diff options
Diffstat (limited to 'perlio.c')
| -rw-r--r-- | perlio.c | 23 |
1 files changed, 22 insertions, 1 deletions
@@ -3156,8 +3156,26 @@ PerlIOStdio_close(pTHX_ PerlIO *f) 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 @@ PerlIOStdio_close(pTHX_ PerlIO *f) #endif if (dupfd >= 0) { PerlLIO_dup2(dupfd,fd); +#ifdef USE_ITHREADS + MUTEX_UNLOCK(&PL_perlio_mutex); +#endif PerlLIO_close(dupfd); } return result; |