From a113434cd68ce30642c4995b1caadcd084be6f09 Mon Sep 17 00:00:00 2001 From: Rich Felker Date: Wed, 6 Apr 2011 12:24:34 -0400 Subject: major semaphore improvements (performance and correctness) 1. make sem_[timed]wait interruptible by signals, per POSIX 2. keep a waiter count in order to avoid unnecessary futex wake syscalls --- src/thread/sem_post.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'src/thread/sem_post.c') diff --git a/src/thread/sem_post.c b/src/thread/sem_post.c index 0bd8a462..8f4700c3 100644 --- a/src/thread/sem_post.c +++ b/src/thread/sem_post.c @@ -3,7 +3,8 @@ int sem_post(sem_t *sem) { - if (!a_fetch_add(sem->__val, 1)) + a_inc(sem->__val); + if (sem->__val[1]) __wake(sem->__val, 1, 0); return 0; } -- cgit v1.2.1