return pop_return();
}
+static CV *
+get_db_sub(sv)
+SV *sv;
+{
+ dTHR;
+ SV *oldsv = sv;
+ GV *gv;
+ CV *cv;
+
+ sv = GvSV(DBsub);
+ save_item(sv);
+ gv = CvGV(cv);
+ if ( (CvFLAGS(cv) & (CVf_ANON | CVf_CLONED))
+ || strEQ(GvNAME(gv), "END")
+ || ((GvCV(gv) != cv) && /* Could be imported, and old sub redefined. */
+ !( (SvTYPE(oldsv) == SVt_PVGV) && (GvCV((GV*)oldsv) == cv)
+ && (gv = (GV*)oldsv) ))) {
+ /* Use GV from the stack as a fallback. */
+ /* GV is potentially non-unique, or contain different CV. */
+ sv_setsv(sv, newRV((SV*)cv));
+ }
+ else {
+ gv_efullname3(sv, gv, Nullch);
+ }
+ cv = GvCV(DBsub);
+ if (CvXSUB(cv))
+ curcopdb = curcop;
+ return cv;
+}
+
PP(pp_entersub)
{
dSP; dPOPss;
}
gimme = GIMME_V;
- if ((op->op_private & OPpENTERSUB_DB) && GvCV(DBsub) && !CvNODEBUG(cv)) {
- SV *oldsv = sv;
- sv = GvSV(DBsub);
- save_item(sv);
- gv = CvGV(cv);
- if ( (CvFLAGS(cv) & (CVf_ANON | CVf_CLONED))
- || strEQ(GvNAME(gv), "END")
- || ((GvCV(gv) != cv) && /* Could be imported, and old sub redefined. */
- !( (SvTYPE(oldsv) == SVt_PVGV) && (GvCV((GV*)oldsv) == cv)
- && (gv = (GV*)oldsv) ))) { /* Use GV from the stack as a fallback. */
- /* GV is potentially non-unique, or contain different CV. */
- sv_setsv(sv, newRV((SV*)cv));
- }
- else {
- gv_efullname3(sv, gv, Nullch);
- }
- cv = GvCV(DBsub);
- if (CvXSUB(cv)) curcopdb = curcop;
- if (!cv)
- DIE("No DBsub routine");
- }
+ if ((op->op_private & OPpENTERSUB_DB) && GvCV(DBsub) && !CvNODEBUG(cv))
+ cv = get_db_sub(sv);
+ if (!cv)
+ DIE("No DBsub routine");
#ifdef USE_THREADS
+ /*
+ * First we need to check if the sub or method requires locking.
+ * If so, we gain a lock on the CV or the first argument, as
+ * appropriate. This has to be inline because for FAKE_THREADS,
+ * COND_WAIT inlines code to reschedule by returning a new op.
+ */
MUTEX_LOCK(CvMUTEXP(cv));
if (CvFLAGS(cv) & CVf_LOCKED) {
MAGIC *mg;
if (CvDEPTH(cv) == 0)
SAVEDESTRUCTOR(unset_cvowner, (void*) cv);
}
+ /*
+ * Now we have permission to enter the sub, we must distinguish
+ * four cases. (0) It's an XSUB (in which case we don't care
+ * about ownership); (1) it's ours already (and we're recursing);
+ * (2) it's free (but we may already be using a cached clone);
+ * (3) another thread owns it. Case (1) is easy: we just use it.
+ * Case (2) means we look for a clone--if we have one, use it
+ * otherwise grab ownership of cv. Case (3) means we look for a
+ * clone (for non-XSUBs) and have to create one if we don't
+ * already have one.
+ * Why look for a clone in case (2) when we could just grab
+ * ownership of cv straight away? Well, we could be recursing,
+ * i.e. we originally tried to enter cv while another thread
+ * owned it (hence we used a clone) but it has been freed up
+ * and we're now recursing into it. It may or may not be "better"
+ * to use the clone but at least CvDEPTH can be trusted.
+ */
+ if (CvOWNER(cv) == thr || CvXSUB(cv))
+ MUTEX_UNLOCK(CvMUTEXP(cv));
else {
+ /* Case (2) or (3) */
+ SV **svp;
+
/*
- * It's an ordinary unsynchronised CV so we must distinguish
- * three cases. (1) It's ours already (and we're recursing);
- * (2) it's free (but we may already be using a cached clone);
- * (3) another thread owns it. Case (1) is easy: we just use it.
- * Case (2) means we look for a clone--if we have one, use it
- * otherwise grab ownership of cv. Case (3) means look we for a
- * clone and have to create one if we don't already have one.
- * Why look for a clone in case (2) when we could just grab
- * ownership of cv straight away? Well, we could be recursing,
- * i.e. we originally tried to enter cv while another thread
- * owned it (hence we used a clone) but it has been freed up
- * and we're now recursing into it. It may or may not be "better"
- * to use the clone but at least CvDEPTH can be trusted.
- */
- if (CvOWNER(cv) == thr)
+ * XXX Might it be better to release CvMUTEXP(cv) while we
+ * do the hv_fetch? We might find someone has pinched it
+ * when we look again, in which case we would be in case
+ * (3) instead of (2) so we'd have to clone. Would the fact
+ * that we released the mutex more quickly make up for this?
+ */
+ svp = hv_fetch(cvcache, (char *)cv, sizeof(cv), FALSE);
+ if (svp) {
+ /* We already have a clone to use */
MUTEX_UNLOCK(CvMUTEXP(cv));
+ cv = *(CV**)svp;
+ DEBUG_L(PerlIO_printf(PerlIO_stderr(),
+ "entersub: 0x%lx already has clone 0x%lx:%s\n",
+ (unsigned long) thr, (unsigned long) cv,
+ SvPEEK((SV*)cv)));
+ CvOWNER(cv) = thr;
+ SvREFCNT_inc(cv);
+ if (CvDEPTH(cv) == 0)
+ SAVEDESTRUCTOR(unset_cvowner, (void*) cv);
+ }
else {
- /* Case (2) or (3) */
- SV **svp;
-
- /*
- * XXX Might it be better to release CvMUTEXP(cv) while we
- * do the hv_fetch? We might find someone has pinched it
- * when we look again, in which case we would be in case
- * (3) instead of (2) so we'd have to clone. Would the fact
- * that we released the mutex more quickly make up for this?
- */
- svp = hv_fetch(cvcache, (char *)cv, sizeof(cv), FALSE);
- if (svp) {
- /* We already have a clone to use */
+ /* (2) => grab ownership of cv. (3) => make clone */
+ if (!CvOWNER(cv)) {
+ CvOWNER(cv) = thr;
+ SvREFCNT_inc(cv);
MUTEX_UNLOCK(CvMUTEXP(cv));
- cv = *(CV**)svp;
DEBUG_L(PerlIO_printf(PerlIO_stderr(),
- "entersub: 0x%lx already has clone 0x%lx:%s\n",
- (unsigned long) thr, (unsigned long) cv,
- SvPEEK((SV*)cv)));
- CvOWNER(cv) = thr;
+ "entersub: 0x%lx grabbing 0x%lx:%s in stash %s\n",
+ (unsigned long) thr, (unsigned long) cv,
+ SvPEEK((SV*)cv), CvSTASH(cv) ?
+ HvNAME(CvSTASH(cv)) : "(none)"));
+ } else {
+ /* Make a new clone. */
+ CV *clonecv;
+ SvREFCNT_inc(cv); /* don't let it vanish from under us */
+ MUTEX_UNLOCK(CvMUTEXP(cv));
+ DEBUG_L((PerlIO_printf(PerlIO_stderr(),
+ "entersub: 0x%lx cloning 0x%lx:%s\n",
+ (unsigned long) thr, (unsigned long) cv,
+ SvPEEK((SV*)cv))));
+ /*
+ * We're creating a new clone so there's no race
+ * between the original MUTEX_UNLOCK and the
+ * SvREFCNT_inc since no one will be trying to undef
+ * it out from underneath us. At least, I don't think
+ * there's a race...
+ */
+ clonecv = cv_clone(cv);
+ SvREFCNT_dec(cv); /* finished with this */
+ hv_store(cvcache, (char*)cv, sizeof(cv), (SV*)clonecv,0);
+ CvOWNER(clonecv) = thr;
+ cv = clonecv;
SvREFCNT_inc(cv);
- if (CvDEPTH(cv) == 0)
- SAVEDESTRUCTOR(unset_cvowner, (void*) cv);
- }
- else {
- /* (2) => grab ownership of cv. (3) => make clone */
- if (!CvOWNER(cv)) {
- CvOWNER(cv) = thr;
- SvREFCNT_inc(cv);
- MUTEX_UNLOCK(CvMUTEXP(cv));
- DEBUG_L(PerlIO_printf(PerlIO_stderr(),
- "entersub: 0x%lx grabbing 0x%lx:%s in stash %s\n",
- (unsigned long) thr, (unsigned long) cv,
- SvPEEK((SV*)cv), CvSTASH(cv) ?
- HvNAME(CvSTASH(cv)) : "(none)"));
- } else {
- /* Make a new clone. */
- CV *clonecv;
- SvREFCNT_inc(cv); /* don't let it vanish from under us */
- MUTEX_UNLOCK(CvMUTEXP(cv));
- DEBUG_L((PerlIO_printf(PerlIO_stderr(),
- "entersub: 0x%lx cloning 0x%lx:%s\n",
- (unsigned long) thr, (unsigned long) cv,
- SvPEEK((SV*)cv))));
- /*
- * We're creating a new clone so there's no race
- * between the original MUTEX_UNLOCK and the
- * SvREFCNT_inc since no one will be trying to undef
- * it out from underneath us. At least, I don't think
- * there's a race...
- */
- clonecv = cv_clone(cv);
- SvREFCNT_dec(cv); /* finished with this */
- hv_store(cvcache, (char*)cv, sizeof(cv), (SV*)clonecv,0);
- CvOWNER(clonecv) = thr;
- cv = clonecv;
- SvREFCNT_inc(cv);
- }
- DEBUG_L(if (CvDEPTH(cv) != 0)
- PerlIO_printf(PerlIO_stderr(), "depth %ld != 0\n",
- CvDEPTH(cv)););
- SAVEDESTRUCTOR(unset_cvowner, (void*) cv);
}
+ DEBUG_L(if (CvDEPTH(cv) != 0)
+ PerlIO_printf(PerlIO_stderr(), "depth %ld != 0\n",
+ CvDEPTH(cv)););
+ SAVEDESTRUCTOR(unset_cvowner, (void*) cv);
}
- }
+ }
#endif /* USE_THREADS */
gimme = GIMME;
projects / platform / upstream / perl.git / commitdiff