ext/threads/shared/shared.xs

   1 /*    shared.xs
   2  *
   3  *    Copyright (c) 2001-2002, Larry Wall
   4  *
   5  *    You may distribute under the terms of either the GNU General Public
   6  *    License or the Artistic License, as specified in the README file.
   7  *
   8  * "Hand any two wizards a piece of rope and they would instinctively pull in
   9  * opposite directions."
  10  *                         --Sourcery
  11  *
  12  * Contributed by Arthur Bergman arthur@contiller.se
  13  * pulled in the (an)other direction by Nick Ing-Simmons nick@ing-simmons.net
  14  */
  15
  16 #define PERL_NO_GET_CONTEXT
  17 #include "EXTERN.h"
  18 #include "perl.h"
  19 #include "XSUB.h"
  20
  21 #ifdef USE_ITHREADS
  22
  23 #define SHAREDSvPTR(a)      ((a)->sv)
  24
  25 /*
  26  * The shared things need an intepreter to live in ...
  27  */
  28 PerlInterpreter *PL_sharedsv_space;             /* The shared sv space */
  29 /* To access shared space we fake aTHX in this scope and thread's context */
  30
  31 /* bug #24255: we include ENTER+SAVETMPS/FREETMPS+LEAVE with
  32  * SHARED_CONTEXT/CALLER_CONTEXT macros, so that any mortals etc created
  33  * while in the shared interpreter context don't languish */
  34
  35 #define SHARED_CONTEXT \
  36     STMT_START {                                        \
  37         PERL_SET_CONTEXT((aTHX = PL_sharedsv_space));   \
  38         ENTER;                                          \
  39         SAVETMPS;                                       \
  40     } STMT_END
  41
  42 /* So we need a way to switch back to the caller's context... */
  43 /* So we declare _another_ copy of the aTHX variable ... */
  44 #define dTHXc PerlInterpreter *caller_perl = aTHX
  45
  46 /* and use it to switch back */
  47 #define CALLER_CONTEXT                                  \
  48     STMT_START {                                        \
  49         FREETMPS;                                       \
  50         LEAVE;                                          \
  51         PERL_SET_CONTEXT((aTHX = caller_perl));         \
  52     } STMT_END
  53
  54 /*
  55  * Only one thread at a time is allowed to mess with shared space.
  56  */
  57
  58 typedef struct
  59 {
  60  perl_mutex              mutex;
  61  PerlInterpreter        *owner;
  62  I32                     locks;
  63  perl_cond               cond;
  64 #ifdef DEBUG_LOCKS
  65  char *                  file;
  66  int                     line;
  67 #endif
  68 } recursive_lock_t;
  69
  70 recursive_lock_t PL_sharedsv_lock;       /* Mutex protecting the shared sv space */
  71
  72 void
  73 recursive_lock_init(pTHX_ recursive_lock_t *lock)
  74 {
  75     Zero(lock,1,recursive_lock_t);
  76     MUTEX_INIT(&lock->mutex);
  77     COND_INIT(&lock->cond);
  78 }
  79
  80 void
  81 recursive_lock_destroy(pTHX_ recursive_lock_t *lock)
  82 {
  83     MUTEX_DESTROY(&lock->mutex);
  84     COND_DESTROY(&lock->cond);
  85 }
  86
  87 void
  88 recursive_lock_release(pTHX_ recursive_lock_t *lock)
  89 {
  90     MUTEX_LOCK(&lock->mutex);
  91     if (lock->owner != aTHX) {
  92         MUTEX_UNLOCK(&lock->mutex);
  93     }
  94     else {
  95         if (--lock->locks == 0) {
  96             lock->owner = NULL;
  97             COND_SIGNAL(&lock->cond);
  98         }
  99     }
 100     MUTEX_UNLOCK(&lock->mutex);
 101 }
 102
 103 void
 104 recursive_lock_acquire(pTHX_ recursive_lock_t *lock,char *file,int line)
 105 {
 106     assert(aTHX);
 107     MUTEX_LOCK(&lock->mutex);
 108     if (lock->owner == aTHX) {
 109         lock->locks++;
 110     }
 111     else {
 112         while (lock->owner) {
 113 #ifdef DEBUG_LOCKS
 114             Perl_warn(aTHX_ " %p waiting - owned by %p %s:%d\n",
 115                       aTHX, lock->owner, lock->file, lock->line);
 116 #endif
 117             COND_WAIT(&lock->cond,&lock->mutex);
 118         }
 119         lock->locks = 1;
 120         lock->owner = aTHX;
 121 #ifdef DEBUG_LOCKS
 122         lock->file  = file;
 123         lock->line  = line;
 124 #endif
 125     }
 126     MUTEX_UNLOCK(&lock->mutex);
 127     SAVEDESTRUCTOR_X(recursive_lock_release,lock);
 128 }
 129
 130 #define ENTER_LOCK         STMT_START { \
 131                               ENTER; \
 132                               recursive_lock_acquire(aTHX_ &PL_sharedsv_lock, __FILE__, __LINE__);   \
 133                             } STMT_END
 134
 135 #define LEAVE_LOCK       LEAVE
 136
 137
 138 /* A common idiom is to acquire access and switch in ... */
 139 #define SHARED_EDIT         STMT_START {        \
 140                                 ENTER_LOCK;     \
 141                                 SHARED_CONTEXT; \
 142                             } STMT_END
 143
 144 /* then switch out and release access. */
 145 #define SHARED_RELEASE     STMT_START { \
 146                                 CALLER_CONTEXT; \
 147                                 LEAVE_LOCK;     \
 148                             } STMT_END
 149
 150
 151 /*
 152
 153   Shared SV
 154
 155   Shared SV is a structure for keeping the backend storage
 156   of shared svs.
 157
 158   Shared-ness really only needs the SV * - the rest is for locks.
 159   (Which suggests further space optimization ... )
 160
 161 */
 162
 163 typedef struct {
 164     SV                 *sv;             /* The actual SV - in shared space */
 165     recursive_lock_t    lock;
 166     perl_cond           user_cond;      /* For user-level conditions */
 167 } shared_sv;
 168
 169 /* The SV in shared-space has a back-pointer to the shared_sv
 170    struct associated with it PERL_MAGIC_ext.
 171
 172    The vtable used has just one entry - when the SV goes away
 173    we free the memory for the above.
 174
 175  */
 176
 177 int
 178 sharedsv_shared_mg_free(pTHX_ SV *sv, MAGIC *mg)
 179 {
 180     shared_sv *shared = (shared_sv *) mg->mg_ptr;
 181     assert( aTHX == PL_sharedsv_space );
 182     if (shared) {
 183         recursive_lock_destroy(aTHX_ &shared->lock);
 184         COND_DESTROY(&shared->user_cond);
 185         PerlMemShared_free(shared);
 186         mg->mg_ptr = NULL;
 187     }
 188     return 0;
 189 }
 190
 191 MGVTBL sharedsv_shared_vtbl = {
 192  0,                             /* get */
 193  0,                             /* set */
 194  0,                             /* len */
 195  0,                             /* clear */
 196  sharedsv_shared_mg_free,       /* free */
 197  0,                             /* copy */
 198  0,                             /* dup */
 199  0                              /* local */
 200 };
 201
 202 /* Access to shared things is heavily based on MAGIC - in mg.h/mg.c/sv.c sense */
 203
 204 /* In any thread that has access to a shared thing there is a "proxy"
 205    for it in its own space which has 'MAGIC' associated which accesses
 206    the shared thing.
 207  */
 208
 209 MGVTBL sharedsv_scalar_vtbl;    /* scalars have this vtable */
 210 MGVTBL sharedsv_array_vtbl;     /* hashes and arrays have this - like 'tie' */
 211 MGVTBL sharedsv_elem_vtbl;      /* elements of hashes and arrays have this
 212                                    _AS WELL AS_ the scalar magic */
 213
 214 /* The sharedsv_elem_vtbl associates the element with the array/hash and
 215    the sharedsv_scalar_vtbl associates it with the value
 216  */
 217
 218
 219 /* Accessor to convert threads::shared::tie objects back shared_sv * */
 220 shared_sv *
 221 SV_to_sharedsv(pTHX_ SV *sv)
 222 {
 223     shared_sv *shared = 0;
 224     if (SvROK(sv))
 225      {
 226       shared = INT2PTR(shared_sv *, SvIV(SvRV(sv)));
 227      }
 228     return shared;
 229 }
 230
 231 =for apidoc sharedsv_find
 232
 233 Given a private side SV tries to find if the SV has a shared backend,
 234 by looking for the magic.
 235
 236 =cut
 237
 238 shared_sv *
 239 Perl_sharedsv_find(pTHX_ SV *sv)
 240 {
 241     MAGIC *mg;
 242     if (SvTYPE(sv) >= SVt_PVMG) {
 243         switch(SvTYPE(sv)) {
 244         case SVt_PVAV:
 245         case SVt_PVHV:
 246             if ((mg = mg_find(sv, PERL_MAGIC_tied))
 247                 && mg->mg_virtual == &sharedsv_array_vtbl) {
 248                 return (shared_sv *) mg->mg_ptr;
 249             }
 250             break;
 251         default:
 252             /* This should work for elements as well as they
 253              * have scalar magic as well as their element magic
 254              */
 255             if ((mg = mg_find(sv, PERL_MAGIC_shared_scalar))
 256                 && mg->mg_virtual == &sharedsv_scalar_vtbl) {
 257                 return (shared_sv *) mg->mg_ptr;
 258             }
 259             break;
 260         }
 261     }
 262     /* Just for tidyness of API also handle tie objects */
 263     if (SvROK(sv) && sv_derived_from(sv, "threads::shared::tie")) {
 264         return SV_to_sharedsv(aTHX_ sv);
 265     }
 266     return NULL;
 267 }
 268
 269 /*
 270  *  Almost all the pain is in this routine.
 271  *
 272  */
 273
 274 shared_sv *
 275 Perl_sharedsv_associate(pTHX_ SV **psv, SV *ssv, shared_sv *data)
 276 {
 277     dTHXc;
 278     MAGIC *mg = 0;
 279     SV *sv    = (psv) ? *psv : Nullsv;
 280
 281     /* If we are asked for an private ops we need a thread */
 282     assert ( aTHX !=  PL_sharedsv_space );
 283
 284     /* To avoid need for recursive locks require caller to hold lock */
 285     assert ( PL_sharedsv_lock.owner == aTHX );
 286
 287     /* First try and get existing global data structure */
 288
 289     /* Try shared SV as 1st choice */
 290     if (!data && ssv && SvTYPE(ssv) >= SVt_PVMG) {
 291         if( (mg = mg_find(ssv, PERL_MAGIC_ext)) ){
 292             data = (shared_sv *) mg->mg_ptr;
 293         }
 294     }
 295
 296     /* Next see if private SV is associated with something */
 297     if (!data && sv) {
 298         data = Perl_sharedsv_find(aTHX_ sv);
 299     }
 300
 301     /* If neither of those then create a new one */
 302     if (!data) {
 303             SHARED_CONTEXT;
 304             if (!ssv) {
 305                 ssv = newSV(0);
 306                 SvREFCNT(ssv) = 0;
 307             }
 308             data = (shared_sv *) PerlMemShared_malloc(sizeof(shared_sv));
 309             Zero(data,1,shared_sv);
 310             SHAREDSvPTR(data) = ssv;
 311             /* Tag shared side SV with data pointer */
 312             sv_magicext(ssv, ssv, PERL_MAGIC_ext, &sharedsv_shared_vtbl,
 313                    (char *)data, 0);
 314             recursive_lock_init(aTHX_ &data->lock);
 315             COND_INIT(&data->user_cond);
 316             CALLER_CONTEXT;
 317     }
 318
 319     if (!ssv)
 320         ssv = SHAREDSvPTR(data);
 321     if (!SHAREDSvPTR(data))
 322         SHAREDSvPTR(data) = ssv;
 323
 324     /* If we know type upgrade shared side SV */
 325     if (sv && SvTYPE(ssv) < SvTYPE(sv)) {
 326         SHARED_CONTEXT;
 327         sv_upgrade(ssv, SvTYPE(*psv));
 328         if (SvTYPE(ssv) == SVt_PVAV)    /* #24061 */
 329             AvREAL_on(ssv);
 330         CALLER_CONTEXT;
 331     }
 332
 333     /* Now if requested allocate private SV */
 334     if (psv && !sv) {
 335         *psv = sv = newSV(0);
 336     }
 337
 338     /* Finally if private SV exists check and add magic */
 339     if (sv) {
 340         MAGIC *mg = 0;
 341         if (SvTYPE(sv) < SvTYPE(ssv)) {
 342             sv_upgrade(sv, SvTYPE(ssv));
 343         }
 344         switch(SvTYPE(sv)) {
 345         case SVt_PVAV:
 346         case SVt_PVHV:
 347             if (!(mg = mg_find(sv, PERL_MAGIC_tied))
 348                 || mg->mg_virtual != &sharedsv_array_vtbl
 349                 || (shared_sv *) mg->mg_ptr != data) {
 350                 SV *obj = newSV(0);
 351                 sv_setref_iv(obj, "threads::shared::tie",PTR2IV(data));
 352                 if (mg) {
 353                     sv_unmagic(sv, PERL_MAGIC_tied);
 354                 }
 355                 mg = sv_magicext(sv, obj, PERL_MAGIC_tied, &sharedsv_array_vtbl,
 356                                 (char *) data, 0);
 357                 mg->mg_flags |= (MGf_COPY|MGf_DUP);
 358                 SvREFCNT_inc(ssv);
 359                 SvREFCNT_dec(obj);
 360                 if(SvOBJECT(ssv)) {
 361                   STRLEN len;
 362                   char* stash_ptr = SvPV((SV*) SvSTASH(ssv), len);
 363                   HV* stash = gv_stashpvn(stash_ptr, len, TRUE);
 364                   SvOBJECT_on(sv);
 365                   SvSTASH_set(sv, (HV*)SvREFCNT_inc(stash));
 366                 }
 367             }
 368             break;
 369
 370         default:
 371             if ((SvTYPE(sv) < SVt_PVMG)
 372                 || !(mg = mg_find(sv, PERL_MAGIC_shared_scalar))
 373                 || mg->mg_virtual != &sharedsv_scalar_vtbl
 374                 || (shared_sv *) mg->mg_ptr != data) {
 375                 if (mg) {
 376                     sv_unmagic(sv, PERL_MAGIC_shared_scalar);
 377                 }
 378                 mg = sv_magicext(sv, Nullsv, PERL_MAGIC_shared_scalar,
 379                                 &sharedsv_scalar_vtbl, (char *)data, 0);
 380                 mg->mg_flags |= (MGf_COPY|MGf_DUP|MGf_LOCAL);
 381                 SvREFCNT_inc(ssv);
 382                 if(SvOBJECT(ssv)) {
 383                   STRLEN len;
 384                   char* stash_ptr = SvPV((SV*) SvSTASH(ssv), len);
 385                   HV* stash = gv_stashpvn(stash_ptr, len, TRUE);
 386                   SvOBJECT_on(sv);
 387                   SvSTASH_set(sv, (HV*)SvREFCNT_inc(stash));
 388                 }
 389             }
 390             break;
 391         }
 392         assert ( Perl_sharedsv_find(aTHX_ *psv) == data );
 393     }
 394     return data;
 395 }
 396
 397 void
 398 Perl_sharedsv_free(pTHX_ shared_sv *shared)
 399 {
 400     if (shared) {
 401         dTHXc;
 402         SHARED_EDIT;
 403         SvREFCNT_dec(SHAREDSvPTR(shared));
 404         SHARED_RELEASE;
 405     }
 406 }
 407
 408 void
 409 Perl_sharedsv_share(pTHX_ SV *sv)
 410 {
 411     switch(SvTYPE(sv)) {
 412     case SVt_PVGV:
 413         Perl_croak(aTHX_ "Cannot share globs yet");
 414         break;
 415
 416     case SVt_PVCV:
 417         Perl_croak(aTHX_ "Cannot share subs yet");
 418         break;
 419
 420     default:
 421         ENTER_LOCK;
 422         Perl_sharedsv_associate(aTHX_ &sv, 0, 0);
 423         LEAVE_LOCK;
 424         SvSETMAGIC(sv);
 425         break;
 426     }
 427 }
 428
 429 #if defined(WIN32) || defined(OS2)
 430 #  define ABS2RELMILLI(abs)        \
 431     do {                                \
 432         abs -= (double)time(NULL);      \
 433         if (abs > 0) { abs *= 1000; }   \
 434         else         { abs  = 0;    }   \
 435     } while (0)
 436 #endif /* WIN32 || OS2 */
 437
 438 bool
 439 Perl_sharedsv_cond_timedwait(perl_cond *cond, perl_mutex *mut, double abs)
 440 {
 441 #if defined(NETWARE) || defined(FAKE_THREADS) || defined(I_MACH_CTHREADS)
 442     Perl_croak_nocontext("cond_timedwait not supported on this platform");
 443 #else
 444 #  ifdef WIN32
 445     int got_it = 0;
 446
 447     ABS2RELMILLI(abs);
 448
 449     cond->waiters++;
 450     MUTEX_UNLOCK(mut);
 451     /* See comments in win32/win32thread.h COND_WAIT vis-a-vis race */
 452     switch (WaitForSingleObject(cond->sem, (DWORD)abs)) {
 453         case WAIT_OBJECT_0:   got_it = 1; break;
 454         case WAIT_TIMEOUT:                break;
 455         default:
 456             /* WAIT_FAILED? WAIT_ABANDONED? others? */
 457             Perl_croak_nocontext("panic: cond_timedwait (%ld)",GetLastError());
 458             break;
 459     }
 460     MUTEX_LOCK(mut);
 461     cond->waiters--;
 462     return got_it;
 463 #  else
 464 #    ifdef OS2
 465     int rc, got_it = 0;
 466     STRLEN n_a;
 467
 468     ABS2RELMILLI(abs);
 469
 470     if ((rc = DosResetEventSem(*cond,&n_a)) && (rc != ERROR_ALREADY_RESET))
 471         Perl_rc = rc, croak_with_os2error("panic: cond_timedwait-reset");
 472     MUTEX_UNLOCK(mut);
 473     if (CheckOSError(DosWaitEventSem(*cond,abs))
 474         && (rc != ERROR_INTERRUPT))
 475         croak_with_os2error("panic: cond_timedwait");
 476     if (rc == ERROR_INTERRUPT) errno = EINTR;
 477     MUTEX_LOCK(mut);
 478     return got_it;
 479 #    else         /* hope you're I_PTHREAD! */
 480     struct timespec ts;
 481     int got_it = 0;
 482
 483     ts.tv_sec = (long)abs;
 484     abs -= (NV)ts.tv_sec;
 485     ts.tv_nsec = (long)(abs * 1000000000.0);
 486
 487     switch (pthread_cond_timedwait(cond, mut, &ts)) {
 488         case 0:         got_it = 1; break;
 489         case ETIMEDOUT:             break;
 490         default:
 491             Perl_croak_nocontext("panic: cond_timedwait");
 492             break;
 493     }
 494     return got_it;
 495 #    endif /* OS2 */
 496 #  endif /* WIN32 */
 497 #endif /* NETWARE || FAKE_THREADS || I_MACH_CTHREADS */
 498 }
 499
 500 /* MAGIC (in mg.h sense) hooks */
 501
 502 int
 503 sharedsv_scalar_mg_get(pTHX_ SV *sv, MAGIC *mg)
 504 {
 505     shared_sv *shared = (shared_sv *) mg->mg_ptr;
 506     assert(shared);
 507
 508     ENTER_LOCK;
 509     if (SHAREDSvPTR(shared)) {
 510         if (SvROK(SHAREDSvPTR(shared))) {
 511             SV *obj = Nullsv;
 512             Perl_sharedsv_associate(aTHX_ &obj, SvRV(SHAREDSvPTR(shared)), NULL);
 513             sv_setsv_nomg(sv, &PL_sv_undef);
 514             SvRV_set(sv, obj);
 515             SvROK_on(sv);
 516
 517         }
 518         else {
 519             sv_setsv_nomg(sv, SHAREDSvPTR(shared));
 520         }
 521     }
 522     LEAVE_LOCK;
 523     return 0;
 524 }
 525
 526 void
 527 sharedsv_scalar_store(pTHX_ SV *sv, shared_sv *shared)
 528 {
 529     dTHXc;
 530     bool allowed = TRUE;
 531     if (SvROK(sv)) {
 532         shared_sv* target = Perl_sharedsv_find(aTHX_ SvRV(sv));
 533         if (target) {
 534             SV *tmp;
 535             SHARED_CONTEXT;
 536             tmp = newRV(SHAREDSvPTR(target));
 537             sv_setsv_nomg(SHAREDSvPTR(shared), tmp);
 538             SvREFCNT_dec(tmp);
 539             if(SvOBJECT(SvRV(sv))) {
 540               SV* fake_stash = newSVpv(HvNAME_get(SvSTASH(SvRV(sv))),0);
 541               SvOBJECT_on(SHAREDSvPTR(target));
 542               SvSTASH_set(SHAREDSvPTR(target), (HV*)fake_stash);
 543             }
 544             CALLER_CONTEXT;
 545         }
 546         else {
 547             allowed = FALSE;
 548         }
 549     }
 550     else {
 551         SvTEMP_off(sv);
 552         SHARED_CONTEXT;
 553         sv_setsv_nomg(SHAREDSvPTR(shared), sv);
 554         if(SvOBJECT(sv)) {
 555           SV* fake_stash = newSVpv(HvNAME_get(SvSTASH(sv)),0);
 556           SvOBJECT_on(SHAREDSvPTR(shared));
 557           SvSTASH_set(SHAREDSvPTR(shared), (HV*)fake_stash);
 558         }
 559         CALLER_CONTEXT;
 560     }
 561     if (!allowed) {
 562         Perl_croak(aTHX_ "Invalid value for shared scalar");
 563     }
 564 }
 565
 566 int
 567 sharedsv_scalar_mg_set(pTHX_ SV *sv, MAGIC *mg)
 568 {
 569     shared_sv *shared;
 570     ENTER_LOCK;
 571     /* We call associate to potentially upgrade shared side SV */
 572     shared = Perl_sharedsv_associate(aTHX_ &sv, Nullsv, (shared_sv *) mg->mg_ptr);
 573     assert(shared);
 574     sharedsv_scalar_store(aTHX_ sv, shared);
 575     LEAVE_LOCK;
 576     return 0;
 577 }
 578
 579 int
 580 sharedsv_scalar_mg_free(pTHX_ SV *sv, MAGIC *mg)
 581 {
 582     shared_sv *shared = (shared_sv *) mg->mg_ptr;
 583 #if 0
 584     assert (SvREFCNT(SHAREDSvPTR(shared)) < 1000);
 585 #endif
 586     Perl_sharedsv_free(aTHX_ shared);
 587     return 0;
 588 }
 589
 590 int
 591 sharedsv_scalar_mg_clear(pTHX_ SV *sv, MAGIC *mg)
 592 {
 593     return 0;
 594 }
 595
 596 /*
 597  * Called during cloning of new threads
 598  */
 599 int
 600 sharedsv_scalar_mg_dup(pTHX_ MAGIC *mg, CLONE_PARAMS *param)
 601 {
 602     shared_sv *shared = (shared_sv *) mg->mg_ptr;
 603     if (shared) {
 604         SvREFCNT_inc(SHAREDSvPTR(shared));
 605     }
 606     return 0;
 607 }
 608
 609
 610 /*
 611  * Called during local $shared
 612  */
 613 int
 614 sharedsv_scalar_mg_local(pTHX_ SV* nsv, MAGIC *mg)
 615 {
 616     MAGIC *nmg;
 617     shared_sv *shared = (shared_sv *) mg->mg_ptr;
 618     if (shared) {
 619         ENTER_LOCK;
 620         SvREFCNT_inc(SHAREDSvPTR(shared));
 621         LEAVE_LOCK;
 622     }
 623     nmg = sv_magicext(nsv, mg->mg_obj, mg->mg_type, mg->mg_virtual,
 624                             mg->mg_ptr, mg->mg_len);
 625     nmg->mg_flags   = mg->mg_flags;
 626     nmg->mg_private = mg->mg_private;
 627
 628     return 0;
 629 }
 630
 631 MGVTBL sharedsv_scalar_vtbl = {
 632  sharedsv_scalar_mg_get,        /* get */
 633  sharedsv_scalar_mg_set,        /* set */
 634  0,                             /* len */
 635  sharedsv_scalar_mg_clear,      /* clear */
 636  sharedsv_scalar_mg_free,       /* free */
 637  0,                             /* copy */
 638  sharedsv_scalar_mg_dup,        /* dup */
 639  sharedsv_scalar_mg_local       /* local */
 640 };
 641
 642 /* Now the arrays/hashes stuff */
 643 int
 644 sharedsv_elem_mg_FETCH(pTHX_ SV *sv, MAGIC *mg)
 645 {
 646     dTHXc;
 647     shared_sv *shared = SV_to_sharedsv(aTHX_ mg->mg_obj);
 648     shared_sv *target = Perl_sharedsv_find(aTHX_ sv);
 649     SV** svp;
 650
 651     assert ( shared );
 652     assert ( SHAREDSvPTR(shared) );
 653
 654     ENTER_LOCK;
 655     if (SvTYPE(SHAREDSvPTR(shared)) == SVt_PVAV) {
 656         assert ( mg->mg_ptr == 0 );
 657         SHARED_CONTEXT;
 658         svp = av_fetch((AV*) SHAREDSvPTR(shared), mg->mg_len, 0);
 659     }
 660     else {
 661         char *key = mg->mg_ptr;
 662         STRLEN len = mg->mg_len;
 663         assert ( mg->mg_ptr != 0 );
 664         if (mg->mg_len == HEf_SVKEY) {
 665            key = SvPV((SV *) mg->mg_ptr, len);
 666         }
 667         SHARED_CONTEXT;
 668         svp = hv_fetch((HV*) SHAREDSvPTR(shared), key, len, 0);
 669     }
 670     CALLER_CONTEXT;
 671     if (svp) {
 672         /* Exists in the array */
 673         if (SvROK(*svp)) {
 674             SV *obj = Nullsv;
 675             Perl_sharedsv_associate(aTHX_ &obj, SvRV(*svp), NULL);
 676             sv_setsv_nomg(sv, &PL_sv_undef);
 677             SvRV_set(sv, obj);
 678             SvROK_on(sv);
 679             SvSETMAGIC(sv);
 680         }
 681         else {
 682             target = Perl_sharedsv_associate(aTHX_ &sv, *svp, target);
 683             sv_setsv(sv, *svp);
 684         }
 685     }
 686     else {
 687         /* Not in the array */
 688         sv_setsv(sv, &PL_sv_undef);
 689     }
 690     LEAVE_LOCK;
 691     return 0;
 692 }
 693
 694 int
 695 sharedsv_elem_mg_STORE(pTHX_ SV *sv, MAGIC *mg)
 696 {
 697     dTHXc;
 698     shared_sv *shared = SV_to_sharedsv(aTHX_ mg->mg_obj);
 699     shared_sv *target;
 700     SV **svp;
 701     /* Theory - SV itself is magically shared - and we have ordered the
 702        magic such that by the time we get here it has been stored
 703        to its shared counterpart
 704      */
 705     ENTER_LOCK;
 706     assert(shared);
 707     assert(SHAREDSvPTR(shared));
 708     if (SvTYPE(SHAREDSvPTR(shared)) == SVt_PVAV) {
 709         assert ( mg->mg_ptr == 0 );
 710         SHARED_CONTEXT;
 711         svp = av_fetch((AV*) SHAREDSvPTR(shared), mg->mg_len, 1);
 712     }
 713     else {
 714         char *key = mg->mg_ptr;
 715         STRLEN len = mg->mg_len;
 716         assert ( mg->mg_ptr != 0 );
 717         if (mg->mg_len == HEf_SVKEY)
 718            key = SvPV((SV *) mg->mg_ptr, len);
 719         SHARED_CONTEXT;
 720         svp = hv_fetch((HV*) SHAREDSvPTR(shared), key, len, 1);
 721     }
 722     CALLER_CONTEXT;
 723     target = Perl_sharedsv_associate(aTHX_ &sv, *svp, 0);
 724     sharedsv_scalar_store(aTHX_ sv, target);
 725     LEAVE_LOCK;
 726     return 0;
 727 }
 728
 729 int
 730 sharedsv_elem_mg_DELETE(pTHX_ SV *sv, MAGIC *mg)
 731 {
 732     dTHXc;
 733     MAGIC *shmg;
 734     shared_sv *shared = SV_to_sharedsv(aTHX_ mg->mg_obj);
 735     ENTER_LOCK;
 736     sharedsv_elem_mg_FETCH(aTHX_ sv, mg);
 737     if ((shmg = mg_find(sv, PERL_MAGIC_shared_scalar)))
 738         sharedsv_scalar_mg_get(aTHX_ sv, shmg);
 739     if (SvTYPE(SHAREDSvPTR(shared)) == SVt_PVAV) {
 740         SHARED_CONTEXT;
 741         av_delete((AV*) SHAREDSvPTR(shared), mg->mg_len, G_DISCARD);
 742     }
 743     else {
 744         char *key = mg->mg_ptr;
 745         STRLEN len = mg->mg_len;
 746         assert ( mg->mg_ptr != 0 );
 747         if (mg->mg_len == HEf_SVKEY)
 748            key = SvPV((SV *) mg->mg_ptr, len);
 749         SHARED_CONTEXT;
 750         hv_delete((HV*) SHAREDSvPTR(shared), key, len, G_DISCARD);
 751     }
 752     CALLER_CONTEXT;
 753     LEAVE_LOCK;
 754     return 0;
 755 }
 756
 757 int
 758 sharedsv_elem_mg_free(pTHX_ SV *sv, MAGIC *mg)
 759 {
 760     Perl_sharedsv_free(aTHX_ SV_to_sharedsv(aTHX_ mg->mg_obj));
 761     return 0;
 762 }
 763
 764 int
 765 sharedsv_elem_mg_dup(pTHX_ MAGIC *mg, CLONE_PARAMS *param)
 766 {
 767     shared_sv *shared = SV_to_sharedsv(aTHX_ mg->mg_obj);
 768     SvREFCNT_inc(SHAREDSvPTR(shared));
 769     mg->mg_flags |= MGf_DUP;
 770     return 0;
 771 }
 772
 773 MGVTBL sharedsv_elem_vtbl = {
 774  sharedsv_elem_mg_FETCH,        /* get */
 775  sharedsv_elem_mg_STORE,        /* set */
 776  0,                             /* len */
 777  sharedsv_elem_mg_DELETE,       /* clear */
 778  sharedsv_elem_mg_free,         /* free */
 779  0,                             /* copy */
 780  sharedsv_elem_mg_dup,          /* dup */
 781  0                              /* local */
 782 };
 783
 784 U32
 785 sharedsv_array_mg_FETCHSIZE(pTHX_ SV *sv, MAGIC *mg)
 786 {
 787     dTHXc;
 788     shared_sv *shared = (shared_sv *) mg->mg_ptr;
 789     U32 val;
 790     SHARED_EDIT;
 791     if (SvTYPE(SHAREDSvPTR(shared)) == SVt_PVAV) {
 792         val = av_len((AV*) SHAREDSvPTR(shared));
 793     }
 794     else {
 795         /* not actually defined by tie API but ... */
 796         val = HvKEYS((HV*) SHAREDSvPTR(shared));
 797     }
 798     SHARED_RELEASE;
 799     return val;
 800 }
 801
 802 int
 803 sharedsv_array_mg_CLEAR(pTHX_ SV *sv, MAGIC *mg)
 804 {
 805     dTHXc;
 806     shared_sv *shared = (shared_sv *) mg->mg_ptr;
 807     SHARED_EDIT;
 808     if (SvTYPE(SHAREDSvPTR(shared)) == SVt_PVAV) {
 809         av_clear((AV*) SHAREDSvPTR(shared));
 810     }
 811     else {
 812         hv_clear((HV*) SHAREDSvPTR(shared));
 813     }
 814     SHARED_RELEASE;
 815     return 0;
 816 }
 817
 818 int
 819 sharedsv_array_mg_free(pTHX_ SV *sv, MAGIC *mg)
 820 {
 821     Perl_sharedsv_free(aTHX_ (shared_sv *) mg->mg_ptr);
 822     return 0;
 823 }
 824
 825 /*
 826  * This is called when perl is about to access an element of
 827  * the array -
 828  */
 829 int
 830 sharedsv_array_mg_copy(pTHX_ SV *sv, MAGIC* mg,
 831                        SV *nsv, const char *name, int namlen)
 832 {
 833     shared_sv *shared = (shared_sv *) mg->mg_ptr;
 834     MAGIC *nmg = sv_magicext(nsv,mg->mg_obj,
 835                             toLOWER(mg->mg_type),&sharedsv_elem_vtbl,
 836                             name, namlen);
 837     ENTER_LOCK;
 838     SvREFCNT_inc(SHAREDSvPTR(shared));
 839     LEAVE_LOCK;
 840     nmg->mg_flags |= MGf_DUP;
 841     return 1;
 842 }
 843
 844 int
 845 sharedsv_array_mg_dup(pTHX_ MAGIC *mg, CLONE_PARAMS *param)
 846 {
 847     shared_sv *shared = (shared_sv *) mg->mg_ptr;
 848     SvREFCNT_inc(SHAREDSvPTR(shared));
 849     mg->mg_flags |= MGf_DUP;
 850     return 0;
 851 }
 852
 853 MGVTBL sharedsv_array_vtbl = {
 854  0,                             /* get */
 855  0,                             /* set */
 856  sharedsv_array_mg_FETCHSIZE,   /* len */
 857  sharedsv_array_mg_CLEAR,       /* clear */
 858  sharedsv_array_mg_free,        /* free */
 859  sharedsv_array_mg_copy,        /* copy */
 860  sharedsv_array_mg_dup,         /* dup */
 861  0                              /* local */
 862 };
 863
 864 =for apidoc sharedsv_unlock
 865
 866 Recursively unlocks a shared sv.
 867
 868 =cut
 869
 870 void
 871 Perl_sharedsv_unlock(pTHX_ shared_sv* ssv)
 872 {
 873     recursive_lock_release(aTHX_ &ssv->lock);
 874 }
 875
 876 =for apidoc sharedsv_lock
 877
 878 Recursive locks on a sharedsv.
 879 Locks are dynamically scoped at the level of the first lock.
 880
 881 =cut
 882
 883 void
 884 Perl_sharedsv_lock(pTHX_ shared_sv* ssv)
 885 {
 886     if (!ssv)
 887         return;
 888     recursive_lock_acquire(aTHX_ &ssv->lock, __FILE__, __LINE__);
 889 }
 890
 891 /* handles calls from lock() builtin via PL_lockhook */
 892
 893 void
 894 Perl_sharedsv_locksv(pTHX_ SV *sv)
 895 {
 896     shared_sv* shared;
 897
 898     if(SvROK(sv))
 899         sv = SvRV(sv);
 900     shared = Perl_sharedsv_find(aTHX_ sv);
 901     if(!shared)
 902        croak("lock can only be used on shared values");
 903     Perl_sharedsv_lock(aTHX_ shared);
 904 }
 905
 906 =head1 Shared SV Functions
 907
 908 =for apidoc sharedsv_init
 909
 910 Saves a space for keeping SVs wider than an interpreter,
 911
 912 =cut
 913
 914 void
 915 Perl_sharedsv_init(pTHX)
 916 {
 917   dTHXc;
 918   /* This pair leaves us in shared context ... */
 919   PL_sharedsv_space = perl_alloc();
 920   perl_construct(PL_sharedsv_space);
 921   CALLER_CONTEXT;
 922   recursive_lock_init(aTHX_ &PL_sharedsv_lock);
 923   PL_lockhook = &Perl_sharedsv_locksv;
 924   PL_sharehook = &Perl_sharedsv_share;
 925 }
 926
 927 #endif /* USE_ITHREADS */
 928
 929 MODULE = threads::shared        PACKAGE = threads::shared::tie
 930
 931 PROTOTYPES: DISABLE
 932
 933 #ifdef USE_ITHREADS
 934
 935 void
 936 PUSH(shared_sv *shared, ...)
 937 CODE:
 938         dTHXc;
 939         int i;
 940         for(i = 1; i < items; i++) {
 941             SV* tmp = newSVsv(ST(i));
 942             shared_sv *target;
 943             ENTER_LOCK;
 944             target = Perl_sharedsv_associate(aTHX_ &tmp, Nullsv, 0);
 945             sharedsv_scalar_store(aTHX_ tmp, target);
 946             SHARED_CONTEXT;
 947             av_push((AV*) SHAREDSvPTR(shared), SHAREDSvPTR(target));
 948             SvREFCNT_inc(SHAREDSvPTR(target));
 949             SHARED_RELEASE;
 950             SvREFCNT_dec(tmp);
 951         }
 952
 953 void
 954 UNSHIFT(shared_sv *shared, ...)
 955 CODE:
 956         dTHXc;
 957         int i;
 958         ENTER_LOCK;
 959         SHARED_CONTEXT;
 960         av_unshift((AV*)SHAREDSvPTR(shared), items - 1);
 961         CALLER_CONTEXT;
 962         for(i = 1; i < items; i++) {
 963             SV* tmp = newSVsv(ST(i));
 964             shared_sv *target = Perl_sharedsv_associate(aTHX_ &tmp, Nullsv, 0);
 965             sharedsv_scalar_store(aTHX_ tmp, target);
 966             SHARED_CONTEXT;
 967             av_store((AV*) SHAREDSvPTR(shared), i - 1, SHAREDSvPTR(target));
 968             SvREFCNT_inc(SHAREDSvPTR(target));
 969             CALLER_CONTEXT;
 970             SvREFCNT_dec(tmp);
 971         }
 972         LEAVE_LOCK;
 973
 974 void
 975 POP(shared_sv *shared)
 976 CODE:
 977         dTHXc;
 978         SV* sv;
 979         ENTER_LOCK;
 980         SHARED_CONTEXT;
 981         sv = av_pop((AV*)SHAREDSvPTR(shared));
 982         CALLER_CONTEXT;
 983         ST(0) = sv_newmortal();
 984         Perl_sharedsv_associate(aTHX_ &ST(0), sv, 0);
 985         SvREFCNT_dec(sv);
 986         LEAVE_LOCK;
 987         XSRETURN(1);
 988
 989 void
 990 SHIFT(shared_sv *shared)
 991 CODE:
 992         dTHXc;
 993         SV* sv;
 994         ENTER_LOCK;
 995         SHARED_CONTEXT;
 996         sv = av_shift((AV*)SHAREDSvPTR(shared));
 997         CALLER_CONTEXT;
 998         ST(0) = sv_newmortal();
 999         Perl_sharedsv_associate(aTHX_ &ST(0), sv, 0);
1000         SvREFCNT_dec(sv);
1001         LEAVE_LOCK;
1002         XSRETURN(1);
1003
1004 void
1005 EXTEND(shared_sv *shared, IV count)
1006 CODE:
1007         dTHXc;
1008         SHARED_EDIT;
1009         av_extend((AV*)SHAREDSvPTR(shared), count);
1010         SHARED_RELEASE;
1011
1012 void
1013 STORESIZE(shared_sv *shared,IV count)
1014 CODE:
1015         dTHXc;
1016         SHARED_EDIT;
1017         av_fill((AV*) SHAREDSvPTR(shared), count);
1018         SHARED_RELEASE;
1019
1020
1021
1022
1023 void
1024 EXISTS(shared_sv *shared, SV *index)
1025 CODE:
1026         dTHXc;
1027         bool exists;
1028         if (SvTYPE(SHAREDSvPTR(shared)) == SVt_PVAV) {
1029             SHARED_EDIT;
1030             exists = av_exists((AV*) SHAREDSvPTR(shared), SvIV(index));
1031         }
1032         else {
1033             STRLEN len;
1034             char *key = SvPV(index,len);
1035             SHARED_EDIT;
1036             exists = hv_exists((HV*) SHAREDSvPTR(shared), key, len);
1037         }
1038         SHARED_RELEASE;
1039         ST(0) = (exists) ? &PL_sv_yes : &PL_sv_no;
1040         XSRETURN(1);
1041
1042
1043 void
1044 FIRSTKEY(shared_sv *shared)
1045 CODE:
1046         dTHXc;
1047         char* key = NULL;
1048         I32 len = 0;
1049         HE* entry;
1050         ENTER_LOCK;
1051         SHARED_CONTEXT;
1052         hv_iterinit((HV*) SHAREDSvPTR(shared));
1053         entry = hv_iternext((HV*) SHAREDSvPTR(shared));
1054         if (entry) {
1055                 key = hv_iterkey(entry,&len);
1056                 CALLER_CONTEXT;
1057                 ST(0) = sv_2mortal(newSVpv(key, len));
1058         } else {
1059              CALLER_CONTEXT;
1060              ST(0) = &PL_sv_undef;
1061         }
1062         LEAVE_LOCK;
1063         XSRETURN(1);
1064
1065 void
1066 NEXTKEY(shared_sv *shared, SV *oldkey)
1067 CODE:
1068         dTHXc;
1069         char* key = NULL;
1070         I32 len = 0;
1071         HE* entry;
1072         ENTER_LOCK;
1073         SHARED_CONTEXT;
1074         entry = hv_iternext((HV*) SHAREDSvPTR(shared));
1075         if (entry) {
1076                 key = hv_iterkey(entry,&len);
1077                 CALLER_CONTEXT;
1078                 ST(0) = sv_2mortal(newSVpv(key, len));
1079         } else {
1080              CALLER_CONTEXT;
1081              ST(0) = &PL_sv_undef;
1082         }
1083         LEAVE_LOCK;
1084         XSRETURN(1);
1085
1086 MODULE = threads::shared                PACKAGE = threads::shared
1087
1088 PROTOTYPES: ENABLE
1089
1090 void
1091 _id(SV *ref)
1092         PROTOTYPE: \[$@%]
1093 CODE:
1094         shared_sv *shared;
1095         ref = SvRV(ref);
1096         if(SvROK(ref))
1097             ref = SvRV(ref);
1098         if( (shared = Perl_sharedsv_find(aTHX_ ref)) ){
1099             ST(0) = sv_2mortal(newSViv(PTR2IV(shared)));
1100             XSRETURN(1);
1101         }
1102         XSRETURN_UNDEF;
1103
1104
1105 void
1106 _refcnt(SV *ref)
1107         PROTOTYPE: \[$@%]
1108 CODE:
1109         shared_sv *shared;
1110         ref = SvRV(ref);
1111         if(SvROK(ref))
1112             ref = SvRV(ref);
1113         if( (shared = Perl_sharedsv_find(aTHX_ ref)) ){
1114           if (SHAREDSvPTR(shared)) {
1115             ST(0) = sv_2mortal(newSViv(SvREFCNT(SHAREDSvPTR(shared))));
1116             XSRETURN(1);
1117           }
1118           else {
1119              Perl_warn(aTHX_ "%" SVf " s=%p has no shared SV",ST(0),shared);
1120           }
1121         }
1122         else {
1123              Perl_warn(aTHX_ "%" SVf " is not shared",ST(0));
1124         }
1125         XSRETURN_UNDEF;
1126
1127 SV*
1128 share(SV *ref)
1129         PROTOTYPE: \[$@%]
1130         CODE:
1131         if(!SvROK(ref))
1132             Perl_croak(aTHX_ "Argument to share needs to be passed as ref");
1133         ref = SvRV(ref);
1134         if(SvROK(ref))
1135             ref = SvRV(ref);
1136         Perl_sharedsv_share(aTHX_ ref);
1137         RETVAL = newRV(ref);
1138         OUTPUT:
1139         RETVAL
1140
1141 void
1142 lock_enabled(SV *ref)
1143         PROTOTYPE: \[$@%]
1144         CODE:
1145         shared_sv* shared;
1146         if(!SvROK(ref))
1147             Perl_croak(aTHX_ "Argument to lock needs to be passed as ref");
1148         ref = SvRV(ref);
1149         if(SvROK(ref))
1150             ref = SvRV(ref);
1151         shared = Perl_sharedsv_find(aTHX_ ref);
1152         if(!shared)
1153            croak("lock can only be used on shared values");
1154         Perl_sharedsv_lock(aTHX_ shared);
1155
1156 void
1157 cond_wait_enabled(SV *ref_cond, SV *ref_lock = 0)
1158         PROTOTYPE: \[$@%];\[$@%]
1159         PREINIT:
1160         shared_sv* shared;
1161         perl_cond* user_condition;
1162         int locks;
1163         int same = 0;
1164
1165         CODE:
1166         if (!ref_lock || ref_lock == ref_cond) same = 1;
1167
1168         if(!SvROK(ref_cond))
1169             Perl_croak(aTHX_ "Argument to cond_wait needs to be passed as ref");
1170         ref_cond = SvRV(ref_cond);
1171         if(SvROK(ref_cond))
1172             ref_cond = SvRV(ref_cond);
1173         shared = Perl_sharedsv_find(aTHX_ ref_cond);
1174         if(!shared)
1175             croak("cond_wait can only be used on shared values");
1176
1177         user_condition = &shared->user_cond;
1178         if (! same) {
1179             if (!SvROK(ref_lock))
1180                 Perl_croak(aTHX_ "cond_wait lock needs to be passed as ref");
1181             ref_lock = SvRV(ref_lock);
1182             if (SvROK(ref_lock)) ref_lock = SvRV(ref_lock);
1183             shared = Perl_sharedsv_find(aTHX_ ref_lock);
1184             if (!shared)
1185                 croak("cond_wait lock must be a shared value");
1186         }
1187         if(shared->lock.owner != aTHX)
1188             croak("You need a lock before you can cond_wait");
1189         /* Stealing the members of the lock object worries me - NI-S */
1190         MUTEX_LOCK(&shared->lock.mutex);
1191         shared->lock.owner = NULL;
1192         locks = shared->lock.locks;
1193         shared->lock.locks = 0;
1194
1195         /* since we are releasing the lock here we need to tell other
1196         people that is ok to go ahead and use it */
1197         COND_SIGNAL(&shared->lock.cond);
1198         COND_WAIT(user_condition, &shared->lock.mutex);
1199         while(shared->lock.owner != NULL) {
1200             /* OK -- must reacquire the lock */
1201             COND_WAIT(&shared->lock.cond, &shared->lock.mutex);
1202         }
1203         shared->lock.owner = aTHX;
1204         shared->lock.locks = locks;
1205         MUTEX_UNLOCK(&shared->lock.mutex);
1206
1207 int
1208 cond_timedwait_enabled(SV *ref_cond, double abs, SV *ref_lock = 0)
1209         PROTOTYPE: \[$@%]$;\[$@%]
1210         PREINIT:
1211         shared_sv* shared;
1212         perl_cond* user_condition;
1213         int locks;
1214         int same = 0;
1215
1216         CODE:
1217         if (!ref_lock || ref_cond == ref_lock) same = 1;
1218
1219         if(!SvROK(ref_cond))
1220             Perl_croak(aTHX_ "Argument to cond_timedwait needs to be passed as ref");
1221         ref_cond = SvRV(ref_cond);
1222         if(SvROK(ref_cond))
1223             ref_cond = SvRV(ref_cond);
1224         shared = Perl_sharedsv_find(aTHX_ ref_cond);
1225         if(!shared)
1226             croak("cond_timedwait can only be used on shared values");
1227
1228         user_condition = &shared->user_cond;
1229         if (! same) {
1230             if (!SvROK(ref_lock))
1231                 Perl_croak(aTHX_ "cond_timedwait lock needs to be passed as ref");
1232             ref_lock = SvRV(ref_lock);
1233             if (SvROK(ref_lock)) ref_lock = SvRV(ref_lock);
1234             shared = Perl_sharedsv_find(aTHX_ ref_lock);
1235             if (!shared)
1236                 croak("cond_timedwait lock must be a shared value");
1237         }
1238         if(shared->lock.owner != aTHX)
1239             croak("You need a lock before you can cond_wait");
1240
1241         MUTEX_LOCK(&shared->lock.mutex);
1242         shared->lock.owner = NULL;
1243         locks = shared->lock.locks;
1244         shared->lock.locks = 0;
1245         /* since we are releasing the lock here we need to tell other
1246         people that is ok to go ahead and use it */
1247         COND_SIGNAL(&shared->lock.cond);
1248         RETVAL = Perl_sharedsv_cond_timedwait(user_condition, &shared->lock.mutex, abs);
1249         while (shared->lock.owner != NULL) {
1250             /* OK -- must reacquire the lock... */
1251             COND_WAIT(&shared->lock.cond, &shared->lock.mutex);
1252         }
1253         shared->lock.owner = aTHX;
1254         shared->lock.locks = locks;
1255         MUTEX_UNLOCK(&shared->lock.mutex);
1256
1257         if (RETVAL == 0)
1258             XSRETURN_UNDEF;
1259         OUTPUT:
1260         RETVAL
1261
1262 void
1263 cond_signal_enabled(SV *ref)
1264         PROTOTYPE: \[$@%]
1265         CODE:
1266         shared_sv* shared;
1267         if(!SvROK(ref))
1268             Perl_croak(aTHX_ "Argument to cond_signal needs to be passed as ref");
1269         ref = SvRV(ref);
1270         if(SvROK(ref))
1271             ref = SvRV(ref);
1272         shared = Perl_sharedsv_find(aTHX_ ref);
1273         if(!shared)
1274             croak("cond_signal can only be used on shared values");
1275         if (ckWARN(WARN_THREADS) && shared->lock.owner != aTHX)
1276             Perl_warner(aTHX_ packWARN(WARN_THREADS),
1277                             "cond_signal() called on unlocked variable");
1278         COND_SIGNAL(&shared->user_cond);
1279
1280 void
1281 cond_broadcast_enabled(SV *ref)
1282         PROTOTYPE: \[$@%]
1283         CODE:
1284         shared_sv* shared;
1285         if(!SvROK(ref))
1286             Perl_croak(aTHX_ "Argument to cond_broadcast needs to be passed as ref");
1287         ref = SvRV(ref);
1288         if(SvROK(ref))
1289             ref = SvRV(ref);
1290         shared = Perl_sharedsv_find(aTHX_ ref);
1291         if(!shared)
1292             croak("cond_broadcast can only be used on shared values");
1293         if (ckWARN(WARN_THREADS) && shared->lock.owner != aTHX)
1294             Perl_warner(aTHX_ packWARN(WARN_THREADS),
1295                             "cond_broadcast() called on unlocked variable");
1296         COND_BROADCAST(&shared->user_cond);
1297
1298
1299 SV*
1300 bless(SV* ref, ...);
1301         PROTOTYPE: $;$
1302         CODE:
1303         {
1304           HV* stash;
1305           shared_sv* shared;
1306           if (items == 1)
1307             stash = CopSTASH(PL_curcop);
1308           else {
1309             SV* ssv = ST(1);
1310             STRLEN len;
1311             char *ptr;
1312
1313             if (ssv && !SvGMAGICAL(ssv) && !SvAMAGIC(ssv) && SvROK(ssv))
1314               Perl_croak(aTHX_ "Attempt to bless into a reference");
1315             ptr = SvPV(ssv,len);
1316             if (ckWARN(WARN_MISC) && len == 0)
1317               Perl_warner(aTHX_ packWARN(WARN_MISC),
1318                           "Explicit blessing to '' (assuming package main)");
1319             stash = gv_stashpvn(ptr, len, TRUE);
1320           }
1321           SvREFCNT_inc(ref);
1322           (void)sv_bless(ref, stash);
1323           RETVAL = ref;
1324           shared = Perl_sharedsv_find(aTHX_ ref);
1325           if(shared) {
1326             dTHXc;
1327             ENTER_LOCK;
1328             SHARED_CONTEXT;
1329             {
1330               SV* fake_stash = newSVpv(HvNAME_get(stash),0);
1331               (void)sv_bless(SHAREDSvPTR(shared),(HV*)fake_stash);
1332             }
1333             CALLER_CONTEXT;
1334             LEAVE_LOCK;
1335           }
1336         }
1337         OUTPUT:
1338         RETVAL
1339
1340 #endif /* USE_ITHREADS */
1341
1342 BOOT:
1343 {
1344 #ifdef USE_ITHREADS
1345      Perl_sharedsv_init(aTHX);
1346 #endif /* USE_ITHREADS */
1347 }
1348
1349
1350