bugfix, AutoLoader 0.67

[p5sagit/p5-mst-13.2.git] / perlio.c

diff --git a/perlio.c b/perlio.c
index a0f96cc..7eb7e27 100644 (file)
--- a/perlio.c
+++ b/perlio.c
@@ -1295,7 +1295,7 @@ PerlIORaw_pushed(pTHX_ PerlIO *f, const char *mode, SV *arg, PerlIO_funcs *tab)
        while (t && (l = *t)) {
            if (l->tab->Binmode) {
                /* Has a handler - normal case */
-               if ((*l->tab->Binmode)(aTHX_ f) == 0) {
+               if ((*l->tab->Binmode)(aTHX_ t) == 0) {
                    if (*t == l) {
                        /* Layer still there - move down a layer */
                        t = PerlIONext(t);
@@ -3131,6 +3131,9 @@ PerlIOStdio_close(pTHX_ PerlIO *f)
        IV result = 0;
        int saveerr = 0;
        int dupfd = -1;
+#ifdef USE_ITHREADS
+       dVAR;
+#endif
 #ifdef SOCKS5_VERSION_NAME
        /* Socks lib overrides close() but stdio isn't linked to
           that library (though we are) - so we must call close()
@@ -3157,19 +3160,30 @@ PerlIOStdio_close(pTHX_ PerlIO *f)
            saveerr = errno;
            invalidate = PerlIOStdio_invalidate_fileno(aTHX_ stdio);
            if (!invalidate) {
+#ifdef USE_ITHREADS
+               MUTEX_LOCK(&PL_perlio_mutex);
+               /* Right. We need a mutex here because for a brief while we
+                  will have the situation that fd is actually closed. Hence if
+                  a second thread were to get into this block, its dup() would
+                  likely return our fd as its dupfd. (after all, it is closed)
+                  Then if we get to the dup2() first, we blat the fd back
+                  (messing up its temporary as a side effect) only for it to
+                  then close its dupfd (== our fd) in its close(dupfd) */
+
+               /* There is, of course, a race condition, that any other thread
+                  trying to input/output/whatever on this fd will be stuffed
+                  for the duration of this little manoeuvrer. Perhaps we
+                  should hold an IO mutex for the duration of every IO
+                  operation if we know that invalidate doesn't work on this
+                  platform, but that would suck, and could kill performance.
+
+                  Except that correctness trumps speed.
+                  Advice from klortho #11912. */
+#endif
                dupfd = PerlLIO_dup(fd);
 #ifdef USE_ITHREADS
-               if (dupfd >= 0) {
-                   /* Right. We need a mutex here because for a brief while we
-                      will have the situation that fd is actually closed.
-                      Hence if a second thread were to get into this block,
-                      its dup() would likely return our fd as its dupfd.
-                      (after all, it is closed). Then if we get to the dup2()
-                      first, we blat the fd back (messing up its temporary as
-                      a side effect) only for it to then close its dupfd
-                      (== our fd) in its close(dupfd) */
-                   MUTEX_LOCK(&PL_perlio_mutex);
-               } else {
+               if (dupfd < 0) {
+                   MUTEX_UNLOCK(&PL_perlio_mutex);
                    /* Oh cXap. This isn't going to go well. Not sure if we can
                       recover from here, or if closing this particular FILE *
                       is a good idea now.  */
@@ -3191,10 +3205,10 @@ PerlIOStdio_close(pTHX_ PerlIO *f)
 #endif
        if (dupfd >= 0) {
            PerlLIO_dup2(dupfd,fd);
+           PerlLIO_close(dupfd);
 #ifdef USE_ITHREADS
-       MUTEX_UNLOCK(&PL_perlio_mutex);
+           MUTEX_UNLOCK(&PL_perlio_mutex);
 #endif
-           PerlLIO_close(dupfd);
        }
        return result;
     }