RE: [PATCH h2xs] Use of static data in XS modules

Message-ID: <AIEAJICLCBDNAAOLLOKLMEJGDDAA.Paul_Marquess@Yahoo.co.uk>

Add compat.h.

p4raw-id: //depot/perl@12780

1 files changed, 134 insertions, 0 deletions

diff --git a/utils/h2xs.PL b/utils/h2xs.PL
index 6d6169b824..b856d891ad 100644
--- a/utils/h2xs.PL
+++ b/utils/h2xs.PL
@@ -818,6 +818,139 @@ my %vdecl_hash;
 my @vdecls;
 
 if( ! $opt_X ){  # use XS, unless it was disabled
+  open(COMPAT, ">compat.h") || die "Can't create $ext$modpname/compat.h: $!\n";
+  warn "Writing $ext$modpname/compat.h\n";
+  print COMPAT <<EOM, <<'EOM';
+/* WARNING: This file has been autogenerated by h2xs $H2XS_VERSION */
+
+EOM
+
+
+#ifndef PERL_VERSION
+
+#    include "patchlevel.h"
+#    define PERL_REVISION	5
+#    define PERL_VERSION	PATCHLEVEL
+#    define PERL_SUBVERSION	SUBVERSION
+
+#endif /* PERL_VERSION */
+
+
+
+/* 
+ * This file is taken from perl.h  & modified slightly to make it backward 
+ * comapable with older versions of Perl.
+ * 
+ */
+
+#if PERL_REVISION == 5 && \
+    (PERL_VERSION < 7 || (PERL_VERSION == 7 && PERL_SUBVERSION < 2 ))
+
+/*
+ * Boilerplate macros for initializing and accessing interpreter-local
+ * data from C.  All statics in extensions should be reworked to use
+ * this, if you want to make the extension thread-safe.  See ext/re/re.xs
+ * for an example of the use of these macros.
+ *
+ * Code that uses these macros is responsible for the following:
+ * 1. #define MY_CXT_KEY to a unique string, e.g. "DynaLoader_guts"
+ * 2. Declare a typedef named my_cxt_t that is a structure that contains
+ *    all the data that needs to be interpreter-local.
+ * 3. Use the START_MY_CXT macro after the declaration of my_cxt_t.
+ * 4. Use the MY_CXT_INIT macro such that it is called exactly once
+ *    (typically put in the BOOT: section).
+ * 5. Use the members of the my_cxt_t structure everywhere as
+ *    MY_CXT.member.
+ * 6. Use the dMY_CXT macro (a declaration) in all the functions that
+ *    access MY_CXT.
+ */
+
+#if defined(MULTIPLICITY) || defined(PERL_OBJECT) || \
+    defined(PERL_CAPI)    || defined(PERL_IMPLICIT_CONTEXT)
+
+/* This must appear in all extensions that define a my_cxt_t structure,
+ * right after the definition (i.e. at file scope).  The non-threads
+ * case below uses it to declare the data as static. */
+#define START_MY_CXT
+
+#if PERL_REVISION == 5 && \
+    (PERL_VERSION < 4 || (PERL_VERSION == 4 && PERL_SUBVERSION < 68 ))
+/* Fetches the SV that keeps the per-interpreter data. */
+#define dMY_CXT_SV \
+	SV *my_cxt_sv = perl_get_sv(MY_CXT_KEY, FALSE)
+#else /* >= perl5.004_68 */
+#define dMY_CXT_SV \
+	SV *my_cxt_sv = *hv_fetch(PL_modglobal, MY_CXT_KEY,		\
+				  sizeof(MY_CXT_KEY)-1, TRUE)
+#endif /* < perl5.004_68 */
+
+/* This declaration should be used within all functions that use the
+ * interpreter-local data. */
+#define dMY_CXT	\
+	dMY_CXT_SV;							\
+	my_cxt_t *my_cxtp = (my_cxt_t*)SvUV(my_cxt_sv)
+
+/* Creates and zeroes the per-interpreter data.
+ * (We allocate my_cxtp in a Perl SV so that it will be released when
+ * the interpreter goes away.) */
+#define MY_CXT_INIT \
+	dMY_CXT_SV;							\
+	/* newSV() allocates one more than needed */			\
+	my_cxt_t *my_cxtp = (my_cxt_t*)SvPVX(newSV(sizeof(my_cxt_t)-1));\
+	Zero(my_cxtp, 1, my_cxt_t);					\
+	sv_setuv(my_cxt_sv, (UV)my_cxtp)
+
+/* This macro must be used to access members of the my_cxt_t structure.
+ * e.g. MYCXT.some_data */
+#define MY_CXT		(*my_cxtp)
+
+/* Judicious use of these macros can reduce the number of times dMY_CXT
+ * is used.  Use is similar to pTHX, aTHX etc. */
+#define pMY_CXT		my_cxt_t *my_cxtp
+#define pMY_CXT_	pMY_CXT,
+#define _pMY_CXT	,pMY_CXT
+#define aMY_CXT		my_cxtp
+#define aMY_CXT_	aMY_CXT,
+#define _aMY_CXT	,aMY_CXT
+
+#else /* single interpreter */
+
+#ifndef NOOP
+#  define NOOP (void)0
+#endif
+
+#ifdef HASATTRIBUTE
+#  define PERL_UNUSED_DECL __attribute__((unused))
+#else
+#  define PERL_UNUSED_DECL
+#endif    
+
+#ifndef dNOOP
+#  define dNOOP extern int Perl___notused PERL_UNUSED_DECL
+#endif
+
+#define START_MY_CXT	static my_cxt_t my_cxt;
+#define dMY_CXT_SV	dNOOP
+#define dMY_CXT		dNOOP
+#define MY_CXT_INIT	NOOP
+#define MY_CXT		my_cxt
+
+#define pMY_CXT		void
+#define pMY_CXT_
+#define _pMY_CXT
+#define aMY_CXT
+#define aMY_CXT_
+#define _aMY_CXT
+
+#endif 
+
+#endif /* perl < 5.7.2 */
+
+/* End of file compat.h */
+
+EOM
+  close COMPAT ;
+
   open(XS, ">$modfname.xs") || die "Can't create $ext$modpname/$modfname.xs: $!\n";
   if ($opt_x) {
     require Config;		# Run-time directive
@@ -1197,6 +1330,7 @@ print XS <<"END";
 #include "EXTERN.h"
 #include "perl.h"
 #include "XSUB.h"
+#include "compat.h"
 
 END
 if( @path_h ){