Documentation to explain the behaviour of map().

[p5sagit/p5-mst-13.2.git] / sv.h

diff --git a/sv.h b/sv.h
index f350498..c670f80 100644 (file)
--- a/sv.h
+++ b/sv.h
@@ -363,7 +363,19 @@ struct xpvio {
 
     PerlIO *   xio_ifp;        /* ifp and ofp are normally the same */
     PerlIO *   xio_ofp;        /* but sockets need separate streams */
-    DIR *      xio_dirp;       /* for opendir, readdir, etc */
+    /* Cray addresses everything by word boundaries (64 bits) and
+     * code and data pointers cannot be mixed (which is exactly what
+     * Perl_filter_add() tries to do with the dirp), hence the following
+     * union trick (as suggested by Gurusamy Sarathy).
+     * For further information see Geir Johansen's problem report titled
+       [ID 20000612.002] Perl problem on Cray system
+     * The any pointer (known as IoANY()) will also be a good place
+     * to hang any IO disciplines to.
+     */
+    union {
+       DIR *   xiou_dirp;      /* for opendir, readdir, etc */
+       void *  xiou_any;       /* for alignment */
+    } xio_dirpu;
     long       xio_lines;      /* $. */
     long       xio_page;       /* $% */
     long       xio_page_len;   /* $= */
@@ -378,6 +390,8 @@ struct xpvio {
     char       xio_type;
     char       xio_flags;
 };
+#define xio_dirp       xio_dirpu.xiou_dirp
+#define xio_any                xio_dirpu.xiou_any
 
 #define IOf_ARGV       1       /* this fp iterates over ARGV */
 #define IOf_START      2       /* check for null ARGV and substitute '-' */
@@ -704,6 +718,7 @@ Set the length of the string which is in the SV.  See C<SvCUR>.
 #define IoIFP(sv)      ((XPVIO*)  SvANY(sv))->xio_ifp
 #define IoOFP(sv)      ((XPVIO*)  SvANY(sv))->xio_ofp
 #define IoDIRP(sv)     ((XPVIO*)  SvANY(sv))->xio_dirp
+#define IoANY(sv)      ((XPVIO*)  SvANY(sv))->xio_any
 #define IoLINES(sv)    ((XPVIO*)  SvANY(sv))->xio_lines
 #define IoPAGE(sv)     ((XPVIO*)  SvANY(sv))->xio_page
 #define IoPAGE_LEN(sv) ((XPVIO*)  SvANY(sv))->xio_page_len
@@ -1007,13 +1022,6 @@ indicated number of bytes (remember to reserve space for an extra trailing
 NUL character).  Calls C<sv_grow> to perform the expansion if necessary. 
 Returns a pointer to the character buffer.
 
-=for apidoc Am|void|SvLOCK|SV* sv
-Aquires an internal mutex for a SV. Used to make sure multiple threads
-don't stomp on the guts of an SV at the same time
-
-=for apidoc Am|void|SvUNLOCK|SV* sv
-Release the internal mutex for an SV.
-
 =cut
 */
 
@@ -1049,9 +1057,6 @@ Release the internal mutex for an SV.
                SvSetSV_nosteal_and(dst,src,SvSETMAGIC(dst))
 
 #ifdef DEBUGGING
-
-#define SvLOCK(sv)     MUTEX_LOCK(&PL_sv_lock_mutex)
-#define SvUNLOCK(sv)   MUTEX_UNLOCK(&PL_sv_lock_mutex)
 #define SvPEEK(sv) sv_peek(sv)
 #else
 #define SvPEEK(sv) ""
@@ -1066,10 +1071,3 @@ Release the internal mutex for an SV.
 #define SvGROW(sv,len) (SvLEN(sv) < (len) ? sv_grow(sv,len) : SvPVX(sv))
 #define Sv_Grow sv_grow
 
-#ifdef USE_THREADS
-#   define FDPID_LOCK          MUTEX_LOCK(&PL_fdpid_mutex)
-#   define FDPID_UNLOCK                MUTEX_UNLOCK(&PL_fdpid_mutex)
-#else
-#   define FDPID_LOCK
-#   define FDPID_UNLOCK
-#endif