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        MUTEX_UNLOCK(&thread->mutex);
 202     }
 203     else {
 204         MUTEX_UNLOCK(&thread->mutex);
 205     }
 206     return 0;
 207 }
 208
 209 int
 210 ithread_mg_dup(pTHX_ MAGIC *mg, CLONE_PARAMS *param)
 211 {
 212     ithread *thread = (ithread *) mg->mg_ptr;
 213     MUTEX_LOCK(&thread->mutex);
 214     thread->count++;
 215     MUTEX_UNLOCK(&thread->mutex);
 216     return 0;
 217 }
 218
 219 MGVTBL ithread_vtbl = {
 220  ithread_mg_get,        /* get */
 221  0,                     /* set */
 222  0,                     /* len */
 223  0,                     /* clear */
 224  ithread_mg_free,       /* free */
 225  0,                     /* copy */
 226  ithread_mg_dup         /* dup */
 227 };
 228
 229
 230 /*
 231  *      Starts executing the thread. Needs to clean up memory a tad better.
 232  *      Passed as the C level function to run in the new thread
 233  */
 234
 235 #ifdef WIN32
 236 THREAD_RET_TYPE
 237 Perl_ithread_run(LPVOID arg) {
 238 #else
 239 void*
 240 Perl_ithread_run(void * arg) {
 241 #endif
 242         ithread* thread = (ithread*) arg;
 243         dTHXa(thread->interp);
 244         PERL_SET_CONTEXT(thread->interp);
 245         PERL_THREAD_SETSPECIFIC(self_key,thread);
 246
 247 #if 0
 248         /* Far from clear messing with ->thr child-side is a good idea */
 249         MUTEX_LOCK(&thread->mutex);
 250 #ifdef WIN32
 251         thread->thr = GetCurrentThreadId();
 252 #else
 253         thread->thr = pthread_self();
 254 #endif
 255         MUTEX_UNLOCK(&thread->mutex);
 256 #endif
 257
 258         PL_perl_destruct_level = 2;
 259
 260         {
 261                 AV* params = (AV*) SvRV(thread->params);
 262                 I32 len = av_len(params)+1;
 263                 int i;
 264                 dSP;
 265                 ENTER;
 266                 SAVETMPS;
 267                 PUSHMARK(SP);
 268                 for(i = 0; i < len; i++) {
 269                     XPUSHs(av_shift(params));
 270                 }
 271                 PUTBACK;
 272                 len = call_sv(thread->init_function, thread->gimme|G_EVAL);
 273                 SPAGAIN;
 274                 for (i=len-1; i >= 0; i--) {
 275                   SV *sv = POPs;
 276                   av_store(params, i, SvREFCNT_inc(sv));
 277                 }
 278                 PUTBACK;
 279                 if (SvTRUE(ERRSV)) {
 280                     Perl_warn(aTHX_ "Died:%_",ERRSV);
 281                 }
 282                 FREETMPS;
 283                 LEAVE;
 284                 SvREFCNT_dec(thread->init_function);
 285         }
 286
 287         PerlIO_flush((PerlIO*)NULL);
 288         MUTEX_LOCK(&create_destruct_mutex);
 289         active_threads--;
 290         assert( active_threads >= 0 );
 291         MUTEX_UNLOCK(&create_destruct_mutex);
 292         MUTEX_LOCK(&thread->mutex);
 293         thread->state |= PERL_ITHR_FINISHED;
 294
 295         if (thread->state & PERL_ITHR_DETACHED) {
 296                 MUTEX_UNLOCK(&thread->mutex);
 297                 Perl_ithread_destruct(aTHX_ thread, "detached finish");
 298         } else {
 299                 MUTEX_UNLOCK(&thread->mutex);
 300         }
 301 #ifdef WIN32
 302         return (DWORD)0;
 303 #else
 304         return 0;
 305 #endif
 306 }
 307
 308 SV *
 309 ithread_to_SV(pTHX_ SV *obj, ithread *thread, char *classname, bool inc)
 310 {
 311     SV *sv;
 312     MAGIC *mg;
 313     if (inc) {
 314         MUTEX_LOCK(&thread->mutex);
 315         thread->count++;
 316         MUTEX_UNLOCK(&thread->mutex);
 317     }
 318     if (!obj)
 319      obj = newSV(0);
 320     sv = newSVrv(obj,classname);
 321     sv_setiv(sv,PTR2IV(thread));
 322     mg = sv_magicext(sv,Nullsv,PERL_MAGIC_shared_scalar,&ithread_vtbl,(char *)thread,0);
 323     mg->mg_flags |= MGf_DUP;
 324     SvREADONLY_on(sv);
 325     return obj;
 326 }
 327
 328 ithread *
 329 SV_to_ithread(pTHX_ SV *sv)
 330 {
 331     ithread *thread;
 332     if (SvROK(sv))
 333      {
 334       thread = INT2PTR(ithread*, SvIV(SvRV(sv)));
 335      }
 336     else
 337      {
 338       PERL_THREAD_GETSPECIFIC(self_key,thread);
 339      }
 340     return thread;
 341 }
 342
 343 /*
 344  * iThread->create(); ( aka iThread->new() )
 345  * Called in context of parent thread
 346  */
 347
 348 SV *
 349 Perl_ithread_create(pTHX_ SV *obj, char* classname, SV* init_function, SV* params)
 350 {
 351         ithread*        thread;
 352         CLONE_PARAMS    clone_param;
 353
 354         MUTEX_LOCK(&create_destruct_mutex);
 355         thread = PerlMemShared_malloc(sizeof(ithread));
 356         Zero(thread,1,ithread);
 357         thread->next = threads;
 358         thread->prev = threads->prev;
 359         threads->prev = thread;
 360         thread->prev->next = thread;
 361         /* Set count to 1 immediately in case thread exits before
 362          * we return to caller !
 363          */
 364         thread->count = 1;
 365         MUTEX_INIT(&thread->mutex);
 366         thread->tid = tid_counter++;
 367         thread->gimme = GIMME_V;
 368         thread->state = (thread->gimme == G_VOID) ? 1 : 0;
 369
 370         /* "Clone" our interpreter into the thread's interpreter
 371          * This gives thread access to "static data" and code.
 372          */
 373
 374         PerlIO_flush((PerlIO*)NULL);
 375
 376 #ifdef WIN32
 377         thread->interp = perl_clone(aTHX, CLONEf_KEEP_PTR_TABLE | CLONEf_CLONE_HOST);
 378 #else
 379         thread->interp = perl_clone(aTHX, CLONEf_KEEP_PTR_TABLE);
 380 #endif
 381         /* perl_clone leaves us in new interpreter's context.
 382            As it is tricky to spot implcit aTHX create a new scope
 383            with aTHX matching the context for the duration of
 384            our work for new interpreter.
 385          */
 386         {
 387             dTHXa(thread->interp);
 388             /* Here we remove END blocks since they should only run
 389                in the thread they are created
 390             */
 391             SvREFCNT_dec(PL_endav);
 392             PL_endav = newAV();
 393             clone_param.flags = 0;
 394             thread->init_function = sv_dup(init_function, &clone_param);
 395             if (SvREFCNT(thread->init_function) == 0) {
 396                 SvREFCNT_inc(thread->init_function);
 397             }
 398
 399             thread->params = sv_dup(params, &clone_param);
 400             SvREFCNT_inc(thread->params);
 401             SvTEMP_off(thread->init_function);
 402             ptr_table_free(PL_ptr_table);
 403             PL_ptr_table = NULL;
 404         }
 405
 406         PERL_SET_CONTEXT(aTHX);
 407
 408         /* Start the thread */
 409
 410 #ifdef WIN32
 411
 412         thread->handle = CreateThread(NULL, 0, Perl_ithread_run,
 413                         (LPVOID)thread, 0, &thread->thr);
 414
 415 #else
 416         {
 417           static pthread_attr_t attr;
 418           static int attr_inited = 0;
 419           static int attr_joinable = PTHREAD_CREATE_JOINABLE;
 420           if (!attr_inited) {
 421             attr_inited = 1;
 422             pthread_attr_init(&attr);
 423           }
 424 #  ifdef PTHREAD_ATTR_SETDETACHSTATE
 425             PTHREAD_ATTR_SETDETACHSTATE(&attr, attr_joinable);
 426 #  endif
 427 #  ifdef THREAD_CREATE_NEEDS_STACK
 428             if(pthread_attr_setstacksize(&attr, THREAD_CREATE_NEEDS_STACK))
 429               croak("panic: pthread_attr_setstacksize failed");
 430 #  endif
 431
 432 #ifdef OLD_PTHREADS_API
 433           pthread_create( &thread->thr, attr, Perl_ithread_run, (void *)thread);
 434 #else
 435           pthread_create( &thread->thr, &attr, Perl_ithread_run, (void *)thread);
 436 #endif
 437         }
 438 #endif
 439         known_threads++;
 440         active_threads++;
 441         MUTEX_UNLOCK(&create_destruct_mutex);
 442         sv_2mortal(params);
 443         return ithread_to_SV(aTHX_ obj, thread, classname, FALSE);
 444 }
 445
 446 SV*
 447 Perl_ithread_self (pTHX_ SV *obj, char* Class)
 448 {
 449     ithread *thread;
 450     PERL_THREAD_GETSPECIFIC(self_key,thread);
 451     return ithread_to_SV(aTHX_ obj, thread, Class, TRUE);
 452 }
 453
 454 /*
 455  * Joins the thread this code needs to take the returnvalue from the
 456  * call_sv and send it back
 457  */
 458
 459 void
 460 Perl_ithread_CLONE(pTHX_ SV *obj)
 461 {
 462  if (SvROK(obj))
 463   {
 464    ithread *thread = SV_to_ithread(aTHX_ obj);
 465   }
 466  else
 467   {
 468    Perl_warn(aTHX_ "CLONE %_",obj);
 469   }
 470 }
 471
 472 AV*
 473 Perl_ithread_join(pTHX_ SV *obj)
 474 {
 475     ithread *thread = SV_to_ithread(aTHX_ obj);
 476     MUTEX_LOCK(&thread->mutex);
 477     if (thread->state & PERL_ITHR_DETACHED) {
 478         MUTEX_UNLOCK(&thread->mutex);
 479         Perl_croak(aTHX_ "Cannot join a detached thread");
 480     }
 481     else if (thread->state & PERL_ITHR_JOINED) {
 482         MUTEX_UNLOCK(&thread->mutex);
 483         Perl_croak(aTHX_ "Thread already joined");
 484     }
 485     else {
 486         AV* retparam;
 487 #ifdef WIN32
 488         DWORD waitcode;
 489 #else
 490         void *retval;
 491 #endif
 492         MUTEX_UNLOCK(&thread->mutex);
 493 #ifdef WIN32
 494         waitcode = WaitForSingleObject(thread->handle, INFINITE);
 495 #else
 496         pthread_join(thread->thr,&retval);
 497 #endif
 498         MUTEX_LOCK(&thread->mutex);
 499
 500         /* sv_dup over the args */
 501         {
 502           AV* params = (AV*) SvRV(thread->params);
 503           CLONE_PARAMS clone_params;
 504           clone_params.stashes = newAV();
 505           PL_ptr_table = ptr_table_new();
 506           retparam = (AV*) sv_dup((SV*)params, &clone_params);
 507           SvREFCNT_dec(clone_params.stashes);
 508           SvREFCNT_inc(retparam);
 509           ptr_table_free(PL_ptr_table);
 510           PL_ptr_table = NULL;
 511
 512         }
 513         /* We have finished with it */
 514         thread->state |= PERL_ITHR_JOINED;
 515         MUTEX_UNLOCK(&thread->mutex);
 516         return retparam;
 517     }
 518     return (AV*)NULL;
 519 }
 520
 521 void
 522 Perl_ithread_DESTROY(pTHX_ SV *sv)
 523 {
 524     ithread *thread = SV_to_ithread(aTHX_ sv);
 525     sv_unmagic(SvRV(sv),PERL_MAGIC_shared_scalar);
 526 }
 527
 528 #endif /* USE_ITHREADS */
 529
 530 MODULE = threads                PACKAGE = threads       PREFIX = ithread_
 531 PROTOTYPES: DISABLE
 532
 533 #ifdef USE_ITHREADS
 534
 535 void
 536 ithread_new (classname, function_to_call, ...)
 537 char *  classname
 538 SV *    function_to_call
 539 CODE:
 540 {
 541     AV* params = newAV();
 542     if (items > 2) {
 543         int i;
 544         for(i = 2; i < items ; i++) {
 545             av_push(params, SvREFCNT_inc(ST(i)));
 546         }
 547     }
 548     ST(0) = sv_2mortal(Perl_ithread_create(aTHX_ Nullsv, classname, function_to_call, newRV_noinc((SV*) params)));
 549     XSRETURN(1);
 550 }
 551
 552 void
 553 ithread_self(char *classname)
 554 CODE:
 555 {
 556         ST(0) = sv_2mortal(Perl_ithread_self(aTHX_ Nullsv,classname));
 557         XSRETURN(1);
 558 }
 559
 560 int
 561 ithread_tid(ithread *thread)
 562
 563 void
 564 ithread_join(SV *obj)
 565 PPCODE:
 566 {
 567   AV* params = Perl_ithread_join(aTHX_ obj);
 568   int i;
 569   I32 len = AvFILL(params);
 570   for (i = 0; i <= len; i++) {
 571     SV* tmp = av_shift(params);
 572     XPUSHs(tmp);
 573     sv_2mortal(tmp);
 574   }
 575   SvREFCNT_dec(params);
 576 }
 577
 578 void
 579 ithread_yield(ithread *thread)
 580
 581 void
 582 ithread_detach(ithread *thread)
 583
 584 void
 585 ithread_DESTROY(SV *thread)
 586
 587 #endif /* USE_ITHREADS */
 588
 589 BOOT:
 590 {
 591 #ifdef USE_ITHREADS
 592         ithread* thread;
 593         PL_perl_destruct_level = 2;
 594         PERL_THREAD_ALLOC_SPECIFIC(self_key);
 595         MUTEX_INIT(&create_destruct_mutex);
 596         MUTEX_LOCK(&create_destruct_mutex);
 597         PL_threadhook = &Perl_ithread_hook;
 598         thread  = PerlMemShared_malloc(sizeof(ithread));
 599         Zero(thread,1,ithread);
 600         PL_perl_destruct_level = 2;
 601         MUTEX_INIT(&thread->mutex);
 602         threads = thread;
 603         thread->next = thread;
 604         thread->prev = thread;
 605         thread->interp = aTHX;
 606         thread->count  = 1;  /* imortal */
 607         thread->tid = tid_counter++;
 608         known_threads++;
 609         active_threads++;
 610         thread->state = 1;
 611 #ifdef WIN32
 612         thread->thr = GetCurrentThreadId();
 613 #else
 614         thread->thr = pthread_self();
 615 #endif
 616
 617         PERL_THREAD_SETSPECIFIC(self_key,thread);
 618         MUTEX_UNLOCK(&create_destruct_mutex);
 619 #endif /* USE_ITHREADS */
 620 }
 621