[PATHC] sharedsv.[c|h]

From: "Artur Bergman" <artur@contiller.se>
Date: Mon, 13 Aug 2001 14:38:41 +0200
Message-ID: <005401c123f4$e1f53360$21000a0a@vogw2kdev>  

Subject: [PATCH] embed.pl
From: Arthur Bergman <arthur@contiller.se>
Date: Mon, 13 Aug 2001 14:38:14 +0200
Message-ID: <B79D96D6.3088%arthur@contiller.se>

Subject: [PATCH] sharedsv cleanups
From: "Arthur Bergman" <arthur@contiller.se>
Date: Mon, 13 Aug 2001 15:14:25 +0200
Message-ID: <005a01c123f9$dfe525d0$21000a0a@vogw2kdev>  

Plus few tweaks: _init needs to be Adp, the prototypes
should not be revealed unless using ithreads, #endif FOO
must be #endif /* FOO */, adding (parentheses) around
do { } while doesn't work too well.

p4raw-id: //depot/perl@11659

1 files changed, 201 insertions, 0 deletions

diff --git a/sharedsv.c b/sharedsv.c
new file mode 100644
index 0000000000..43596941de
--- /dev/null
+++ b/sharedsv.c
@@ -0,0 +1,201 @@
+/*    sharedsv.c
+ *
+ *    Copyright (c) 2001, Larry Wall
+ *
+ *    You may distribute under the terms of either the GNU General Public
+ *    License or the Artistic License, as specified in the README file.
+ *
+ */
+
+/*
+* Contributed by Arthur Bergman arthur@contiller.se
+*
+* "Hand any two wizards a piece of rope and they would instinctively pull in
+* opposite directions."
+*                         --Sourcery
+*
+*/
+
+#include "EXTERN.h"
+#define PERL_IN_SHAREDSV_C
+#include "perl.h"
+
+PerlInterpreter* sharedsv_space;
+
+#ifdef USE_ITHREADS
+
+/*
+  Shared SV
+
+  Shared SV is a structure for keeping the backend storage
+  of shared svs.
+
+ */
+
+/*
+=for apidoc sharedsv_init
+
+Saves a space for keeping SVs wider than an interpreter,
+currently only stores a pointer to the first interpreter.
+
+=cut
+*/
+
+void
+Perl_sharedsv_init(pTHX)
+{
+    sharedsv_space = PERL_GET_CONTEXT;
+}
+
+/*
+=for apidoc sharedsv_new
+
+Allocates a new shared sv struct, you must yourself create the SV/AV/HV.
+=cut
+*/
+
+shared_sv *
+Perl_sharedsv_new(pTHX)
+{
+    shared_sv* ssv;
+    New(2555,ssv,1,shared_sv);
+    MUTEX_INIT(&ssv->mutex);
+    COND_INIT(&ssv->cond);
+    ssv->locks = 0;
+    return ssv;
+}
+
+
+/*
+=for apidoc sharedsv_find
+
+Tries to find if a given SV has a shared backend, either by
+looking at magic, or by checking if it is tied again threads::shared.
+
+=cut
+*/
+
+shared_sv *
+Perl_sharedsv_find(pTHX_ SV* sv)
+{
+    /* does all it can to find a shared_sv struct, returns NULL otherwise */
+    shared_sv* ssv = NULL;
+    return ssv;
+}
+
+/*
+=for apidoc sharedsv_lock
+
+Recursive locks on a sharedsv.
+Locks are dynamicly scoped at the level of the first lock.
+=cut
+*/
+void
+Perl_sharedsv_lock(pTHX_ shared_sv* ssv)
+{
+    if(!ssv)
+        return;
+    if(ssv->owner && ssv->owner == my_perl) {
+        ssv->locks++;
+        return;
+    }
+    MUTEX_LOCK(&ssv->mutex);
+    ssv->locks++;
+    ssv->owner = my_perl;
+    if(ssv->locks == 1)
+        SAVEDESTRUCTOR_X(Perl_sharedsv_unlock_scope,ssv);
+}
+
+/*
+=for apidoc sharedsv_unlock
+
+Recursively unlocks a shared sv.
+
+=cut
+*/
+
+void
+Perl_sharedsv_unlock(pTHX_ shared_sv* ssv)
+{
+    if(ssv->owner != my_perl)
+        return;
+
+    if(--ssv->locks == 0) {
+        ssv->owner = NULL;
+        MUTEX_UNLOCK(&ssv->mutex);
+    }
+ }
+
+void
+Perl_sharedsv_unlock_scope(pTHX_ shared_sv* ssv)
+{
+    if(ssv->owner != my_perl)
+        return;
+    ssv->locks = 0;
+    ssv->owner = NULL;
+    MUTEX_UNLOCK(&ssv->mutex);
+}
+
+/*
+=for apidoc sharedsv_thrcnt_inc
+
+Increments the threadcount of a sharedsv.
+=cut
+*/
+void
+Perl_sharedsv_thrcnt_inc(pTHX_ shared_sv* ssv)
+{
+  SHAREDSvLOCK(ssv);
+  SvREFCNT_inc(ssv->sv);
+  SHAREDSvUNLOCK(ssv);
+}
+
+/*
+=for apidoc sharedsv_thrcnt_dec
+
+Decrements the threadcount of a shared sv. When a threads frontend is freed
+this function should be called.
+
+=cut
+*/
+
+void
+Perl_sharedsv_thrcnt_dec(pTHX_ shared_sv* ssv)
+{
+    SV* sv;
+    SHAREDSvLOCK(ssv);
+    SHAREDSvEDIT(ssv);
+    sv = SHAREDSvGET(ssv);
+    if (SvREFCNT(sv) == 1) {
+        switch (SvTYPE(sv)) {
+        case SVt_RV:
+            if (SvROK(sv))
+            Perl_sharedsv_thrcnt_dec(aTHX_ (shared_sv *)SvIV(SvRV(sv)));
+            break;
+        case SVt_PVAV: {
+            SV **src_ary  = AvARRAY((AV *)sv);
+            SSize_t items = AvFILLp((AV *)sv) + 1;
+
+            while (items-- > 0) {
+            if(SvTYPE(*src_ary))
+                Perl_sharedsv_thrcnt_dec(aTHX_ (shared_sv *)SvIV(*src_ary++));
+            }
+            break;
+        }
+        case SVt_PVHV: {
+            HE *entry;
+            (void)hv_iterinit((HV *)sv);
+            while ((entry = hv_iternext((HV *)sv)))
+                Perl_sharedsv_thrcnt_dec(
+                    aTHX_ (shared_sv *)SvIV(hv_iterval((HV *)sv, entry))
+                );
+            break;
+        }
+        }
+    }
+    SvREFCNT_dec(sv);
+    SHAREDSvRELEASE(ssv);
+    SHAREDSvUNLOCK(ssv);
+}
+
+#endif