From 85e1cb51b21c2d194647e16b81b5a1344d2ff911 Mon Sep 17 00:00:00 2001 From: Joshua Colp Date: Fri, 28 Aug 2015 21:57:14 -0300 Subject: sched: ast_sched_del may return prematurely due to spurious wakeup When deleting a scheduled item if the item in question is currently executing the ast_sched_del function waits until it has completed. This is accomplished using ast_cond_wait. Unfortunately the ast_cond_wait function can suffer from spurious wakeups so the predicate needs to be checked after it returns to make sure it has really woken up as a result of being signaled. This change adds a loop around the ast_cond_wait to make sure that it only exits when the executing task has really completed. ASTERISK-25355 #close Change-Id: I51198270eb0b637c956c61aa409f46283432be61 --- main/sched.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'main/sched.c') diff --git a/main/sched.c b/main/sched.c index 4443497c5..033d238c7 100644 --- a/main/sched.c +++ b/main/sched.c @@ -497,7 +497,9 @@ int _ast_sched_del(struct ast_sched_context *con, int id, const char *file, int /* Wait for executing task to complete so that caller of ast_sched_del() does not * free memory out from under the task. */ - ast_cond_wait(&s->cond, &con->lock); + while (con->currently_executing && (id == con->currently_executing->id)) { + ast_cond_wait(&s->cond, &con->lock); + } /* Do not sched_release() here because ast_sched_runq() will do it */ } -- cgit v1.2.3