From fbbcfae769770ca1191e0610ad43722a5768aa40 Mon Sep 17 00:00:00 2001 From: Lennart Poettering Date: Tue, 21 Apr 2009 21:25:27 +0200 Subject: semaphore: introduce static semaphores --- src/pulsecore/semaphore-posix.c | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) (limited to 'src/pulsecore/semaphore-posix.c') diff --git a/src/pulsecore/semaphore-posix.c b/src/pulsecore/semaphore-posix.c index 616d897d..2aa1bce9 100644 --- a/src/pulsecore/semaphore-posix.c +++ b/src/pulsecore/semaphore-posix.c @@ -65,3 +65,25 @@ void pa_semaphore_wait(pa_semaphore *s) { pa_assert(ret == 0); } + +pa_semaphore* pa_static_semaphore_get(pa_static_semaphore *s, unsigned value) { + pa_semaphore *m; + + pa_assert(s); + + /* First, check if already initialized and short cut */ + if ((m = pa_atomic_ptr_load(&s->ptr))) + return m; + + /* OK, not initialized, so let's allocate, and fill in */ + m = pa_semaphore_new(value); + if ((pa_atomic_ptr_cmpxchg(&s->ptr, NULL, m))) + return m; + + pa_semaphore_free(m); + + /* Him, filling in failed, so someone else must have filled in + * already */ + pa_assert_se(m = pa_atomic_ptr_load(&s->ptr)); + return m; +} -- cgit