From 4da80956418bbe1fdc23cad0b1cbb24cd7b87609 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Patrik=20H=C3=A4gglund?= Date: Sat, 2 Feb 2013 20:21:05 +0100 Subject: [PATCH] PATCH [perl #106212] Add PL_perlio_mutex to atfork_lock/unlock Using threads + fork() on Linux, and IO operations in the threads, the PL_perlio_mutex may be left in a locked state at the call of fork(), potentially leading to deadlock in the child process at subsequent IO operations. (Threads are pre-empted and not continued in the child process after the fork.) Therefore, ensure that the PL_perlio_mutex is unlocked in the child process, right after fork(), by using atfork_lock/unlock. (The RT text gives ways to reproduce the problem, but are not easily added to Perl's test suite) --- util.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/util.c b/util.c index 5c695b8..75381f1 100644 --- a/util.c +++ b/util.c @@ -2798,6 +2798,9 @@ Perl_atfork_lock(void) dVAR; #if defined(USE_ITHREADS) /* locks must be held in locking order (if any) */ +# ifdef USE_PERLIO + MUTEX_LOCK(&PL_perlio_mutex); +# endif # ifdef MYMALLOC MUTEX_LOCK(&PL_malloc_mutex); # endif @@ -2812,6 +2815,9 @@ Perl_atfork_unlock(void) dVAR; #if defined(USE_ITHREADS) /* locks must be released in same order as in atfork_lock() */ +# ifdef USE_PERLIO + MUTEX_UNLOCK(&PL_perlio_mutex); +# endif # ifdef MYMALLOC MUTEX_UNLOCK(&PL_malloc_mutex); # endif -- 1.8.3.1