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 static 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 static 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, const 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 const static MGVTBL sharedsv_userlock_vtbl = {
299 sharedsv_userlock_free, /* free */
308 /* Support for dual-valued variables */
310 # define DUALVAR_FLAGS(sv) \
312 ? ((SvNOK(sv) || SvNOKp(sv)) ? SVf_NOK \
313 : ((SvIsUV(sv)) ? (SVf_IOK | SVf_IVisUV) \
314 : ((SvIOK(sv) || SvIOKp(sv)) ? SVf_IOK : 0))) \
317 # define DUALVAR_FLAGS(sv) \
319 ? ((SvNOK(sv) || SvNOKp(sv)) ? SVf_NOK \
320 : ((SvIOK(sv) || SvIOKp(sv)) ? SVf_IOK : 0)) \
326 * Access to shared things is heavily based on MAGIC
327 * - in mg.h/mg.c/sv.c sense
330 /* In any thread that has access to a shared thing there is a "proxy"
331 for it in its own space which has 'MAGIC' associated which accesses
335 const static MGVTBL sharedsv_scalar_vtbl; /* Scalars have this vtable */
336 const static MGVTBL sharedsv_array_vtbl; /* Hashes and arrays have this
338 const static MGVTBL sharedsv_elem_vtbl; /* Elements of hashes and arrays have
339 this _AS WELL AS_ the scalar magic:
340 The sharedsv_elem_vtbl associates the element with the array/hash and
341 the sharedsv_scalar_vtbl associates it with the value
345 /* Get shared aggregate SV pointed to by threads::shared::tie magic object */
347 #define SHAREDSV_FROM_OBJ(sv) ((SvROK(sv)) ? INT2PTR(SV *, SvIV(SvRV(sv))) : NULL)
350 /* Return the user_lock structure (if any) associated with a shared SV.
351 * If create is true, create one if it doesn't exist
354 S_get_userlock(pTHX_ SV* ssv, bool create)
357 user_lock *ul = NULL;
360 /* XXX Redesign the storage of user locks so we don't need a global
361 * lock to access them ???? DAPM */
364 /* Version of mg_find that also checks the private signature */
365 for (mg = SvMAGIC(ssv); mg; mg = mg->mg_moremagic) {
366 if ((mg->mg_type == PERL_MAGIC_ext) &&
367 (mg->mg_private == UL_MAGIC_SIG))
374 ul = (user_lock*)(mg->mg_ptr);
378 ul = (user_lock *) PerlMemShared_malloc(sizeof(user_lock));
379 Zero(ul, 1, user_lock);
380 /* Attach to shared SV using ext magic */
381 mg = sv_magicext(ssv, NULL, PERL_MAGIC_ext, &sharedsv_userlock_vtbl,
383 mg->mg_private = UL_MAGIC_SIG; /* Set private signature */
384 recursive_lock_init(aTHX_ &ul->lock);
385 COND_INIT(&ul->user_cond);
393 /* Given a private side SV tries to find if the SV has a shared backend,
394 * by looking for the magic.
397 Perl_sharedsv_find(pTHX_ SV *sv)
400 if (SvTYPE(sv) >= SVt_PVMG) {
404 if ((mg = mg_find(sv, PERL_MAGIC_tied))
405 && mg->mg_virtual == &sharedsv_array_vtbl) {
406 return ((SV *)mg->mg_ptr);
410 /* This should work for elements as well as they
411 * have scalar magic as well as their element magic
413 if ((mg = mg_find(sv, PERL_MAGIC_shared_scalar))
414 && mg->mg_virtual == &sharedsv_scalar_vtbl) {
415 return ((SV *)mg->mg_ptr);
420 /* Just for tidyness of API also handle tie objects */
421 if (SvROK(sv) && sv_derived_from(sv, "threads::shared::tie")) {
422 return (SHAREDSV_FROM_OBJ(sv));
428 /* Associate a private SV with a shared SV by pointing the appropriate
430 * Assumes lock is held.
433 Perl_sharedsv_associate(pTHX_ SV *sv, SV *ssv)
437 /* If we are asked for any private ops we need a thread */
438 assert ( aTHX != PL_sharedsv_space );
440 /* To avoid need for recursive locks require caller to hold lock */
441 assert ( PL_sharedsv_lock.owner == aTHX );
446 if (!(mg = mg_find(sv, PERL_MAGIC_tied))
447 || mg->mg_virtual != &sharedsv_array_vtbl
448 || (SV*) mg->mg_ptr != ssv)
451 sv_setref_iv(obj, "threads::shared::tie", PTR2IV(ssv));
453 sv_unmagic(sv, PERL_MAGIC_tied);
455 mg = sv_magicext(sv, obj, PERL_MAGIC_tied, &sharedsv_array_vtbl,
457 mg->mg_flags |= (MGf_COPY|MGf_DUP);
458 SvREFCNT_inc_void(ssv);
464 if ((SvTYPE(sv) < SVt_PVMG)
465 || !(mg = mg_find(sv, PERL_MAGIC_shared_scalar))
466 || mg->mg_virtual != &sharedsv_scalar_vtbl
467 || (SV*) mg->mg_ptr != ssv)
470 sv_unmagic(sv, PERL_MAGIC_shared_scalar);
472 mg = sv_magicext(sv, Nullsv, PERL_MAGIC_shared_scalar,
473 &sharedsv_scalar_vtbl, (char *)ssv, 0);
474 mg->mg_flags |= (MGf_DUP
479 SvREFCNT_inc_void(ssv);
484 assert ( Perl_sharedsv_find(aTHX_ sv) == ssv );
488 /* Given a private SV, create and return an associated shared SV.
489 * Assumes lock is held.
492 S_sharedsv_new_shared(pTHX_ SV *sv)
497 assert(PL_sharedsv_lock.owner == aTHX);
498 assert(aTHX != PL_sharedsv_space);
502 SvREFCNT(ssv) = 0; /* Will be upped to 1 by Perl_sharedsv_associate */
503 sv_upgrade(ssv, SvTYPE(sv));
505 Perl_sharedsv_associate(aTHX_ sv, ssv);
510 /* Given a shared SV, create and return an associated private SV.
511 * Assumes lock is held.
514 S_sharedsv_new_private(pTHX_ SV *ssv)
518 assert(PL_sharedsv_lock.owner == aTHX);
519 assert(aTHX != PL_sharedsv_space);
522 sv_upgrade(sv, SvTYPE(ssv));
523 Perl_sharedsv_associate(aTHX_ sv, ssv);
528 /* A threadsafe version of SvREFCNT_dec(ssv) */
531 S_sharedsv_dec(pTHX_ SV* ssv)
536 if (SvREFCNT(ssv) > 1) {
537 /* No side effects, so can do it lightweight */
549 /* Implements Perl-level share() and :shared */
552 Perl_sharedsv_share(pTHX_ SV *sv)
556 Perl_croak(aTHX_ "Cannot share globs yet");
560 Perl_croak(aTHX_ "Cannot share subs yet");
565 (void) S_sharedsv_new_shared(aTHX_ sv);
574 /* Number of milliseconds from 1/1/1601 to 1/1/1970 */
575 #define EPOCH_BIAS 11644473600000.
577 /* Returns relative time in milliseconds. (Adapted from Time::HiRes.) */
579 S_abs_2_rel_milli(double abs)
583 /* Get current time (in units of 100 nanoseconds since 1/1/1601) */
586 __int64 i64; /* 'signed' to keep compilers happy */
589 GetSystemTimeAsFileTime(&now.ft);
591 /* Relative time in milliseconds */
592 rel = (abs * 1000.) - (((double)now.i64 / 10000.) - EPOCH_BIAS);
601 # define ABS2RELMILLI(abs) \
603 abs -= (double)time(NULL); \
604 if (abs > 0) { abs *= 1000; } \
610 /* Do OS-specific condition timed wait */
613 Perl_sharedsv_cond_timedwait(perl_cond *cond, perl_mutex *mut, double abs)
615 #if defined(NETWARE) || defined(I_MACH_CTHREADS)
616 Perl_croak_nocontext("cond_timedwait not supported on this platform");
623 /* See comments in win32/win32thread.h COND_WAIT vis-a-vis race */
624 switch (WaitForSingleObject(cond->sem, S_abs_2_rel_milli(abs))) {
625 case WAIT_OBJECT_0: got_it = 1; break;
626 case WAIT_TIMEOUT: break;
628 /* WAIT_FAILED? WAIT_ABANDONED? others? */
629 Perl_croak_nocontext("panic: cond_timedwait (%ld)",GetLastError());
642 if ((rc = DosResetEventSem(*cond,&n_a)) && (rc != ERROR_ALREADY_RESET))
643 Perl_rc = rc, croak_with_os2error("panic: cond_timedwait-reset");
645 if (CheckOSError(DosWaitEventSem(*cond,abs))
646 && (rc != ERROR_INTERRUPT))
647 croak_with_os2error("panic: cond_timedwait");
648 if (rc == ERROR_INTERRUPT) errno = EINTR;
651 # else /* Hope you're I_PTHREAD! */
655 ts.tv_sec = (long)abs;
656 abs -= (NV)ts.tv_sec;
657 ts.tv_nsec = (long)(abs * 1000000000.0);
659 switch (pthread_cond_timedwait(cond, mut, &ts)) {
660 case 0: got_it = 1; break;
661 case ETIMEDOUT: break;
664 if (errno == ETIMEDOUT || errno == EAGAIN)
668 Perl_croak_nocontext("panic: cond_timedwait");
674 #endif /* NETWARE || I_MACH_CTHREADS */
678 /* Given a thingy referenced by a shared RV, copy it's value to a private
679 * RV, also copying the object status of the referent.
680 * If the private side is already an appropriate RV->SV combination, keep
684 S_get_RV(pTHX_ SV *sv, SV *sobj) {
687 ((obj = SvRV(sv))) &&
688 (Perl_sharedsv_find(aTHX_ obj) == sobj) &&
689 (SvTYPE(obj) == SvTYPE(sobj))))
691 /* Can't reuse obj */
693 SvREFCNT_dec(SvRV(sv));
695 assert(SvTYPE(sv) >= SVt_RV);
696 sv_setsv_nomg(sv, &PL_sv_undef);
699 obj = S_sharedsv_new_private(aTHX_ sobj);
704 /* Remove any old blessing */
705 SvREFCNT_dec(SvSTASH(obj));
708 if (SvOBJECT(sobj)) {
709 /* Add any new old blessing */
711 char* stash_ptr = SvPV((SV*) SvSTASH(sobj), len);
712 HV* stash = gv_stashpvn(stash_ptr, len, TRUE);
714 SvSTASH_set(obj, (HV*)SvREFCNT_inc(stash));
718 /* Every caller of S_get_RV needs this incantation (which cannot go inside
719 S_get_RV itself, as we do not want recursion beyond one level): */
720 #define get_RV(sv, sobj) \
721 S_get_RV(aTHX_ sv, sobj); \
722 /* Look ahead for refs of refs */ \
724 SvROK_on(SvRV(sv)); \
725 S_get_RV(aTHX_ SvRV(sv), SvRV(sobj)); \
729 /* ------------ PERL_MAGIC_shared_scalar(n) functions -------------- */
731 /* Get magic for PERL_MAGIC_shared_scalar(n) */
734 sharedsv_scalar_mg_get(pTHX_ SV *sv, MAGIC *mg)
736 SV *ssv = (SV *) mg->mg_ptr;
741 get_RV(sv, SvRV(ssv));
743 sv_setsv_nomg(sv, ssv);
749 /* Copy the contents of a private SV to a shared SV.
750 * Used by various mg_set()-type functions.
751 * Assumes lock is held.
754 sharedsv_scalar_store(pTHX_ SV *sv, SV *ssv)
759 assert(PL_sharedsv_lock.owner == aTHX);
760 if (!PL_dirty && SvROK(ssv) && SvREFCNT(SvRV(ssv)) == 1) {
761 SV *sv = sv_newmortal();
762 sv_upgrade(sv, SVt_RV);
763 get_RV(sv, SvRV(ssv));
767 SV *sobj = Perl_sharedsv_find(aTHX_ obj);
770 (void)SvUPGRADE(ssv, SVt_RV);
771 sv_setsv_nomg(ssv, &PL_sv_undef);
773 SvRV_set(ssv, SvREFCNT_inc(sobj));
775 if (SvOBJECT(sobj)) {
776 /* Remove any old blessing */
777 SvREFCNT_dec(SvSTASH(sobj));
781 SV* fake_stash = newSVpv(HvNAME_get(SvSTASH(obj)),0);
783 SvSTASH_set(sobj, (HV*)fake_stash);
792 sv_setsv_nomg(ssv, sv);
794 /* Remove any old blessing */
795 SvREFCNT_dec(SvSTASH(ssv));
799 SV* fake_stash = newSVpv(HvNAME_get(SvSTASH(sv)),0);
801 SvSTASH_set(ssv, (HV*)fake_stash);
806 Perl_croak(aTHX_ "Invalid value for shared scalar");
810 /* Set magic for PERL_MAGIC_shared_scalar(n) */
813 sharedsv_scalar_mg_set(pTHX_ SV *sv, MAGIC *mg)
815 SV *ssv = (SV*)(mg->mg_ptr);
818 if (SvTYPE(ssv) < SvTYPE(sv)) {
821 sv_upgrade(ssv, SvTYPE(sv));
824 sharedsv_scalar_store(aTHX_ sv, ssv);
829 /* Free magic for PERL_MAGIC_shared_scalar(n) */
832 sharedsv_scalar_mg_free(pTHX_ SV *sv, MAGIC *mg)
837 && SvROK((SV *)mg->mg_ptr) && SvREFCNT(SvRV((SV *)mg->mg_ptr)) == 1) {
838 SV *sv = sv_newmortal();
839 sv_upgrade(sv, SVt_RV);
840 get_RV(sv, SvRV((SV *)mg->mg_ptr));
842 S_sharedsv_dec(aTHX_ (SV*)mg->mg_ptr);
848 * Called during cloning of PERL_MAGIC_shared_scalar(n) magic in new thread
851 sharedsv_scalar_mg_dup(pTHX_ MAGIC *mg, CLONE_PARAMS *param)
853 PERL_UNUSED_ARG(param);
854 SvREFCNT_inc_void(mg->mg_ptr);
860 * Called during local $shared
863 sharedsv_scalar_mg_local(pTHX_ SV* nsv, MAGIC *mg)
866 SV *ssv = (SV *) mg->mg_ptr;
869 SvREFCNT_inc_void(ssv);
872 nmg = sv_magicext(nsv, mg->mg_obj, mg->mg_type, mg->mg_virtual,
873 mg->mg_ptr, mg->mg_len);
874 nmg->mg_flags = mg->mg_flags;
875 nmg->mg_private = mg->mg_private;
881 const static MGVTBL sharedsv_scalar_vtbl = {
882 sharedsv_scalar_mg_get, /* get */
883 sharedsv_scalar_mg_set, /* set */
886 sharedsv_scalar_mg_free, /* free */
888 sharedsv_scalar_mg_dup, /* dup */
890 sharedsv_scalar_mg_local, /* local */
894 /* ------------ PERL_MAGIC_tiedelem(p) functions -------------- */
896 /* Get magic for PERL_MAGIC_tiedelem(p) */
899 sharedsv_elem_mg_FETCH(pTHX_ SV *sv, MAGIC *mg)
902 SV *saggregate = SHAREDSV_FROM_OBJ(mg->mg_obj);
906 if (saggregate) { /* During global destruction, underlying
907 aggregate may no longer exist */
908 if (SvTYPE(saggregate) == SVt_PVAV) {
909 assert ( mg->mg_ptr == 0 );
911 svp = av_fetch((AV*) saggregate, mg->mg_len, 0);
913 char *key = mg->mg_ptr;
914 I32 len = mg->mg_len;
915 assert ( mg->mg_ptr != 0 );
916 if (mg->mg_len == HEf_SVKEY) {
918 key = SvPV((SV *)mg->mg_ptr, slen);
920 if (SvUTF8((SV *)mg->mg_ptr)) {
925 svp = hv_fetch((HV*) saggregate, key, len, 0);
930 /* Exists in the array */
932 get_RV(sv, SvRV(*svp));
934 /* $ary->[elem] or $ary->{elem} is a scalar */
935 Perl_sharedsv_associate(aTHX_ sv, *svp);
939 /* Not in the array */
940 sv_setsv(sv, &PL_sv_undef);
946 /* Set magic for PERL_MAGIC_tiedelem(p) */
949 sharedsv_elem_mg_STORE(pTHX_ SV *sv, MAGIC *mg)
952 SV *saggregate = SHAREDSV_FROM_OBJ(mg->mg_obj);
954 U32 dualvar_flags = DUALVAR_FLAGS(sv);
956 /* Theory - SV itself is magically shared - and we have ordered the
957 magic such that by the time we get here it has been stored
958 to its shared counterpart
962 if (SvTYPE(saggregate) == SVt_PVAV) {
963 assert ( mg->mg_ptr == 0 );
965 svp = av_fetch((AV*) saggregate, mg->mg_len, 1);
967 char *key = mg->mg_ptr;
968 I32 len = mg->mg_len;
969 assert ( mg->mg_ptr != 0 );
970 if (mg->mg_len == HEf_SVKEY) {
972 key = SvPV((SV *)mg->mg_ptr, slen);
974 if (SvUTF8((SV *)mg->mg_ptr)) {
979 svp = hv_fetch((HV*) saggregate, key, len, 1);
982 Perl_sharedsv_associate(aTHX_ sv, *svp);
983 sharedsv_scalar_store(aTHX_ sv, *svp);
984 SvFLAGS(*svp) |= dualvar_flags;
989 /* Clear magic for PERL_MAGIC_tiedelem(p) */
992 sharedsv_elem_mg_DELETE(pTHX_ SV *sv, MAGIC *mg)
996 SV *saggregate = SHAREDSV_FROM_OBJ(mg->mg_obj);
998 /* Object may not exist during global destruction */
1004 sharedsv_elem_mg_FETCH(aTHX_ sv, mg);
1005 if ((shmg = mg_find(sv, PERL_MAGIC_shared_scalar)))
1006 sharedsv_scalar_mg_get(aTHX_ sv, shmg);
1007 if (SvTYPE(saggregate) == SVt_PVAV) {
1009 av_delete((AV*) saggregate, mg->mg_len, G_DISCARD);
1011 char *key = mg->mg_ptr;
1012 I32 len = mg->mg_len;
1013 assert ( mg->mg_ptr != 0 );
1014 if (mg->mg_len == HEf_SVKEY) {
1016 key = SvPV((SV *)mg->mg_ptr, slen);
1018 if (SvUTF8((SV *)mg->mg_ptr)) {
1023 (void) hv_delete((HV*) saggregate, key, len, G_DISCARD);
1030 /* Called during cloning of PERL_MAGIC_tiedelem(p) magic in new
1034 sharedsv_elem_mg_dup(pTHX_ MAGIC *mg, CLONE_PARAMS *param)
1036 PERL_UNUSED_ARG(param);
1037 SvREFCNT_inc_void(SHAREDSV_FROM_OBJ(mg->mg_obj));
1038 assert(mg->mg_flags & MGf_DUP);
1042 const static MGVTBL sharedsv_elem_vtbl = {
1043 sharedsv_elem_mg_FETCH, /* get */
1044 sharedsv_elem_mg_STORE, /* set */
1046 sharedsv_elem_mg_DELETE, /* clear */
1049 sharedsv_elem_mg_dup, /* dup */
1055 /* ------------ PERL_MAGIC_tied(P) functions -------------- */
1057 /* Len magic for PERL_MAGIC_tied(P) */
1060 sharedsv_array_mg_FETCHSIZE(pTHX_ SV *sv, MAGIC *mg)
1063 SV *ssv = (SV *) mg->mg_ptr;
1065 PERL_UNUSED_ARG(sv);
1067 if (SvTYPE(ssv) == SVt_PVAV) {
1068 val = av_len((AV*) ssv);
1070 /* Not actually defined by tie API but ... */
1071 val = HvUSEDKEYS((HV*) ssv);
1077 /* Clear magic for PERL_MAGIC_tied(P) */
1080 sharedsv_array_mg_CLEAR(pTHX_ SV *sv, MAGIC *mg)
1083 SV *ssv = (SV *) mg->mg_ptr;
1084 const bool isav = SvTYPE(ssv) == SVt_PVAV;
1085 PERL_UNUSED_ARG(sv);
1088 SV **svp = isav ? AvARRAY((AV *)ssv) : NULL;
1089 I32 items = isav ? AvFILLp((AV *)ssv) + 1 : 0;
1091 if (!isav) hv_iterinit((HV *)ssv);
1092 while (isav ? items-- : !!(iter = hv_iternext((HV *)ssv))) {
1093 SV *sv = isav ? *svp++ : HeVAL(iter);
1095 if ( (SvOBJECT(sv) || (SvROK(sv) && (sv = SvRV(sv))))
1096 && SvREFCNT(sv) == 1 ) {
1097 SV *tmp = Perl_sv_newmortal(caller_perl);
1098 PERL_SET_CONTEXT((aTHX = caller_perl));
1099 sv_upgrade(tmp, SVt_RV);
1101 PERL_SET_CONTEXT((aTHX = PL_sharedsv_space));
1105 if (isav) av_clear((AV*) ssv);
1106 else hv_clear((HV*) ssv);
1111 /* Free magic for PERL_MAGIC_tied(P) */
1114 sharedsv_array_mg_free(pTHX_ SV *sv, MAGIC *mg)
1116 PERL_UNUSED_ARG(sv);
1117 S_sharedsv_dec(aTHX_ (SV*)mg->mg_ptr);
1122 * Copy magic for PERL_MAGIC_tied(P)
1123 * This is called when perl is about to access an element of
1126 #if PERL_VERSION >= 11
1128 sharedsv_array_mg_copy(pTHX_ SV *sv, MAGIC* mg,
1129 SV *nsv, const char *name, I32 namlen)
1132 sharedsv_array_mg_copy(pTHX_ SV *sv, MAGIC* mg,
1133 SV *nsv, const char *name, int namlen)
1136 MAGIC *nmg = sv_magicext(nsv,mg->mg_obj,
1137 toLOWER(mg->mg_type),&sharedsv_elem_vtbl,
1139 PERL_UNUSED_ARG(sv);
1140 nmg->mg_flags |= MGf_DUP;
1144 /* Called during cloning of PERL_MAGIC_tied(P) magic in new thread */
1147 sharedsv_array_mg_dup(pTHX_ MAGIC *mg, CLONE_PARAMS *param)
1149 PERL_UNUSED_ARG(param);
1150 SvREFCNT_inc_void((SV*)mg->mg_ptr);
1151 assert(mg->mg_flags & MGf_DUP);
1155 const static MGVTBL sharedsv_array_vtbl = {
1158 sharedsv_array_mg_FETCHSIZE,/* len */
1159 sharedsv_array_mg_CLEAR, /* clear */
1160 sharedsv_array_mg_free, /* free */
1161 sharedsv_array_mg_copy, /* copy */
1162 sharedsv_array_mg_dup, /* dup */
1169 /* Recursively unlocks a shared sv. */
1172 Perl_sharedsv_unlock(pTHX_ SV *ssv)
1174 user_lock *ul = S_get_userlock(aTHX_ ssv, 0);
1176 recursive_lock_release(aTHX_ &ul->lock);
1180 /* Recursive locks on a sharedsv.
1181 * Locks are dynamically scoped at the level of the first lock.
1184 Perl_sharedsv_lock(pTHX_ SV *ssv)
1189 ul = S_get_userlock(aTHX_ ssv, 1);
1190 recursive_lock_acquire(aTHX_ &ul->lock, __FILE__, __LINE__);
1193 /* Handles calls from lock() builtin via PL_lockhook */
1196 Perl_sharedsv_locksv(pTHX_ SV *sv)
1202 ssv = Perl_sharedsv_find(aTHX_ sv);
1204 croak("lock can only be used on shared values");
1205 Perl_sharedsv_lock(aTHX_ ssv);
1209 /* Can a shared object be destroyed?
1210 * True if not a shared,
1211 * or if destroying last proxy on a shared object
1213 #ifdef PL_destroyhook
1215 Perl_shared_object_destroy(pTHX_ SV *sv)
1221 ssv = Perl_sharedsv_find(aTHX_ sv);
1222 return (!ssv || (SvREFCNT(ssv) <= 1));
1226 /* veto signal dispatch if we have the lock */
1228 #ifdef PL_signalhook
1230 STATIC despatch_signals_proc_t prev_signal_hook = NULL;
1233 S_shared_signal_hook(pTHX) {
1235 MUTEX_LOCK(&PL_sharedsv_lock.mutex);
1236 us = (PL_sharedsv_lock.owner == aTHX);
1237 MUTEX_UNLOCK(&PL_sharedsv_lock.mutex);
1239 return; /* try again later */
1240 prev_signal_hook(aTHX);
1244 /* Saves a space for keeping SVs wider than an interpreter. */
1247 Perl_sharedsv_init(pTHX)
1250 PL_sharedsv_space = perl_alloc();
1251 perl_construct(PL_sharedsv_space);
1252 /* The pair above leaves us in shared context (what dTHX would get),
1253 * but aTHX still points to caller context */
1254 aTHX = PL_sharedsv_space;
1255 LEAVE; /* This balances the ENTER at the end of perl_construct. */
1256 PERL_SET_CONTEXT((aTHX = caller_perl));
1257 recursive_lock_init(aTHX_ &PL_sharedsv_lock);
1258 PL_lockhook = &Perl_sharedsv_locksv;
1259 PL_sharehook = &Perl_sharedsv_share;
1260 #ifdef PL_destroyhook
1261 PL_destroyhook = &Perl_shared_object_destroy;
1263 #ifdef PL_signalhook
1264 if (!prev_signal_hook) {
1265 prev_signal_hook = PL_signalhook;
1266 PL_signalhook = &S_shared_signal_hook;
1271 #endif /* USE_ITHREADS */
1273 MODULE = threads::shared PACKAGE = threads::shared::tie
1283 SV *sobj = SHAREDSV_FROM_OBJ(obj);
1285 for (ii = 1; ii < items; ii++) {
1286 SV* tmp = newSVsv(ST(ii));
1288 U32 dualvar_flags = DUALVAR_FLAGS(tmp);
1290 stmp = S_sharedsv_new_shared(aTHX_ tmp);
1291 sharedsv_scalar_store(aTHX_ tmp, stmp);
1292 SvFLAGS(stmp) |= dualvar_flags;
1294 av_push((AV*) sobj, stmp);
1295 SvREFCNT_inc_void(stmp);
1302 UNSHIFT(SV *obj, ...)
1305 SV *sobj = SHAREDSV_FROM_OBJ(obj);
1309 av_unshift((AV*)sobj, items - 1);
1311 for (ii = 1; ii < items; ii++) {
1312 SV *tmp = newSVsv(ST(ii));
1313 U32 dualvar_flags = DUALVAR_FLAGS(tmp);
1314 SV *stmp = S_sharedsv_new_shared(aTHX_ tmp);
1315 sharedsv_scalar_store(aTHX_ tmp, stmp);
1317 SvFLAGS(stmp) |= dualvar_flags;
1318 av_store((AV*) sobj, ii - 1, stmp);
1319 SvREFCNT_inc_void(stmp);
1330 SV *sobj = SHAREDSV_FROM_OBJ(obj);
1334 ssv = av_pop((AV*)sobj);
1336 ST(0) = sv_newmortal();
1337 Perl_sharedsv_associate(aTHX_ ST(0), ssv);
1340 /* XSRETURN(1); - implied */
1347 SV *sobj = SHAREDSV_FROM_OBJ(obj);
1351 ssv = av_shift((AV*)sobj);
1353 ST(0) = sv_newmortal();
1354 Perl_sharedsv_associate(aTHX_ ST(0), ssv);
1357 /* XSRETURN(1); - implied */
1361 EXTEND(SV *obj, IV count)
1364 SV *sobj = SHAREDSV_FROM_OBJ(obj);
1366 av_extend((AV*)sobj, count);
1371 STORESIZE(SV *obj,IV count)
1374 SV *ssv = SHAREDSV_FROM_OBJ(obj);
1377 assert(SvTYPE(ssv) == SVt_PVAV);
1379 SV **svp = AvARRAY((AV *)ssv);
1380 I32 ix = AvFILLp((AV *)ssv);
1381 for (;ix >= count; ix--) {
1385 if ( (SvOBJECT(sv) || (SvROK(sv) && (sv = SvRV(sv))))
1386 && SvREFCNT(sv) == 1 )
1388 SV *tmp = Perl_sv_newmortal(caller_perl);
1389 PERL_SET_CONTEXT((aTHX = caller_perl));
1390 sv_upgrade(tmp, SVt_RV);
1392 PERL_SET_CONTEXT((aTHX = PL_sharedsv_space));
1396 av_fill((AV*) ssv, count - 1);
1401 EXISTS(SV *obj, SV *index)
1404 SV *sobj = SHAREDSV_FROM_OBJ(obj);
1406 if (SvTYPE(sobj) == SVt_PVAV) {
1408 exists = av_exists((AV*) sobj, SvIV(index));
1412 char *key = SvPVutf8(index, slen);
1414 if (SvUTF8(index)) {
1418 exists = hv_exists((HV*) sobj, key, len);
1421 ST(0) = (exists) ? &PL_sv_yes : &PL_sv_no;
1422 /* XSRETURN(1); - implied */
1429 SV *sobj = SHAREDSV_FROM_OBJ(obj);
1435 hv_iterinit((HV*) sobj);
1436 entry = hv_iternext((HV*) sobj);
1438 I32 utf8 = HeKUTF8(entry);
1439 key = hv_iterkey(entry,&len);
1441 ST(0) = newSVpvn_flags(key, len, SVs_TEMP | (utf8 ? SVf_UTF8 : 0));
1444 ST(0) = &PL_sv_undef;
1447 /* XSRETURN(1); - implied */
1451 NEXTKEY(SV *obj, SV *oldkey)
1454 SV *sobj = SHAREDSV_FROM_OBJ(obj);
1459 PERL_UNUSED_VAR(oldkey);
1463 entry = hv_iternext((HV*) sobj);
1465 I32 utf8 = HeKUTF8(entry);
1466 key = hv_iterkey(entry,&len);
1468 ST(0) = newSVpvn_flags(key, len, SVs_TEMP | (utf8 ? SVf_UTF8 : 0));
1471 ST(0) = &PL_sv_undef;
1474 /* XSRETURN(1); - implied */
1477 MODULE = threads::shared PACKAGE = threads::shared
1487 myref = SvRV(myref);
1488 if (SvMAGICAL(myref))
1491 myref = SvRV(myref);
1492 ssv = Perl_sharedsv_find(aTHX_ myref);
1495 ST(0) = sv_2mortal(newSVuv(PTR2UV(ssv)));
1496 /* XSRETURN(1); - implied */
1505 myref = SvRV(myref);
1507 myref = SvRV(myref);
1508 ssv = Perl_sharedsv_find(aTHX_ myref);
1510 if (ckWARN(WARN_THREADS)) {
1511 Perl_warner(aTHX_ packWARN(WARN_THREADS),
1512 "%" SVf " is not shared", ST(0));
1516 ST(0) = sv_2mortal(newSViv(SvREFCNT(ssv)));
1517 /* XSRETURN(1); - implied */
1525 Perl_croak(aTHX_ "Argument to share needs to be passed as ref");
1526 myref = SvRV(myref);
1528 myref = SvRV(myref);
1529 Perl_sharedsv_share(aTHX_ myref);
1530 ST(0) = sv_2mortal(newRV_inc(myref));
1531 /* XSRETURN(1); - implied */
1535 cond_wait(SV *ref_cond, SV *ref_lock = 0)
1536 PROTOTYPE: \[$@%];\[$@%]
1539 perl_cond* user_condition;
1543 if (!SvROK(ref_cond))
1544 Perl_croak(aTHX_ "Argument to cond_wait needs to be passed as ref");
1545 ref_cond = SvRV(ref_cond);
1546 if (SvROK(ref_cond))
1547 ref_cond = SvRV(ref_cond);
1548 ssv = Perl_sharedsv_find(aTHX_ ref_cond);
1550 Perl_croak(aTHX_ "cond_wait can only be used on shared values");
1551 ul = S_get_userlock(aTHX_ ssv, 1);
1553 user_condition = &ul->user_cond;
1554 if (ref_lock && (ref_cond != ref_lock)) {
1555 if (!SvROK(ref_lock))
1556 Perl_croak(aTHX_ "cond_wait lock needs to be passed as ref");
1557 ref_lock = SvRV(ref_lock);
1558 if (SvROK(ref_lock)) ref_lock = SvRV(ref_lock);
1559 ssv = Perl_sharedsv_find(aTHX_ ref_lock);
1561 Perl_croak(aTHX_ "cond_wait lock must be a shared value");
1562 ul = S_get_userlock(aTHX_ ssv, 1);
1564 if (ul->lock.owner != aTHX)
1565 croak("You need a lock before you can cond_wait");
1567 /* Stealing the members of the lock object worries me - NI-S */
1568 MUTEX_LOCK(&ul->lock.mutex);
1569 ul->lock.owner = NULL;
1570 locks = ul->lock.locks;
1573 /* Since we are releasing the lock here, we need to tell other
1574 * people that it is ok to go ahead and use it */
1575 COND_SIGNAL(&ul->lock.cond);
1576 COND_WAIT(user_condition, &ul->lock.mutex);
1577 while (ul->lock.owner != NULL) {
1578 /* OK -- must reacquire the lock */
1579 COND_WAIT(&ul->lock.cond, &ul->lock.mutex);
1581 ul->lock.owner = aTHX;
1582 ul->lock.locks = locks;
1583 MUTEX_UNLOCK(&ul->lock.mutex);
1587 cond_timedwait(SV *ref_cond, double abs, SV *ref_lock = 0)
1588 PROTOTYPE: \[$@%]$;\[$@%]
1591 perl_cond* user_condition;
1595 if (! SvROK(ref_cond))
1596 Perl_croak(aTHX_ "Argument to cond_timedwait needs to be passed as ref");
1597 ref_cond = SvRV(ref_cond);
1598 if (SvROK(ref_cond))
1599 ref_cond = SvRV(ref_cond);
1600 ssv = Perl_sharedsv_find(aTHX_ ref_cond);
1602 Perl_croak(aTHX_ "cond_timedwait can only be used on shared values");
1603 ul = S_get_userlock(aTHX_ ssv, 1);
1605 user_condition = &ul->user_cond;
1606 if (ref_lock && (ref_cond != ref_lock)) {
1607 if (! SvROK(ref_lock))
1608 Perl_croak(aTHX_ "cond_timedwait lock needs to be passed as ref");
1609 ref_lock = SvRV(ref_lock);
1610 if (SvROK(ref_lock)) ref_lock = SvRV(ref_lock);
1611 ssv = Perl_sharedsv_find(aTHX_ ref_lock);
1613 Perl_croak(aTHX_ "cond_timedwait lock must be a shared value");
1614 ul = S_get_userlock(aTHX_ ssv, 1);
1616 if (ul->lock.owner != aTHX)
1617 Perl_croak(aTHX_ "You need a lock before you can cond_wait");
1619 MUTEX_LOCK(&ul->lock.mutex);
1620 ul->lock.owner = NULL;
1621 locks = ul->lock.locks;
1623 /* Since we are releasing the lock here, we need to tell other
1624 * people that it is ok to go ahead and use it */
1625 COND_SIGNAL(&ul->lock.cond);
1626 RETVAL = Perl_sharedsv_cond_timedwait(user_condition, &ul->lock.mutex, abs);
1627 while (ul->lock.owner != NULL) {
1628 /* OK -- must reacquire the lock... */
1629 COND_WAIT(&ul->lock.cond, &ul->lock.mutex);
1631 ul->lock.owner = aTHX;
1632 ul->lock.locks = locks;
1633 MUTEX_UNLOCK(&ul->lock.mutex);
1642 cond_signal(SV *myref)
1649 Perl_croak(aTHX_ "Argument to cond_signal needs to be passed as ref");
1650 myref = SvRV(myref);
1652 myref = SvRV(myref);
1653 ssv = Perl_sharedsv_find(aTHX_ myref);
1655 Perl_croak(aTHX_ "cond_signal can only be used on shared values");
1656 ul = S_get_userlock(aTHX_ ssv, 1);
1657 if (ckWARN(WARN_THREADS) && ul->lock.owner != aTHX) {
1658 Perl_warner(aTHX_ packWARN(WARN_THREADS),
1659 "cond_signal() called on unlocked variable");
1661 COND_SIGNAL(&ul->user_cond);
1665 cond_broadcast(SV *myref)
1672 Perl_croak(aTHX_ "Argument to cond_broadcast needs to be passed as ref");
1673 myref = SvRV(myref);
1675 myref = SvRV(myref);
1676 ssv = Perl_sharedsv_find(aTHX_ myref);
1678 Perl_croak(aTHX_ "cond_broadcast can only be used on shared values");
1679 ul = S_get_userlock(aTHX_ ssv, 1);
1680 if (ckWARN(WARN_THREADS) && ul->lock.owner != aTHX) {
1681 Perl_warner(aTHX_ packWARN(WARN_THREADS),
1682 "cond_broadcast() called on unlocked variable");
1684 COND_BROADCAST(&ul->user_cond);
1688 bless(SV* myref, ...)
1695 stash = CopSTASH(PL_curcop);
1697 SV* classname = ST(1);
1702 ! SvGMAGICAL(classname) &&
1703 ! SvAMAGIC(classname) &&
1706 Perl_croak(aTHX_ "Attempt to bless into a reference");
1708 ptr = SvPV(classname, len);
1709 if (ckWARN(WARN_MISC) && len == 0) {
1710 Perl_warner(aTHX_ packWARN(WARN_MISC),
1711 "Explicit blessing to '' (assuming package main)");
1713 stash = gv_stashpvn(ptr, len, TRUE);
1715 SvREFCNT_inc_void(myref);
1716 (void)sv_bless(myref, stash);
1717 ST(0) = sv_2mortal(myref);
1718 ssv = Perl_sharedsv_find(aTHX_ myref);
1724 SV* fake_stash = newSVpv(HvNAME_get(stash), 0);
1725 (void)sv_bless(ssv, (HV*)fake_stash);
1730 /* XSRETURN(1); - implied */
1732 #endif /* USE_ITHREADS */
1737 Perl_sharedsv_init(aTHX);
1738 #endif /* USE_ITHREADS */