ext/threads/threads.xs

   1 #define PERL_NO_GET_CONTEXT
   2 #include "EXTERN.h"
   3 #include "perl.h"
   4 #include "XSUB.h"
   5
   6 #ifdef USE_ITHREADS
   7
   8 #ifdef WIN32
   9 #include <windows.h>
  10 #include <win32thread.h>
  11 #define PERL_THREAD_SETSPECIFIC(k,v) TlsSetValue(k,v)
  12 #define PERL_THREAD_GETSPECIFIC(k,v) v = TlsGetValue(k)
  13 #define PERL_THREAD_ALLOC_SPECIFIC(k) \
  14 STMT_START {\
  15   if((k = TlsAlloc()) == TLS_OUT_OF_INDEXES) {\
  16     PerlIO_printf(PerlIO_stderr(),"panic threads.h: TlsAlloc");\
  17     exit(1);\
  18   }\
  19 } STMT_END
  20 #else
  21 #include <pthread.h>
  22 #include <thread.h>
  23
  24 #define PERL_THREAD_SETSPECIFIC(k,v) pthread_setspecific(k,v)
  25 #ifdef OLD_PTHREADS_API
  26 #define PERL_THREAD_DETACH(t) pthread_detach(&(t))
  27 #define PERL_THREAD_GETSPECIFIC(k,v) pthread_getspecific(k,&v)
  28 #define PERL_THREAD_ALLOC_SPECIFIC(k) STMT_START {\
  29   if(pthread_keycreate(&(k),0)) {\
  30     PerlIO_printf(PerlIO_stderr(), "panic threads.h: pthread_key_create");\
  31     exit(1);\
  32   }\
  33 } STMT_END
  34 #else
  35 #define PERL_THREAD_DETACH(t) pthread_detach((t))
  36 #define PERL_THREAD_GETSPECIFIC(k,v) v = pthread_getspecific(k)
  37 #define PERL_THREAD_ALLOC_SPECIFIC(k) STMT_START {\
  38   if(pthread_key_create(&(k),0)) {\
  39     PerlIO_printf(PerlIO_stderr(), "panic threads.h: pthread_key_create");\
  40     exit(1);\
  41   }\
  42 } STMT_END
  43 #endif
  44 #endif
  45
  46 /* Values for 'state' member */
  47 #define PERL_ITHR_JOINABLE              0
  48 #define PERL_ITHR_DETACHED              1
  49 #define PERL_ITHR_FINISHED              4
  50 #define PERL_ITHR_JOINED                2
  51
  52 typedef struct ithread_s {
  53     struct ithread_s *next;     /* next thread in the list */
  54     struct ithread_s *prev;     /* prev thread in the list */
  55     PerlInterpreter *interp;    /* The threads interpreter */
  56     I32 tid;                    /* threads module's thread id */
  57     perl_mutex mutex;           /* mutex for updating things in this struct */
  58     I32 count;                  /* how many SVs have a reference to us */
  59     signed char state;          /* are we detached ? */
  60     int gimme;                  /* Context of create */
  61     SV* init_function;          /* Code to run */
  62     SV* params;                 /* args to pass function */
  63 #ifdef WIN32
  64         DWORD   thr;            /* OS's idea if thread id */
  65         HANDLE handle;          /* OS's waitable handle */
  66 #else
  67         pthread_t thr;          /* OS's handle for the thread */
  68 #endif
  69 } ithread;
  70
  71 ithread *threads;
  72
  73 /* Macros to supply the aTHX_ in an embed.h like manner */
  74 #define ithread_join(thread)            Perl_ithread_join(aTHX_ thread)
  75 #define ithread_DESTROY(thread)         Perl_ithread_DESTROY(aTHX_ thread)
  76 #define ithread_CLONE(thread)           Perl_ithread_CLONE(aTHX_ thread)
  77 #define ithread_detach(thread)          Perl_ithread_detach(aTHX_ thread)
  78 #define ithread_tid(thread)             ((thread)->tid)
  79 #define ithread_yield(thread)           (YIELD);
  80
  81 static perl_mutex create_destruct_mutex;  /* protects the creation and destruction of threads*/
  82
  83 I32 tid_counter = 0;
  84 I32 known_threads = 0;
  85 I32 active_threads = 0;
  86 perl_key self_key;
  87
  88 /*
  89  *  Clear up after thread is done with
  90  */
  91 void
  92 Perl_ithread_destruct (pTHX_ ithread* thread, const char *why)
  93 {
  94         MUTEX_LOCK(&thread->mutex);
  95         if (!thread->next) {
  96             Perl_croak(aTHX_ "panic: destruct destroyed thread %p (%s)",thread, why);
  97         }
  98         if (thread->count != 0) {
  99                 MUTEX_UNLOCK(&thread->mutex);
 100                 return;
 101         }
 102         MUTEX_LOCK(&create_destruct_mutex);
 103         /* Remove from circular list of threads */
 104         if (thread->next == thread) {
 105             /* last one should never get here ? */
 106             threads = NULL;
 107         }
 108         else {
 109             thread->next->prev = thread->prev;
 110             thread->prev->next = thread->next;
 111             if (threads == thread) {
 112                 threads = thread->next;
 113             }
 114             thread->next = NULL;
 115             thread->prev = NULL;
 116         }
 117         known_threads--;
 118         assert( known_threads >= 0 );
 119 #if 0
 120         Perl_warn(aTHX_ "destruct %d @ %p by %p now %d",
 121                   thread->tid,thread->interp,aTHX, known_threads);
 122 #endif
 123         MUTEX_UNLOCK(&create_destruct_mutex);
 124         /* Thread is now disowned */
 125         if (thread->interp) {
 126             dTHXa(thread->interp);
 127             PERL_SET_CONTEXT(thread->interp);
 128             SvREFCNT_dec(thread->params);
 129             thread->params = Nullsv;
 130             perl_destruct(thread->interp);
 131             perl_free(thread->interp);
 132             thread->interp = NULL;
 133         }
 134         PERL_SET_CONTEXT(aTHX);
 135         MUTEX_UNLOCK(&thread->mutex);
 136         MUTEX_DESTROY(&thread->mutex);
 137         PerlMemShared_free(thread);
 138 }
 139
 140 int
 141 Perl_ithread_hook(pTHX)
 142 {
 143     int veto_cleanup = 0;
 144     MUTEX_LOCK(&create_destruct_mutex);
 145     if (aTHX == PL_curinterp && active_threads != 1) {
 146         Perl_warn(aTHX_ "Cleanup skipped %d active threads", active_threads);
 147         veto_cleanup = 1;
 148     }
 149     MUTEX_UNLOCK(&create_destruct_mutex);
 150     return veto_cleanup;
 151 }
 152
 153 void
 154 Perl_ithread_detach(pTHX_ ithread *thread)
 155 {
 156     MUTEX_LOCK(&thread->mutex);
 157     if (!(thread->state & (PERL_ITHR_DETACHED|PERL_ITHR_JOINED))) {
 158         thread->state |= PERL_ITHR_DETACHED;
 159 #ifdef WIN32
 160         CloseHandle(thread->handle);
 161         thread->handle = 0;
 162 #else
 163         PERL_THREAD_DETACH(thread->thr);
 164 #endif
 165     }
 166     if ((thread->state & PERL_ITHR_FINISHED) &&
 167         (thread->state & PERL_ITHR_DETACHED)) {
 168         MUTEX_UNLOCK(&thread->mutex);
 169         Perl_ithread_destruct(aTHX_ thread, "detach");
 170     }
 171     else {
 172         MUTEX_UNLOCK(&thread->mutex);
 173     }
 174 }
 175
 176 /* MAGIC (in mg.h sense) hooks */
 177
 178 int
 179 ithread_mg_get(pTHX_ SV *sv, MAGIC *mg)
 180 {
 181     ithread *thread = (ithread *) mg->mg_ptr;
 182     SvIVX(sv) = PTR2IV(thread);
 183     SvIOK_on(sv);
 184     return 0;
 185 }
 186
 187 int
 188 ithread_mg_free(pTHX_ SV *sv, MAGIC *mg)
 189 {
 190     ithread *thread = (ithread *) mg->mg_ptr;
 191     MUTEX_LOCK(&thread->mutex);
 192     thread->count--;
 193     if (thread->count == 0) {
 194        if(thread->state & PERL_ITHR_FINISHED &&
 195           (thread->state & PERL_ITHR_DETACHED ||
 196            thread->state & PERL_ITHR_JOINED))
 197        {
 198             MUTEX_UNLOCK(&thread->mutex);
 199             Perl_ithread_destruct(aTHX_ thread, "no reference");
 200        }
 201        else {
 202             MUTEX_UNLOCK(&thread->mutex);
 203        }
 204     }
 205     else {
 206         MUTEX_UNLOCK(&thread->mutex);
 207     }
 208     return 0;
 209 }
 210
 211 int
 212 ithread_mg_dup(pTHX_ MAGIC *mg, CLONE_PARAMS *param)
 213 {
 214     ithread *thread = (ithread *) mg->mg_ptr;
 215     MUTEX_LOCK(&thread->mutex);
 216     thread->count++;
 217     MUTEX_UNLOCK(&thread->mutex);
 218     return 0;
 219 }
 220
 221 MGVTBL ithread_vtbl = {
 222  ithread_mg_get,        /* get */
 223  0,                     /* set */
 224  0,                     /* len */
 225  0,                     /* clear */
 226  ithread_mg_free,       /* free */
 227  0,                     /* copy */
 228  ithread_mg_dup         /* dup */
 229 };
 230
 231
 232 /*
 233  *      Starts executing the thread. Needs to clean up memory a tad better.
 234  *      Passed as the C level function to run in the new thread
 235  */
 236
 237 #ifdef WIN32
 238 THREAD_RET_TYPE
 239 Perl_ithread_run(LPVOID arg) {
 240 #else
 241 void*
 242 Perl_ithread_run(void * arg) {
 243 #endif
 244         ithread* thread = (ithread*) arg;
 245         dTHXa(thread->interp);
 246         PERL_SET_CONTEXT(thread->interp);
 247         PERL_THREAD_SETSPECIFIC(self_key,thread);
 248
 249 #if 0
 250         /* Far from clear messing with ->thr child-side is a good idea */
 251         MUTEX_LOCK(&thread->mutex);
 252 #ifdef WIN32
 253         thread->thr = GetCurrentThreadId();
 254 #else
 255         thread->thr = pthread_self();
 256 #endif
 257         MUTEX_UNLOCK(&thread->mutex);
 258 #endif
 259
 260         PL_perl_destruct_level = 2;
 261
 262         {
 263                 AV* params = (AV*) SvRV(thread->params);
 264                 I32 len = av_len(params)+1;
 265                 int i;
 266                 dSP;
 267                 ENTER;
 268                 SAVETMPS;
 269                 PUSHMARK(SP);
 270                 for(i = 0; i < len; i++) {
 271                     XPUSHs(av_shift(params));
 272                 }
 273                 PUTBACK;
 274                 len = call_sv(thread->init_function, thread->gimme|G_EVAL);
 275                 SPAGAIN;
 276                 for (i=len-1; i >= 0; i--) {
 277                   SV *sv = POPs;
 278                   av_store(params, i, SvREFCNT_inc(sv));
 279                 }
 280                 PUTBACK;
 281                 if (SvTRUE(ERRSV)) {
 282                     Perl_warn(aTHX_ "Died:%_",ERRSV);
 283                 }
 284                 FREETMPS;
 285                 LEAVE;
 286                 SvREFCNT_dec(thread->init_function);
 287         }
 288
 289         PerlIO_flush((PerlIO*)NULL);
 290         MUTEX_LOCK(&create_destruct_mutex);
 291         active_threads--;
 292         assert( active_threads >= 0 );
 293         MUTEX_UNLOCK(&create_destruct_mutex);
 294         MUTEX_LOCK(&thread->mutex);
 295         thread->state |= PERL_ITHR_FINISHED;
 296
 297         if (thread->state & PERL_ITHR_DETACHED) {
 298                 MUTEX_UNLOCK(&thread->mutex);
 299                 Perl_ithread_destruct(aTHX_ thread, "detached finish");
 300         } else {
 301                 MUTEX_UNLOCK(&thread->mutex);
 302         }
 303 #ifdef WIN32
 304         return (DWORD)0;
 305 #else
 306         return 0;
 307 #endif
 308 }
 309
 310 SV *
 311 ithread_to_SV(pTHX_ SV *obj, ithread *thread, char *classname, bool inc)
 312 {
 313     SV *sv;
 314     MAGIC *mg;
 315     if (inc) {
 316         MUTEX_LOCK(&thread->mutex);
 317         thread->count++;
 318         MUTEX_UNLOCK(&thread->mutex);
 319     }
 320     if (!obj)
 321      obj = newSV(0);
 322     sv = newSVrv(obj,classname);
 323     sv_setiv(sv,PTR2IV(thread));
 324     mg = sv_magicext(sv,Nullsv,PERL_MAGIC_shared_scalar,&ithread_vtbl,(char *)thread,0);
 325     mg->mg_flags |= MGf_DUP;
 326     SvREADONLY_on(sv);
 327     return obj;
 328 }
 329
 330 ithread *
 331 SV_to_ithread(pTHX_ SV *sv)
 332 {
 333     ithread *thread;
 334     if (SvROK(sv))
 335      {
 336       thread = INT2PTR(ithread*, SvIV(SvRV(sv)));
 337      }
 338     else
 339      {
 340       PERL_THREAD_GETSPECIFIC(self_key,thread);
 341      }
 342     return thread;
 343 }
 344
 345 /*
 346  * iThread->create(); ( aka iThread->new() )
 347  * Called in context of parent thread
 348  */
 349
 350 SV *
 351 Perl_ithread_create(pTHX_ SV *obj, char* classname, SV* init_function, SV* params)
 352 {
 353         ithread*        thread;
 354         CLONE_PARAMS    clone_param;
 355
 356         MUTEX_LOCK(&create_destruct_mutex);
 357         thread = PerlMemShared_malloc(sizeof(ithread));
 358         Zero(thread,1,ithread);
 359         thread->next = threads;
 360         thread->prev = threads->prev;
 361         threads->prev = thread;
 362         thread->prev->next = thread;
 363         /* Set count to 1 immediately in case thread exits before
 364          * we return to caller !
 365          */
 366         thread->count = 1;
 367         MUTEX_INIT(&thread->mutex);
 368         thread->tid = tid_counter++;
 369         thread->gimme = GIMME_V;
 370         thread->state = (thread->gimme == G_VOID) ? 1 : 0;
 371
 372         /* "Clone" our interpreter into the thread's interpreter
 373          * This gives thread access to "static data" and code.
 374          */
 375
 376         PerlIO_flush((PerlIO*)NULL);
 377
 378 #ifdef WIN32
 379         thread->interp = perl_clone(aTHX, CLONEf_KEEP_PTR_TABLE | CLONEf_CLONE_HOST);
 380 #else
 381         thread->interp = perl_clone(aTHX, CLONEf_KEEP_PTR_TABLE);
 382 #endif
 383         /* perl_clone leaves us in new interpreter's context.
 384            As it is tricky to spot implcit aTHX create a new scope
 385            with aTHX matching the context for the duration of
 386            our work for new interpreter.
 387          */
 388         {
 389             dTHXa(thread->interp);
 390             /* Here we remove END blocks since they should only run
 391                in the thread they are created
 392             */
 393             SvREFCNT_dec(PL_endav);
 394             PL_endav = newAV();
 395             clone_param.flags = 0;
 396             thread->init_function = sv_dup(init_function, &clone_param);
 397             if (SvREFCNT(thread->init_function) == 0) {
 398                 SvREFCNT_inc(thread->init_function);
 399             }
 400
 401             thread->params = sv_dup(params, &clone_param);
 402             SvREFCNT_inc(thread->params);
 403             SvTEMP_off(thread->init_function);
 404             ptr_table_free(PL_ptr_table);
 405             PL_ptr_table = NULL;
 406             PL_exit_flags |= PERL_EXIT_DESTRUCT_END;
 407         }
 408
 409         PERL_SET_CONTEXT(aTHX);
 410
 411         /* Start the thread */
 412
 413 #ifdef WIN32
 414
 415         thread->handle = CreateThread(NULL, 0, Perl_ithread_run,
 416                         (LPVOID)thread, 0, &thread->thr);
 417
 418 #else
 419         {
 420           static pthread_attr_t attr;
 421           static int attr_inited = 0;
 422           static int attr_joinable = PTHREAD_CREATE_JOINABLE;
 423           if (!attr_inited) {
 424             attr_inited = 1;
 425             pthread_attr_init(&attr);
 426           }
 427 #  ifdef PTHREAD_ATTR_SETDETACHSTATE
 428             PTHREAD_ATTR_SETDETACHSTATE(&attr, attr_joinable);
 429 #  endif
 430 #  ifdef THREAD_CREATE_NEEDS_STACK
 431             if(pthread_attr_setstacksize(&attr, THREAD_CREATE_NEEDS_STACK))
 432               croak("panic: pthread_attr_setstacksize failed");
 433 #  endif
 434
 435 #ifdef OLD_PTHREADS_API
 436           pthread_create( &thread->thr, attr, Perl_ithread_run, (void *)thread);
 437 #else
 438           pthread_create( &thread->thr, &attr, Perl_ithread_run, (void *)thread);
 439 #endif
 440         }
 441 #endif
 442         known_threads++;
 443         active_threads++;
 444         MUTEX_UNLOCK(&create_destruct_mutex);
 445         sv_2mortal(params);
 446         return ithread_to_SV(aTHX_ obj, thread, classname, FALSE);
 447 }
 448
 449 SV*
 450 Perl_ithread_self (pTHX_ SV *obj, char* Class)
 451 {
 452     ithread *thread;
 453     PERL_THREAD_GETSPECIFIC(self_key,thread);
 454     return ithread_to_SV(aTHX_ obj, thread, Class, TRUE);
 455 }
 456
 457 /*
 458  * Joins the thread this code needs to take the returnvalue from the
 459  * call_sv and send it back
 460  */
 461
 462 void
 463 Perl_ithread_CLONE(pTHX_ SV *obj)
 464 {
 465  if (SvROK(obj))
 466   {
 467    ithread *thread = SV_to_ithread(aTHX_ obj);
 468   }
 469  else
 470   {
 471    Perl_warn(aTHX_ "CLONE %_",obj);
 472   }
 473 }
 474
 475 AV*
 476 Perl_ithread_join(pTHX_ SV *obj)
 477 {
 478     ithread *thread = SV_to_ithread(aTHX_ obj);
 479     MUTEX_LOCK(&thread->mutex);
 480     if (thread->state & PERL_ITHR_DETACHED) {
 481         MUTEX_UNLOCK(&thread->mutex);
 482         Perl_croak(aTHX_ "Cannot join a detached thread");
 483     }
 484     else if (thread->state & PERL_ITHR_JOINED) {
 485         MUTEX_UNLOCK(&thread->mutex);
 486         Perl_croak(aTHX_ "Thread already joined");
 487     }
 488     else {
 489         AV* retparam;
 490 #ifdef WIN32
 491         DWORD waitcode;
 492 #else
 493         void *retval;
 494 #endif
 495         MUTEX_UNLOCK(&thread->mutex);
 496 #ifdef WIN32
 497         waitcode = WaitForSingleObject(thread->handle, INFINITE);
 498 #else
 499         pthread_join(thread->thr,&retval);
 500 #endif
 501         MUTEX_LOCK(&thread->mutex);
 502
 503         /* sv_dup over the args */
 504         {
 505           AV* params = (AV*) SvRV(thread->params);
 506           CLONE_PARAMS clone_params;
 507           clone_params.stashes = newAV();
 508           PL_ptr_table = ptr_table_new();
 509           retparam = (AV*) sv_dup((SV*)params, &clone_params);
 510           SvREFCNT_dec(clone_params.stashes);
 511           SvREFCNT_inc(retparam);
 512           ptr_table_free(PL_ptr_table);
 513           PL_ptr_table = NULL;
 514
 515         }
 516         /* We have finished with it */
 517         thread->state |= PERL_ITHR_JOINED;
 518         MUTEX_UNLOCK(&thread->mutex);
 519         return retparam;
 520     }
 521     return (AV*)NULL;
 522 }
 523
 524 void
 525 Perl_ithread_DESTROY(pTHX_ SV *sv)
 526 {
 527     ithread *thread = SV_to_ithread(aTHX_ sv);
 528     sv_unmagic(SvRV(sv),PERL_MAGIC_shared_scalar);
 529 }
 530
 531 #endif /* USE_ITHREADS */
 532
 533 MODULE = threads                PACKAGE = threads       PREFIX = ithread_
 534 PROTOTYPES: DISABLE
 535
 536 #ifdef USE_ITHREADS
 537
 538 void
 539 ithread_new (classname, function_to_call, ...)
 540 char *  classname
 541 SV *    function_to_call
 542 CODE:
 543 {
 544     AV* params = newAV();
 545     if (items > 2) {
 546         int i;
 547         for(i = 2; i < items ; i++) {
 548             av_push(params, SvREFCNT_inc(ST(i)));
 549         }
 550     }
 551     ST(0) = sv_2mortal(Perl_ithread_create(aTHX_ Nullsv, classname, function_to_call, newRV_noinc((SV*) params)));
 552     XSRETURN(1);
 553 }
 554
 555 void
 556 ithread_self(char *classname)
 557 CODE:
 558 {
 559         ST(0) = sv_2mortal(Perl_ithread_self(aTHX_ Nullsv,classname));
 560         XSRETURN(1);
 561 }
 562
 563 int
 564 ithread_tid(ithread *thread)
 565
 566 void
 567 ithread_join(SV *obj)
 568 PPCODE:
 569 {
 570   AV* params = Perl_ithread_join(aTHX_ obj);
 571   int i;
 572   I32 len = AvFILL(params);
 573   for (i = 0; i <= len; i++) {
 574     SV* tmp = av_shift(params);
 575     XPUSHs(tmp);
 576     sv_2mortal(tmp);
 577   }
 578   SvREFCNT_dec(params);
 579 }
 580
 581 void
 582 ithread_yield(ithread *thread)
 583
 584 void
 585 ithread_detach(ithread *thread)
 586
 587 void
 588 ithread_DESTROY(SV *thread)
 589
 590 #endif /* USE_ITHREADS */
 591
 592 BOOT:
 593 {
 594 #ifdef USE_ITHREADS
 595         ithread* thread;
 596         PL_perl_destruct_level = 2;
 597         PERL_THREAD_ALLOC_SPECIFIC(self_key);
 598         MUTEX_INIT(&create_destruct_mutex);
 599         MUTEX_LOCK(&create_destruct_mutex);
 600         PL_threadhook = &Perl_ithread_hook;
 601         thread  = PerlMemShared_malloc(sizeof(ithread));
 602         Zero(thread,1,ithread);
 603         PL_perl_destruct_level = 2;
 604         MUTEX_INIT(&thread->mutex);
 605         threads = thread;
 606         thread->next = thread;
 607         thread->prev = thread;
 608         thread->interp = aTHX;
 609         thread->count  = 1;  /* imortal */
 610         thread->tid = tid_counter++;
 611         known_threads++;
 612         active_threads++;
 613         thread->state = 1;
 614 #ifdef WIN32
 615         thread->thr = GetCurrentThreadId();
 616 #else
 617         thread->thr = pthread_self();
 618 #endif
 619
 620         PERL_THREAD_SETSPECIFIC(self_key,thread);
 621         MUTEX_UNLOCK(&create_destruct_mutex);
 622 #endif /* USE_ITHREADS */
 623 }
 624