3 * Copyright (c) 2001-2002, Larry Wall
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.
8 * "Hand any two wizards a piece of rope and they would instinctively pull in
9 * opposite directions."
12 * Contributed by Arthur Bergman arthur@contiller.se
13 * pulled in the (an)other direction by Nick Ing-Simmons nick@ing-simmons.net
17 * Shared variables are implemented by a scheme similar to tieing.
18 * Each thread has a proxy SV with attached magic -- "private SVs" --
19 * which all point to a single SV in a separate shared interpreter
20 * (PL_sharedsv_space) -- "shared SVs".
22 * The shared SV holds the variable's true values, and its state is
23 * copied between the shared and private SVs with the usual
24 * mg_get()/mg_set() arrangement.
26 * Aggregates (AVs and HVs) are implemented using tie magic, except that
27 * the vtable used is one defined in this file rather than the standard one.
28 * This means that where a tie function like is FETCH is normally invoked by
29 * the tie magic's mg_get() function, we completely bypass the calling of a
30 * perl-level function, and directly call C-level code to handle it. On
31 * the other hand. calls to functions like PUSH are done directly by code
32 * in av.c etc, which we can't bypass. So the best we can do is to provide
33 * XS versions of these functions. We also have to attach a tie object,
34 * blessed into the class threads::shared::tie, to keep the method-calling
37 * Access to aggregate elements is done the usual tied way by returning a
38 * proxy PVLV element with attached element magic.
40 * Pointers to the shared SV are squirrelled away in the mg->mg_ptr field
41 * of magic (with mg_len == 0), and in the IV2PTR(SvIV(sv)) field of tied
42 * object SVs. These pointers have to be hidden like this because they
43 * cross interpreter boundaries, and we don't want sv_clear() and friends
46 * The three basic shared types look like the following:
50 * Shared scalar (my $s : shared):
52 * SV = PVMG(0x7ba238) at 0x7387a8
53 * FLAGS = (PADMY,GMG,SMG)
55 * MG_TYPE = PERL_MAGIC_shared_scalar(n)
56 * MG_PTR = 0x810358 <<<< pointer to the shared SV
60 * Shared aggregate (my @a : shared; my %h : shared):
62 * SV = PVAV(0x7175d0) at 0x738708
65 * MG_TYPE = PERL_MAGIC_tied(P)
66 * MG_OBJ = 0x7136e0 <<<< ref to the tied object
67 * SV = RV(0x7136f0) at 0x7136e0
69 * SV = PVMG(0x7ba238) at 0x738640 <<<< the tied object
70 * FLAGS = (OBJECT,IOK,pIOK)
71 * IV = 8455000 <<<< pointer to the shared AV
72 * STASH = 0x80abf0 "threads::shared::tie"
73 * MG_PTR = 0x810358 "" <<<< another pointer to the shared AV
78 * Aggregate element (my @a : shared; $a[0])
80 * SV = PVLV(0x77f628) at 0x713550
81 * FLAGS = (GMG,SMG,RMG,pIOK)
83 * MG_TYPE = PERL_MAGIC_shared_scalar(n)
84 * MG_PTR = 0x8103c0 "" <<<< pointer to the shared element
86 * MG_TYPE = PERL_MAGIC_tiedelem(p)
87 * MG_OBJ = 0x7136e0 <<<< ref to the tied object
88 * SV = RV(0x7136f0) at 0x7136e0
90 * SV = PVMG(0x7ba278) at 0x738660 <<<< the tied object
91 * FLAGS = (OBJECT,IOK,pIOK)
92 * IV = 8455064 <<<< pointer to the shared AV
93 * STASH = 0x80ac30 "threads::shared::tie"
96 * Note that PERL_MAGIC_tiedelem(p) magic doesn't have a pointer to a
97 * shared SV in mg_ptr; instead this is used to store the hash key,
98 * if any, like normal tied elements. Note also that element SVs may have
99 * pointers to both the shared aggregate and the shared element
104 * if a shared variable is used as a perl-level lock or condition
105 * variable, then PERL_MAGIC_ext magic is attached to the associated
106 * *shared* SV, whose mg_ptr field points to a malloced structure
107 * containing the necessary mutexes and condition variables.
111 * In this file, any variable name prefixed with 's', eg ssv, stmp or sobj,
112 * usually represents a shared SV which correspondis to a private SV named
113 * without the prefix, eg sv, tmp or obj.
116 #define PERL_NO_GET_CONTEXT
124 * The shared things need an intepreter to live in ...
126 PerlInterpreter *PL_sharedsv_space; /* The shared sv space */
127 /* To access shared space we fake aTHX in this scope and thread's context */
129 /* bug #24255: we include ENTER+SAVETMPS/FREETMPS+LEAVE with
130 * SHARED_CONTEXT/CALLER_CONTEXT macros, so that any mortals etc created
131 * while in the shared interpreter context don't languish */
133 #define SHARED_CONTEXT \
135 PERL_SET_CONTEXT((aTHX = PL_sharedsv_space)); \
140 /* So we need a way to switch back to the caller's context... */
141 /* So we declare _another_ copy of the aTHX variable ... */
142 #define dTHXc PerlInterpreter *caller_perl = aTHX
144 /* and use it to switch back */
145 #define CALLER_CONTEXT \
149 PERL_SET_CONTEXT((aTHX = caller_perl)); \
153 * Only one thread at a time is allowed to mess with shared space.
159 PerlInterpreter *owner;
168 recursive_lock_t PL_sharedsv_lock; /* Mutex protecting the shared sv space */
171 recursive_lock_init(pTHX_ recursive_lock_t *lock)
173 Zero(lock,1,recursive_lock_t);
174 MUTEX_INIT(&lock->mutex);
175 COND_INIT(&lock->cond);
179 recursive_lock_destroy(pTHX_ recursive_lock_t *lock)
181 MUTEX_DESTROY(&lock->mutex);
182 COND_DESTROY(&lock->cond);
186 recursive_lock_release(pTHX_ recursive_lock_t *lock)
188 MUTEX_LOCK(&lock->mutex);
189 if (lock->owner != aTHX) {
190 MUTEX_UNLOCK(&lock->mutex);
193 if (--lock->locks == 0) {
195 COND_SIGNAL(&lock->cond);
198 MUTEX_UNLOCK(&lock->mutex);
202 recursive_lock_acquire(pTHX_ recursive_lock_t *lock,char *file,int line)
205 MUTEX_LOCK(&lock->mutex);
206 if (lock->owner == aTHX) {
210 while (lock->owner) {
212 Perl_warn(aTHX_ " %p waiting - owned by %p %s:%d\n",
213 aTHX, lock->owner, lock->file, lock->line);
215 COND_WAIT(&lock->cond,&lock->mutex);
224 MUTEX_UNLOCK(&lock->mutex);
225 SAVEDESTRUCTOR_X(recursive_lock_release,lock);
228 #define ENTER_LOCK STMT_START { \
230 recursive_lock_acquire(aTHX_ &PL_sharedsv_lock, __FILE__, __LINE__); \
233 /* the unlocking is done automatically at scope exit */
234 #define LEAVE_LOCK LEAVE
237 /* A common idiom is to acquire access and switch in ... */
238 #define SHARED_EDIT STMT_START { \
243 /* then switch out and release access. */
244 #define SHARED_RELEASE STMT_START { \
251 This structure is attached (using ext magic) to any shared SV that
252 is used by user-level locking or condition code
256 recursive_lock_t lock; /* for user-levl locks */
257 perl_cond user_cond; /* For user-level conditions */
260 /* magic used for attaching user_lock structs to shared SVs
262 The vtable used has just one entry - when the SV goes away
263 we free the memory for the above.
267 sharedsv_userlock_free(pTHX_ SV *sv, MAGIC *mg)
269 user_lock *ul = (user_lock *) mg->mg_ptr;
270 assert(aTHX == PL_sharedsv_space);
272 recursive_lock_destroy(aTHX_ &ul->lock);
273 COND_DESTROY(&ul->user_cond);
274 PerlMemShared_free(ul);
280 MGVTBL sharedsv_uesrlock_vtbl = {
285 sharedsv_userlock_free, /* free */
291 /* Access to shared things is heavily based on MAGIC - in mg.h/mg.c/sv.c sense */
293 /* In any thread that has access to a shared thing there is a "proxy"
294 for it in its own space which has 'MAGIC' associated which accesses
298 MGVTBL sharedsv_scalar_vtbl; /* scalars have this vtable */
299 MGVTBL sharedsv_array_vtbl; /* hashes and arrays have this - like 'tie' */
300 MGVTBL sharedsv_elem_vtbl; /* elements of hashes and arrays have this
301 _AS WELL AS_ the scalar magic:
302 The sharedsv_elem_vtbl associates the element with the array/hash and
303 the sharedsv_scalar_vtbl associates it with the value
307 /* get shared aggregate SV pointed to by threads::shared::tie magic object */
310 S_sharedsv_from_obj(pTHX_ SV *sv)
312 return SvROK(sv) ? INT2PTR(SV *, SvIV(SvRV(sv))) : NULL;
316 /* Return the user_lock structure (if any) associated with a shared SV.
317 * If create is true, create one if it doesn't exist */
320 S_get_userlock(pTHX_ SV* ssv, bool create)
323 user_lock *ul = NULL;
326 /* XXX redsign the storage of user locks so we dont need a global
327 * lock to access them ???? DAPM */
329 mg = mg_find(ssv, PERL_MAGIC_ext);
331 ul = (user_lock*)(mg->mg_ptr);
335 ul = (user_lock *) PerlMemShared_malloc(sizeof(user_lock));
336 Zero(ul, 1, user_lock);
337 /* attach to shared SV using ext magic */
338 sv_magicext(ssv, NULL, PERL_MAGIC_ext, &sharedsv_uesrlock_vtbl,
340 recursive_lock_init(aTHX_ &ul->lock);
341 COND_INIT(&ul->user_cond);
349 =for apidoc sharedsv_find
351 Given a private side SV tries to find if the SV has a shared backend,
352 by looking for the magic.
357 Perl_sharedsv_find(pTHX_ SV *sv)
360 if (SvTYPE(sv) >= SVt_PVMG) {
364 if ((mg = mg_find(sv, PERL_MAGIC_tied))
365 && mg->mg_virtual == &sharedsv_array_vtbl) {
366 return (SV *) mg->mg_ptr;
370 /* This should work for elements as well as they
371 * have scalar magic as well as their element magic
373 if ((mg = mg_find(sv, PERL_MAGIC_shared_scalar))
374 && mg->mg_virtual == &sharedsv_scalar_vtbl) {
375 return (SV *) mg->mg_ptr;
380 /* Just for tidyness of API also handle tie objects */
381 if (SvROK(sv) && sv_derived_from(sv, "threads::shared::tie")) {
382 return S_sharedsv_from_obj(aTHX_ sv);
388 /* associate a private SV with a shared SV by pointing the appropriate
389 * magics at it. Assumes lock is held */
392 Perl_sharedsv_associate(pTHX_ SV *sv, SV *ssv)
397 /* If we are asked for any private ops we need a thread */
398 assert ( aTHX != PL_sharedsv_space );
400 /* To avoid need for recursive locks require caller to hold lock */
401 assert ( PL_sharedsv_lock.owner == aTHX );
406 if (!(mg = mg_find(sv, PERL_MAGIC_tied))
407 || mg->mg_virtual != &sharedsv_array_vtbl
408 || (SV*) mg->mg_ptr != ssv)
411 sv_setref_iv(obj, "threads::shared::tie",PTR2IV(ssv));
413 sv_unmagic(sv, PERL_MAGIC_tied);
415 mg = sv_magicext(sv, obj, PERL_MAGIC_tied, &sharedsv_array_vtbl,
417 mg->mg_flags |= (MGf_COPY|MGf_DUP);
422 char* stash_ptr = SvPV((SV*) SvSTASH(ssv), len);
423 HV* stash = gv_stashpvn(stash_ptr, len, TRUE);
425 SvSTASH_set(sv, (HV*)SvREFCNT_inc(stash));
431 if ((SvTYPE(sv) < SVt_PVMG)
432 || !(mg = mg_find(sv, PERL_MAGIC_shared_scalar))
433 || mg->mg_virtual != &sharedsv_scalar_vtbl
434 || (SV*) mg->mg_ptr != ssv)
437 sv_unmagic(sv, PERL_MAGIC_shared_scalar);
439 mg = sv_magicext(sv, Nullsv, PERL_MAGIC_shared_scalar,
440 &sharedsv_scalar_vtbl, (char *)ssv, 0);
441 mg->mg_flags |= (MGf_COPY|MGf_DUP|MGf_LOCAL);
445 char* stash_ptr = SvPV((SV*) SvSTASH(ssv), len);
446 HV* stash = gv_stashpvn(stash_ptr, len, TRUE);
448 SvSTASH_set(sv, (HV*)SvREFCNT_inc(stash));
453 assert ( Perl_sharedsv_find(aTHX_ sv) == ssv );
457 /* Given a private SV, create and return an associated shared SV.
458 * Assumes lock is held */
461 S_sharedsv_new_shared(pTHX_ SV *sv)
466 assert(PL_sharedsv_lock.owner == aTHX);
467 assert(aTHX != PL_sharedsv_space);
471 SvREFCNT(ssv) = 0; /* will be upped to 1 by Perl_sharedsv_associate */
472 sv_upgrade(ssv, SvTYPE(sv));
474 Perl_sharedsv_associate(aTHX_ sv, ssv);
479 /* Given a shared SV, create and return an associated private SV.
480 * Assumes lock is held */
483 S_sharedsv_new_private(pTHX_ SV *ssv)
487 assert(PL_sharedsv_lock.owner == aTHX);
488 assert(aTHX != PL_sharedsv_space);
491 sv_upgrade(sv, SvTYPE(ssv));
492 Perl_sharedsv_associate(aTHX_ sv, ssv);
497 /* a threadsafe version of SvREFCNT_dec(ssv) */
500 S_sharedsv_dec(pTHX_ SV* ssv)
505 if (SvREFCNT(ssv) > 1) {
506 /* no side effects, so can do it lightweight */
518 /* implements Perl-level share() and :shared */
521 Perl_sharedsv_share(pTHX_ SV *sv)
525 Perl_croak(aTHX_ "Cannot share globs yet");
529 Perl_croak(aTHX_ "Cannot share subs yet");
534 (void) S_sharedsv_new_shared(aTHX_ sv);
541 #if defined(WIN32) || defined(OS2)
542 # define ABS2RELMILLI(abs) \
544 abs -= (double)time(NULL); \
545 if (abs > 0) { abs *= 1000; } \
548 #endif /* WIN32 || OS2 */
550 /* do OS-specific condition timed wait */
553 Perl_sharedsv_cond_timedwait(perl_cond *cond, perl_mutex *mut, double abs)
555 #if defined(NETWARE) || defined(FAKE_THREADS) || defined(I_MACH_CTHREADS)
556 Perl_croak_nocontext("cond_timedwait not supported on this platform");
565 /* See comments in win32/win32thread.h COND_WAIT vis-a-vis race */
566 switch (WaitForSingleObject(cond->sem, (DWORD)abs)) {
567 case WAIT_OBJECT_0: got_it = 1; break;
568 case WAIT_TIMEOUT: break;
570 /* WAIT_FAILED? WAIT_ABANDONED? others? */
571 Perl_croak_nocontext("panic: cond_timedwait (%ld)",GetLastError());
584 if ((rc = DosResetEventSem(*cond,&n_a)) && (rc != ERROR_ALREADY_RESET))
585 Perl_rc = rc, croak_with_os2error("panic: cond_timedwait-reset");
587 if (CheckOSError(DosWaitEventSem(*cond,abs))
588 && (rc != ERROR_INTERRUPT))
589 croak_with_os2error("panic: cond_timedwait");
590 if (rc == ERROR_INTERRUPT) errno = EINTR;
593 # else /* hope you're I_PTHREAD! */
597 ts.tv_sec = (long)abs;
598 abs -= (NV)ts.tv_sec;
599 ts.tv_nsec = (long)(abs * 1000000000.0);
601 switch (pthread_cond_timedwait(cond, mut, &ts)) {
602 case 0: got_it = 1; break;
603 case ETIMEDOUT: break;
605 Perl_croak_nocontext("panic: cond_timedwait");
611 #endif /* NETWARE || FAKE_THREADS || I_MACH_CTHREADS */
614 /* ------------ PERL_MAGIC_shared_scalar(n) functions -------------- */
616 /* get magic for PERL_MAGIC_shared_scalar(n) */
619 sharedsv_scalar_mg_get(pTHX_ SV *sv, MAGIC *mg)
621 SV *ssv = (SV *) mg->mg_ptr;
626 SV *obj = S_sharedsv_new_private(aTHX_ SvRV(ssv));
627 sv_setsv_nomg(sv, &PL_sv_undef);
632 sv_setsv_nomg(sv, ssv);
638 /* copy the contents of a private SV to a shared SV:
639 * used by various mg_set()-type functions.
640 * Assumes lock is held */
643 sharedsv_scalar_store(pTHX_ SV *sv, SV *ssv)
648 assert(PL_sharedsv_lock.owner == aTHX);
651 SV *sobj = Perl_sharedsv_find(aTHX_ obj);
654 SvUPGRADE(ssv, SVt_RV);
655 sv_setsv_nomg(ssv, &PL_sv_undef);
657 SvRV_set(ssv, SvREFCNT_inc(sobj));
660 SV* fake_stash = newSVpv(HvNAME_get(SvSTASH(obj)),0);
662 SvSTASH_set(sobj, (HV*)fake_stash);
673 sv_setsv_nomg(ssv, sv);
675 SV* fake_stash = newSVpv(HvNAME_get(SvSTASH(sv)),0);
677 SvSTASH_set(ssv, (HV*)fake_stash);
682 Perl_croak(aTHX_ "Invalid value for shared scalar");
686 /* set magic for PERL_MAGIC_shared_scalar(n) */
689 sharedsv_scalar_mg_set(pTHX_ SV *sv, MAGIC *mg)
691 SV *ssv = (SV*)(mg->mg_ptr);
694 if (SvTYPE(ssv) < SvTYPE(sv)) {
697 sv_upgrade(ssv, SvTYPE(sv));
700 sharedsv_scalar_store(aTHX_ sv, ssv);
705 /* free magic for PERL_MAGIC_shared_scalar(n) */
708 sharedsv_scalar_mg_free(pTHX_ SV *sv, MAGIC *mg)
710 S_sharedsv_dec(aTHX_ (SV*)mg->mg_ptr);
715 * Called during cloning of PERL_MAGIC_shared_scalar(n) magic in new thread
718 sharedsv_scalar_mg_dup(pTHX_ MAGIC *mg, CLONE_PARAMS *param)
720 SvREFCNT_inc(mg->mg_ptr);
725 * Called during local $shared
728 sharedsv_scalar_mg_local(pTHX_ SV* nsv, MAGIC *mg)
731 SV *ssv = (SV *) mg->mg_ptr;
737 nmg = sv_magicext(nsv, mg->mg_obj, mg->mg_type, mg->mg_virtual,
738 mg->mg_ptr, mg->mg_len);
739 nmg->mg_flags = mg->mg_flags;
740 nmg->mg_private = mg->mg_private;
745 MGVTBL sharedsv_scalar_vtbl = {
746 sharedsv_scalar_mg_get, /* get */
747 sharedsv_scalar_mg_set, /* set */
750 sharedsv_scalar_mg_free, /* free */
752 sharedsv_scalar_mg_dup, /* dup */
753 sharedsv_scalar_mg_local /* local */
756 /* ------------ PERL_MAGIC_tiedelem(p) functions -------------- */
758 /* get magic for PERL_MAGIC_tiedelem(p) */
761 sharedsv_elem_mg_FETCH(pTHX_ SV *sv, MAGIC *mg)
764 SV *saggregate = S_sharedsv_from_obj(aTHX_ mg->mg_obj);
768 if (SvTYPE(saggregate) == SVt_PVAV) {
769 assert ( mg->mg_ptr == 0 );
771 svp = av_fetch((AV*) saggregate, mg->mg_len, 0);
774 char *key = mg->mg_ptr;
775 STRLEN len = mg->mg_len;
776 assert ( mg->mg_ptr != 0 );
777 if (mg->mg_len == HEf_SVKEY) {
778 key = SvPV((SV *) mg->mg_ptr, len);
781 svp = hv_fetch((HV*) saggregate, key, len, 0);
785 /* Exists in the array */
787 SV *obj = S_sharedsv_new_private(aTHX_ SvRV(*svp));
788 sv_setsv_nomg(sv, &PL_sv_undef);
794 /* XXX can this branch ever happen? DAPM */
795 /* XXX assert("no such branch"); */
796 Perl_sharedsv_associate(aTHX_ sv, *svp);
801 /* Not in the array */
802 sv_setsv(sv, &PL_sv_undef);
808 /* set magic for PERL_MAGIC_tiedelem(p) */
811 sharedsv_elem_mg_STORE(pTHX_ SV *sv, MAGIC *mg)
814 SV *saggregate = S_sharedsv_from_obj(aTHX_ mg->mg_obj);
816 /* Theory - SV itself is magically shared - and we have ordered the
817 magic such that by the time we get here it has been stored
818 to its shared counterpart
822 if (SvTYPE(saggregate) == SVt_PVAV) {
823 assert ( mg->mg_ptr == 0 );
825 svp = av_fetch((AV*) saggregate, mg->mg_len, 1);
828 char *key = mg->mg_ptr;
829 STRLEN len = mg->mg_len;
830 assert ( mg->mg_ptr != 0 );
831 if (mg->mg_len == HEf_SVKEY)
832 key = SvPV((SV *) mg->mg_ptr, len);
834 svp = hv_fetch((HV*) saggregate, key, len, 1);
837 Perl_sharedsv_associate(aTHX_ sv, *svp);
838 sharedsv_scalar_store(aTHX_ sv, *svp);
843 /* clear magic for PERL_MAGIC_tiedelem(p) */
846 sharedsv_elem_mg_DELETE(pTHX_ SV *sv, MAGIC *mg)
850 SV *saggregate = S_sharedsv_from_obj(aTHX_ mg->mg_obj);
852 sharedsv_elem_mg_FETCH(aTHX_ sv, mg);
853 if ((shmg = mg_find(sv, PERL_MAGIC_shared_scalar)))
854 sharedsv_scalar_mg_get(aTHX_ sv, shmg);
855 if (SvTYPE(saggregate) == SVt_PVAV) {
857 av_delete((AV*) saggregate, mg->mg_len, G_DISCARD);
860 char *key = mg->mg_ptr;
861 STRLEN len = mg->mg_len;
862 assert ( mg->mg_ptr != 0 );
863 if (mg->mg_len == HEf_SVKEY)
864 key = SvPV((SV *) mg->mg_ptr, len);
866 hv_delete((HV*) saggregate, key, len, G_DISCARD);
873 /* free magic for PERL_MAGIC_tiedelem(p) */
876 sharedsv_elem_mg_free(pTHX_ SV *sv, MAGIC *mg)
878 S_sharedsv_dec(aTHX_ S_sharedsv_from_obj(aTHX_ mg->mg_obj));
882 /* Called during cloning of PERL_MAGIC_tiedelem(p) magic in new
886 sharedsv_elem_mg_dup(pTHX_ MAGIC *mg, CLONE_PARAMS *param)
888 SvREFCNT_inc(S_sharedsv_from_obj(aTHX_ mg->mg_obj));
889 assert(mg->mg_flags & MGf_DUP);
893 MGVTBL sharedsv_elem_vtbl = {
894 sharedsv_elem_mg_FETCH, /* get */
895 sharedsv_elem_mg_STORE, /* set */
897 sharedsv_elem_mg_DELETE, /* clear */
898 sharedsv_elem_mg_free, /* free */
900 sharedsv_elem_mg_dup, /* dup */
904 /* ------------ PERL_MAGIC_tied(P) functions -------------- */
906 /* len magic for PERL_MAGIC_tied(P) */
909 sharedsv_array_mg_FETCHSIZE(pTHX_ SV *sv, MAGIC *mg)
912 SV *ssv = (SV *) mg->mg_ptr;
915 if (SvTYPE(ssv) == SVt_PVAV) {
916 val = av_len((AV*) ssv);
919 /* not actually defined by tie API but ... */
920 val = HvKEYS((HV*) ssv);
926 /* clear magic for PERL_MAGIC_tied(P) */
929 sharedsv_array_mg_CLEAR(pTHX_ SV *sv, MAGIC *mg)
932 SV *ssv = (SV *) mg->mg_ptr;
934 if (SvTYPE(ssv) == SVt_PVAV) {
944 /* free magic for PERL_MAGIC_tied(P) */
947 sharedsv_array_mg_free(pTHX_ SV *sv, MAGIC *mg)
949 S_sharedsv_dec(aTHX_ (SV*)mg->mg_ptr);
954 * copy magic for PERL_MAGIC_tied(P)
955 * This is called when perl is about to access an element of
959 sharedsv_array_mg_copy(pTHX_ SV *sv, MAGIC* mg,
960 SV *nsv, const char *name, int namlen)
962 MAGIC *nmg = sv_magicext(nsv,mg->mg_obj,
963 toLOWER(mg->mg_type),&sharedsv_elem_vtbl,
966 SvREFCNT_inc((SV*)mg->mg_ptr);
968 nmg->mg_flags |= MGf_DUP;
972 /* Called during cloning of PERL_MAGIC_tied(P) magic in new thread */
975 sharedsv_array_mg_dup(pTHX_ MAGIC *mg, CLONE_PARAMS *param)
977 SvREFCNT_inc((SV*)mg->mg_ptr);
978 assert(mg->mg_flags & MGf_DUP);
982 MGVTBL sharedsv_array_vtbl = {
985 sharedsv_array_mg_FETCHSIZE, /* len */
986 sharedsv_array_mg_CLEAR, /* clear */
987 sharedsv_array_mg_free, /* free */
988 sharedsv_array_mg_copy, /* copy */
989 sharedsv_array_mg_dup, /* dup */
993 =for apidoc sharedsv_unlock
995 Recursively unlocks a shared sv.
1000 Perl_sharedsv_unlock(pTHX_ SV *ssv)
1002 user_lock *ul = S_get_userlock(aTHX_ ssv, 0);
1004 recursive_lock_release(aTHX_ &ul->lock);
1007 =for apidoc sharedsv_lock
1009 Recursive locks on a sharedsv.
1010 Locks are dynamically scoped at the level of the first lock.
1015 Perl_sharedsv_lock(pTHX_ SV *ssv)
1020 ul = S_get_userlock(aTHX_ ssv, 1);
1021 recursive_lock_acquire(aTHX_ &ul->lock, __FILE__, __LINE__);
1024 /* handles calls from lock() builtin via PL_lockhook */
1027 Perl_sharedsv_locksv(pTHX_ SV *sv)
1033 ssv = Perl_sharedsv_find(aTHX_ sv);
1035 croak("lock can only be used on shared values");
1036 Perl_sharedsv_lock(aTHX_ ssv);
1039 =head1 Shared SV Functions
1041 =for apidoc sharedsv_init
1043 Saves a space for keeping SVs wider than an interpreter,
1048 Perl_sharedsv_init(pTHX)
1051 /* This pair leaves us in shared context ... */
1052 PL_sharedsv_space = perl_alloc();
1053 perl_construct(PL_sharedsv_space);
1055 recursive_lock_init(aTHX_ &PL_sharedsv_lock);
1056 PL_lockhook = &Perl_sharedsv_locksv;
1057 PL_sharehook = &Perl_sharedsv_share;
1060 #endif /* USE_ITHREADS */
1062 MODULE = threads::shared PACKAGE = threads::shared::tie
1072 SV *sobj = S_sharedsv_from_obj(aTHX_ obj);
1074 for(i = 1; i < items; i++) {
1075 SV* tmp = newSVsv(ST(i));
1078 stmp = S_sharedsv_new_shared(aTHX_ tmp);
1079 sharedsv_scalar_store(aTHX_ tmp, stmp);
1081 av_push((AV*) sobj, stmp);
1088 UNSHIFT(SV *obj, ...)
1091 SV *sobj = S_sharedsv_from_obj(aTHX_ obj);
1095 av_unshift((AV*)sobj, items - 1);
1097 for(i = 1; i < items; i++) {
1098 SV *tmp = newSVsv(ST(i));
1099 SV *stmp = S_sharedsv_new_shared(aTHX_ tmp);
1100 sharedsv_scalar_store(aTHX_ tmp, stmp);
1102 av_store((AV*) sobj, i - 1, stmp);
1113 SV *sobj = S_sharedsv_from_obj(aTHX_ obj);
1117 ssv = av_pop((AV*)sobj);
1119 ST(0) = sv_newmortal();
1120 Perl_sharedsv_associate(aTHX_ ST(0), ssv);
1129 SV *sobj = S_sharedsv_from_obj(aTHX_ obj);
1133 ssv = av_shift((AV*)sobj);
1135 ST(0) = sv_newmortal();
1136 Perl_sharedsv_associate(aTHX_ ST(0), ssv);
1142 EXTEND(SV *obj, IV count)
1145 SV *sobj = S_sharedsv_from_obj(aTHX_ obj);
1147 av_extend((AV*)sobj, count);
1151 STORESIZE(SV *obj,IV count)
1154 SV *sobj = S_sharedsv_from_obj(aTHX_ obj);
1156 av_fill((AV*) sobj, count);
1163 EXISTS(SV *obj, SV *index)
1166 SV *sobj = S_sharedsv_from_obj(aTHX_ obj);
1168 if (SvTYPE(sobj) == SVt_PVAV) {
1170 exists = av_exists((AV*) sobj, SvIV(index));
1174 char *key = SvPV(index,len);
1176 exists = hv_exists((HV*) sobj, key, len);
1179 ST(0) = (exists) ? &PL_sv_yes : &PL_sv_no;
1187 SV *sobj = S_sharedsv_from_obj(aTHX_ obj);
1193 hv_iterinit((HV*) sobj);
1194 entry = hv_iternext((HV*) sobj);
1196 key = hv_iterkey(entry,&len);
1198 ST(0) = sv_2mortal(newSVpv(key, len));
1201 ST(0) = &PL_sv_undef;
1207 NEXTKEY(SV *obj, SV *oldkey)
1210 SV *sobj = S_sharedsv_from_obj(aTHX_ obj);
1216 entry = hv_iternext((HV*) sobj);
1218 key = hv_iterkey(entry,&len);
1220 ST(0) = sv_2mortal(newSVpv(key, len));
1223 ST(0) = &PL_sv_undef;
1228 MODULE = threads::shared PACKAGE = threads::shared
1240 if( (ssv = Perl_sharedsv_find(aTHX_ ref)) ){
1241 ST(0) = sv_2mortal(newSViv(PTR2IV(ssv)));
1255 if( (ssv = Perl_sharedsv_find(aTHX_ ref)) ) {
1256 ST(0) = sv_2mortal(newSViv(SvREFCNT(ssv)));
1260 Perl_warn(aTHX_ "%" SVf " is not shared",ST(0));
1269 Perl_croak(aTHX_ "Argument to share needs to be passed as ref");
1273 Perl_sharedsv_share(aTHX_ ref);
1274 RETVAL = newRV(ref);
1279 lock_enabled(SV *ref)
1284 Perl_croak(aTHX_ "Argument to lock needs to be passed as ref");
1288 ssv = Perl_sharedsv_find(aTHX_ ref);
1290 croak("lock can only be used on shared values");
1291 Perl_sharedsv_lock(aTHX_ ssv);
1294 cond_wait_enabled(SV *ref_cond, SV *ref_lock = 0)
1295 PROTOTYPE: \[$@%];\[$@%]
1298 perl_cond* user_condition;
1304 if (!ref_lock || ref_lock == ref_cond) same = 1;
1306 if(!SvROK(ref_cond))
1307 Perl_croak(aTHX_ "Argument to cond_wait needs to be passed as ref");
1308 ref_cond = SvRV(ref_cond);
1310 ref_cond = SvRV(ref_cond);
1311 ssv = Perl_sharedsv_find(aTHX_ ref_cond);
1313 croak("cond_wait can only be used on shared values");
1314 ul = S_get_userlock(aTHX_ ssv, 1);
1316 user_condition = &ul->user_cond;
1318 if (!SvROK(ref_lock))
1319 Perl_croak(aTHX_ "cond_wait lock needs to be passed as ref");
1320 ref_lock = SvRV(ref_lock);
1321 if (SvROK(ref_lock)) ref_lock = SvRV(ref_lock);
1322 ssv = Perl_sharedsv_find(aTHX_ ref_lock);
1324 croak("cond_wait lock must be a shared value");
1325 ul = S_get_userlock(aTHX_ ssv, 1);
1327 if(ul->lock.owner != aTHX)
1328 croak("You need a lock before you can cond_wait");
1329 /* Stealing the members of the lock object worries me - NI-S */
1330 MUTEX_LOCK(&ul->lock.mutex);
1331 ul->lock.owner = NULL;
1332 locks = ul->lock.locks;
1335 /* since we are releasing the lock here we need to tell other
1336 people that is ok to go ahead and use it */
1337 COND_SIGNAL(&ul->lock.cond);
1338 COND_WAIT(user_condition, &ul->lock.mutex);
1339 while(ul->lock.owner != NULL) {
1340 /* OK -- must reacquire the lock */
1341 COND_WAIT(&ul->lock.cond, &ul->lock.mutex);
1343 ul->lock.owner = aTHX;
1344 ul->lock.locks = locks;
1345 MUTEX_UNLOCK(&ul->lock.mutex);
1348 cond_timedwait_enabled(SV *ref_cond, double abs, SV *ref_lock = 0)
1349 PROTOTYPE: \[$@%]$;\[$@%]
1352 perl_cond* user_condition;
1358 if (!ref_lock || ref_cond == ref_lock) same = 1;
1360 if(!SvROK(ref_cond))
1361 Perl_croak(aTHX_ "Argument to cond_timedwait needs to be passed as ref");
1362 ref_cond = SvRV(ref_cond);
1364 ref_cond = SvRV(ref_cond);
1365 ssv = Perl_sharedsv_find(aTHX_ ref_cond);
1367 croak("cond_timedwait can only be used on shared values");
1368 ul = S_get_userlock(aTHX_ ssv, 1);
1370 user_condition = &ul->user_cond;
1372 if (!SvROK(ref_lock))
1373 Perl_croak(aTHX_ "cond_timedwait lock needs to be passed as ref");
1374 ref_lock = SvRV(ref_lock);
1375 if (SvROK(ref_lock)) ref_lock = SvRV(ref_lock);
1376 ssv = Perl_sharedsv_find(aTHX_ ref_lock);
1378 croak("cond_timedwait lock must be a shared value");
1379 ul = S_get_userlock(aTHX_ ssv, 1);
1381 if(ul->lock.owner != aTHX)
1382 croak("You need a lock before you can cond_wait");
1384 MUTEX_LOCK(&ul->lock.mutex);
1385 ul->lock.owner = NULL;
1386 locks = ul->lock.locks;
1388 /* since we are releasing the lock here we need to tell other
1389 people that is ok to go ahead and use it */
1390 COND_SIGNAL(&ul->lock.cond);
1391 RETVAL = Perl_sharedsv_cond_timedwait(user_condition, &ul->lock.mutex, abs);
1392 while (ul->lock.owner != NULL) {
1393 /* OK -- must reacquire the lock... */
1394 COND_WAIT(&ul->lock.cond, &ul->lock.mutex);
1396 ul->lock.owner = aTHX;
1397 ul->lock.locks = locks;
1398 MUTEX_UNLOCK(&ul->lock.mutex);
1406 cond_signal_enabled(SV *ref)
1413 Perl_croak(aTHX_ "Argument to cond_signal needs to be passed as ref");
1417 ssv = Perl_sharedsv_find(aTHX_ ref);
1419 croak("cond_signal can only be used on shared values");
1420 ul = S_get_userlock(aTHX_ ssv, 1);
1421 if (ckWARN(WARN_THREADS) && ul->lock.owner != aTHX)
1422 Perl_warner(aTHX_ packWARN(WARN_THREADS),
1423 "cond_signal() called on unlocked variable");
1424 COND_SIGNAL(&ul->user_cond);
1427 cond_broadcast_enabled(SV *ref)
1434 Perl_croak(aTHX_ "Argument to cond_broadcast needs to be passed as ref");
1438 ssv = Perl_sharedsv_find(aTHX_ ref);
1440 croak("cond_broadcast can only be used on shared values");
1441 ul = S_get_userlock(aTHX_ ssv, 1);
1442 if (ckWARN(WARN_THREADS) && ul->lock.owner != aTHX)
1443 Perl_warner(aTHX_ packWARN(WARN_THREADS),
1444 "cond_broadcast() called on unlocked variable");
1445 COND_BROADCAST(&ul->user_cond);
1449 bless(SV* ref, ...);
1456 stash = CopSTASH(PL_curcop);
1458 SV* classname = ST(1);
1462 if (classname && !SvGMAGICAL(classname) &&
1463 !SvAMAGIC(classname) && SvROK(classname))
1464 Perl_croak(aTHX_ "Attempt to bless into a reference");
1465 ptr = SvPV(classname,len);
1466 if (ckWARN(WARN_MISC) && len == 0)
1467 Perl_warner(aTHX_ packWARN(WARN_MISC),
1468 "Explicit blessing to '' (assuming package main)");
1469 stash = gv_stashpvn(ptr, len, TRUE);
1472 (void)sv_bless(ref, stash);
1474 ssv = Perl_sharedsv_find(aTHX_ ref);
1480 SV* fake_stash = newSVpv(HvNAME_get(stash),0);
1481 (void)sv_bless(ssv,(HV*)fake_stash);
1490 #endif /* USE_ITHREADS */
1495 Perl_sharedsv_init(aTHX);
1496 #endif /* USE_ITHREADS */