3 * Copyright (c) 2001-2002, 2006 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 Artur Bergman <sky AT crucially DOT net>
13 * Pulled in the (an)other direction by Nick Ing-Simmons
14 * <nick AT ing-simmons DOT net>
15 * CPAN version produced by Jerry D. Hedden <jdhedden AT cpan DOT org>
19 * Shared variables are implemented by a scheme similar to tieing.
20 * Each thread has a proxy SV with attached magic -- "private SVs" --
21 * which all point to a single SV in a separate shared interpreter
22 * (PL_sharedsv_space) -- "shared SVs".
24 * The shared SV holds the variable's true values, and its state is
25 * copied between the shared and private SVs with the usual
26 * mg_get()/mg_set() arrangement.
28 * Aggregates (AVs and HVs) are implemented using tie magic, except that
29 * the vtable used is one defined in this file rather than the standard one.
30 * This means that where a tie function like FETCH is normally invoked by
31 * the tie magic's mg_get() function, we completely bypass the calling of a
32 * perl-level function, and directly call C-level code to handle it. On
33 * the other hand, calls to functions like PUSH are done directly by code
34 * in av.c, etc., which we can't bypass. So the best we can do is to provide
35 * XS versions of these functions. We also have to attach a tie object,
36 * blessed into the class threads::shared::tie, to keep the method-calling
39 * Access to aggregate elements is done the usual tied way by returning a
40 * proxy PVLV element with attached element magic.
42 * Pointers to the shared SV are squirrelled away in the mg->mg_ptr field
43 * of magic (with mg_len == 0), and in the IV2PTR(SvIV(sv)) field of tied
44 * object SVs. These pointers have to be hidden like this because they
45 * cross interpreter boundaries, and we don't want sv_clear() and friends
48 * The three basic shared types look like the following:
52 * Shared scalar (my $s : shared):
54 * SV = PVMG(0x7ba238) at 0x7387a8
55 * FLAGS = (PADMY,GMG,SMG)
57 * MG_TYPE = PERL_MAGIC_shared_scalar(n)
58 * MG_PTR = 0x810358 <<<< pointer to the shared SV
62 * Shared aggregate (my @a : shared; my %h : shared):
64 * SV = PVAV(0x7175d0) at 0x738708
67 * MG_TYPE = PERL_MAGIC_tied(P)
68 * MG_OBJ = 0x7136e0 <<<< ref to the tied object
69 * SV = RV(0x7136f0) at 0x7136e0
71 * SV = PVMG(0x7ba238) at 0x738640 <<<< the tied object
72 * FLAGS = (OBJECT,IOK,pIOK)
73 * IV = 8455000 <<<< pointer to the shared AV
74 * STASH = 0x80abf0 "threads::shared::tie"
75 * MG_PTR = 0x810358 "" <<<< another pointer to the shared AV
80 * Aggregate element (my @a : shared; $a[0])
82 * SV = PVLV(0x77f628) at 0x713550
83 * FLAGS = (GMG,SMG,RMG,pIOK)
85 * MG_TYPE = PERL_MAGIC_shared_scalar(n)
86 * MG_PTR = 0x8103c0 "" <<<< pointer to the shared element
88 * MG_TYPE = PERL_MAGIC_tiedelem(p)
89 * MG_OBJ = 0x7136e0 <<<< ref to the tied object
90 * SV = RV(0x7136f0) at 0x7136e0
92 * SV = PVMG(0x7ba278) at 0x738660 <<<< the tied object
93 * FLAGS = (OBJECT,IOK,pIOK)
94 * IV = 8455064 <<<< pointer to the shared AV
95 * STASH = 0x80ac30 "threads::shared::tie"
98 * Note that PERL_MAGIC_tiedelem(p) magic doesn't have a pointer to a
99 * shared SV in mg_ptr; instead this is used to store the hash key,
100 * if any, like normal tied elements. Note also that element SVs may have
101 * pointers to both the shared aggregate and the shared element.
106 * If a shared variable is used as a perl-level lock or condition
107 * variable, then PERL_MAGIC_ext magic is attached to the associated
108 * *shared* SV, whose mg_ptr field points to a malloc'ed structure
109 * containing the necessary mutexes and condition variables.
113 * In this file, any variable name prefixed with 's' (e.g., ssv, stmp or sobj)
114 * usually represents a shared SV which corresponds to a private SV named
115 * without the prefix (e.g., sv, tmp or obj).
118 #define PERL_NO_GET_CONTEXT
123 # define NEED_sv_2pv_flags
124 # define NEED_vnewSVpvf
126 # define NEED_newSVpvn_flags
133 /* Magic signature(s) for mg_private to make PERL_MAGIC_ext magic safer */
134 #define UL_MAGIC_SIG 0x554C /* UL = user lock */
137 * The shared things need an interpreter to live in ...
139 PerlInterpreter *PL_sharedsv_space; /* The shared sv space */
140 /* To access shared space we fake aTHX in this scope and thread's context */
142 /* Bug #24255: We include ENTER+SAVETMPS/FREETMPS+LEAVE with
143 * SHARED_CONTEXT/CALLER_CONTEXT macros, so that any mortals, etc. created
144 * while in the shared interpreter context don't languish */
146 #define SHARED_CONTEXT \
148 PERL_SET_CONTEXT((aTHX = PL_sharedsv_space)); \
153 /* So we need a way to switch back to the caller's context... */
154 /* So we declare _another_ copy of the aTHX variable ... */
155 #define dTHXc PerlInterpreter *caller_perl = aTHX
157 /* ... and use it to switch back */
158 #define CALLER_CONTEXT \
162 PERL_SET_CONTEXT((aTHX = caller_perl)); \
166 * Only one thread at a time is allowed to mess with shared space.
171 PerlInterpreter *owner;
180 recursive_lock_t PL_sharedsv_lock; /* Mutex protecting the shared sv space */
183 recursive_lock_init(pTHX_ recursive_lock_t *lock)
185 Zero(lock,1,recursive_lock_t);
186 MUTEX_INIT(&lock->mutex);
187 COND_INIT(&lock->cond);
191 recursive_lock_destroy(pTHX_ recursive_lock_t *lock)
193 MUTEX_DESTROY(&lock->mutex);
194 COND_DESTROY(&lock->cond);
198 recursive_lock_release(pTHX_ recursive_lock_t *lock)
200 MUTEX_LOCK(&lock->mutex);
201 if (lock->owner == aTHX) {
202 if (--lock->locks == 0) {
204 COND_SIGNAL(&lock->cond);
207 MUTEX_UNLOCK(&lock->mutex);
211 recursive_lock_acquire(pTHX_ recursive_lock_t *lock, char *file, int line)
213 PERL_UNUSED_ARG(file);
214 PERL_UNUSED_ARG(line);
216 MUTEX_LOCK(&lock->mutex);
217 if (lock->owner == aTHX) {
220 while (lock->owner) {
222 Perl_warn(aTHX_ " %p waiting - owned by %p %s:%d\n",
223 aTHX, lock->owner, lock->file, lock->line);
225 COND_WAIT(&lock->cond,&lock->mutex);
234 MUTEX_UNLOCK(&lock->mutex);
235 SAVEDESTRUCTOR_X(recursive_lock_release,lock);
241 recursive_lock_acquire(aTHX_ &PL_sharedsv_lock, __FILE__, __LINE__);\
244 /* The unlocking is done automatically at scope exit */
245 #define LEAVE_LOCK LEAVE
248 /* A common idiom is to acquire access and switch in ... */
249 #define SHARED_EDIT \
255 /* ... then switch out and release access. */
256 #define SHARED_RELEASE \
264 This structure is attached (using ext magic) to any shared SV that
265 is used by user-level locking or condition code
269 recursive_lock_t lock; /* For user-levl locks */
270 perl_cond user_cond; /* For user-level conditions */
273 /* Magic used for attaching user_lock structs to shared SVs
275 The vtable used has just one entry - when the SV goes away
276 we free the memory for the above.
280 sharedsv_userlock_free(pTHX_ SV *sv, MAGIC *mg)
282 user_lock *ul = (user_lock *) mg->mg_ptr;
284 assert(aTHX == PL_sharedsv_space);
286 recursive_lock_destroy(aTHX_ &ul->lock);
287 COND_DESTROY(&ul->user_cond);
288 PerlMemShared_free(ul);
294 MGVTBL sharedsv_userlock_vtbl = {
299 sharedsv_userlock_free, /* free */
308 * Access to shared things is heavily based on MAGIC
309 * - in mg.h/mg.c/sv.c sense
312 /* In any thread that has access to a shared thing there is a "proxy"
313 for it in its own space which has 'MAGIC' associated which accesses
317 extern MGVTBL sharedsv_scalar_vtbl; /* Scalars have this vtable */
318 extern MGVTBL sharedsv_array_vtbl; /* Hashes and arrays have this
320 extern MGVTBL sharedsv_elem_vtbl; /* Elements of hashes and arrays have
321 this _AS WELL AS_ the scalar magic:
322 The sharedsv_elem_vtbl associates the element with the array/hash and
323 the sharedsv_scalar_vtbl associates it with the value
327 /* Get shared aggregate SV pointed to by threads::shared::tie magic object */
330 S_sharedsv_from_obj(pTHX_ SV *sv)
332 return ((SvROK(sv)) ? INT2PTR(SV *, SvIV(SvRV(sv))) : NULL);
336 /* Return the user_lock structure (if any) associated with a shared SV.
337 * If create is true, create one if it doesn't exist
340 S_get_userlock(pTHX_ SV* ssv, bool create)
343 user_lock *ul = NULL;
346 /* XXX Redesign the storage of user locks so we don't need a global
347 * lock to access them ???? DAPM */
350 /* Version of mg_find that also checks the private signature */
351 for (mg = SvMAGIC(ssv); mg; mg = mg->mg_moremagic) {
352 if ((mg->mg_type == PERL_MAGIC_ext) &&
353 (mg->mg_private == UL_MAGIC_SIG))
360 ul = (user_lock*)(mg->mg_ptr);
364 ul = (user_lock *) PerlMemShared_malloc(sizeof(user_lock));
365 Zero(ul, 1, user_lock);
366 /* Attach to shared SV using ext magic */
367 mg = sv_magicext(ssv, NULL, PERL_MAGIC_ext, &sharedsv_userlock_vtbl,
369 mg->mg_private = UL_MAGIC_SIG; /* Set private signature */
370 recursive_lock_init(aTHX_ &ul->lock);
371 COND_INIT(&ul->user_cond);
379 /* Given a private side SV tries to find if the SV has a shared backend,
380 * by looking for the magic.
383 Perl_sharedsv_find(pTHX_ SV *sv)
386 if (SvTYPE(sv) >= SVt_PVMG) {
390 if ((mg = mg_find(sv, PERL_MAGIC_tied))
391 && mg->mg_virtual == &sharedsv_array_vtbl) {
392 return ((SV *)mg->mg_ptr);
396 /* This should work for elements as well as they
397 * have scalar magic as well as their element magic
399 if ((mg = mg_find(sv, PERL_MAGIC_shared_scalar))
400 && mg->mg_virtual == &sharedsv_scalar_vtbl) {
401 return ((SV *)mg->mg_ptr);
406 /* Just for tidyness of API also handle tie objects */
407 if (SvROK(sv) && sv_derived_from(sv, "threads::shared::tie")) {
408 return (S_sharedsv_from_obj(aTHX_ sv));
414 /* Associate a private SV with a shared SV by pointing the appropriate
416 * Assumes lock is held.
419 Perl_sharedsv_associate(pTHX_ SV *sv, SV *ssv)
423 /* If we are asked for any private ops we need a thread */
424 assert ( aTHX != PL_sharedsv_space );
426 /* To avoid need for recursive locks require caller to hold lock */
427 assert ( PL_sharedsv_lock.owner == aTHX );
432 if (!(mg = mg_find(sv, PERL_MAGIC_tied))
433 || mg->mg_virtual != &sharedsv_array_vtbl
434 || (SV*) mg->mg_ptr != ssv)
437 sv_setref_iv(obj, "threads::shared::tie", PTR2IV(ssv));
439 sv_unmagic(sv, PERL_MAGIC_tied);
441 mg = sv_magicext(sv, obj, PERL_MAGIC_tied, &sharedsv_array_vtbl,
443 mg->mg_flags |= (MGf_COPY|MGf_DUP);
444 SvREFCNT_inc_void(ssv);
450 if ((SvTYPE(sv) < SVt_PVMG)
451 || !(mg = mg_find(sv, PERL_MAGIC_shared_scalar))
452 || mg->mg_virtual != &sharedsv_scalar_vtbl
453 || (SV*) mg->mg_ptr != ssv)
456 sv_unmagic(sv, PERL_MAGIC_shared_scalar);
458 mg = sv_magicext(sv, Nullsv, PERL_MAGIC_shared_scalar,
459 &sharedsv_scalar_vtbl, (char *)ssv, 0);
460 mg->mg_flags |= (MGf_DUP
465 SvREFCNT_inc_void(ssv);
470 assert ( Perl_sharedsv_find(aTHX_ sv) == ssv );
474 /* Given a private SV, create and return an associated shared SV.
475 * Assumes lock is held.
478 S_sharedsv_new_shared(pTHX_ SV *sv)
483 assert(PL_sharedsv_lock.owner == aTHX);
484 assert(aTHX != PL_sharedsv_space);
488 SvREFCNT(ssv) = 0; /* Will be upped to 1 by Perl_sharedsv_associate */
489 sv_upgrade(ssv, SvTYPE(sv));
491 Perl_sharedsv_associate(aTHX_ sv, ssv);
496 /* Given a shared SV, create and return an associated private SV.
497 * Assumes lock is held.
500 S_sharedsv_new_private(pTHX_ SV *ssv)
504 assert(PL_sharedsv_lock.owner == aTHX);
505 assert(aTHX != PL_sharedsv_space);
508 sv_upgrade(sv, SvTYPE(ssv));
509 Perl_sharedsv_associate(aTHX_ sv, ssv);
514 /* A threadsafe version of SvREFCNT_dec(ssv) */
517 S_sharedsv_dec(pTHX_ SV* ssv)
522 if (SvREFCNT(ssv) > 1) {
523 /* No side effects, so can do it lightweight */
535 /* Implements Perl-level share() and :shared */
538 Perl_sharedsv_share(pTHX_ SV *sv)
542 Perl_croak(aTHX_ "Cannot share globs yet");
546 Perl_croak(aTHX_ "Cannot share subs yet");
551 (void) S_sharedsv_new_shared(aTHX_ sv);
560 /* Number of milliseconds from 1/1/1601 to 1/1/1970 */
561 #define EPOCH_BIAS 11644473600000.
563 /* Returns relative time in milliseconds. (Adapted from Time::HiRes.) */
565 S_abs_2_rel_milli(double abs)
569 /* Get current time (in units of 100 nanoseconds since 1/1/1601) */
572 __int64 i64; /* 'signed' to keep compilers happy */
575 GetSystemTimeAsFileTime(&now.ft);
577 /* Relative time in milliseconds */
578 rel = (abs * 1000.) - (((double)now.i64 / 10000.) - EPOCH_BIAS);
587 # define ABS2RELMILLI(abs) \
589 abs -= (double)time(NULL); \
590 if (abs > 0) { abs *= 1000; } \
596 /* Do OS-specific condition timed wait */
599 Perl_sharedsv_cond_timedwait(perl_cond *cond, perl_mutex *mut, double abs)
601 #if defined(NETWARE) || defined(FAKE_THREADS) || defined(I_MACH_CTHREADS)
602 Perl_croak_nocontext("cond_timedwait not supported on this platform");
609 /* See comments in win32/win32thread.h COND_WAIT vis-a-vis race */
610 switch (WaitForSingleObject(cond->sem, S_abs_2_rel_milli(abs))) {
611 case WAIT_OBJECT_0: got_it = 1; break;
612 case WAIT_TIMEOUT: break;
614 /* WAIT_FAILED? WAIT_ABANDONED? others? */
615 Perl_croak_nocontext("panic: cond_timedwait (%ld)",GetLastError());
628 if ((rc = DosResetEventSem(*cond,&n_a)) && (rc != ERROR_ALREADY_RESET))
629 Perl_rc = rc, croak_with_os2error("panic: cond_timedwait-reset");
631 if (CheckOSError(DosWaitEventSem(*cond,abs))
632 && (rc != ERROR_INTERRUPT))
633 croak_with_os2error("panic: cond_timedwait");
634 if (rc == ERROR_INTERRUPT) errno = EINTR;
637 # else /* Hope you're I_PTHREAD! */
641 ts.tv_sec = (long)abs;
642 abs -= (NV)ts.tv_sec;
643 ts.tv_nsec = (long)(abs * 1000000000.0);
645 switch (pthread_cond_timedwait(cond, mut, &ts)) {
646 case 0: got_it = 1; break;
647 case ETIMEDOUT: break;
650 if (errno == ETIMEDOUT || errno == EAGAIN)
654 Perl_croak_nocontext("panic: cond_timedwait");
660 #endif /* NETWARE || FAKE_THREADS || I_MACH_CTHREADS */
664 /* Given a thingy referenced by a shared RV, copy it's value to a private
665 * RV, also copying the object status of the referent.
666 * If the private side is already an appropriate RV->SV combination, keep
670 S_get_RV(pTHX_ SV *sv, SV *sobj) {
673 ((obj = SvRV(sv))) &&
674 (Perl_sharedsv_find(aTHX_ obj) == sobj) &&
675 (SvTYPE(obj) == SvTYPE(sobj))))
677 /* Can't reuse obj */
679 SvREFCNT_dec(SvRV(sv));
681 assert(SvTYPE(sv) >= SVt_RV);
682 sv_setsv_nomg(sv, &PL_sv_undef);
685 obj = S_sharedsv_new_private(aTHX_ sobj);
690 /* Remove any old blessing */
691 SvREFCNT_dec(SvSTASH(obj));
694 if (SvOBJECT(sobj)) {
695 /* Add any new old blessing */
697 char* stash_ptr = SvPV((SV*) SvSTASH(sobj), len);
698 HV* stash = gv_stashpvn(stash_ptr, len, TRUE);
700 SvSTASH_set(obj, (HV*)SvREFCNT_inc(stash));
704 /* Every caller of S_get_RV needs this incantation (which cannot go inside
705 S_get_RV itself, as we do not want recursion beyond one level): */
706 #define get_RV(sv, sobj) \
707 S_get_RV(aTHX_ sv, sobj); \
708 /* Look ahead for refs of refs */ \
710 SvROK_on(SvRV(sv)); \
711 S_get_RV(aTHX_ SvRV(sv), SvRV(sobj)); \
715 /* ------------ PERL_MAGIC_shared_scalar(n) functions -------------- */
717 /* Get magic for PERL_MAGIC_shared_scalar(n) */
720 sharedsv_scalar_mg_get(pTHX_ SV *sv, MAGIC *mg)
722 SV *ssv = (SV *) mg->mg_ptr;
727 get_RV(sv, SvRV(ssv));
729 sv_setsv_nomg(sv, ssv);
735 /* Copy the contents of a private SV to a shared SV.
736 * Used by various mg_set()-type functions.
737 * Assumes lock is held.
740 sharedsv_scalar_store(pTHX_ SV *sv, SV *ssv)
745 assert(PL_sharedsv_lock.owner == aTHX);
746 if (!PL_dirty && SvROK(ssv) && SvREFCNT(SvRV(ssv)) == 1) {
747 SV *sv = sv_newmortal();
748 sv_upgrade(sv, SVt_RV);
749 get_RV(sv, SvRV(ssv));
753 SV *sobj = Perl_sharedsv_find(aTHX_ obj);
756 (void)SvUPGRADE(ssv, SVt_RV);
757 sv_setsv_nomg(ssv, &PL_sv_undef);
759 SvRV_set(ssv, SvREFCNT_inc(sobj));
761 if (SvOBJECT(sobj)) {
762 /* Remove any old blessing */
763 SvREFCNT_dec(SvSTASH(sobj));
767 SV* fake_stash = newSVpv(HvNAME_get(SvSTASH(obj)),0);
769 SvSTASH_set(sobj, (HV*)fake_stash);
778 sv_setsv_nomg(ssv, sv);
780 /* Remove any old blessing */
781 SvREFCNT_dec(SvSTASH(ssv));
785 SV* fake_stash = newSVpv(HvNAME_get(SvSTASH(sv)),0);
787 SvSTASH_set(ssv, (HV*)fake_stash);
792 Perl_croak(aTHX_ "Invalid value for shared scalar");
796 /* Set magic for PERL_MAGIC_shared_scalar(n) */
799 sharedsv_scalar_mg_set(pTHX_ SV *sv, MAGIC *mg)
801 SV *ssv = (SV*)(mg->mg_ptr);
804 if (SvTYPE(ssv) < SvTYPE(sv)) {
807 sv_upgrade(ssv, SvTYPE(sv));
810 sharedsv_scalar_store(aTHX_ sv, ssv);
815 /* Free magic for PERL_MAGIC_shared_scalar(n) */
818 sharedsv_scalar_mg_free(pTHX_ SV *sv, MAGIC *mg)
823 && SvROK((SV *)mg->mg_ptr) && SvREFCNT(SvRV((SV *)mg->mg_ptr)) == 1) {
824 SV *sv = sv_newmortal();
825 sv_upgrade(sv, SVt_RV);
826 get_RV(sv, SvRV((SV *)mg->mg_ptr));
828 S_sharedsv_dec(aTHX_ (SV*)mg->mg_ptr);
834 * Called during cloning of PERL_MAGIC_shared_scalar(n) magic in new thread
837 sharedsv_scalar_mg_dup(pTHX_ MAGIC *mg, CLONE_PARAMS *param)
839 PERL_UNUSED_ARG(param);
840 SvREFCNT_inc_void(mg->mg_ptr);
846 * Called during local $shared
849 sharedsv_scalar_mg_local(pTHX_ SV* nsv, MAGIC *mg)
852 SV *ssv = (SV *) mg->mg_ptr;
855 SvREFCNT_inc_void(ssv);
858 nmg = sv_magicext(nsv, mg->mg_obj, mg->mg_type, mg->mg_virtual,
859 mg->mg_ptr, mg->mg_len);
860 nmg->mg_flags = mg->mg_flags;
861 nmg->mg_private = mg->mg_private;
867 MGVTBL sharedsv_scalar_vtbl = {
868 sharedsv_scalar_mg_get, /* get */
869 sharedsv_scalar_mg_set, /* set */
872 sharedsv_scalar_mg_free, /* free */
874 sharedsv_scalar_mg_dup, /* dup */
876 sharedsv_scalar_mg_local, /* local */
880 /* ------------ PERL_MAGIC_tiedelem(p) functions -------------- */
882 /* Get magic for PERL_MAGIC_tiedelem(p) */
885 sharedsv_elem_mg_FETCH(pTHX_ SV *sv, MAGIC *mg)
888 SV *saggregate = S_sharedsv_from_obj(aTHX_ mg->mg_obj);
892 if (saggregate) { /* During global destruction, underlying
893 aggregate may no longer exist */
894 if (SvTYPE(saggregate) == SVt_PVAV) {
895 assert ( mg->mg_ptr == 0 );
897 svp = av_fetch((AV*) saggregate, mg->mg_len, 0);
899 char *key = mg->mg_ptr;
900 I32 len = mg->mg_len;
901 assert ( mg->mg_ptr != 0 );
902 if (mg->mg_len == HEf_SVKEY) {
904 key = SvPV((SV *)mg->mg_ptr, slen);
906 if (SvUTF8((SV *)mg->mg_ptr)) {
911 svp = hv_fetch((HV*) saggregate, key, len, 0);
916 /* Exists in the array */
918 get_RV(sv, SvRV(*svp));
920 /* $ary->[elem] or $ary->{elem} is a scalar */
921 Perl_sharedsv_associate(aTHX_ sv, *svp);
925 /* Not in the array */
926 sv_setsv(sv, &PL_sv_undef);
932 /* Set magic for PERL_MAGIC_tiedelem(p) */
935 sharedsv_elem_mg_STORE(pTHX_ SV *sv, MAGIC *mg)
938 SV *saggregate = S_sharedsv_from_obj(aTHX_ mg->mg_obj);
940 /* Theory - SV itself is magically shared - and we have ordered the
941 magic such that by the time we get here it has been stored
942 to its shared counterpart
946 if (SvTYPE(saggregate) == SVt_PVAV) {
947 assert ( mg->mg_ptr == 0 );
949 svp = av_fetch((AV*) saggregate, mg->mg_len, 1);
951 char *key = mg->mg_ptr;
952 I32 len = mg->mg_len;
953 assert ( mg->mg_ptr != 0 );
954 if (mg->mg_len == HEf_SVKEY) {
956 key = SvPV((SV *)mg->mg_ptr, slen);
958 if (SvUTF8((SV *)mg->mg_ptr)) {
963 svp = hv_fetch((HV*) saggregate, key, len, 1);
966 Perl_sharedsv_associate(aTHX_ sv, *svp);
967 sharedsv_scalar_store(aTHX_ sv, *svp);
972 /* Clear magic for PERL_MAGIC_tiedelem(p) */
975 sharedsv_elem_mg_DELETE(pTHX_ SV *sv, MAGIC *mg)
979 SV *saggregate = S_sharedsv_from_obj(aTHX_ mg->mg_obj);
981 /* Object may not exist during global destruction */
987 sharedsv_elem_mg_FETCH(aTHX_ sv, mg);
988 if ((shmg = mg_find(sv, PERL_MAGIC_shared_scalar)))
989 sharedsv_scalar_mg_get(aTHX_ sv, shmg);
990 if (SvTYPE(saggregate) == SVt_PVAV) {
992 av_delete((AV*) saggregate, mg->mg_len, G_DISCARD);
994 char *key = mg->mg_ptr;
995 I32 len = mg->mg_len;
996 assert ( mg->mg_ptr != 0 );
997 if (mg->mg_len == HEf_SVKEY) {
999 key = SvPV((SV *)mg->mg_ptr, slen);
1001 if (SvUTF8((SV *)mg->mg_ptr)) {
1006 (void) hv_delete((HV*) saggregate, key, len, G_DISCARD);
1013 /* Called during cloning of PERL_MAGIC_tiedelem(p) magic in new
1017 sharedsv_elem_mg_dup(pTHX_ MAGIC *mg, CLONE_PARAMS *param)
1019 PERL_UNUSED_ARG(param);
1020 SvREFCNT_inc_void(S_sharedsv_from_obj(aTHX_ mg->mg_obj));
1021 assert(mg->mg_flags & MGf_DUP);
1025 MGVTBL sharedsv_elem_vtbl = {
1026 sharedsv_elem_mg_FETCH, /* get */
1027 sharedsv_elem_mg_STORE, /* set */
1029 sharedsv_elem_mg_DELETE, /* clear */
1032 sharedsv_elem_mg_dup, /* dup */
1038 /* ------------ PERL_MAGIC_tied(P) functions -------------- */
1040 /* Len magic for PERL_MAGIC_tied(P) */
1043 sharedsv_array_mg_FETCHSIZE(pTHX_ SV *sv, MAGIC *mg)
1046 SV *ssv = (SV *) mg->mg_ptr;
1048 PERL_UNUSED_ARG(sv);
1050 if (SvTYPE(ssv) == SVt_PVAV) {
1051 val = av_len((AV*) ssv);
1053 /* Not actually defined by tie API but ... */
1054 val = HvUSEDKEYS((HV*) ssv);
1060 /* Clear magic for PERL_MAGIC_tied(P) */
1063 sharedsv_array_mg_CLEAR(pTHX_ SV *sv, MAGIC *mg)
1066 SV *ssv = (SV *) mg->mg_ptr;
1067 const bool isav = SvTYPE(ssv) == SVt_PVAV;
1068 PERL_UNUSED_ARG(sv);
1071 SV **svp = isav ? AvARRAY((AV *)ssv) : NULL;
1072 I32 items = isav ? AvFILLp((AV *)ssv) + 1 : 0;
1074 if (!isav) hv_iterinit((HV *)ssv);
1075 while (isav ? items-- : !!(iter = hv_iternext((HV *)ssv))) {
1076 SV *sv = isav ? *svp++ : HeVAL(iter);
1078 if ( (SvOBJECT(sv) || (SvROK(sv) && (sv = SvRV(sv))))
1079 && SvREFCNT(sv) == 1 ) {
1080 SV *tmp = Perl_sv_newmortal(caller_perl);
1081 PERL_SET_CONTEXT((aTHX = caller_perl));
1082 sv_upgrade(tmp, SVt_RV);
1084 PERL_SET_CONTEXT((aTHX = PL_sharedsv_space));
1088 if (isav) av_clear((AV*) ssv);
1089 else hv_clear((HV*) ssv);
1094 /* Free magic for PERL_MAGIC_tied(P) */
1097 sharedsv_array_mg_free(pTHX_ SV *sv, MAGIC *mg)
1099 PERL_UNUSED_ARG(sv);
1100 S_sharedsv_dec(aTHX_ (SV*)mg->mg_ptr);
1105 * Copy magic for PERL_MAGIC_tied(P)
1106 * This is called when perl is about to access an element of
1109 #if PERL_VERSION >= 11
1111 sharedsv_array_mg_copy(pTHX_ SV *sv, MAGIC* mg,
1112 SV *nsv, const char *name, I32 namlen)
1115 sharedsv_array_mg_copy(pTHX_ SV *sv, MAGIC* mg,
1116 SV *nsv, const char *name, int namlen)
1119 MAGIC *nmg = sv_magicext(nsv,mg->mg_obj,
1120 toLOWER(mg->mg_type),&sharedsv_elem_vtbl,
1122 PERL_UNUSED_ARG(sv);
1123 nmg->mg_flags |= MGf_DUP;
1127 /* Called during cloning of PERL_MAGIC_tied(P) magic in new thread */
1130 sharedsv_array_mg_dup(pTHX_ MAGIC *mg, CLONE_PARAMS *param)
1132 PERL_UNUSED_ARG(param);
1133 SvREFCNT_inc_void((SV*)mg->mg_ptr);
1134 assert(mg->mg_flags & MGf_DUP);
1138 MGVTBL sharedsv_array_vtbl = {
1141 sharedsv_array_mg_FETCHSIZE,/* len */
1142 sharedsv_array_mg_CLEAR, /* clear */
1143 sharedsv_array_mg_free, /* free */
1144 sharedsv_array_mg_copy, /* copy */
1145 sharedsv_array_mg_dup, /* dup */
1152 /* Recursively unlocks a shared sv. */
1155 Perl_sharedsv_unlock(pTHX_ SV *ssv)
1157 user_lock *ul = S_get_userlock(aTHX_ ssv, 0);
1159 recursive_lock_release(aTHX_ &ul->lock);
1163 /* Recursive locks on a sharedsv.
1164 * Locks are dynamically scoped at the level of the first lock.
1167 Perl_sharedsv_lock(pTHX_ SV *ssv)
1172 ul = S_get_userlock(aTHX_ ssv, 1);
1173 recursive_lock_acquire(aTHX_ &ul->lock, __FILE__, __LINE__);
1176 /* Handles calls from lock() builtin via PL_lockhook */
1179 Perl_sharedsv_locksv(pTHX_ SV *sv)
1185 ssv = Perl_sharedsv_find(aTHX_ sv);
1187 croak("lock can only be used on shared values");
1188 Perl_sharedsv_lock(aTHX_ ssv);
1192 /* Can a shared object be destroyed?
1193 * True if not a shared,
1194 * or if destroying last proxy on a shared object
1196 #ifdef PL_destroyhook
1198 Perl_shared_object_destroy(pTHX_ SV *sv)
1204 ssv = Perl_sharedsv_find(aTHX_ sv);
1205 return (!ssv || (SvREFCNT(ssv) <= 1));
1209 /* veto signal dispatch if we have the lock */
1211 #ifdef PL_signalhook
1213 STATIC despatch_signals_proc_t prev_signal_hook = NULL;
1216 S_shared_signal_hook(pTHX) {
1218 MUTEX_LOCK(&PL_sharedsv_lock.mutex);
1219 us = (PL_sharedsv_lock.owner == aTHX);
1220 MUTEX_UNLOCK(&PL_sharedsv_lock.mutex);
1222 return; /* try again later */
1223 prev_signal_hook(aTHX);
1227 /* Saves a space for keeping SVs wider than an interpreter. */
1230 Perl_sharedsv_init(pTHX)
1233 /* This pair leaves us in shared context ... */
1234 PL_sharedsv_space = perl_alloc();
1235 perl_construct(PL_sharedsv_space);
1236 LEAVE; /* This balances the ENTER at the end of perl_construct. */
1237 PERL_SET_CONTEXT((aTHX = caller_perl));
1238 recursive_lock_init(aTHX_ &PL_sharedsv_lock);
1239 PL_lockhook = &Perl_sharedsv_locksv;
1240 PL_sharehook = &Perl_sharedsv_share;
1241 #ifdef PL_destroyhook
1242 PL_destroyhook = &Perl_shared_object_destroy;
1244 #ifdef PL_signalhook
1245 if (!prev_signal_hook) {
1246 prev_signal_hook = PL_signalhook;
1247 PL_signalhook = &S_shared_signal_hook;
1252 #endif /* USE_ITHREADS */
1254 MODULE = threads::shared PACKAGE = threads::shared::tie
1264 SV *sobj = S_sharedsv_from_obj(aTHX_ obj);
1266 for (i = 1; i < items; i++) {
1267 SV* tmp = newSVsv(ST(i));
1270 stmp = S_sharedsv_new_shared(aTHX_ tmp);
1271 sharedsv_scalar_store(aTHX_ tmp, stmp);
1273 av_push((AV*) sobj, stmp);
1274 SvREFCNT_inc_void(stmp);
1281 UNSHIFT(SV *obj, ...)
1284 SV *sobj = S_sharedsv_from_obj(aTHX_ obj);
1288 av_unshift((AV*)sobj, items - 1);
1290 for (i = 1; i < items; i++) {
1291 SV *tmp = newSVsv(ST(i));
1292 SV *stmp = S_sharedsv_new_shared(aTHX_ tmp);
1293 sharedsv_scalar_store(aTHX_ tmp, stmp);
1295 av_store((AV*) sobj, i - 1, stmp);
1296 SvREFCNT_inc_void(stmp);
1307 SV *sobj = S_sharedsv_from_obj(aTHX_ obj);
1311 ssv = av_pop((AV*)sobj);
1313 ST(0) = sv_newmortal();
1314 Perl_sharedsv_associate(aTHX_ ST(0), ssv);
1317 /* XSRETURN(1); - implied */
1324 SV *sobj = S_sharedsv_from_obj(aTHX_ obj);
1328 ssv = av_shift((AV*)sobj);
1330 ST(0) = sv_newmortal();
1331 Perl_sharedsv_associate(aTHX_ ST(0), ssv);
1334 /* XSRETURN(1); - implied */
1338 EXTEND(SV *obj, IV count)
1341 SV *sobj = S_sharedsv_from_obj(aTHX_ obj);
1343 av_extend((AV*)sobj, count);
1348 STORESIZE(SV *obj,IV count)
1351 SV *sobj = S_sharedsv_from_obj(aTHX_ obj);
1353 av_fill((AV*) sobj, count);
1358 EXISTS(SV *obj, SV *index)
1361 SV *sobj = S_sharedsv_from_obj(aTHX_ obj);
1363 if (SvTYPE(sobj) == SVt_PVAV) {
1365 exists = av_exists((AV*) sobj, SvIV(index));
1369 char *key = SvPVutf8(index, slen);
1371 if (SvUTF8(index)) {
1375 exists = hv_exists((HV*) sobj, key, len);
1378 ST(0) = (exists) ? &PL_sv_yes : &PL_sv_no;
1379 /* XSRETURN(1); - implied */
1386 SV *sobj = S_sharedsv_from_obj(aTHX_ obj);
1392 hv_iterinit((HV*) sobj);
1393 entry = hv_iternext((HV*) sobj);
1395 I32 utf8 = HeKUTF8(entry);
1396 key = hv_iterkey(entry,&len);
1398 ST(0) = newSVpvn_flags(key, len, SVs_TEMP | (utf8 ? SVf_UTF8 : 0));
1401 ST(0) = &PL_sv_undef;
1404 /* XSRETURN(1); - implied */
1408 NEXTKEY(SV *obj, SV *oldkey)
1411 SV *sobj = S_sharedsv_from_obj(aTHX_ obj);
1416 PERL_UNUSED_VAR(oldkey);
1420 entry = hv_iternext((HV*) sobj);
1422 I32 utf8 = HeKUTF8(entry);
1423 key = hv_iterkey(entry,&len);
1425 ST(0) = newSVpvn_flags(key, len, SVs_TEMP | (utf8 ? SVf_UTF8 : 0));
1428 ST(0) = &PL_sv_undef;
1431 /* XSRETURN(1); - implied */
1434 MODULE = threads::shared PACKAGE = threads::shared
1444 myref = SvRV(myref);
1445 if (SvMAGICAL(myref))
1448 myref = SvRV(myref);
1449 ssv = Perl_sharedsv_find(aTHX_ myref);
1452 ST(0) = sv_2mortal(newSVuv(PTR2UV(ssv)));
1453 /* XSRETURN(1); - implied */
1462 myref = SvRV(myref);
1464 myref = SvRV(myref);
1465 ssv = Perl_sharedsv_find(aTHX_ myref);
1467 if (ckWARN(WARN_THREADS)) {
1468 Perl_warner(aTHX_ packWARN(WARN_THREADS),
1469 "%" SVf " is not shared", ST(0));
1473 ST(0) = sv_2mortal(newSViv(SvREFCNT(ssv)));
1474 /* XSRETURN(1); - implied */
1482 Perl_croak(aTHX_ "Argument to share needs to be passed as ref");
1483 myref = SvRV(myref);
1485 myref = SvRV(myref);
1486 Perl_sharedsv_share(aTHX_ myref);
1487 ST(0) = sv_2mortal(newRV_inc(myref));
1488 /* XSRETURN(1); - implied */
1492 cond_wait(SV *ref_cond, SV *ref_lock = 0)
1493 PROTOTYPE: \[$@%];\[$@%]
1496 perl_cond* user_condition;
1500 if (!SvROK(ref_cond))
1501 Perl_croak(aTHX_ "Argument to cond_wait needs to be passed as ref");
1502 ref_cond = SvRV(ref_cond);
1503 if (SvROK(ref_cond))
1504 ref_cond = SvRV(ref_cond);
1505 ssv = Perl_sharedsv_find(aTHX_ ref_cond);
1507 Perl_croak(aTHX_ "cond_wait can only be used on shared values");
1508 ul = S_get_userlock(aTHX_ ssv, 1);
1510 user_condition = &ul->user_cond;
1511 if (ref_lock && (ref_cond != ref_lock)) {
1512 if (!SvROK(ref_lock))
1513 Perl_croak(aTHX_ "cond_wait lock needs to be passed as ref");
1514 ref_lock = SvRV(ref_lock);
1515 if (SvROK(ref_lock)) ref_lock = SvRV(ref_lock);
1516 ssv = Perl_sharedsv_find(aTHX_ ref_lock);
1518 Perl_croak(aTHX_ "cond_wait lock must be a shared value");
1519 ul = S_get_userlock(aTHX_ ssv, 1);
1521 if (ul->lock.owner != aTHX)
1522 croak("You need a lock before you can cond_wait");
1524 /* Stealing the members of the lock object worries me - NI-S */
1525 MUTEX_LOCK(&ul->lock.mutex);
1526 ul->lock.owner = NULL;
1527 locks = ul->lock.locks;
1530 /* Since we are releasing the lock here, we need to tell other
1531 * people that it is ok to go ahead and use it */
1532 COND_SIGNAL(&ul->lock.cond);
1533 COND_WAIT(user_condition, &ul->lock.mutex);
1534 while (ul->lock.owner != NULL) {
1535 /* OK -- must reacquire the lock */
1536 COND_WAIT(&ul->lock.cond, &ul->lock.mutex);
1538 ul->lock.owner = aTHX;
1539 ul->lock.locks = locks;
1540 MUTEX_UNLOCK(&ul->lock.mutex);
1544 cond_timedwait(SV *ref_cond, double abs, SV *ref_lock = 0)
1545 PROTOTYPE: \[$@%]$;\[$@%]
1548 perl_cond* user_condition;
1552 if (! SvROK(ref_cond))
1553 Perl_croak(aTHX_ "Argument to cond_timedwait needs to be passed as ref");
1554 ref_cond = SvRV(ref_cond);
1555 if (SvROK(ref_cond))
1556 ref_cond = SvRV(ref_cond);
1557 ssv = Perl_sharedsv_find(aTHX_ ref_cond);
1559 Perl_croak(aTHX_ "cond_timedwait can only be used on shared values");
1560 ul = S_get_userlock(aTHX_ ssv, 1);
1562 user_condition = &ul->user_cond;
1563 if (ref_lock && (ref_cond != ref_lock)) {
1564 if (! SvROK(ref_lock))
1565 Perl_croak(aTHX_ "cond_timedwait lock needs to be passed as ref");
1566 ref_lock = SvRV(ref_lock);
1567 if (SvROK(ref_lock)) ref_lock = SvRV(ref_lock);
1568 ssv = Perl_sharedsv_find(aTHX_ ref_lock);
1570 Perl_croak(aTHX_ "cond_timedwait lock must be a shared value");
1571 ul = S_get_userlock(aTHX_ ssv, 1);
1573 if (ul->lock.owner != aTHX)
1574 Perl_croak(aTHX_ "You need a lock before you can cond_wait");
1576 MUTEX_LOCK(&ul->lock.mutex);
1577 ul->lock.owner = NULL;
1578 locks = ul->lock.locks;
1580 /* Since we are releasing the lock here, we need to tell other
1581 * people that it is ok to go ahead and use it */
1582 COND_SIGNAL(&ul->lock.cond);
1583 RETVAL = Perl_sharedsv_cond_timedwait(user_condition, &ul->lock.mutex, abs);
1584 while (ul->lock.owner != NULL) {
1585 /* OK -- must reacquire the lock... */
1586 COND_WAIT(&ul->lock.cond, &ul->lock.mutex);
1588 ul->lock.owner = aTHX;
1589 ul->lock.locks = locks;
1590 MUTEX_UNLOCK(&ul->lock.mutex);
1599 cond_signal(SV *myref)
1606 Perl_croak(aTHX_ "Argument to cond_signal needs to be passed as ref");
1607 myref = SvRV(myref);
1609 myref = SvRV(myref);
1610 ssv = Perl_sharedsv_find(aTHX_ myref);
1612 Perl_croak(aTHX_ "cond_signal can only be used on shared values");
1613 ul = S_get_userlock(aTHX_ ssv, 1);
1614 if (ckWARN(WARN_THREADS) && ul->lock.owner != aTHX) {
1615 Perl_warner(aTHX_ packWARN(WARN_THREADS),
1616 "cond_signal() called on unlocked variable");
1618 COND_SIGNAL(&ul->user_cond);
1622 cond_broadcast(SV *myref)
1629 Perl_croak(aTHX_ "Argument to cond_broadcast needs to be passed as ref");
1630 myref = SvRV(myref);
1632 myref = SvRV(myref);
1633 ssv = Perl_sharedsv_find(aTHX_ myref);
1635 Perl_croak(aTHX_ "cond_broadcast can only be used on shared values");
1636 ul = S_get_userlock(aTHX_ ssv, 1);
1637 if (ckWARN(WARN_THREADS) && ul->lock.owner != aTHX) {
1638 Perl_warner(aTHX_ packWARN(WARN_THREADS),
1639 "cond_broadcast() called on unlocked variable");
1641 COND_BROADCAST(&ul->user_cond);
1645 bless(SV* myref, ...);
1652 stash = CopSTASH(PL_curcop);
1654 SV* classname = ST(1);
1659 ! SvGMAGICAL(classname) &&
1660 ! SvAMAGIC(classname) &&
1663 Perl_croak(aTHX_ "Attempt to bless into a reference");
1665 ptr = SvPV(classname, len);
1666 if (ckWARN(WARN_MISC) && len == 0) {
1667 Perl_warner(aTHX_ packWARN(WARN_MISC),
1668 "Explicit blessing to '' (assuming package main)");
1670 stash = gv_stashpvn(ptr, len, TRUE);
1672 SvREFCNT_inc_void(myref);
1673 (void)sv_bless(myref, stash);
1674 ST(0) = sv_2mortal(myref);
1675 ssv = Perl_sharedsv_find(aTHX_ myref);
1681 SV* fake_stash = newSVpv(HvNAME_get(stash), 0);
1682 (void)sv_bless(ssv, (HV*)fake_stash);
1687 /* XSRETURN(1); - implied */
1689 #endif /* USE_ITHREADS */
1694 Perl_sharedsv_init(aTHX);
1695 #endif /* USE_ITHREADS */