Change 33492 by [EMAIL PROTECTED] on 2008/03/12 12:23:55
We need mutex protection in PerlIOStdio_close() for the duration of
holding our true love file handle open, to stop anything else
temporarily using it for a quick dup() fling, and then closing the
file handle underneath us.
I suspect that the lack of this protection was the cause of the threads
free.t and blocks.t failures on OS X on 5.8.x, where usefaststdio is
the default, and PerlIO is unable to "invalidate" the FILE *.
Affected files ...
... //depot/perl/perlio.c#383 edit
Differences ...
==== //depot/perl/perlio.c#383 (text) ====
Index: perl/perlio.c
--- perl/perlio.c#382~33491~ 2008-03-12 04:46:17.000000000 -0700
+++ perl/perlio.c 2008-03-12 05:23:55.000000000 -0700
@@ -3156,8 +3156,26 @@
result = PerlIO_flush(f);
saveerr = errno;
invalidate = PerlIOStdio_invalidate_fileno(aTHX_ stdio);
- if (!invalidate)
+ if (!invalidate) {
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 {
+ /* 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. */
+ }
+#endif
+ }
}
result = PerlSIO_fclose(stdio);
/* We treat error from stdio as success if we invalidated
@@ -3173,6 +3191,9 @@
#endif
if (dupfd >= 0) {
PerlLIO_dup2(dupfd,fd);
+#ifdef USE_ITHREADS
+ MUTEX_UNLOCK(&PL_perlio_mutex);
+#endif
PerlLIO_close(dupfd);
}
return result;
End of Patch.
