37 #include "arch.h"
  38 #include "target-arch-os.h"
  39 #include "os.h"
  40 #include "globals.h"
  41 #include "dynbind.h"
  42 #include "genesis/cons.h"
  43 #include "genesis/fdefn.h"
  44 #include "interr.h"             /* for lose() */
  45 #include "alloc.h"
  46 #include "gc-internal.h"
  47 #include "cpputil.h"
  48 #include "pseudo-atomic.h"
  49 #include "interrupt.h"
  50 #include "lispregs.h"
  51
  52 #if defined(LISP_FEATURE_WIN32) && defined(LISP_FEATURE_SB_THREAD)
  53 # define IMMEDIATE_POST_MORTEM
  54 #endif
  55
  56 #if defined(LISP_FEATURE_DARWIN) && defined(LISP_FEATURE_SB_THREAD)
  57 #define DELAY_THREAD_POST_MORTEM 5
  58 #define LOCK_CREATE_THREAD
  59 #endif
  60
  61 #ifdef LISP_FEATURE_FREEBSD
  62 #define CREATE_CLEANUP_THREAD
  63 #define LOCK_CREATE_THREAD
  64 #endif
  65
  66 #ifdef LISP_FEATURE_SB_THREAD
  67 struct thread_post_mortem {
  68 #ifdef DELAY_THREAD_POST_MORTEM
  69     struct thread_post_mortem *next;
  70 #endif
  71     os_thread_t os_thread;
  72     pthread_attr_t *os_attr;
  73     os_vm_address_t os_address;
  74 };
  75
  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;
  79 #endif
  80 static struct thread_post_mortem * volatile pending_thread_post_mortem = 0;
  81 #endif
  82
  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;
  86
  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;
  91 #endif
  92 #ifdef LISP_FEATURE_GCC_TLS
  93 __thread struct thread *current_thread;
  94 #endif
  95 pthread_key_t lisp_thread = 0;
  96 #endif
  97
  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);
 100 #endif
 101
 102 static void
 103 link_thread(struct thread *th)
 104 {
 105     if (all_threads) all_threads->prev=th;
 106     th->next=all_threads;
 107     th->prev=0;
 108     all_threads=th;
 109 }
 110
 111 #ifdef LISP_FEATURE_SB_THREAD
 112 static void
 113 unlink_thread(struct thread *th)
 114 {
 115     if (th->prev)
 116         th->prev->next = th->next;
 117     else
 118         all_threads = th->next;
 119     if (th->next)
 120         th->next->prev = th->prev;
 121 }
 122
 123 /* Only access thread state with blockables blocked. */
 124 lispobj
 125 thread_state(struct thread *thread)
 126 {
 127     lispobj state;
 128     sigset_t old;
 129     block_blockable_signals(NULL, &old);
 130     os_sem_wait(thread->state_sem, "thread_state");
 131     state = thread->state;
 132     os_sem_post(thread->state_sem, "thread_state");
 133     thread_sigmask(SIG_SETMASK, &old, NULL);
 134     return state;
 135 }
 136
 137 void
 138 set_thread_state(struct thread *thread, lispobj state)
 139 {
 140     int i, waitcount = 0;
 141     sigset_t old;
 142     block_blockable_signals(NULL, &old);
 143     os_sem_wait(thread->state_sem, "set_thread_state");
 144     if (thread->state != state) {
 145         if ((STATE_STOPPED==state) ||
 146             (STATE_DEAD==state)) {
 147             waitcount = thread->state_not_running_waitcount;
 148             thread->state_not_running_waitcount = 0;
 149             for (i=0; i<waitcount; i++)
 150                 os_sem_post(thread->state_not_running_sem, "set_thread_state (not running)");
 151         }
 152         if ((STATE_RUNNING==state) ||
 153             (STATE_DEAD==state)) {
 154             waitcount = thread->state_not_stopped_waitcount;
 155             thread->state_not_stopped_waitcount = 0;
 156             for (i=0; i<waitcount; i++)
 157                 os_sem_post(thread->state_not_stopped_sem, "set_thread_state (not stopped)");
 158         }
 159         thread->state = state;
 160     }
 161     os_sem_post(thread->state_sem, "set_thread_state");
 162     thread_sigmask(SIG_SETMASK, &old, NULL);
 163 }
 164
 165 void
 166 wait_for_thread_state_change(struct thread *thread, lispobj state)
 167 {
 168     sigset_t old;
 169     os_sem_t *wait_sem;
 170     block_blockable_signals(NULL, &old);
 171   start:
 172     os_sem_wait(thread->state_sem, "wait_for_thread_state_change");
 173     if (thread->state == state) {
 174         switch (state) {
 175         case STATE_RUNNING:
 176             wait_sem = thread->state_not_running_sem;
 177             thread->state_not_running_waitcount++;
 178             break;
 179         case STATE_STOPPED:
 180             wait_sem = thread->state_not_stopped_sem;
 181             thread->state_not_stopped_waitcount++;
 182             break;
 183         default:
 184             lose("Invalid state in wait_for_thread_state_change: "OBJ_FMTX"\n", state);
 185         }
 186     } else {
 187         wait_sem = NULL;
 188     }
 189     os_sem_post(thread->state_sem, "wait_for_thread_state_change");
 190     if (wait_sem) {
 191         os_sem_wait(wait_sem, "wait_for_thread_state_change");
 192         goto start;
 193     }
 194     thread_sigmask(SIG_SETMASK, &old, NULL);
 195 }
 196 #endif
 197
 198 static int
 199 initial_thread_trampoline(struct thread *th)
 200 {
 201     lispobj function;
 202 #if defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64)
 203     lispobj *args = NULL;
 204 #endif
 205 #ifdef LISP_FEATURE_SB_THREAD
 206     pthread_setspecific(lisp_thread, (void *)1);
 207 #endif
 208 #if defined(THREADS_USING_GCSIGNAL) && defined(LISP_FEATURE_PPC)
 209     /* SIG_STOP_FOR_GC defaults to blocked on PPC? */
 210     unblock_gc_signals(0,0);
 211 #endif
 212     function = th->no_tls_value_marker;
 213     th->no_tls_value_marker = NO_TLS_VALUE_MARKER_WIDETAG;
 214     if(arch_os_thread_init(th)==0) return 1;
 215 #ifdef LISP_FEATURE_SB_SAFEPOINT
 216     pthread_mutex_lock(thread_qrl(th));
 217 #endif
 218     link_thread(th);
 219     th->os_thread=thread_self();
 220 #ifndef LISP_FEATURE_WIN32
 221     protect_control_stack_hard_guard_page(1, NULL);
 222 #endif
 223     protect_binding_stack_hard_guard_page(1, NULL);
 224     protect_alien_stack_hard_guard_page(1, NULL);
 225 #ifndef LISP_FEATURE_WIN32
 226     protect_control_stack_guard_page(1, NULL);
 227 #endif
 228     protect_binding_stack_guard_page(1, NULL);
 229     protect_alien_stack_guard_page(1, NULL);
 230
 231 #if defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64)
 232     return call_into_lisp_first_time(function,args,0);
 233 #else
 234     return funcall0(function);
 235 #endif
 236 }
 237
 238 #ifdef LISP_FEATURE_SB_THREAD
 239
 240 # if defined(IMMEDIATE_POST_MORTEM)
 241
 242 /*
 243  * If this feature is set, we are running on a stack managed by the OS,
 244  * and no fancy delays are required for anything.  Just do it.
 245  */
 246 static void
 247 schedule_thread_post_mortem(struct thread *corpse)
 248 {
 249     pthread_detach(pthread_self());
 250     gc_assert(!pthread_attr_destroy(corpse->os_attr));
 251     free(corpse->os_attr);
 252 #if defined(LISP_FEATURE_WIN32)
 253     os_invalidate_free(corpse->os_address, THREAD_STRUCT_SIZE);
 254 #else
 255     os_invalidate(corpse->os_address, THREAD_STRUCT_SIZE);
 256 #endif
 257 }
 258
 259 # else
 260
 261 /* THREAD POST MORTEM CLEANUP
 262  *
 263  * Memory allocated for the thread stacks cannot be reclaimed while
 264  * the thread is still alive, so we need a mechanism for post mortem
 265  * cleanups. FIXME: We actually have three, for historical reasons as
 266  * the saying goes. Do we really need three? Nikodemus guesses that
 267  * not anymore, now that we properly call pthread_attr_destroy before
 268  * freeing the stack. */
 269
 270 static struct thread_post_mortem *
 271 plan_thread_post_mortem(struct thread *corpse)
 272 {
 273     if (corpse) {
 274         struct thread_post_mortem *post_mortem = malloc(sizeof(struct thread_post_mortem));
 275         gc_assert(post_mortem);
 276         post_mortem->os_thread = corpse->os_thread;
 277         post_mortem->os_attr = corpse->os_attr;
 278         post_mortem->os_address = corpse->os_address;
 279 #ifdef DELAY_THREAD_POST_MORTEM
 280         post_mortem->next = NULL;
 281 #endif
 282         return post_mortem;
 283     } else {
 284         /* FIXME: When does this happen? */
 285         return NULL;
 286     }
 287 }
 288
 289 static void
 290 perform_thread_post_mortem(struct thread_post_mortem *post_mortem)
 291 {
 292 #ifdef CREATE_POST_MORTEM_THREAD
 293     pthread_detach(pthread_self());
 294 #endif
 295     if (post_mortem) {
 296         gc_assert(!pthread_join(post_mortem->os_thread, NULL));
 297         gc_assert(!pthread_attr_destroy(post_mortem->os_attr));
 298         free(post_mortem->os_attr);
 299         os_invalidate(post_mortem->os_address, THREAD_STRUCT_SIZE);
 300         free(post_mortem);
 301     }
 302 }
 303
 304 static void
 305 schedule_thread_post_mortem(struct thread *corpse)
 306 {
 307     struct thread_post_mortem *post_mortem = NULL;
 308     if (corpse) {
 309         post_mortem = plan_thread_post_mortem(corpse);
 310
 311 #ifdef DELAY_THREAD_POST_MORTEM
 312         pthread_mutex_lock(&thread_post_mortem_lock);
 313         /* First stick the new post mortem to the end of the queue. */
 314         if (pending_thread_post_mortem) {
 315             struct thread_post_mortem *next = pending_thread_post_mortem;
 316             while (next->next) {
 317                 next = next->next;
 318             }
 319             next->next = post_mortem;
 320         } else {
 321             pending_thread_post_mortem = post_mortem;
 322         }
 323         /* Then, if there are enough things in the queue, clean up one
 324          * from the head -- or increment the count, and null out the
 325          * post_mortem we have. */
 326         if (pending_thread_post_mortem_count > DELAY_THREAD_POST_MORTEM) {
 327             post_mortem = pending_thread_post_mortem;
 328             pending_thread_post_mortem = post_mortem->next;
 329         } else {
 330             pending_thread_post_mortem_count++;
 331             post_mortem = NULL;
 332         }
 333         pthread_mutex_unlock(&thread_post_mortem_lock);
 334         /* Finally run, the cleanup, if any. */
 335         perform_thread_post_mortem(post_mortem);
 336 #elif defined(CREATE_POST_MORTEM_THREAD)
 337         gc_assert(!pthread_create(&thread, NULL, perform_thread_post_mortem, post_mortem));
 338 #else
 339         post_mortem = (struct thread_post_mortem *)
 340             swap_lispobjs((lispobj *)(void *)&pending_thread_post_mortem,
 341                           (lispobj)post_mortem);
 342         perform_thread_post_mortem(post_mortem);
 343 #endif
 344     }
 345 }
 346
 347 # endif /* !IMMEDIATE_POST_MORTEM */
 348
 349 /* this is the first thing that runs in the child (which is why the
 350  * silly calling convention).  Basically it calls the user's requested
 351  * lisp function after doing arch_os_thread_init and whatever other
 352  * bookkeeping needs to be done
 353  */
 354 int
 355 new_thread_trampoline(struct thread *th)
 356 {
 357     lispobj function;
 358     int result, lock_ret;
 359
 360     FSHOW((stderr,"/creating thread %lu\n", thread_self()));
 361     check_deferrables_blocked_or_lose(0);
 362 #ifndef LISP_FEATURE_SB_SAFEPOINT
 363     check_gc_signals_unblocked_or_lose(0);
 364 #endif
 365     pthread_setspecific(lisp_thread, (void *)1);
 366     function = th->no_tls_value_marker;
 367     th->no_tls_value_marker = NO_TLS_VALUE_MARKER_WIDETAG;
 368     if(arch_os_thread_init(th)==0) {
 369         /* FIXME: handle error */
 370         lose("arch_os_thread_init failed\n");
 371     }
 372
 373     th->os_thread=thread_self();
 374     protect_control_stack_guard_page(1, NULL);
 375     protect_binding_stack_guard_page(1, NULL);
 376     protect_alien_stack_guard_page(1, NULL);
 377     /* Since GC can only know about this thread from the all_threads
 378      * list and we're just adding this thread to it, there is no
 379      * danger of deadlocking even with SIG_STOP_FOR_GC blocked (which
 380      * it is not). */
 381 #ifdef LISP_FEATURE_SB_SAFEPOINT
 382     *th->csp_around_foreign_call = (lispobj)&function;
 383     pthread_mutex_lock(thread_qrl(th));
 384 #endif
 385     lock_ret = pthread_mutex_lock(&all_threads_lock);
 386     gc_assert(lock_ret == 0);
 387     link_thread(th);
 388     lock_ret = pthread_mutex_unlock(&all_threads_lock);
 389     gc_assert(lock_ret == 0);
 390
 391     /* Kludge: Changed the order of some steps between the safepoint/
 392      * non-safepoint versions of this code.  Can we unify this more?
 393      */
 394 #ifdef LISP_FEATURE_SB_SAFEPOINT
 395     WITH_GC_AT_SAFEPOINTS_ONLY() {
 396         result = funcall0(function);
 397         block_blockable_signals(0, 0);
 398         gc_alloc_update_page_tables(BOXED_PAGE_FLAG, &th->alloc_region);
 399     }
 400     lock_ret = pthread_mutex_lock(&all_threads_lock);
 401     gc_assert(lock_ret == 0);
 402     unlink_thread(th);
 403     lock_ret = pthread_mutex_unlock(&all_threads_lock);
 404     gc_assert(lock_ret == 0);
 405     pthread_mutex_unlock(thread_qrl(th));
 406     set_thread_state(th,STATE_DEAD);
 407 #else
 408     result = funcall0(function);
 409
 410     /* Block GC */
 411     block_blockable_signals(0, 0);
 412     set_thread_state(th, STATE_DEAD);
 413
 414     /* SIG_STOP_FOR_GC is blocked and GC might be waiting for this
 415      * thread, but since we are already dead it won't wait long. */
 416     lock_ret = pthread_mutex_lock(&all_threads_lock);
 417     gc_assert(lock_ret == 0);
 418
 419     gc_alloc_update_page_tables(BOXED_PAGE_FLAG, &th->alloc_region);
 420     unlink_thread(th);
 421     pthread_mutex_unlock(&all_threads_lock);
 422     gc_assert(lock_ret == 0);
 423 #endif
 424
 425     if(th->tls_cookie>=0) arch_os_thread_cleanup(th);
 426     os_sem_destroy(th->state_sem);
 427     os_sem_destroy(th->state_not_running_sem);
 428     os_sem_destroy(th->state_not_stopped_sem);
 429
 430 #if defined(LISP_FEATURE_WIN32)
 431     free((os_vm_address_t)th->interrupt_data);
 432 #else
 433     os_invalidate((os_vm_address_t)th->interrupt_data,
 434                   (sizeof (struct interrupt_data)));
 435 #endif
 436
 437 #ifdef LISP_FEATURE_MACH_EXCEPTION_HANDLER
 438     mach_lisp_thread_destroy(th);
 439 #endif
 440
 441 #if defined(LISP_FEATURE_WIN32)
 442     int i;
 443     for (i = 0; i<
 444              (int) (sizeof(th->private_events.events)/
 445                     sizeof(th->private_events.events[0])); ++i) {
 446       CloseHandle(th->private_events.events[i]);
 447     }
 448     TlsSetValue(OUR_TLS_INDEX,NULL);
 449 #endif
 450
 451     schedule_thread_post_mortem(th);
 452     FSHOW((stderr,"/exiting thread %lu\n", thread_self()));
 453     return result;
 454 }
 455
 456 #endif /* LISP_FEATURE_SB_THREAD */
 457
 458 static void
 459 free_thread_struct(struct thread *th)
 460 {
 461 #if defined(LISP_FEATURE_WIN32)
 462     if (th->interrupt_data) {
 463         os_invalidate_free((os_vm_address_t) th->interrupt_data,
 464                       (sizeof (struct interrupt_data)));
 465     }
 466     os_invalidate_free((os_vm_address_t) th->os_address,
 467                   THREAD_STRUCT_SIZE);
 468 #else
 469     if (th->interrupt_data)
 470         os_invalidate((os_vm_address_t) th->interrupt_data,
 471                       (sizeof (struct interrupt_data)));
 472     os_invalidate((os_vm_address_t) th->os_address,
 473                   THREAD_STRUCT_SIZE);
 474 #endif
 475 }
 476
 477 #ifdef LISP_FEATURE_SB_THREAD
 478 /* FIXME: should be MAX_INTERRUPTS -1 ? */
 479 const unsigned int tls_index_start =
 480   MAX_INTERRUPTS + sizeof(struct thread)/sizeof(lispobj);
 481 #endif
 482
 483 /* this is called from any other thread to create the new one, and
 484  * initialize all parts of it that can be initialized from another
 485  * thread
 486  */
 487
 488 static struct thread *
 489 create_thread_struct(lispobj initial_function) {
 490     union per_thread_data *per_thread;
 491     struct thread *th=0;        /*  subdue gcc */
 492     void *spaces=0;
 493     void *aligned_spaces=0;
 494 #if defined(LISP_FEATURE_SB_THREAD) || defined(LISP_FEATURE_WIN32)
 495     unsigned int i;
 496 #endif
 497
 498     /* May as well allocate all the spaces at once: it saves us from
 499      * having to decide what to do if only some of the allocations
 500      * succeed. SPACES must be appropriately aligned, since the GC
 501      * expects the control stack to start at a page boundary -- and
 502      * the OS may have even more rigorous requirements. We can't rely
 503      * on the alignment passed from os_validate, since that might
 504      * assume the current (e.g. 4k) pagesize, while we calculate with
 505      * the biggest (e.g. 64k) pagesize allowed by the ABI. */
 506     spaces=os_validate(0, THREAD_STRUCT_SIZE);
 507     if(!spaces)
 508         return NULL;
 509     /* Aligning up is safe as THREAD_STRUCT_SIZE has
 510      * THREAD_ALIGNMENT_BYTES padding. */
 511     aligned_spaces = (void *)((((unsigned long)(char *)spaces)
 512                                + THREAD_ALIGNMENT_BYTES-1)
 513                               &~(unsigned long)(THREAD_ALIGNMENT_BYTES-1));
 514     void* csp_page=
 515         (aligned_spaces+
 516          thread_control_stack_size+
 517          BINDING_STACK_SIZE+
 518          ALIEN_STACK_SIZE);
 519     per_thread=(union per_thread_data *)
 520         (csp_page + THREAD_CSP_PAGE_SIZE);
 521     struct nonpointer_thread_data *nonpointer_data
 522         = (void *) &per_thread->dynamic_values[TLS_SIZE];
 523
 524 #ifdef LISP_FEATURE_SB_THREAD
 525     for(i = 0; i < (dynamic_values_bytes / sizeof(lispobj)); i++)
 526         per_thread->dynamic_values[i] = NO_TLS_VALUE_MARKER_WIDETAG;
 527     if (all_threads == 0) {
 528         if(SymbolValue(FREE_TLS_INDEX,0)==UNBOUND_MARKER_WIDETAG) {
 529             SetSymbolValue(FREE_TLS_INDEX,tls_index_start << WORD_SHIFT,0);
 530             SetSymbolValue(TLS_INDEX_LOCK,make_fixnum(0),0);
 531         }
 532 #define STATIC_TLS_INIT(sym,field) \
 533   ((struct symbol *)(sym-OTHER_POINTER_LOWTAG))->tls_index= \
 534   (THREAD_SLOT_OFFSET_WORDS(field) << WORD_SHIFT)
 535
 536         STATIC_TLS_INIT(BINDING_STACK_START,binding_stack_start);
 537 #ifdef BINDING_STACK_POINTER
 538         STATIC_TLS_INIT(BINDING_STACK_POINTER,binding_stack_pointer);
 539 #endif
 540         STATIC_TLS_INIT(CONTROL_STACK_START,control_stack_start);
 541         STATIC_TLS_INIT(CONTROL_STACK_END,control_stack_end);
 542 #ifdef ALIEN_STACK
 543         STATIC_TLS_INIT(ALIEN_STACK,alien_stack_pointer);
 544 #endif
 545 #if defined(LISP_FEATURE_X86) || defined (LISP_FEATURE_X86_64)
 546         STATIC_TLS_INIT(PSEUDO_ATOMIC_BITS,pseudo_atomic_bits);
 547 #endif
 548 #undef STATIC_TLS_INIT
 549     }
 550 #endif
 551
 552     th=&per_thread->thread;
 553     th->os_address = spaces;
 554     th->control_stack_start = aligned_spaces;
 555     th->binding_stack_start=
 556         (lispobj*)((void*)th->control_stack_start+thread_control_stack_size);
 557     th->control_stack_end = th->binding_stack_start;
 558     th->control_stack_guard_page_protected = T;
 559     th->alien_stack_start=
 560         (lispobj*)((void*)th->binding_stack_start+BINDING_STACK_SIZE);
 561     set_binding_stack_pointer(th,th->binding_stack_start);
 562     th->this=th;
 563     th->os_thread=0;
 564
 565 #ifdef LISP_FEATURE_SB_SAFEPOINT
 566     th->pc_around_foreign_call = 0;
 567     th->csp_around_foreign_call = csp_page;
 568 #endif
 569
 570 #ifdef LISP_FEATURE_SB_THREAD
 571     /* Contrary to the "allocate all the spaces at once" comment above,
 572      * the os_attr is allocated separately.  We cannot put it into the
 573      * nonpointer data, because it's used for post_mortem and freed
 574      * separately */
 575     th->os_attr=malloc(sizeof(pthread_attr_t));
 576     th->nonpointer_data = nonpointer_data;
 577     th->state_sem=&nonpointer_data->state_sem;
 578     th->state_not_running_sem=&nonpointer_data->state_not_running_sem;
 579     th->state_not_stopped_sem=&nonpointer_data->state_not_stopped_sem;
 580     th->state_not_running_waitcount = 0;
 581     th->state_not_stopped_waitcount = 0;
 582     os_sem_init(th->state_sem, 1);
 583     os_sem_init(th->state_not_running_sem, 0);
 584     os_sem_init(th->state_not_stopped_sem, 0);
 585 # ifdef LISP_FEATURE_SB_SAFEPOINT
 586     pthread_mutex_init(thread_qrl(th), NULL);
 587 # endif
 588 #endif
 589     th->state=STATE_RUNNING;
 590 #ifdef LISP_FEATURE_STACK_GROWS_DOWNWARD_NOT_UPWARD
 591     th->alien_stack_pointer=((void *)th->alien_stack_start
 592                              + ALIEN_STACK_SIZE-N_WORD_BYTES);
 593 #else
 594     th->alien_stack_pointer=((void *)th->alien_stack_start);
 595 #endif
 596 #if defined(LISP_FEATURE_X86) || defined (LISP_FEATURE_X86_64) || defined(LISP_FEATURE_SB_THREAD)
 597     th->pseudo_atomic_bits=0;
 598 #endif
 599 #ifdef LISP_FEATURE_GENCGC
 600     gc_set_region_empty(&th->alloc_region);
 601 #endif
 602 #ifdef LISP_FEATURE_SB_THREAD
 603     /* This parallels the same logic in globals.c for the
 604      * single-threaded foreign_function_call_active, KLUDGE and
 605      * all. */
 606 #if defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64)
 607     th->foreign_function_call_active = 0;
 608 #else
 609     th->foreign_function_call_active = 1;
 610 #endif
 611 #endif
 612
 613 #ifndef LISP_FEATURE_SB_THREAD
 614     /* the tls-points-into-struct-thread trick is only good for threaded
 615      * sbcl, because unithread sbcl doesn't have tls.  So, we copy the
 616      * appropriate values from struct thread here, and make sure that
 617      * we use the appropriate SymbolValue macros to access any of the
 618      * variable quantities from the C runtime.  It's not quite OAOOM,
 619      * it just feels like it */
 620     SetSymbolValue(BINDING_STACK_START,(lispobj)th->binding_stack_start,th);
 621     SetSymbolValue(CONTROL_STACK_START,(lispobj)th->control_stack_start,th);
 622     SetSymbolValue(CONTROL_STACK_END,(lispobj)th->control_stack_end,th);
 623 #if defined(LISP_FEATURE_X86) || defined (LISP_FEATURE_X86_64)
 624     SetSymbolValue(ALIEN_STACK,(lispobj)th->alien_stack_pointer,th);
 625     SetSymbolValue(PSEUDO_ATOMIC_BITS,(lispobj)th->pseudo_atomic_bits,th);
 626 #endif
 627 #endif
 628     bind_variable(CURRENT_CATCH_BLOCK,make_fixnum(0),th);
 629     bind_variable(CURRENT_UNWIND_PROTECT_BLOCK,make_fixnum(0),th);
 630     bind_variable(FREE_INTERRUPT_CONTEXT_INDEX,make_fixnum(0),th);
 631     bind_variable(INTERRUPT_PENDING, NIL,th);
 632     bind_variable(INTERRUPTS_ENABLED,T,th);
 633     bind_variable(ALLOW_WITH_INTERRUPTS,T,th);
 634     bind_variable(GC_PENDING,NIL,th);
 635     bind_variable(ALLOC_SIGNAL,NIL,th);
 636 #ifdef PINNED_OBJECTS
 637     bind_variable(PINNED_OBJECTS,NIL,th);
 638 #endif
 639 #ifdef LISP_FEATURE_SB_THREAD
 640     bind_variable(STOP_FOR_GC_PENDING,NIL,th);
 641 #endif
 642 #if defined(LISP_FEATURE_SB_SAFEPOINT)
 643     bind_variable(GC_SAFE,NIL,th);
 644     bind_variable(IN_SAFEPOINT,NIL,th);
 645 #endif
 646 #ifdef LISP_FEATURE_SB_THRUPTION
 647     bind_variable(THRUPTION_PENDING,NIL,th);
 648     bind_variable(RESTART_CLUSTERS,NIL,th);
 649 #endif
 650 #ifndef LISP_FEATURE_C_STACK_IS_CONTROL_STACK
 651     access_control_stack_pointer(th)=th->control_stack_start;
 652 #endif
 653
 654 #if defined(LISP_FEATURE_WIN32)
 655     th->interrupt_data = (struct interrupt_data *)
 656         calloc((sizeof (struct interrupt_data)),1);
 657 #else
 658     th->interrupt_data = (struct interrupt_data *)
 659         os_validate(0,(sizeof (struct interrupt_data)));
 660 #endif
 661     if (!th->interrupt_data) {
 662         free_thread_struct(th);
 663         return 0;
 664     }
 665     th->interrupt_data->pending_handler = 0;
 666     th->interrupt_data->gc_blocked_deferrables = 0;
 667 #ifdef GENCGC_IS_PRECISE
 668     th->interrupt_data->allocation_trap_context = 0;
 669 #endif
 670     th->no_tls_value_marker=initial_function;
 671
 672 #if defined(LISP_FEATURE_WIN32)
 673     for (i = 0; i<sizeof(th->private_events.events)/
 674            sizeof(th->private_events.events[0]); ++i) {
 675       th->private_events.events[i] = CreateEvent(NULL,FALSE,FALSE,NULL);
 676     }
 677 #endif
 678     th->stepping = NIL;
 679     return th;
 680 }
 681
 682 void create_initial_thread(lispobj initial_function) {
 683     struct thread *th=create_thread_struct(initial_function);
 684 #ifdef LISP_FEATURE_SB_THREAD
 685     pthread_key_create(&lisp_thread, 0);
 686 #endif
 687     if(th) {
 688         initial_thread_trampoline(th); /* no return */
 689     } else lose("can't create initial thread\n");
 690 }
 691
 692 #ifdef LISP_FEATURE_SB_THREAD
 693
 694 #ifndef __USE_XOPEN2K
 695 extern int pthread_attr_setstack (pthread_attr_t *__attr, void *__stackaddr,
 696                                   size_t __stacksize);
 697 #endif
 698
 699 boolean create_os_thread(struct thread *th,os_thread_t *kid_tid)
 700 {
 701     /* The new thread inherits the restrictive signal mask set here,
 702      * and enables signals again when it is set up properly. */
 703     sigset_t oldset;
 704     boolean r=1;
 705     int retcode = 0, initcode;
 706
 707     FSHOW_SIGNAL((stderr,"/create_os_thread: creating new thread\n"));
 708
 709     /* Blocking deferrable signals is enough, no need to block
 710      * SIG_STOP_FOR_GC because the child process is not linked onto
 711      * all_threads until it's ready. */
 712     block_deferrable_signals(0, &oldset);
 713
 714 #ifdef LOCK_CREATE_THREAD
 715     retcode = pthread_mutex_lock(&create_thread_lock);
 716     gc_assert(retcode == 0);
 717     FSHOW_SIGNAL((stderr,"/create_os_thread: got lock\n"));
 718 #endif
 719
 720     if((initcode = pthread_attr_init(th->os_attr)) ||
 721        /* call_into_lisp_first_time switches the stack for the initial
 722         * thread. For the others, we use this. */
 723 #if defined(LISP_FEATURE_WIN32)
 724        (pthread_attr_setstacksize(th->os_attr, thread_control_stack_size)) ||
 725 #else
 726        (pthread_attr_setstack(th->os_attr,th->control_stack_start,
 727                               thread_control_stack_size)) ||
 728 #endif
 729        (retcode = pthread_create
 730         (kid_tid,th->os_attr,(void *(*)(void *))new_thread_trampoline,th))) {
 731         FSHOW_SIGNAL((stderr, "init = %d\n", initcode));
 732         FSHOW_SIGNAL((stderr, "pthread_create returned %d, errno %d\n",
 733                       retcode, errno));
 734         if(retcode < 0) {
 735             perror("create_os_thread");
 736         }
 737         r=0;
 738     }
 739
 740 #ifdef LOCK_CREATE_THREAD
 741     retcode = pthread_mutex_unlock(&create_thread_lock);
 742     gc_assert(retcode == 0);
 743     FSHOW_SIGNAL((stderr,"/create_os_thread: released lock\n"));
 744 #endif
 745     thread_sigmask(SIG_SETMASK,&oldset,0);
 746     return r;
 747 }
 748
 749 os_thread_t create_thread(lispobj initial_function) {
 750     struct thread *th, *thread = arch_os_get_current_thread();
 751     os_thread_t kid_tid = 0;
 752
 753     /* Must defend against async unwinds. */
 754     if (SymbolValue(INTERRUPTS_ENABLED, thread) != NIL)
 755         lose("create_thread is not safe when interrupts are enabled.\n");
 756
 757     /* Assuming that a fresh thread struct has no lisp objects in it,
 758      * linking it to all_threads can be left to the thread itself
 759      * without fear of gc lossage. initial_function violates this
 760      * assumption and must stay pinned until the child starts up. */
 761     th = create_thread_struct(initial_function);
 762     if (th && !create_os_thread(th,&kid_tid)) {
 763         free_thread_struct(th);
 764         kid_tid = 0;
 765     }
 766     return kid_tid;
 767 }
 768
 769 /* stopping the world is a two-stage process.  From this thread we signal
 770  * all the others with SIG_STOP_FOR_GC.  The handler for this signal does
 771  * the usual pseudo-atomic checks (we don't want to stop a thread while
 772  * it's in the middle of allocation) then waits for another SIG_STOP_FOR_GC.
 773  */
 774 /*
 775  * (With SB-SAFEPOINT, see the definitions in safepoint.c instead.)
 776  */
 777 #ifndef LISP_FEATURE_SB_SAFEPOINT
 778
 779 /* To avoid deadlocks when gc stops the world all clients of each
 780  * mutex must enable or disable SIG_STOP_FOR_GC for the duration of
 781  * holding the lock, but they must agree on which. */
 782 void gc_stop_the_world()
 783 {
 784     struct thread *p,*th=arch_os_get_current_thread();
 785     int status, lock_ret;
 786 #ifdef LOCK_CREATE_THREAD
 787     /* KLUDGE: Stopping the thread during pthread_create() causes deadlock
 788      * on FreeBSD. */
 789     FSHOW_SIGNAL((stderr,"/gc_stop_the_world:waiting on create_thread_lock\n"));
 790     lock_ret = pthread_mutex_lock(&create_thread_lock);
 791     gc_assert(lock_ret == 0);
 792     FSHOW_SIGNAL((stderr,"/gc_stop_the_world:got create_thread_lock\n"));
 793 #endif
 794     FSHOW_SIGNAL((stderr,"/gc_stop_the_world:waiting on lock\n"));
 795     /* keep threads from starting while the world is stopped. */
 796     lock_ret = pthread_mutex_lock(&all_threads_lock);      \
 797     gc_assert(lock_ret == 0);
 798
 799     FSHOW_SIGNAL((stderr,"/gc_stop_the_world:got lock\n"));
 800     /* stop all other threads by sending them SIG_STOP_FOR_GC */
 801     for(p=all_threads; p; p=p->next) {
 802         gc_assert(p->os_thread != 0);
 803         FSHOW_SIGNAL((stderr,"/gc_stop_the_world: thread=%lu, state=%x\n",
 804                       p->os_thread, thread_state(p)));
 805         if((p!=th) && ((thread_state(p)==STATE_RUNNING))) {
 806             FSHOW_SIGNAL((stderr,"/gc_stop_the_world: suspending thread %lu\n",
 807                           p->os_thread));
 808             /* We already hold all_thread_lock, P can become DEAD but
 809              * cannot exit, ergo it's safe to use pthread_kill. */
 810             status=pthread_kill(p->os_thread,SIG_STOP_FOR_GC);
 811             if (status==ESRCH) {
 812                 /* This thread has exited. */
 813                 gc_assert(thread_state(p)==STATE_DEAD);
 814             } else if (status) {
 815                 lose("cannot send suspend thread=%lu: %d, %s\n",
 816                      p->os_thread,status,strerror(status));
 817             }
 818         }
 819     }
 820     FSHOW_SIGNAL((stderr,"/gc_stop_the_world:signals sent\n"));
 821     for(p=all_threads;p;p=p->next) {
 822         if (p!=th) {
 823             FSHOW_SIGNAL
 824                 ((stderr,
 825                   "/gc_stop_the_world: waiting for thread=%lu: state=%x\n",
 826                   p->os_thread, thread_state(p)));
 827             wait_for_thread_state_change(p, STATE_RUNNING);
 828             if (p->state == STATE_RUNNING)
 829                 lose("/gc_stop_the_world: unexpected state");
 830         }
 831     }
 832     FSHOW_SIGNAL((stderr,"/gc_stop_the_world:end\n"));
 833 }
 834
 835 void gc_start_the_world()
 836 {
 837     struct thread *p,*th=arch_os_get_current_thread();
 838     int lock_ret;
 839     /* if a resumed thread creates a new thread before we're done with
 840      * this loop, the new thread will get consed on the front of
 841      * all_threads, but it won't have been stopped so won't need
 842      * restarting */
 843     FSHOW_SIGNAL((stderr,"/gc_start_the_world:begin\n"));
 844     for(p=all_threads;p;p=p->next) {
 845         gc_assert(p->os_thread!=0);
 846         if (p!=th) {
 847             lispobj state = thread_state(p);
 848             if (state != STATE_DEAD) {
 849                 if(state != STATE_STOPPED) {
 850                     lose("gc_start_the_world: wrong thread state is %d\n",
 851                          fixnum_value(state));
 852                 }
 853                 FSHOW_SIGNAL((stderr, "/gc_start_the_world: resuming %lu\n",
 854                               p->os_thread));
 855                 set_thread_state(p, STATE_RUNNING);
 856             }
 857         }
 858     }
 859
 860     lock_ret = pthread_mutex_unlock(&all_threads_lock);
 861     gc_assert(lock_ret == 0);
 862 #ifdef LOCK_CREATE_THREAD
 863     lock_ret = pthread_mutex_unlock(&create_thread_lock);
 864     gc_assert(lock_ret == 0);
 865 #endif
 866
 867     FSHOW_SIGNAL((stderr,"/gc_start_the_world:end\n"));
 868 }
 869
 870 #endif /* !LISP_FEATURE_SB_SAFEPOINT */
 871 #endif /* !LISP_FEATURE_SB_THREAD */
 872
 873 int
 874 thread_yield()
 875 {
 876 #ifdef LISP_FEATURE_SB_THREAD
 877     return sched_yield();
 878 #else
 879     return 0;
 880 #endif
 881 }
 882
 883 int
 884 wake_thread(os_thread_t os_thread)
 885 {
 886 #if defined(LISP_FEATURE_WIN32)
 887     return kill_safely(os_thread, 1);
 888 #elif !defined(LISP_FEATURE_SB_THRUPTION)
 889     return kill_safely(os_thread, SIGPIPE);
 890 #else
 891     return wake_thread_posix(os_thread);
 892 #endif
 893 }
 894
 895 /* If the thread id given does not belong to a running thread (it has
 896  * exited or never even existed) pthread_kill _may_ fail with ESRCH,
 897  * but it is also allowed to just segfault, see
 898  * <http://udrepper.livejournal.com/16844.html>.
 899  *
 900  * Relying on thread ids can easily backfire since ids are recycled
 901  * (NPTL recycles them extremely fast) so a signal can be sent to
 902  * another process if the one it was sent to exited.
 903  *
 904  * For these reasons, we must make sure that the thread is still alive
 905  * when the pthread_kill is called and return if the thread is
 906  * exiting.
 907  *
 908  * Note (DFL, 2011-06-22): At the time of writing, this function is only
 909  * used for INTERRUPT-THREAD, hence the wake_thread special-case for
 910  * Windows is OK. */
 911 int
 912 kill_safely(os_thread_t os_thread, int signal)
 913 {
 914     FSHOW_SIGNAL((stderr,"/kill_safely: %lu, %d\n", os_thread, signal));
 915     {
 916 #ifdef LISP_FEATURE_SB_THREAD
 917         sigset_t oldset;
 918         struct thread *thread;
 919         /* Frequent special case: resignalling to self.  The idea is
 920          * that leave_region safepoint will acknowledge the signal, so
 921          * there is no need to take locks, roll thread to safepoint
 922          * etc. */
 923         /* Kludge (on safepoint builds): At the moment, this isn't just
 924          * an optimization; rather it masks the fact that
 925          * gc_stop_the_world() grabs the all_threads mutex without
 926          * releasing it, and since we're not using recursive pthread
 927          * mutexes, the pthread_mutex_lock() around the all_threads loop
 928          * would go wrong.  Why are we running interruptions while
 929          * stopping the world though?  Test case is (:ASYNC-UNWIND
 930          * :SPECIALS), especially with s/10/100/ in both loops. */
 931         if (os_thread == pthread_self()) {
 932             pthread_kill(os_thread, signal);
 933 #ifdef LISP_FEATURE_WIN32
 934             check_pending_thruptions(NULL);
 935 #endif
 936             return 0;
 937         }
 938
 939         /* pthread_kill is not async signal safe and we don't want to be
 940          * interrupted while holding the lock. */
 941         block_deferrable_signals(0, &oldset);
 942         pthread_mutex_lock(&all_threads_lock);
 943         for (thread = all_threads; thread; thread = thread->next) {
 944             if (thread->os_thread == os_thread) {
 945                 int status = pthread_kill(os_thread, signal);
 946                 if (status)
 947                     lose("kill_safely: pthread_kill failed with %d\n", status);
 948 #if defined(LISP_FEATURE_WIN32) && defined(LISP_FEATURE_SB_THRUPTION)
 949                 wake_thread_win32(thread);
 950 #endif
 951                 break;
 952             }
 953         }
 954         pthread_mutex_unlock(&all_threads_lock);
 955         thread_sigmask(SIG_SETMASK,&oldset,0);
 956         if (thread)
 957             return 0;
 958         else
 959             return -1;
 960 #elif defined(LISP_FEATURE_WIN32)
 961         return 0;
 962 #else
 963         int status;
 964         if (os_thread != 0)
 965             lose("kill_safely: who do you want to kill? %d?\n", os_thread);
 966         /* Dubious (as in don't know why it works) workaround for the
 967          * signal sometimes not being generated on darwin. */
 968 #ifdef LISP_FEATURE_DARWIN
 969         {
 970             sigset_t oldset;
 971             sigprocmask(SIG_BLOCK, &deferrable_sigset, &oldset);
 972             status = raise(signal);
 973             sigprocmask(SIG_SETMASK,&oldset,0);
 974         }
 975 #else
 976         status = raise(signal);
 977 #endif
 978         if (status == 0) {
 979             return 0;
 980         } else {
 981             lose("cannot raise signal %d, %d %s\n",
 982                  signal, status, strerror(errno));
 983         }
 984 #endif
 985     }
 986 }