/* mro.c
*
* Copyright (c) 2007 Brandon L Black
+ * Copyright (c) 2007, 2008 Larry Wall and others
*
* You may distribute under the terms of either the GNU General Public
* License or the Artistic License, as specified in the README file.
*/
/*
- * "Which order shall we go in?" said Frodo. "Eldest first, or quickest first?
- * You'll be last either way, Master Peregrin."
+ * 'Which order shall we go in?' said Frodo. 'Eldest first, or quickest first?
+ * You'll be last either way, Master Peregrin.'
+ *
+ * [p.101 of _The Lord of the Rings_, I/iii: "A Conspiracy Unmasked"]
*/
/*
*/
#include "EXTERN.h"
+#define PERL_IN_MRO_C
#include "perl.h"
+static const struct mro_alg dfs_alg =
+ {S_mro_get_linear_isa_dfs, "dfs", 3, 0, 0};
+
+SV *
+Perl_mro_get_private_data(pTHX_ struct mro_meta *const smeta,
+ const struct mro_alg *const which)
+{
+ SV **data;
+ PERL_ARGS_ASSERT_MRO_GET_PRIVATE_DATA;
+
+ data = (SV **)Perl_hv_common(aTHX_ smeta->mro_linear_all, NULL,
+ which->name, which->length, which->kflags,
+ HV_FETCH_JUST_SV, NULL, which->hash);
+ if (!data)
+ return NULL;
+
+ /* If we've been asked to look up the private data for the current MRO, then
+ cache it. */
+ if (smeta->mro_which == which)
+ smeta->mro_linear_current = *data;
+
+ return *data;
+}
+
+SV *
+Perl_mro_set_private_data(pTHX_ struct mro_meta *const smeta,
+ const struct mro_alg *const which, SV *const data)
+{
+ PERL_ARGS_ASSERT_MRO_SET_PRIVATE_DATA;
+
+ if (!smeta->mro_linear_all) {
+ if (smeta->mro_which == which) {
+ /* If all we need to store is the current MRO's data, then don't use
+ memory on a hash with 1 element - store it direct, and signal
+ this by leaving the would-be-hash NULL. */
+ smeta->mro_linear_current = data;
+ return data;
+ } else {
+ HV *const hv = newHV();
+ /* Start with 2 buckets. It's unlikely we'll need more. */
+ HvMAX(hv) = 1;
+ smeta->mro_linear_all = hv;
+
+ if (smeta->mro_linear_current) {
+ /* If we were storing something directly, put it in the hash
+ before we lose it. */
+ Perl_mro_set_private_data(aTHX_ smeta, smeta->mro_which,
+ smeta->mro_linear_current);
+ }
+ }
+ }
+
+ /* We get here if we're storing more than one linearisation for this stash,
+ or the linearisation we are storing is not that if its current MRO. */
+
+ if (smeta->mro_which == which) {
+ /* If we've been asked to store the private data for the current MRO,
+ then cache it. */
+ smeta->mro_linear_current = data;
+ }
+
+ if (!Perl_hv_common(aTHX_ smeta->mro_linear_all, NULL,
+ which->name, which->length, which->kflags,
+ HV_FETCH_ISSTORE, data, which->hash)) {
+ Perl_croak(aTHX_ "panic: hv_store() failed in set_mro_private_data() "
+ "for '%.*s' %d", (int) which->length, which->name,
+ which->kflags);
+ }
+
+ return data;
+}
+
+const struct mro_alg *
+Perl_mro_get_from_name(pTHX_ SV *name) {
+ SV **data;
+
+ PERL_ARGS_ASSERT_MRO_GET_FROM_NAME;
+
+ data = (SV **)Perl_hv_common(aTHX_ PL_registered_mros, name, NULL, 0, 0,
+ HV_FETCH_JUST_SV, NULL, 0);
+ if (!data)
+ return NULL;
+ assert(SvTYPE(*data) == SVt_IV);
+ assert(SvIOK(*data));
+ return INT2PTR(const struct mro_alg *, SvUVX(*data));
+}
+
+void
+Perl_mro_register(pTHX_ const struct mro_alg *mro) {
+ SV *wrapper = newSVuv(PTR2UV(mro));
+
+ PERL_ARGS_ASSERT_MRO_REGISTER;
+
+
+ if (!Perl_hv_common(aTHX_ PL_registered_mros, NULL,
+ mro->name, mro->length, mro->kflags,
+ HV_FETCH_ISSTORE, wrapper, mro->hash)) {
+ SvREFCNT_dec(wrapper);
+ Perl_croak(aTHX_ "panic: hv_store() failed in mro_register() "
+ "for '%.*s' %d", (int) mro->length, mro->name, mro->kflags);
+ }
+}
+
struct mro_meta*
Perl_mro_meta_init(pTHX_ HV* stash)
{
struct mro_meta* newmeta;
- assert(stash);
+ PERL_ARGS_ASSERT_MRO_META_INIT;
assert(HvAUX(stash));
assert(!(HvAUX(stash)->xhv_mro_meta));
Newxz(newmeta, 1, struct mro_meta);
HvAUX(stash)->xhv_mro_meta = newmeta;
- newmeta->sub_generation = 1;
-
- /* Manually flag UNIVERSAL as being universal.
- This happens early in perl booting (when universal.c
- does the newXS calls for UNIVERSAL::*), and infects
- other packages as they are added to UNIVERSAL's MRO
- */
- if(HvNAMELEN_get(stash) == 9
- && strEQ(HEK_KEY(HvAUX(stash)->xhv_name), "UNIVERSAL")) {
- HvMROMETA(stash)->is_universal = 1;
- }
+ newmeta->cache_gen = 1;
+ newmeta->pkg_gen = 1;
+ newmeta->mro_which = &dfs_alg;
return newmeta;
}
{
struct mro_meta* newmeta;
- assert(smeta);
+ PERL_ARGS_ASSERT_MRO_META_DUP;
Newx(newmeta, 1, struct mro_meta);
Copy(smeta, newmeta, 1, struct mro_meta);
- if (newmeta->mro_linear_dfs)
- newmeta->mro_linear_dfs
- = (AV*) SvREFCNT_inc(sv_dup((SV*)newmeta->mro_linear_dfs, param));
- if (newmeta->mro_linear_c3)
- newmeta->mro_linear_c3
- = (AV*) SvREFCNT_inc(sv_dup((SV*)newmeta->mro_linear_c3, param));
- if (newmeta->mro_isarev)
- newmeta->mro_isarev
- = (HV*) SvREFCNT_inc(sv_dup((SV*)newmeta->mro_isarev, param));
+ if (newmeta->mro_linear_all) {
+ newmeta->mro_linear_all
+ = MUTABLE_HV(sv_dup_inc((const SV *)newmeta->mro_linear_all, param));
+ /* This is just acting as a shortcut pointer, and will be automatically
+ updated on the first get. */
+ newmeta->mro_linear_current = NULL;
+ } else if (newmeta->mro_linear_current) {
+ /* Only the current MRO is stored, so this owns the data. */
+ newmeta->mro_linear_current
+ = sv_dup_inc((const SV *)newmeta->mro_linear_current, param);
+ }
+
if (newmeta->mro_nextmethod)
newmeta->mro_nextmethod
- = (HV*) SvREFCNT_inc(sv_dup((SV*)newmeta->mro_nextmethod, param));
+ = MUTABLE_HV(sv_dup_inc((const SV *)newmeta->mro_nextmethod, param));
+ if (newmeta->isa)
+ newmeta->isa
+ = MUTABLE_HV(sv_dup_inc((const SV *)newmeta->isa, param));
return newmeta;
}
=cut
*/
-AV*
-Perl_mro_get_linear_isa_dfs(pTHX_ HV *stash, I32 level)
+static AV*
+S_mro_get_linear_isa_dfs(pTHX_ HV *stash, U32 level)
{
AV* retval;
GV** gvp;
GV* gv;
AV* av;
- const char* stashname;
+ const HEK* stashhek;
struct mro_meta* meta;
+ SV *our_name;
+ HV *stored = NULL;
- assert(stash);
+ PERL_ARGS_ASSERT_MRO_GET_LINEAR_ISA_DFS;
assert(HvAUX(stash));
- stashname = HvNAME_get(stash);
- if (!stashname)
- Perl_croak(aTHX_
- "Can't linearize anonymous symbol table");
+ stashhek = HvNAME_HEK(stash);
+ if (!stashhek)
+ Perl_croak(aTHX_ "Can't linearize anonymous symbol table");
if (level > 100)
Perl_croak(aTHX_ "Recursive inheritance detected in package '%s'",
- stashname);
+ HEK_KEY(stashhek));
meta = HvMROMETA(stash);
/* return cache if valid */
- if((retval = meta->mro_linear_dfs)) {
+ if((retval = MUTABLE_AV(MRO_GET_PRIVATE_DATA(meta, &dfs_alg)))) {
return retval;
}
/* not in cache, make a new one */
- retval = newAV();
- av_push(retval, newSVpv(stashname, 0)); /* add ourselves at the top */
+ retval = MUTABLE_AV(sv_2mortal(MUTABLE_SV(newAV())));
+ /* We use this later in this function, but don't need a reference to it
+ beyond the end of this function, so reference count is fine. */
+ our_name = newSVhek(stashhek);
+ av_push(retval, our_name); /* add ourselves at the top */
/* fetch our @ISA */
gvp = (GV**)hv_fetchs(stash, "ISA", FALSE);
av = (gvp && (gv = *gvp) && isGV_with_GP(gv)) ? GvAV(gv) : NULL;
- if(av && AvFILLp(av) >= 0) {
+ /* "stored" is used to keep track of all of the classnames we have added to
+ the MRO so far, so we can do a quick exists check and avoid adding
+ duplicate classnames to the MRO as we go.
+ It's then retained to be re-used as a fast lookup for ->isa(), by adding
+ our own name and "UNIVERSAL" to it. */
- /* "stored" is used to keep track of all of the classnames
- we have added to the MRO so far, so we can do a quick
- exists check and avoid adding duplicate classnames to
- the MRO as we go. */
+ if(av && AvFILLp(av) >= 0) {
- HV* stored = (HV*)sv_2mortal((SV*)newHV());
SV **svp = AvARRAY(av);
I32 items = AvFILLp(av) + 1;
}
else {
/* otherwise, recurse into ourselves for the MRO
- of this @ISA member, and append their MRO to ours */
+ of this @ISA member, and append their MRO to ours.
+ The recursive call could throw an exception, which
+ has memory management implications here, hence the use of
+ the mortal. */
const AV *const subrv
= mro_get_linear_isa_dfs(basestash, level + 1);
subrv_p = AvARRAY(subrv);
subrv_items = AvFILLp(subrv) + 1;
}
- while(subrv_items--) {
- SV *const subsv = *subrv_p++;
- if(!hv_exists_ent(stored, subsv, 0)) {
- hv_store_ent(stored, subsv, &PL_sv_undef, 0);
- av_push(retval, newSVsv(subsv));
+ if (stored) {
+ while(subrv_items--) {
+ SV *const subsv = *subrv_p++;
+ /* LVALUE fetch will create a new undefined SV if necessary
+ */
+ HE *const he = hv_fetch_ent(stored, subsv, 1, 0);
+ assert(he);
+ if(HeVAL(he) != &PL_sv_undef) {
+ /* It was newly created. Steal it for our new SV, and
+ replace it in the hash with the "real" thing. */
+ SV *const val = HeVAL(he);
+ HEK *const key = HeKEY_hek(he);
+
+ HeVAL(he) = &PL_sv_undef;
+ /* Save copying by making a shared hash key scalar. We
+ inline this here rather than calling
+ Perl_newSVpvn_share because we already have the
+ scalar, and we already have the hash key. */
+ assert(SvTYPE(val) == SVt_NULL);
+ sv_upgrade(val, SVt_PV);
+ SvPV_set(val, HEK_KEY(share_hek_hek(key)));
+ SvCUR_set(val, HEK_LEN(key));
+ SvREADONLY_on(val);
+ SvFAKE_on(val);
+ SvPOK_on(val);
+ if (HEK_UTF8(key))
+ SvUTF8_on(val);
+
+ av_push(retval, val);
+ }
}
- }
+ } else {
+ /* We are the first (or only) parent. We can short cut the
+ complexity above, because our @ISA is simply us prepended
+ to our parent's @ISA, and our ->isa cache is simply our
+ parent's, with our name added. */
+ /* newSVsv() is slow. This code is only faster if we can avoid
+ it by ensuring that SVs in the arrays are shared hash key
+ scalar SVs, because we can "copy" them very efficiently.
+ Although to be fair, we can't *ensure* this, as a reference
+ to the internal array is returned by mro::get_linear_isa(),
+ so we'll have to be defensive just in case someone faffed
+ with it. */
+ if (basestash) {
+ SV **svp;
+ stored = MUTABLE_HV(sv_2mortal((SV*)newHVhv(HvMROMETA(basestash)->isa)));
+ av_extend(retval, subrv_items);
+ AvFILLp(retval) = subrv_items;
+ svp = AvARRAY(retval);
+ while(subrv_items--) {
+ SV *const val = *subrv_p++;
+ *++svp = SvIsCOW_shared_hash(val)
+ ? newSVhek(SvSHARED_HEK_FROM_PV(SvPVX(val)))
+ : newSVsv(val);
+ }
+ } else {
+ /* They have no stash. So create ourselves an ->isa cache
+ as if we'd copied it from what theirs should be. */
+ stored = MUTABLE_HV(sv_2mortal(MUTABLE_SV(newHV())));
+ (void) hv_store(stored, "UNIVERSAL", 9, &PL_sv_undef, 0);
+ av_push(retval,
+ newSVhek(HeKEY_hek(hv_store_ent(stored, sv,
+ &PL_sv_undef, 0))));
+ }
+ }
}
+ } else {
+ /* We have no parents. */
+ stored = MUTABLE_HV(sv_2mortal(MUTABLE_SV(newHV())));
+ (void) hv_store(stored, "UNIVERSAL", 9, &PL_sv_undef, 0);
}
- /* we don't want anyone modifying the cache entry but us,
- and we do so by replacing it completely */
- SvREADONLY_on(retval);
-
- meta->mro_linear_dfs = retval;
- return retval;
-}
-
-/*
-=for apidoc mro_get_linear_isa_c3
-
-Returns the C3 linearization of @ISA
-the given stash. The return value is a read-only AV*.
-C<level> should be 0 (it is used internally in this
-function's recursion).
-
-You are responsible for C<SvREFCNT_inc()> on the
-return value if you plan to store it anywhere
-semi-permanently (otherwise it might be deleted
-out from under you the next time the cache is
-invalidated).
-
-=cut
-*/
-
-AV*
-Perl_mro_get_linear_isa_c3(pTHX_ HV* stash, I32 level)
-{
- AV* retval;
- GV** gvp;
- GV* gv;
- AV* isa;
- const char* stashname;
- STRLEN stashname_len;
- struct mro_meta* meta;
-
- assert(stash);
- assert(HvAUX(stash));
-
- stashname = HvNAME_get(stash);
- stashname_len = HvNAMELEN_get(stash);
- if (!stashname)
- Perl_croak(aTHX_
- "Can't linearize anonymous symbol table");
-
- if (level > 100)
- Perl_croak(aTHX_ "Recursive inheritance detected in package '%s'",
- stashname);
-
- meta = HvMROMETA(stash);
-
- /* return cache if valid */
- if((retval = meta->mro_linear_c3)) {
- return retval;
- }
-
- /* not in cache, make a new one */
-
- retval = newAV();
- av_push(retval, newSVpvn(stashname, stashname_len)); /* us first */
+ (void) hv_store_ent(stored, our_name, &PL_sv_undef, 0);
- gvp = (GV**)hv_fetchs(stash, "ISA", FALSE);
- isa = (gvp && (gv = *gvp) && isGV_with_GP(gv)) ? GvAV(gv) : NULL;
+ SvREFCNT_inc_simple_void_NN(stored);
+ SvTEMP_off(stored);
+ SvREADONLY_on(stored);
- /* For a better idea how the rest of this works, see the much clearer
- pure perl version in Algorithm::C3 0.01:
- http://search.cpan.org/src/STEVAN/Algorithm-C3-0.01/lib/Algorithm/C3.pm
- (later versions go about it differently than this code for speed reasons)
- */
+ meta->isa = stored;
- if(isa && AvFILLp(isa) >= 0) {
- SV** seqs_ptr;
- I32 seqs_items;
- HV* tails = (HV*)sv_2mortal((SV*)newHV());
- AV* seqs = (AV*)sv_2mortal((SV*)newAV());
- I32* heads;
-
- /* This builds @seqs, which is an array of arrays.
- The members of @seqs are the MROs of
- the members of @ISA, followed by @ISA itself.
- */
- I32 items = AvFILLp(isa) + 1;
- SV** isa_ptr = AvARRAY(isa);
- while(items--) {
- AV* isa_lin;
- SV* isa_item = *isa_ptr++;
- HV* isa_item_stash = gv_stashsv(isa_item, 0);
- if(!isa_item_stash) {
- /* if no stash, make a temporary fake MRO
- containing just itself */
- isa_lin = (AV*)sv_2mortal((SV*)newAV());
- av_push(isa_lin, newSVsv(isa_item));
- }
- else {
- isa_lin = mro_get_linear_isa_c3(isa_item_stash, level + 1); /* recursion */
- }
- av_push(seqs, (SV*)isa_lin);
- }
- av_push(seqs, (SV*)isa);
-
- /* This builds "heads", which as an array of integer array
- indices, one per seq, which point at the virtual "head"
- of the seq (initially zero) */
- Newxz(heads, AvFILLp(seqs)+1, I32);
-
- /* This builds %tails, which has one key for every class
- mentioned in the tail of any sequence in @seqs (tail meaning
- everything after the first class, the "head"). The value
- is how many times this key appears in the tails of @seqs.
- */
- seqs_ptr = AvARRAY(seqs);
- seqs_items = AvFILLp(seqs) + 1;
- while(seqs_items--) {
- AV* seq = (AV*)*seqs_ptr++;
- I32 seq_items = AvFILLp(seq);
- if(seq_items > 0) {
- SV** seq_ptr = AvARRAY(seq) + 1;
- while(seq_items--) {
- SV* seqitem = *seq_ptr++;
- HE* he = hv_fetch_ent(tails, seqitem, 0, 0);
- if(!he) {
- hv_store_ent(tails, seqitem, newSViv(1), 0);
- }
- else {
- SV* val = HeVAL(he);
- sv_inc(val);
- }
- }
- }
- }
-
- /* This loop won't terminate until we either finish building
- the MRO, or get an exception. */
- while(1) {
- SV* seqhead = NULL;
- SV* cand = NULL;
- SV* winner = NULL;
- SV* val;
- HE* tail_entry;
- AV* seq;
- int s;
-
- /* "foreach $seq (@seqs)" */
- SV** avptr = AvARRAY(seqs);
- for(s = 0; s <= AvFILLp(seqs); s++) {
- SV** svp;
- seq = (AV*)(avptr[s]);
- if(!seq) continue; /* skip empty seqs */
- svp = av_fetch(seq, heads[s], 0);
- seqhead = *svp; /* seqhead = head of this seq */
- if(!winner) {
- /* if we haven't found a winner for this round yet,
- and this seqhead is not in tails (or the count
- for it in tails has dropped to zero), then this
- seqhead is our new winner, and is added to the
- final MRO immediately */
- cand = seqhead;
- if((tail_entry = hv_fetch_ent(tails, cand, 0, 0))
- && (val = HeVAL(tail_entry))
- && (SvIVX(val) > 0))
- continue;
- winner = newSVsv(cand);
- av_push(retval, winner);
- /* note however that even when we find a winner,
- we continue looping over @seqs to do housekeeping */
- }
- if(!sv_cmp(seqhead, winner)) {
- /* Once we have a winner (including the iteration
- where we first found him), inc the head ptr
- for any seq which had the winner as a head,
- NULL out any seq which is now empty,
- and adjust tails for consistency */
-
- int new_head = ++heads[s];
- if(new_head > AvFILLp(seq)) {
- avptr[s] = NULL;
- }
- else {
- /* Because we know this new seqhead used to be
- a tail, we can assume it is in tails and has
- a positive value, which we need to dec */
- svp = av_fetch(seq, new_head, 0);
- seqhead = *svp;
- tail_entry = hv_fetch_ent(tails, seqhead, 0, 0);
- val = HeVAL(tail_entry);
- sv_dec(val);
- }
- }
- }
-
- /* if we found no candidates, we are done building the MRO.
- !cand means no seqs have any entries left to check */
- if(!cand) {
- Safefree(heads);
- break;
- }
-
- /* If we had candidates, but nobody won, then the @ISA
- hierarchy is not C3-incompatible */
- if(!winner) {
- /* we have to do some cleanup before we croak */
- SV** svp = AvARRAY(seqs);
- items = AvFILLp(seqs) + 1;
- while (items--)
- *svp++ = NULL;
-
- SvREFCNT_dec(retval);
- Safefree(heads);
-
- Perl_croak(aTHX_ "Inconsistent hierarchy during C3 merge of class '%s': "
- "merging failed on parent '%"SVf"'", stashname, SVfARG(cand));
- }
- }
- }
+ /* now that we're past the exception dangers, grab our own reference to
+ the AV we're about to use for the result. The reference owned by the
+ mortals' stack will be released soon, so everything will balance. */
+ SvREFCNT_inc_simple_void_NN(retval);
+ SvTEMP_off(retval);
/* we don't want anyone modifying the cache entry but us,
and we do so by replacing it completely */
SvREADONLY_on(retval);
- meta->mro_linear_c3 = retval;
- return retval;
+ return MUTABLE_AV(Perl_mro_set_private_data(aTHX_ meta, &dfs_alg,
+ MUTABLE_SV(retval)));
}
/*
Perl_mro_get_linear_isa(pTHX_ HV *stash)
{
struct mro_meta* meta;
- assert(stash);
- assert(HvAUX(stash));
+
+ PERL_ARGS_ASSERT_MRO_GET_LINEAR_ISA;
+ if(!SvOOK(stash))
+ Perl_croak(aTHX_ "Can't linearize anonymous symbol table");
meta = HvMROMETA(stash);
- if(meta->mro_which == MRO_DFS) {
- return mro_get_linear_isa_dfs(stash, 0);
- } else if(meta->mro_which == MRO_C3) {
- return mro_get_linear_isa_c3(stash, 0);
- } else {
+ if (!meta->mro_which)
Perl_croak(aTHX_ "panic: invalid MRO!");
- }
- return NULL; /* NOT REACHED */
+ return meta->mro_which->resolve(aTHX_ stash, 0);
}
/*
HE* iter;
SV** svp;
I32 items;
- struct mro_meta* meta;
- char* stashname;
+ bool is_universal;
+ struct mro_meta * meta;
- stashname = HvNAME_get(stash);
+ const char * const stashname = HvNAME_get(stash);
+ const STRLEN stashname_len = HvNAMELEN_get(stash);
+
+ PERL_ARGS_ASSERT_MRO_ISA_CHANGED_IN;
+
+ if(!stashname)
+ Perl_croak(aTHX_ "Can't call mro_isa_changed_in() on anonymous symbol table");
/* wipe out the cached linearizations for this stash */
meta = HvMROMETA(stash);
- SvREFCNT_dec((SV*)meta->mro_linear_dfs);
- SvREFCNT_dec((SV*)meta->mro_linear_c3);
- meta->mro_linear_dfs = NULL;
- meta->mro_linear_c3 = NULL;
+ if (meta->mro_linear_all) {
+ SvREFCNT_dec(MUTABLE_SV(meta->mro_linear_all));
+ meta->mro_linear_all = NULL;
+ /* This is just acting as a shortcut pointer. */
+ meta->mro_linear_current = NULL;
+ } else if (meta->mro_linear_current) {
+ /* Only the current MRO is stored, so this owns the data. */
+ SvREFCNT_dec(meta->mro_linear_current);
+ meta->mro_linear_current = NULL;
+ }
+ if (meta->isa) {
+ SvREFCNT_dec(meta->isa);
+ meta->isa = NULL;
+ }
+
+ /* Inc the package generation, since our @ISA changed */
+ meta->pkg_gen++;
/* Wipe the global method cache if this package
is UNIVERSAL or one of its parents */
- if(meta->is_universal)
- PL_sub_generation++;
- /* Wipe the local method cache otherwise */
- else
- meta->sub_generation++;
+ svp = hv_fetch(PL_isarev, stashname, stashname_len, 0);
+ isarev = svp ? MUTABLE_HV(*svp) : NULL;
+
+ if((stashname_len == 9 && strEQ(stashname, "UNIVERSAL"))
+ || (isarev && hv_exists(isarev, "UNIVERSAL", 9))) {
+ PL_sub_generation++;
+ is_universal = TRUE;
+ }
+ else { /* Wipe the local method cache otherwise */
+ meta->cache_gen++;
+ is_universal = FALSE;
+ }
/* wipe next::method cache too */
if(meta->mro_nextmethod) hv_clear(meta->mro_nextmethod);
-
+
/* Iterate the isarev (classes that are our children),
- wiping out their linearization and method caches */
- if((isarev = meta->mro_isarev)) {
+ wiping out their linearization, method and isa caches */
+ if(isarev) {
hv_iterinit(isarev);
while((iter = hv_iternext(isarev))) {
- SV* revkey = hv_iterkeysv(iter);
- HV* revstash = gv_stashsv(revkey, 0);
- struct mro_meta* revmeta = HvMROMETA(revstash);
- SvREFCNT_dec((SV*)revmeta->mro_linear_dfs);
- SvREFCNT_dec((SV*)revmeta->mro_linear_c3);
- revmeta->mro_linear_dfs = NULL;
- revmeta->mro_linear_c3 = NULL;
- if(!meta->is_universal)
- revmeta->sub_generation++;
+ I32 len;
+ const char* const revkey = hv_iterkey(iter, &len);
+ HV* revstash = gv_stashpvn(revkey, len, 0);
+ struct mro_meta* revmeta;
+
+ if(!revstash) continue;
+ revmeta = HvMROMETA(revstash);
+ if (revmeta->mro_linear_all) {
+ SvREFCNT_dec(MUTABLE_SV(revmeta->mro_linear_all));
+ revmeta->mro_linear_all = NULL;
+ /* This is just acting as a shortcut pointer. */
+ revmeta->mro_linear_current = NULL;
+ } else if (revmeta->mro_linear_current) {
+ /* Only the current MRO is stored, so this owns the data. */
+ SvREFCNT_dec(revmeta->mro_linear_current);
+ revmeta->mro_linear_current = NULL;
+ }
+ if(!is_universal)
+ revmeta->cache_gen++;
if(revmeta->mro_nextmethod)
hv_clear(revmeta->mro_nextmethod);
+ if (revmeta->isa) {
+ SvREFCNT_dec(revmeta->isa);
+ revmeta->isa = NULL;
+ }
}
}
while (items--) {
SV* const sv = *svp++;
- struct mro_meta* mrometa;
HV* mroisarev;
- HV* mrostash = gv_stashsv(sv, 0);
- if(!mrostash) {
- mrostash = gv_stashsv(sv, GV_ADD);
- /*
- We created the package on the fly, so
- that we could store isarev information.
- This flag lets gv_fetchmeth know about it,
- so that it can still generate the very useful
- "Can't locate package Foo for @Bar::ISA" warning.
- */
- HvMROMETA(mrostash)->fake = 1;
- }
+ HE *he = hv_fetch_ent(PL_isarev, sv, TRUE, 0);
- mrometa = HvMROMETA(mrostash);
- mroisarev = mrometa->mro_isarev;
+ /* That fetch should not fail. But if it had to create a new SV for
+ us, then will need to upgrade it to an HV (which sv_upgrade() can
+ now do for us. */
- /* is_universal is viral */
- if(meta->is_universal)
- mrometa->is_universal = 1;
+ mroisarev = MUTABLE_HV(HeVAL(he));
- if(!mroisarev)
- mroisarev = mrometa->mro_isarev = newHV();
+ SvUPGRADE(MUTABLE_SV(mroisarev), SVt_PVHV);
/* This hash only ever contains PL_sv_yes. Storing it over itself is
almost as cheap as calling hv_exists, so on aggregate we expect to
save time by not making two calls to the common HV code for the
case where it doesn't exist. */
- hv_store(mroisarev, stashname, strlen(stashname), &PL_sv_yes, 0);
+ (void)hv_store(mroisarev, stashname, stashname_len, &PL_sv_yes, 0);
if(isarev) {
hv_iterinit(isarev);
while((iter = hv_iternext(isarev))) {
- SV* revkey = hv_iterkeysv(iter);
- hv_store_ent(mroisarev, revkey, &PL_sv_yes, 0);
+ I32 revkeylen;
+ char* const revkey = hv_iterkey(iter, &revkeylen);
+ (void)hv_store(mroisarev, revkey, revkeylen, &PL_sv_yes, 0);
}
}
}
the changes in this one.
Ideally, all instances of C<PL_sub_generation++> in
-the perl source outside of C<mro.c> should be
-replaced by calls to this. This conversion is
-nearly complete.
+perl source outside of C<mro.c> should be
+replaced by calls to this.
-Perl has always had problems with method caches
-getting out of sync when one directly manipulates
-stashes via things like C<%{Foo::} = %{Bar::}> or
-C<${Foo::}{bar} = ...> or the equivalent. If
-you do this in core or XS code, call this afterwards
-on the destination stash to get things back in sync.
+Perl automatically handles most of the common
+ways a method might be redefined. However, there
+are a few ways you could change a method in a stash
+without the cache code noticing, in which case you
+need to call this method afterwards:
-If you're doing such a thing from pure perl, use
-C<mro::method_changed_in(classname)>, which
-just calls this.
+1) Directly manipulating the stash HV entries from
+XS code.
+
+2) Assigning a reference to a readonly scalar
+constant into a stash entry in order to create
+a constant subroutine (like constant.pm
+does).
+
+This same method is available from pure perl
+via, C<mro::method_changed_in(classname)>.
=cut
*/
void
Perl_mro_method_changed_in(pTHX_ HV *stash)
{
- struct mro_meta* meta = HvMROMETA(stash);
- HV* isarev;
- HE* iter;
+ const char * const stashname = HvNAME_get(stash);
+ const STRLEN stashname_len = HvNAMELEN_get(stash);
+
+ SV ** const svp = hv_fetch(PL_isarev, stashname, stashname_len, 0);
+ HV * const isarev = svp ? MUTABLE_HV(*svp) : NULL;
+
+ PERL_ARGS_ASSERT_MRO_METHOD_CHANGED_IN;
+
+ if(!stashname)
+ Perl_croak(aTHX_ "Can't call mro_method_changed_in() on anonymous symbol table");
+
+ /* Inc the package generation, since a local method changed */
+ HvMROMETA(stash)->pkg_gen++;
/* If stash is UNIVERSAL, or one of UNIVERSAL's parents,
invalidate all method caches globally */
- if(meta->is_universal) {
+ if((stashname_len == 9 && strEQ(stashname, "UNIVERSAL"))
+ || (isarev && hv_exists(isarev, "UNIVERSAL", 9))) {
PL_sub_generation++;
return;
}
/* else, invalidate the method caches of all child classes,
but not itself */
- if((isarev = meta->mro_isarev)) {
+ if(isarev) {
+ HE* iter;
+
hv_iterinit(isarev);
while((iter = hv_iternext(isarev))) {
- SV* revkey = hv_iterkeysv(iter);
- HV* revstash = gv_stashsv(revkey, 0);
- struct mro_meta* mrometa = HvMROMETA(revstash);
- mrometa->sub_generation++;
+ I32 len;
+ const char* const revkey = hv_iterkey(iter, &len);
+ HV* const revstash = gv_stashpvn(revkey, len, 0);
+ struct mro_meta* mrometa;
+
+ if(!revstash) continue;
+ mrometa = HvMROMETA(revstash);
+ mrometa->cache_gen++;
if(mrometa->mro_nextmethod)
hv_clear(mrometa->mro_nextmethod);
}
}
}
-/* These two are static helpers for next::method and friends,
- and re-implement a bunch of the code from pp_caller() in
- a more efficient manner for this particular usage.
-*/
-
-STATIC I32
-__dopoptosub_at(const PERL_CONTEXT *cxstk, I32 startingblock) {
- I32 i;
- for (i = startingblock; i >= 0; i--) {
- if(CxTYPE((PERL_CONTEXT*)(&cxstk[i])) == CXt_SUB) return i;
- }
- return i;
-}
-
-STATIC SV*
-__nextcan(pTHX_ SV* self, I32 throw_nomethod)
-{
- register I32 cxix;
- register const PERL_CONTEXT *ccstack = cxstack;
- const PERL_SI *top_si = PL_curstackinfo;
- HV* selfstash;
- GV* cvgv;
- SV *stashname;
- const char *fq_subname;
- const char *subname;
- STRLEN fq_subname_len;
- STRLEN stashname_len;
- STRLEN subname_len;
- SV* sv;
- GV** gvp;
- AV* linear_av;
- SV** linear_svp;
- SV* linear_sv;
- HV* curstash;
- GV* candidate = NULL;
- CV* cand_cv = NULL;
- const char *hvname;
- I32 items;
- struct mro_meta* selfmeta;
- HV* nmcache;
- HE* cache_entry;
-
- if(sv_isobject(self))
- selfstash = SvSTASH(SvRV(self));
- else
- selfstash = gv_stashsv(self, 0);
-
- assert(selfstash);
-
- hvname = HvNAME_get(selfstash);
- if (!hvname)
- Perl_croak(aTHX_ "Can't use anonymous symbol table for method lookup");
-
- cxix = __dopoptosub_at(cxstack, cxstack_ix);
-
- /* This block finds the contextually-enclosing fully-qualified subname,
- much like looking at (caller($i))[3] until you find a real sub that
- isn't ANON, etc */
- for (;;) {
- /* we may be in a higher stacklevel, so dig down deeper */
- while (cxix < 0) {
- if(top_si->si_type == PERLSI_MAIN)
- Perl_croak(aTHX_ "next::method/next::can/maybe::next::method must be used in method context");
- top_si = top_si->si_prev;
- ccstack = top_si->si_cxstack;
- cxix = __dopoptosub_at(ccstack, top_si->si_cxix);
- }
-
- if(CxTYPE((PERL_CONTEXT*)(&ccstack[cxix])) != CXt_SUB
- || (PL_DBsub && GvCV(PL_DBsub) && ccstack[cxix].blk_sub.cv == GvCV(PL_DBsub))) {
- cxix = __dopoptosub_at(ccstack, cxix - 1);
- continue;
- }
-
- {
- const I32 dbcxix = __dopoptosub_at(ccstack, cxix - 1);
- if (PL_DBsub && GvCV(PL_DBsub) && dbcxix >= 0 && ccstack[dbcxix].blk_sub.cv == GvCV(PL_DBsub)) {
- if(CxTYPE((PERL_CONTEXT*)(&ccstack[dbcxix])) != CXt_SUB) {
- cxix = dbcxix;
- continue;
- }
- }
- }
-
- cvgv = CvGV(ccstack[cxix].blk_sub.cv);
-
- if(!isGV(cvgv)) {
- cxix = __dopoptosub_at(ccstack, cxix - 1);
- continue;
- }
-
- /* we found a real sub here */
- sv = sv_2mortal(newSV(0));
-
- gv_efullname3(sv, cvgv, NULL);
-
- fq_subname = SvPVX(sv);
- fq_subname_len = SvCUR(sv);
-
- subname = strrchr(fq_subname, ':');
- if(!subname)
- Perl_croak(aTHX_ "next::method/next::can/maybe::next::method cannot find enclosing method");
-
- subname++;
- subname_len = fq_subname_len - (subname - fq_subname);
- if(subname_len == 8 && strEQ(subname, "__ANON__")) {
- cxix = __dopoptosub_at(ccstack, cxix - 1);
- continue;
- }
- break;
- }
-
- /* If we made it to here, we found our context */
-
- /* Initialize the next::method cache for this stash
- if necessary */
- selfmeta = HvMROMETA(selfstash);
- if(!(nmcache = selfmeta->mro_nextmethod)) {
- nmcache = selfmeta->mro_nextmethod = newHV();
- }
-
- /* Use the cached coderef if it exists */
- else if((cache_entry = hv_fetch_ent(nmcache, sv, 0, 0))) {
- SV* val = HeVAL(cache_entry);
- if(val == &PL_sv_undef) {
- if(throw_nomethod)
- Perl_croak(aTHX_ "No next::method '%s' found for %s", subname, hvname);
- }
- return val;
- }
-
- /* beyond here is just for cache misses, so perf isn't as critical */
-
- stashname_len = subname - fq_subname - 2;
- stashname = sv_2mortal(newSVpvn(fq_subname, stashname_len));
-
- linear_av = mro_get_linear_isa_c3(selfstash, 0); /* has ourselves at the top of the list */
-
- linear_svp = AvARRAY(linear_av);
- items = AvFILLp(linear_av) + 1;
-
- /* Walk down our MRO, skipping everything up
- to the contextually enclosing class */
- while (items--) {
- linear_sv = *linear_svp++;
- assert(linear_sv);
- if(sv_eq(linear_sv, stashname))
- break;
- }
-
- /* Now search the remainder of the MRO for the
- same method name as the contextually enclosing
- method */
- if(items > 0) {
- while (items--) {
- linear_sv = *linear_svp++;
- assert(linear_sv);
- curstash = gv_stashsv(linear_sv, FALSE);
-
- if (!curstash || (HvMROMETA(curstash)->fake && !HvFILL(curstash))) {
- if (ckWARN(WARN_SYNTAX))
- Perl_warner(aTHX_ packWARN(WARN_SYNTAX), "Can't locate package %"SVf" for @%s::ISA",
- (void*)linear_sv, hvname);
- continue;
- }
-
- assert(curstash);
-
- gvp = (GV**)hv_fetch(curstash, subname, subname_len, 0);
- if (!gvp) continue;
-
- candidate = *gvp;
- assert(candidate);
-
- if (SvTYPE(candidate) != SVt_PVGV)
- gv_init(candidate, curstash, subname, subname_len, TRUE);
-
- /* Notably, we only look for real entries, not method cache
- entries, because in C3 the method cache of a parent is not
- valid for the child */
- if (SvTYPE(candidate) == SVt_PVGV && (cand_cv = GvCV(candidate)) && !GvCVGEN(candidate)) {
- SvREFCNT_inc_simple_void_NN((SV*)cand_cv);
- hv_store_ent(nmcache, newSVsv(sv), (SV*)cand_cv, 0);
- return (SV*)cand_cv;
- }
- }
- }
-
- hv_store_ent(nmcache, newSVsv(sv), &PL_sv_undef, 0);
- if(throw_nomethod)
- Perl_croak(aTHX_ "No next::method '%s' found for %s", subname, hvname);
- return &PL_sv_undef;
-}
-
-#include "XSUB.h"
-
-XS(XS_mro_get_linear_isa);
-XS(XS_mro_set_mro);
-XS(XS_mro_get_mro);
-XS(XS_mro_get_isarev);
-XS(XS_mro_is_universal);
-XS(XS_mro_get_global_sub_gen);
-XS(XS_mro_invalidate_method_caches);
-XS(XS_mro_get_sub_generation);
-XS(XS_mro_method_changed_in);
-XS(XS_next_can);
-XS(XS_next_method);
-XS(XS_maybe_next_method);
-
void
-Perl_boot_core_mro(pTHX)
+Perl_mro_set_mro(pTHX_ struct mro_meta *const meta, SV *const name)
{
- dVAR;
- static const char file[] = __FILE__;
-
- newXSproto("mro::get_linear_isa", XS_mro_get_linear_isa, file, "$;$");
- newXSproto("mro::set_mro", XS_mro_set_mro, file, "$$");
- newXSproto("mro::get_mro", XS_mro_get_mro, file, "$");
- newXSproto("mro::get_isarev", XS_mro_get_isarev, file, "$");
- newXSproto("mro::is_universal", XS_mro_is_universal, file, "$");
- newXSproto("mro::get_global_sub_generation", XS_mro_get_global_sub_gen, file, "");
- newXSproto("mro::invalidate_all_method_caches", XS_mro_invalidate_method_caches, file, "");
- newXSproto("mro::get_sub_generation", XS_mro_get_sub_generation, file, "$");
- newXSproto("mro::method_changed_in", XS_mro_method_changed_in, file, "$");
- newXS("next::can", XS_next_can, file);
- newXS("next::method", XS_next_method, file);
- newXS("maybe::next::method", XS_maybe_next_method, file);
-}
-
-XS(XS_mro_get_linear_isa) {
- dVAR;
- dXSARGS;
- AV* RETVAL;
- HV* class_stash;
- SV* classname;
-
- PERL_UNUSED_ARG(cv);
+ const struct mro_alg *const which = Perl_mro_get_from_name(aTHX_ name);
+
+ PERL_ARGS_ASSERT_MRO_SET_MRO;
- if(items < 1 || items > 2)
- Perl_croak(aTHX_ "Usage: mro::get_linear_isa(classname [, type ])");
-
- classname = ST(0);
- class_stash = gv_stashsv(classname, 0);
- if(!class_stash) Perl_croak(aTHX_ "No such class: '%"SVf"'!", SVfARG(classname));
-
- if(items > 1) {
- char* which = SvPV_nolen(ST(1));
- if(strEQ(which, "dfs"))
- RETVAL = mro_get_linear_isa_dfs(class_stash, 0);
- else if(strEQ(which, "c3"))
- RETVAL = mro_get_linear_isa_c3(class_stash, 0);
- else
- Perl_croak(aTHX_ "Invalid mro name: '%s'", which);
- }
- else {
- RETVAL = mro_get_linear_isa(class_stash);
- }
-
- ST(0) = newRV_inc((SV*)RETVAL);
- sv_2mortal(ST(0));
- XSRETURN(1);
-}
-
-XS(XS_mro_set_mro)
-{
- dVAR;
- dXSARGS;
- SV* classname;
- char* whichstr;
- mro_alg which;
- HV* class_stash;
- struct mro_meta* meta;
-
- PERL_UNUSED_ARG(cv);
-
- if (items != 2)
- Perl_croak(aTHX_ "Usage: mro::set_mro(classname, type)");
-
- classname = ST(0);
- whichstr = SvPV_nolen(ST(1));
- class_stash = gv_stashsv(classname, GV_ADD);
- if(!class_stash) Perl_croak(aTHX_ "Cannot create class: '%"SVf"'!", SVfARG(classname));
- meta = HvMROMETA(class_stash);
-
- if(strEQ(whichstr, "dfs"))
- which = MRO_DFS;
- else if(strEQ(whichstr, "c3"))
- which = MRO_C3;
- else
- Perl_croak(aTHX_ "Invalid mro name: '%s'", whichstr);
+ if (!which)
+ Perl_croak(aTHX_ "Invalid mro name: '%"SVf"'", name);
if(meta->mro_which != which) {
- meta->mro_which = which;
+ if (meta->mro_linear_current && !meta->mro_linear_all) {
+ /* If we were storing something directly, put it in the hash before
+ we lose it. */
+ Perl_mro_set_private_data(aTHX_ meta, meta->mro_which,
+ MUTABLE_SV(meta->mro_linear_current));
+ }
+ meta->mro_which = which;
+ /* Scrub our cached pointer to the private data. */
+ meta->mro_linear_current = NULL;
/* Only affects local method cache, not
even child classes */
- meta->sub_generation++;
+ meta->cache_gen++;
if(meta->mro_nextmethod)
hv_clear(meta->mro_nextmethod);
}
-
- XSRETURN_EMPTY;
-}
-
-
-XS(XS_mro_get_mro)
-{
- dVAR;
- dXSARGS;
- SV* classname;
- HV* class_stash;
- struct mro_meta* meta;
-
- PERL_UNUSED_ARG(cv);
-
- if (items != 1)
- Perl_croak(aTHX_ "Usage: mro::get_mro(classname)");
-
- classname = ST(0);
- class_stash = gv_stashsv(classname, 0);
- if(!class_stash) Perl_croak(aTHX_ "No such class: '%"SVf"'!", SVfARG(classname));
- meta = HvMROMETA(class_stash);
-
- if(meta->mro_which == MRO_DFS)
- ST(0) = sv_2mortal(newSVpvn("dfs", 3));
- else
- ST(0) = sv_2mortal(newSVpvn("c3", 2));
-
- XSRETURN(1);
-}
-
-XS(XS_mro_get_isarev)
-{
- dVAR;
- dXSARGS;
- SV* classname;
- HV* class_stash;
- HV* isarev;
-
- PERL_UNUSED_ARG(cv);
-
- if (items != 1)
- Perl_croak(aTHX_ "Usage: mro::get_isarev(classname)");
-
- classname = ST(0);
-
- class_stash = gv_stashsv(classname, 0);
- if(!class_stash) Perl_croak(aTHX_ "No such class: '%"SVf"'!", SVfARG(classname));
-
- SP -= items;
-
- if((isarev = HvMROMETA(class_stash)->mro_isarev)) {
- HE* iter;
- hv_iterinit(isarev);
- while((iter = hv_iternext(isarev)))
- XPUSHs(hv_iterkeysv(iter));
- }
-
- PUTBACK;
- return;
}
-XS(XS_mro_is_universal)
-{
- dVAR;
- dXSARGS;
- SV* classname;
- HV* class_stash;
-
- PERL_UNUSED_ARG(cv);
-
- if (items != 1)
- Perl_croak(aTHX_ "Usage: mro::get_mro(classname)");
-
- classname = ST(0);
- class_stash = gv_stashsv(classname, 0);
- if(!class_stash) Perl_croak(aTHX_ "No such class: '%"SVf"'!", SVfARG(classname));
-
- if (HvMROMETA(class_stash)->is_universal)
- XSRETURN_YES;
- else
- XSRETURN_NO;
-}
-
-XS(XS_mro_get_global_sub_gen)
-{
- dVAR;
- dXSARGS;
-
- PERL_UNUSED_ARG(cv);
-
- if (items != 0)
- Perl_croak(aTHX_ "Usage: mro::get_global_sub_generation()");
-
- ST(0) = sv_2mortal(newSViv(PL_sub_generation));
- XSRETURN(1);
-}
-
-XS(XS_mro_invalidate_method_caches)
-{
- dVAR;
- dXSARGS;
-
- PERL_UNUSED_ARG(cv);
-
- if (items != 0)
- Perl_croak(aTHX_ "Usage: mro::invalidate_all_method_caches()");
-
- PL_sub_generation++;
+#include "XSUB.h"
- XSRETURN_EMPTY;
-}
+XS(XS_mro_method_changed_in);
-XS(XS_mro_get_sub_generation)
+void
+Perl_boot_core_mro(pTHX)
{
dVAR;
- dXSARGS;
- SV* classname;
- HV* class_stash;
-
- PERL_UNUSED_ARG(cv);
-
- if(items != 1)
- Perl_croak(aTHX_ "Usage: mro::get_sub_generation(classname)");
+ static const char file[] = __FILE__;
- classname = ST(0);
- class_stash = gv_stashsv(classname, 0);
- if(!class_stash) Perl_croak(aTHX_ "No such class: '%"SVf"'!", SVfARG(classname));
+ Perl_mro_register(aTHX_ &dfs_alg);
- ST(0) = sv_2mortal(newSViv(HvMROMETA(class_stash)->sub_generation));
- XSRETURN(1);
+ newXSproto("mro::method_changed_in", XS_mro_method_changed_in, file, "$");
}
XS(XS_mro_method_changed_in)
SV* classname;
HV* class_stash;
- PERL_UNUSED_ARG(cv);
-
if(items != 1)
- Perl_croak(aTHX_ "Usage: mro::method_changed_in(classname)");
+ croak_xs_usage(cv, "classname");
classname = ST(0);
XSRETURN_EMPTY;
}
-XS(XS_next_can)
-{
- dVAR;
- dXSARGS;
- SV* self = ST(0);
- SV* methcv = __nextcan(aTHX_ self, 0);
-
- PERL_UNUSED_ARG(cv);
- PERL_UNUSED_VAR(items);
-
- if(methcv == &PL_sv_undef) {
- ST(0) = &PL_sv_undef;
- }
- else {
- ST(0) = sv_2mortal(newRV_inc(methcv));
- }
-
- XSRETURN(1);
-}
-
-XS(XS_next_method)
-{
- dMARK;
- dAX;
- SV* self = ST(0);
- SV* methcv = __nextcan(aTHX_ self, 1);
-
- PERL_UNUSED_ARG(cv);
-
- PL_markstack_ptr++;
- call_sv(methcv, GIMME_V);
-}
-
-XS(XS_maybe_next_method)
-{
- dMARK;
- dAX;
- SV* self = ST(0);
- SV* methcv = __nextcan(aTHX_ self, 0);
-
- PERL_UNUSED_ARG(cv);
-
- if(methcv == &PL_sv_undef) {
- ST(0) = &PL_sv_undef;
- XSRETURN(1);
- }
-
- PL_markstack_ptr++;
- call_sv(methcv, GIMME_V);
-}
-
/*
* Local variables:
* c-indentation-style: bsd
https://perl5.git.perl.org / perl5.git / blobdiff