X-Git-Url: http://git.vpit.fr/?a=blobdiff_plain;f=Magic.xs;h=73536b861649b32eb497cc082f611ba15e567fdc;hb=03eb870636b3e9f56a04a7a5291752e26f36829e;hp=00384fe62b8fa1eff3ecb353ed5d646c2940fb82;hpb=f346204d7035c0bc27598666f04408cd67b905c4;p=perl%2Fmodules%2FVariable-Magic.git

diff --git a/Magic.xs b/Magic.xs
index 00384fe..73536b8 100644
--- a/Magic.xs
+++ b/Magic.xs
@@ -12,12 +12,6 @@
 
 #define __PACKAGE__ "Variable::Magic"
 
-#define R(S) fprintf(stderr, "R(" #S ") = %d\n", SvREFCNT(S))
-
-#define PERL_VERSION_GE(R, V, S) (PERL_REVISION > (R) || (PERL_REVISION == (R) && (PERL_VERSION > (V) || (PERL_VERSION == (V) && (PERL_SUBVERSION >= (S))))))
-
-#define PERL_VERSION_LE(R, V, S) (PERL_REVISION < (R) || (PERL_REVISION == (R) && (PERL_VERSION < (V) || (PERL_VERSION == (V) && (PERL_SUBVERSION <= (S))))))
-
 #ifndef VMG_PERL_PATCHLEVEL
 # ifdef PERL_PATCHNUM
 #  define VMG_PERL_PATCHLEVEL PERL_PATCHNUM
@@ -26,9 +20,11 @@
 # endif
 #endif
 
-#define VMG_HAS_PERL_OR(P, R, V, S) ((VMG_PERL_PATCHLEVEL >= (P)) || (!VMG_PERL_PATCHLEVEL && PERL_VERSION_GE((R), (V), (S))))
+#define VMG_HAS_PERL(R, V, S) (PERL_REVISION > (R) || (PERL_REVISION == (R) && (PERL_VERSION > (V) || (PERL_VERSION == (V) && (PERL_SUBVERSION >= (S))))))
 
-#define VMG_HAS_PERL_AND(P, R, V, S) (PERL_VERSION_GE((R), (V), (S)) && (!VMG_PERL_PATCHLEVEL || (VMG_PERL_PATCHLEVEL >= (P))))
+#define VMG_HAS_PERL_BRANCH(R, V, S) (PERL_REVISION == (R) && PERL_VERSION == (V) && PERL_SUBVERSION >= (S))
+
+#define VMG_HAS_PERL_MAINT(R, V, S, P) (PERL_REVISION == (R) && PERL_VERSION == (V) && (VMG_PERL_PATCHLEVEL >= (P) || (!VMG_PERL_PATCHLEVEL && PERL_SUBVERSION >= (S))))
 
 /* --- Threads and multiplicity -------------------------------------------- */
 
@@ -40,23 +36,32 @@
 # define dNOOP
 #endif
 
-#if defined(MULTIPLICITY) || defined(PERL_IMPLICIT_CONTEXT)
-# define VMG_MULTIPLICITY 1
-# ifndef tTHX
-#  define tTHX PerlInterpreter*
+#ifndef VMG_MULTIPLICITY
+# if defined(MULTIPLICITY) || defined(PERL_IMPLICIT_CONTEXT)
+#  define VMG_MULTIPLICITY 1
+# else
+#  define VMG_MULTIPLICITY 0
 # endif
-#else
-# define VMG_MULTIPLICITY 0
+#endif
+#if VMG_MULTIPLICITY && !defined(tTHX)
+# define tTHX PerlInterpreter*
 #endif
 
-#if VMG_MULTIPLICITY && defined(dMY_CXT) && defined(MY_CXT) && defined(START_MY_CXT) && defined(MY_CXT_INIT) && defined(MY_CXT_CLONE)
+#if VMG_MULTIPLICITY && defined(USE_ITHREADS) && defined(dMY_CXT) && defined(MY_CXT) && defined(START_MY_CXT) && defined(MY_CXT_INIT) && (defined(MY_CXT_CLONE) || defined(dMY_CXT_SV))
 # define VMG_THREADSAFE 1
+# ifndef MY_CXT_CLONE
+#  define MY_CXT_CLONE \
+    dMY_CXT_SV;                                                      \
+    my_cxt_t *my_cxtp = (my_cxt_t*)SvPVX(newSV(sizeof(my_cxt_t)-1)); \
+    Copy(INT2PTR(my_cxt_t*, SvUV(my_cxt_sv)), my_cxtp, 1, my_cxt_t); \
+    sv_setuv(my_cxt_sv, PTR2UV(my_cxtp))
+# endif
 #else
 # define VMG_THREADSAFE 0
 # undef  dMY_CXT
 # define dMY_CXT      dNOOP
 # undef  MY_CXT
-# define MY_CXT vmg_globaldata
+# define MY_CXT       vmg_globaldata
 # undef  START_MY_CXT
 # define START_MY_CXT STATIC my_cxt_t MY_CXT;
 # undef  MY_CXT_INIT
@@ -65,12 +70,29 @@
 # define MY_CXT_CLONE NOOP
 #endif
 
+#if VMG_THREADSAFE
+
+STATIC SV *vmg_clone(pTHX_ SV *sv, tTHX owner) {
+#define vmg_clone(P, O) vmg_clone(aTHX_ (P), (O))
+ CLONE_PARAMS param;
+ param.stashes    = NULL; /* don't need it unless sv is a PVHV */
+ param.flags      = 0;
+ param.proto_perl = owner;
+ return sv_dup(sv, &param);
+}
+
+#endif /* VMG_THREADSAFE */
+
 /* --- Compatibility ------------------------------------------------------- */
 
 #ifndef Newx
 # define Newx(v, n, c) New(0, v, n, c)
 #endif
 
+#ifndef NewOp
+# define NewOp(m, var, c, type) Newz(m, var, c, type)
+#endif
+
 #ifndef SvMAGIC_set
 # define SvMAGIC_set(sv, val) (SvMAGIC(sv) = (val))
 #endif
@@ -83,6 +105,10 @@
 # define PERL_MAGIC_ext '~'
 #endif
 
+#ifndef PERL_MAGIC_tied
+# define PERL_MAGIC_tied 'P'
+#endif
+
 #ifndef MGf_COPY
 # define MGf_COPY 0
 #endif
@@ -95,27 +121,51 @@
 # define MGf_LOCAL 0
 #endif
 
-/* uvar magic and Hash::Util::FieldHash were commited with p28419 */
-#if VMG_HAS_PERL_AND(28419, 5, 9, 4)
+#ifndef IN_PERL_COMPILETIME
+# define IN_PERL_COMPILETIME (PL_curcop == &PL_compiling)
+#endif
+
+#if VMG_HAS_PERL(5, 10, 0) || defined(PL_parser)
+# ifndef PL_error_count
+#  define PL_error_count PL_parser->error_count
+# endif
+#else
+# ifndef PL_error_count
+#  define PL_error_count PL_Ierror_count
+# endif
+#endif
+
+/* uvar magic and Hash::Util::FieldHash were commited with 28419 */
+#if VMG_HAS_PERL_MAINT(5, 9, 4, 28419) || VMG_HAS_PERL(5, 10, 0)
 # define VMG_UVAR 1
 #else
 # define VMG_UVAR 0
 #endif
 
-#if !defined(VMG_COMPAT_ARRAY_PUSH_NOLEN) && VMG_HAS_PERL_OR(25854, 5, 9, 3)
-# define VMG_COMPAT_ARRAY_PUSH_NOLEN 1
+/* Applied to dev-5.9 as 25854, integrated to maint-5.8 as 28160 */
+#ifndef VMG_COMPAT_ARRAY_PUSH_NOLEN
+# if VMG_HAS_PERL_MAINT(5, 8, 9, 28160) || VMG_HAS_PERL_MAINT(5, 9, 3, 25854) || VMG_HAS_PERL(5, 10, 0)
+#  define VMG_COMPAT_ARRAY_PUSH_NOLEN 1
+# else
+#  define VMG_COMPAT_ARRAY_PUSH_NOLEN 0
+# endif
+#endif
+
+/* Applied to dev-5.11 as 34908 */
+#if VMG_HAS_PERL_MAINT(5, 11, 0, 34908)
+# define VMG_COMPAT_ARRAY_UNSHIFT_NOLEN_VOID 1
 #else
-# define VMG_COMPAT_ARRAY_PUSH_NOLEN 0
+# define VMG_COMPAT_ARRAY_UNSHIFT_NOLEN_VOID 0
 #endif
 
-/* since 5.9.5 - see #43357 */
-#if VMG_HAS_PERL_OR(31473, 5, 9, 5)
+/* Applied to dev-5.9 as 31473 (see #43357), integrated to maint-5.8 as 32542 */
+#if VMG_HAS_PERL_MAINT(5, 8, 9, 32542) || VMG_HAS_PERL_MAINT(5, 9, 5, 31473) || VMG_HAS_PERL(5, 10, 0)
 # define VMG_COMPAT_ARRAY_UNDEF_CLEAR 1
 #else
 # define VMG_COMPAT_ARRAY_UNDEF_CLEAR 0
 #endif
 
-#if VMG_HAS_PERL_OR(32969, 5, 11, 0)
+#if VMG_HAS_PERL_MAINT(5, 11, 0, 32969)
 # define VMG_COMPAT_SCALAR_LENGTH_NOLEN 1
 #else
 # define VMG_COMPAT_SCALAR_LENGTH_NOLEN 0
@@ -129,7 +179,6 @@ STATIC void vmg_sv_magicuvar(pTHX_ SV *sv, const char *uf, I32 len) {
  const MAGIC* mg;
  sv_magic(sv, NULL, PERL_MAGIC_uvar, uf, len);
  /* uvar magic has set and get magic, hence this has set SVs_GMG and SVs_SMG. */
- PERL_UNUSED_CONTEXT;
  if ((mg = SvMAGIC(sv))) {
   SvRMAGICAL_off(sv);
   do {
@@ -150,30 +199,10 @@ STATIC void vmg_sv_magicuvar(pTHX_ SV *sv, const char *uf, I32 len) {
 
 #define MY_CXT_KEY __PACKAGE__ "::_guts" XS_VERSION
 
-typedef struct {
- HV *wizz;
- U16 count;
-} my_cxt_t;
+typedef HV * my_cxt_t;
 
 START_MY_CXT
 
-STATIC void vmg_cxt_init
-#if defined(pMY_CXT) && defined(aMY_CXT)
- (pTHX_ pMY_CXT) {
-# define vmg_cxt_init() vmg_cxt_init(aTHX_ aMY_CXT)
-#else
- (pTHX) {
- dMY_CXT;
-# define vmg_cxt_init() vmg_cxt_init(aTHX)
-#endif
- MY_CXT.wizz = newHV();
-#ifdef USE_ITHREADS
- HvSHAREKEYS_off(MY_CXT.wizz);
-#endif
- MY_CXT.count = 0;
- return;
-}
-
 /* --- Signatures ---------------------------------------------------------- */
 
 #define SIG_MIN ((U16) (1u << 8))
@@ -191,7 +220,7 @@ STATIC U16 vmg_gensig(pTHX) {
 
  do {
   sig = SIG_NBR * Drand01() + SIG_MIN;
- } while (hv_exists(MY_CXT.wizz, buf, sprintf(buf, "%u", sig)));
+ } while (hv_exists(MY_CXT, buf, sprintf(buf, "%u", sig)));
 
  return sig;
 }
@@ -216,6 +245,9 @@ typedef struct {
 #if VMG_UVAR
  SV *cb_fetch, *cb_store, *cb_exists, *cb_delete;
 #endif /* VMG_UVAR */
+#if VMG_MULTIPLICITY
+ tTHX owner;
+#endif /* VMG_MULTIPLICITY */
 } MGWIZ;
 
 #define MGWIZ2SV(W) (newSVuv(PTR2UV(W)))
@@ -229,7 +261,6 @@ STATIC SV *vmg_data_new(pTHX_ SV *ctor, SV *sv, AV *args) {
  I32 i, alen = (args == NULL) ? 0 : av_len(args);
 
  dSP;
- int count;
 
  ENTER;
  SAVETMPS;
@@ -241,18 +272,15 @@ STATIC SV *vmg_data_new(pTHX_ SV *ctor, SV *sv, AV *args) {
   PUSHs(*av_fetch(args, i, 0));
  PUTBACK;
 
- count = call_sv(ctor, G_SCALAR);
+ call_sv(ctor, G_SCALAR);
 
  SPAGAIN;
-
- if (count != 1) { croak("Callback needs to return 1 scalar\n"); }
  nsv = POPs;
-#if PERL_VERSION_LE(5, 8, 2)
- nsv = sv_newref(nsv); /* Workaround some bug in SvREFCNT_inc() */
-#else
+#if VMG_HAS_PERL(5, 8, 3)
  SvREFCNT_inc(nsv);    /* Or it will be destroyed in FREETMPS */
+#else
+ nsv = sv_newref(nsv); /* Workaround some bug in SvREFCNT_inc() */
 #endif
-
  PUTBACK;
 
  FREETMPS;
@@ -315,7 +343,7 @@ STATIC UV vmg_cast(pTHX_ SV *sv, SV *wiz, AV *args) {
  if (w->cb_copy)
   mg->mg_flags |= MGf_COPY;
 #endif /* MGf_COPY */
-#if MGf_DUP
+#if 0 /* MGf_DUP */
  if (w->cb_dup)
   mg->mg_flags |= MGf_DUP;
 #endif /* MGf_DUP */
@@ -324,8 +352,11 @@ STATIC UV vmg_cast(pTHX_ SV *sv, SV *wiz, AV *args) {
   mg->mg_flags |= MGf_LOCAL;
 #endif /* MGf_LOCAL */
 
+ if (SvTYPE(sv) < SVt_PVHV)
+  goto done;
+
 #if VMG_UVAR
- if (w->uvar && SvTYPE(sv) >= SVt_PVHV) {
+ if (w->uvar) {
   MAGIC *prevmagic;
   int add_uvar = 1;
   struct ufuncs uf[2];
@@ -353,15 +384,20 @@ STATIC UV vmg_cast(pTHX_ SV *sv, SV *wiz, AV *args) {
     uf[1] = *olduf;
     vmg_uvar_del(sv, prevmagic, mg, moremagic);
    }
-  }
+  } else if (w->cb_get)
+   SvGMAGICAL_off(sv);
 
   if (add_uvar) {
    vmg_sv_magicuvar(sv, (const char *) &uf, sizeof(uf));
   }
 
  }
+#else
+ if (w->cb_get)
+  SvGMAGICAL_off(sv);
 #endif /* VMG_UVAR */
 
+done:
  return 1;
 }
 
@@ -448,14 +484,18 @@ STATIC UV vmg_dispell(pTHX_ SV *sv, U16 sig) {
 
 /* ... svt callbacks ....................................................... */
 
-STATIC int vmg_cb_call(pTHX_ SV *cb, SV *sv, SV *data, unsigned int args, ...) {
+#define VMG_CB_CALL_ARGS_MASK 15
+#define VMG_CB_CALL_EVAL      16
+
+STATIC int vmg_cb_call(pTHX_ SV *cb, SV *sv, SV *data, unsigned int flags, ...){
  va_list ap;
  SV *svr;
  int ret;
  unsigned int i;
+ unsigned int args = flags & VMG_CB_CALL_ARGS_MASK;
+ unsigned int eval = flags & VMG_CB_CALL_EVAL ? G_EVAL : 0;
 
  dSP;
- int count;
 
  ENTER;
  SAVETMPS;
@@ -464,7 +504,7 @@ STATIC int vmg_cb_call(pTHX_ SV *cb, SV *sv, SV *data, unsigned int args, ...) {
  EXTEND(SP, args + 2);
  PUSHs(sv_2mortal(newRV_inc(sv)));
  PUSHs(data ? data : &PL_sv_undef);
- va_start(ap, args);
+ va_start(ap, flags);
  for (i = 0; i < args; ++i) {
   SV *sva = va_arg(ap, SV *);
   PUSHs(sva ? sva : &PL_sv_undef);
@@ -472,14 +512,13 @@ STATIC int vmg_cb_call(pTHX_ SV *cb, SV *sv, SV *data, unsigned int args, ...) {
  va_end(ap);
  PUTBACK;
 
- count = call_sv(cb, G_SCALAR);
+ call_sv(cb, G_SCALAR | eval);
 
  SPAGAIN;
-
- if (count != 1) { croak("Callback needs to return 1 scalar\n"); }
+ if (eval && IN_PERL_COMPILETIME && SvTRUE(ERRSV))
+  ++PL_error_count;
  svr = POPs;
  ret = SvOK(svr) ? SvIV(svr) : 0;
-
  PUTBACK;
 
  FREETMPS;
@@ -489,6 +528,7 @@ STATIC int vmg_cb_call(pTHX_ SV *cb, SV *sv, SV *data, unsigned int args, ...) {
 }
 
 #define vmg_cb_call1(I, S, D)         vmg_cb_call(aTHX_ (I), (S), (D), 0)
+#define vmg_cb_call1e(I, S, D)        vmg_cb_call(aTHX_ (I), (S), (D), VMG_CB_CALL_EVAL)
 #define vmg_cb_call2(I, S, D, S2)     vmg_cb_call(aTHX_ (I), (S), (D), 1, (S2))
 #define vmg_cb_call3(I, S, D, S2, S3) vmg_cb_call(aTHX_ (I), (S), (D), 2, (S2), (S3))
 
@@ -502,12 +542,14 @@ STATIC int vmg_svt_set(pTHX_ SV *sv, MAGIC *mg) {
 
 STATIC U32 vmg_svt_len(pTHX_ SV *sv, MAGIC *mg) {
  SV *svr;
- I32 len;
+ I32 len, has_array;
  U32 ret;
 
  dSP;
  int count;
 
+ has_array = SvTYPE(sv) == SVt_PVAV;
+
  ENTER;
  SAVETMPS;
 
@@ -515,11 +557,11 @@ STATIC U32 vmg_svt_len(pTHX_ SV *sv, MAGIC *mg) {
  EXTEND(SP, 3);
  PUSHs(sv_2mortal(newRV_inc(sv)));
  PUSHs(mg->mg_obj ? mg->mg_obj : &PL_sv_undef);
- if (SvTYPE(sv) == SVt_PVAV) {
+ if (has_array) {
   len = av_len((AV *) sv) + 1;
   mPUSHi(len);
  } else {
-  len = 1;
+  len = 0;
   PUSHs(&PL_sv_undef);
  }
  PUTBACK;
@@ -527,17 +569,14 @@ STATIC U32 vmg_svt_len(pTHX_ SV *sv, MAGIC *mg) {
  count = call_sv(SV2MGWIZ(mg->mg_ptr)->cb_len, G_SCALAR);
 
  SPAGAIN;
-
- if (count != 1) { croak("Callback needs to return 1 scalar\n"); }
  svr = POPs;
  ret = SvOK(svr) ? SvUV(svr) : len;
-
  PUTBACK;
 
  FREETMPS;
  LEAVE;
 
- return ret - 1;
+ return has_array ? ret - 1 : ret;
 }
 
 STATIC int vmg_svt_clear(pTHX_ SV *sv, MAGIC *mg) {
@@ -545,16 +584,37 @@ STATIC int vmg_svt_clear(pTHX_ SV *sv, MAGIC *mg) {
 }
 
 STATIC int vmg_svt_free(pTHX_ SV *sv, MAGIC *mg) {
+ SV *wiz = (SV *) mg->mg_ptr;
+ int ret = 0;
+
+ /* This may happen in global destruction */
+ if (SvTYPE(wiz) == SVTYPEMASK)
+  return 0;
+
  /* So that it can survive tmp cleanup in vmg_cb_call */
  SvREFCNT_inc(sv);
+
+#if !VMG_HAS_PERL_MAINT(5, 11, 0, 32686)
+ /* The previous magic tokens were freed but the magic chain wasn't updated, so
+  * if you access the sv from the callback the old deleted magics will trigger
+  * and cause memory misreads. Change 32686 solved it that way : */
+ SvMAGIC_set(sv, mg);
+#endif
+
  /* Perl_mg_free will get rid of the magic and decrement mg->mg_obj and
   * mg->mg_ptr reference count */
- return vmg_cb_call1(SV2MGWIZ(mg->mg_ptr)->cb_free, sv, mg->mg_obj);
+ ret = vmg_cb_call1e(SV2MGWIZ(wiz)->cb_free, sv, mg->mg_obj);
+
+ /* Calling SvREFCNT_dec() will trigger destructors in an infinite loop, so
+  * we have to rely on SvREFCNT() being a lvalue. Heck, even the core does it */
+ --SvREFCNT(sv);
+
+ return ret;
 }
 
 #if MGf_COPY
 STATIC int vmg_svt_copy(pTHX_ SV *sv, MAGIC *mg, SV *nsv, const char *key,
-# if VMG_HAS_PERL_AND(33256, 5, 11, 0)
+# if VMG_HAS_PERL_MAINT(5, 11, 0, 33256)
   I32 keylen
 # else
   int keylen
@@ -592,15 +652,21 @@ STATIC int vmg_svt_local(pTHX_ SV *nsv, MAGIC *mg) {
 #endif /* MGf_LOCAL */
 
 #if VMG_UVAR
+STATIC OP *vmg_pp_resetuvar(pTHX) {
+ SvRMAGICAL_on(cSVOP_sv);
+ return NORMAL;
+}
+
 STATIC I32 vmg_svt_val(pTHX_ IV action, SV *sv) {
  struct ufuncs *uf;
- MAGIC *mg;
- SV *key = NULL;
+ MAGIC *mg, *umg;
+ SV *key = NULL, *newkey = NULL;
+ int tied = 0;
 
- mg  = mg_find(sv, PERL_MAGIC_uvar);
- /* mg can't be NULL or we wouldn't be there. */
- key = mg->mg_obj;
- uf  = (struct ufuncs *) mg->mg_ptr;
+ umg = mg_find(sv, PERL_MAGIC_uvar);
+ /* umg can't be NULL or we wouldn't be there. */
+ key = umg->mg_obj;
+ uf  = (struct ufuncs *) umg->mg_ptr;
 
  if (uf[1].uf_val != NULL) { uf[1].uf_val(aTHX_ action, sv); }
  if (uf[1].uf_set != NULL) { uf[1].uf_set(aTHX_ action, sv); }
@@ -608,11 +674,25 @@ STATIC I32 vmg_svt_val(pTHX_ IV action, SV *sv) {
  action &= HV_FETCH_ISSTORE | HV_FETCH_ISEXISTS | HV_FETCH_LVALUE | HV_DELETE;
  for (mg = SvMAGIC(sv); mg; mg = mg->mg_moremagic) {
   MGWIZ *w;
-  if ((mg->mg_type != PERL_MAGIC_ext)
-   || (mg->mg_private < SIG_MIN)
-   || (mg->mg_private > SIG_MAX)) { continue; }
+  switch (mg->mg_type) {
+   case PERL_MAGIC_ext:
+    break;
+   case PERL_MAGIC_tied:
+    ++tied;
+    continue;
+   default:
+    continue;
+  }
+  if (mg->mg_private < SIG_MIN || mg->mg_private > SIG_MAX)
+   continue;
   w = SV2MGWIZ(mg->mg_ptr);
-  if (!w->uvar) { continue; }
+  switch (w->uvar) {
+   case 0:
+    continue;
+   case 2:
+    if (!newkey)
+     newkey = key = umg->mg_obj = sv_2mortal(newSVsv(umg->mg_obj));
+  }
   switch (action) {
    case 0:
     if (w->cb_fetch)  { vmg_cb_call2(w->cb_fetch,  sv, mg->mg_obj, key); }
@@ -631,6 +711,25 @@ STATIC I32 vmg_svt_val(pTHX_ IV action, SV *sv) {
   }
  }
 
+ if (SvRMAGICAL(sv) && !tied) {
+  /* Temporarily hide the RMAGICAL flag of the hash so it isn't wrongly
+   * mistaken for a tied hash by the rest of hv_common. It will be reset by
+   * the op_ppaddr of a new fake op injected between the current and the next
+   * one. */
+  OP *o = PL_op;
+  if (!o->op_next || o->op_next->op_ppaddr != vmg_pp_resetuvar) {
+   SVOP *svop;
+   NewOp(1101, svop, 1, SVOP);
+   svop->op_type   = OP_STUB;
+   svop->op_ppaddr = vmg_pp_resetuvar;
+   svop->op_next   = o->op_next;
+   svop->op_flags  = 0;
+   svop->op_sv     = sv;
+   o->op_next      = (OP *) svop;
+  }
+  SvRMAGICAL_off(sv);
+ }
+
  return 0;
 }
 #endif /* VMG_UVAR */
@@ -640,15 +739,21 @@ STATIC I32 vmg_svt_val(pTHX_ IV action, SV *sv) {
 STATIC int vmg_wizard_free(pTHX_ SV *wiz, MAGIC *mg) {
  char buf[8];
  MGWIZ *w;
- dMY_CXT;
 
- if (PL_dirty) /* during global destruction, the context is already freed */
+ if (PL_dirty) /* During global destruction, the context is already freed */
   return 0;
 
  w = SV2MGWIZ(wiz);
+#if VMG_MULTIPLICITY
+ if (w->owner != aTHX)
+  return 0;
+ w->owner = NULL;
+#endif /* VMG_MULTIPLICITY */
 
- if (hv_delete(MY_CXT.wizz, buf, sprintf(buf, "%u", w->sig), 0)) {
-  --MY_CXT.count;
+ {
+  dMY_CXT;
+  if (hv_delete(MY_CXT, buf, sprintf(buf, "%u", w->sig), 0) != wiz)
+   return 0;
  }
  SvFLAGS(wiz) |= SVf_BREAK;
  FREETMPS;
@@ -662,7 +767,7 @@ STATIC int vmg_wizard_free(pTHX_ SV *wiz, MAGIC *mg) {
 #if MGf_COPY
  if (w->cb_copy  != NULL) { SvREFCNT_dec(SvRV(w->cb_copy)); }
 #endif /* MGf_COPY */
-#if MGf_DUP
+#if 0 /* MGf_DUP */
  if (w->cb_dup   != NULL) { SvREFCNT_dec(SvRV(w->cb_dup)); }
 #endif /* MGf_DUP */
 #if MGf_LOCAL
@@ -674,6 +779,7 @@ STATIC int vmg_wizard_free(pTHX_ SV *wiz, MAGIC *mg) {
  if (w->cb_exists != NULL) { SvREFCNT_dec(SvRV(w->cb_exists)); }
  if (w->cb_delete != NULL) { SvREFCNT_dec(SvRV(w->cb_delete)); }
 #endif /* VMG_UVAR */
+
  Safefree(w->vtbl);
  Safefree(w);
 
@@ -698,7 +804,6 @@ STATIC MGVTBL vmg_wizard_vtbl = {
 };
 
 STATIC const char vmg_invalid_wiz[]    = "Invalid wizard object";
-STATIC const char vmg_invalid_sv[]     = "Invalid variable";
 STATIC const char vmg_invalid_sig[]    = "Invalid numeric signature";
 STATIC const char vmg_wrongargnum[]    = "Wrong number of arguments";
 STATIC const char vmg_toomanysigs[]    = "Too many magic signatures used";
@@ -723,6 +828,53 @@ STATIC U16 vmg_sv2sig(pTHX_ SV *sv) {
  return sig;
 }
 
+STATIC U16 vmg_wizard_sig(pTHX_ SV *wiz) {
+#define vmg_wizard_sig(W) vmg_wizard_sig(aTHX_ (W))
+ char buf[8];
+ U16 sig;
+
+ if (SvROK(wiz)) {
+  sig = SV2MGWIZ(SvRV(wiz))->sig;
+ } else if (SvOK(wiz)) {
+  sig = vmg_sv2sig(wiz);
+ } else {
+  croak(vmg_invalid_wiz);
+ }
+
+ {
+  dMY_CXT;
+  if (!hv_fetch(MY_CXT, buf, sprintf(buf, "%u", sig), 0))
+   sig = 0;
+ }
+ return sig;
+}
+
+STATIC SV *vmg_wizard_wiz(pTHX_ SV *wiz) {
+#define vmg_wizard_wiz(W) vmg_wizard_wiz(aTHX_ (W))
+ char buf[8];
+ SV **old;
+ U16 sig;
+
+ if (SvROK(wiz)) {
+  wiz = SvRV(wiz);
+#if VMG_MULTIPLICITY
+  if (SV2MGWIZ(wiz)->owner == aTHX)
+   return wiz;
+#endif /* VMG_MULTIPLICITY */
+  sig = SV2MGWIZ(wiz)->sig;
+ } else if (SvOK(wiz)) {
+  sig = vmg_sv2sig(wiz);
+ } else {
+  croak(vmg_invalid_wiz);
+ }
+
+ {
+  dMY_CXT;
+  return (old = hv_fetch(MY_CXT, buf, sprintf(buf, "%u", sig), 0))
+          ? *old : NULL;
+ }
+}
+
 #define VMG_SET_CB(S, N)              \
  cb = (S);                            \
  w->cb_ ## N = (SvOK(cb) && SvROK(cb)) ? newRV_inc(SvRV(cb)) : NULL;
@@ -737,6 +889,52 @@ STATIC U16 vmg_sv2sig(pTHX_ SV *sv) {
   w->cb_  ## N = NULL;                \
  }
 
+#if VMG_THREADSAFE
+
+#define VMG_CLONE_CB(N) \
+ z->cb_ ## N = (w->cb_ ## N) ? newRV_inc(vmg_clone(SvRV(w->cb_ ## N), \
+                                         w->owner))                   \
+                             : NULL;
+
+STATIC MGWIZ *vmg_wizard_clone(pTHX_ const MGWIZ *w) {
+#define vmg_wizard_clone(W) vmg_wizard_clone(aTHX_ (W))
+ MGVTBL *t;
+ MGWIZ *z;
+
+ Newx(t, 1, MGVTBL);
+ Copy(w->vtbl, t, 1, MGVTBL);
+
+ Newx(z, 1, MGWIZ);
+ VMG_CLONE_CB(data);
+ VMG_CLONE_CB(get);
+ VMG_CLONE_CB(set);
+ VMG_CLONE_CB(len);
+ VMG_CLONE_CB(clear);
+ VMG_CLONE_CB(free);
+#if MGf_COPY
+ VMG_CLONE_CB(copy);
+#endif /* MGf_COPY */
+#if MGf_DUP
+ VMG_CLONE_CB(dup);
+#endif /* MGf_DUP */
+#if MGf_LOCAL
+ VMG_CLONE_CB(local);
+#endif /* MGf_LOCAL */
+#if VMG_UVAR
+ VMG_CLONE_CB(fetch);
+ VMG_CLONE_CB(store);
+ VMG_CLONE_CB(exists);
+ VMG_CLONE_CB(delete);
+#endif /* VMG_UVAR */
+ z->owner = aTHX;
+ z->vtbl  = t;
+ z->sig   = w->sig;
+ z->uvar  = w->uvar;
+
+ return z;
+}
+
+#endif /* VMG_THREADSAFE */
 
 /* --- XS ------------------------------------------------------------------ */
 
@@ -748,7 +946,8 @@ BOOT:
 {
  HV *stash;
  MY_CXT_INIT;
- vmg_cxt_init();
+ MY_CXT = newHV();
+ hv_iterinit(MY_CXT); /* Allocate iterator */
  stash = gv_stashpv(__PACKAGE__, 1);
  newCONSTSUB(stash, "SIG_MIN",   newSVuv(SIG_MIN));
  newCONSTSUB(stash, "SIG_MAX",   newSVuv(SIG_MAX));
@@ -759,6 +958,8 @@ BOOT:
  newCONSTSUB(stash, "VMG_UVAR",  newSVuv(VMG_UVAR));
  newCONSTSUB(stash, "VMG_COMPAT_ARRAY_PUSH_NOLEN",
                     newSVuv(VMG_COMPAT_ARRAY_PUSH_NOLEN));
+ newCONSTSUB(stash, "VMG_COMPAT_ARRAY_UNSHIFT_NOLEN_VOID",
+                    newSVuv(VMG_COMPAT_ARRAY_UNSHIFT_NOLEN_VOID));
  newCONSTSUB(stash, "VMG_COMPAT_ARRAY_UNDEF_CLEAR",
                     newSVuv(VMG_COMPAT_ARRAY_UNDEF_CLEAR));
  newCONSTSUB(stash, "VMG_COMPAT_SCALAR_LENGTH_NOLEN",
@@ -770,11 +971,33 @@ BOOT:
 void
 CLONE(...)
 PROTOTYPE: DISABLE
+PREINIT:
+ HV *hv;
 CODE:
-#ifdef MY_CXT_CLONE
- MY_CXT_CLONE;
- vmg_cxt_init();
-#endif
+#if VMG_THREADSAFE
+ {
+  HE *key;
+  dMY_CXT;
+  hv = newHV();
+  hv_iterinit(hv); /* Allocate iterator */
+  hv_iterinit(MY_CXT);
+  while ((key = hv_iternext(MY_CXT))) {
+   STRLEN len;
+   char *sig = HePV(key, len);
+   SV *sv;
+   MAGIC *mg;
+   sv = MGWIZ2SV(vmg_wizard_clone(SV2MGWIZ(HeVAL(key))));
+   mg = sv_magicext(sv, NULL, PERL_MAGIC_ext, &vmg_wizard_vtbl, NULL, 0);
+   mg->mg_private = SIG_WIZ;
+   SvREADONLY_on(sv);
+   hv_store(hv, sig, len, sv, HeHASH(key));
+  }
+ }
+ {
+  MY_CXT_CLONE;
+  MY_CXT = hv;
+ }
+#endif /* VMG_THREADSAFE */
 
 SV *_wizard(...)
 PROTOTYPE: DISABLE
@@ -802,7 +1025,7 @@ CODE:
               + 1
 #endif /* MGf_LOCAL */
 #if VMG_UVAR
-              + 4
+              + 5
 #endif /* VMG_UVAR */
               ) { croak(vmg_wrongargnum); }
 
@@ -810,12 +1033,12 @@ CODE:
  if (SvOK(svsig)) {
   SV **old;
   sig = vmg_sv2sig(svsig);
-  if ((old = hv_fetch(MY_CXT.wizz, buf, sprintf(buf, "%u", sig), 0))) {
+  if ((old = hv_fetch(MY_CXT, buf, sprintf(buf, "%u", sig), 0))) {
    ST(0) = sv_2mortal(newRV_inc(*old));
    XSRETURN(1);
   }
  } else {
-  if (MY_CXT.count >= SIG_NBR) { croak(vmg_toomanysigs); }
+  if (HvKEYS(MY_CXT) >= SIG_NBR) { croak(vmg_toomanysigs); }
   sig = vmg_gensig();
  }
  
@@ -845,21 +1068,24 @@ CODE:
  VMG_SET_CB(ST(i++), store);
  VMG_SET_CB(ST(i++), exists);
  VMG_SET_CB(ST(i++), delete);
+ cb = ST(i++);
+ if (w->cb_fetch || w->cb_store || w->cb_exists || w->cb_delete)
+  w->uvar = SvTRUE(cb) ? 2 : 1;
+ else
+  w->uvar = 0;
 #endif /* VMG_UVAR */
-
- w->vtbl = t;
- w->sig  = sig;
-#if VMG_UVAR
- w->uvar = (w->cb_fetch || w->cb_store || w->cb_exists || w->cb_delete);
-#endif /* VMG_UVAR */
+#if VMG_MULTIPLICITY
+ w->owner = aTHX;
+#endif /* VMG_MULTIPLICITY */
+ w->vtbl  = t;
+ w->sig   = sig;
 
  sv = MGWIZ2SV(w);
- mg = sv_magicext(sv, NULL, PERL_MAGIC_ext, &vmg_wizard_vtbl, NULL, -1);
+ mg = sv_magicext(sv, NULL, PERL_MAGIC_ext, &vmg_wizard_vtbl, NULL, 0);
  mg->mg_private = SIG_WIZ;
  SvREADONLY_on(sv);
 
- hv_store(MY_CXT.wizz, buf, sprintf(buf, "%u", sig), sv, 0);
- ++MY_CXT.count;
+ hv_store(MY_CXT, buf, sprintf(buf, "%u", sig), sv, 0);
 
  RETVAL = newRV_noinc(sv);
 OUTPUT:
@@ -869,7 +1095,7 @@ SV *gensig()
 PROTOTYPE:
 CODE:
  dMY_CXT;
- if (MY_CXT.count >= SIG_NBR) { croak(vmg_toomanysigs); }
+ if (HvKEYS(MY_CXT) >= SIG_NBR) { croak(vmg_toomanysigs); }
  RETVAL = newSVuv(vmg_gensig());
 OUTPUT:
  RETVAL
@@ -888,21 +1114,9 @@ PREINIT:
  AV *args = NULL;
  SV *ret;
 CODE:
- dMY_CXT;
- if (SvROK(wiz)) {
-  wiz = SvRV(wiz);
- } else if (SvOK(wiz)) {
-  char buf[8];
-  SV **old;
-  U16 sig = vmg_sv2sig(wiz);
-  if ((old = hv_fetch(MY_CXT.wizz, buf, sprintf(buf, "%u", sig), 0))) {
-   wiz = *old;
-  } else {
-   XSRETURN_UNDEF;
-  }
- } else {
-  croak(vmg_invalid_sig);
- }
+ wiz = vmg_wizard_wiz(wiz);
+ if (!wiz)
+  XSRETURN_UNDEF;
  if (items > 2) {
   I32 i;
   args = newAV();
@@ -925,18 +1139,9 @@ PREINIT:
  SV *data;
  U16 sig;
 CODE:
- dMY_CXT;
- if (SvROK(wiz)) {
-  sig = SV2MGWIZ(SvRV(wiz))->sig;
- } else if (SvOK(wiz)) {
-  char buf[8];
-  sig = vmg_sv2sig(wiz);
-  if (!hv_fetch(MY_CXT.wizz, buf, sprintf(buf, "%u", sig), 0)) {
-   XSRETURN_UNDEF;
-  }
- } else {
-  croak(vmg_invalid_wiz);
- }
+ sig = vmg_wizard_sig(wiz);
+ if (!sig)
+  XSRETURN_UNDEF;
  data = vmg_data_get(SvRV(sv), sig);
  if (!data) { XSRETURN_UNDEF; }
  ST(0) = data;
@@ -947,18 +1152,9 @@ PROTOTYPE: \[$@%&*]$
 PREINIT:
  U16 sig;
 CODE:
- dMY_CXT;
- if (SvROK(wiz)) {
-  sig = SV2MGWIZ(SvRV(wiz))->sig;
- } else if (SvOK(wiz)) {
-  char buf[8];
-  sig = vmg_sv2sig(wiz);
-  if (!hv_fetch(MY_CXT.wizz, buf, sprintf(buf, "%u", sig), 0)) {
-   XSRETURN_UNDEF;
-  }
- } else {
-  croak(vmg_invalid_wiz);
- }
+ sig = vmg_wizard_sig(wiz);
+ if (!sig)
+  XSRETURN_UNDEF;
  RETVAL = newSVuv(vmg_dispell(SvRV(sv), sig));
 OUTPUT:
  RETVAL