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| author | Rich Felker <dalias@aerifal.cx> | 2011-09-28 19:45:37 -0400 |
|---|---|---|
| committer | Rich Felker <dalias@aerifal.cx> | 2011-09-28 19:45:37 -0400 |
| commit | de543b05c87d79a9313991810e9ee8ecdaad8f19 (patch) | |
| tree | abde9355e67731c9e8b48ccdd107405cb35b6e03 /src | |
| parent | ede5ae7b0bb5a7ed9edeb2eeb8e24d30af64d185 (diff) | |
| download | musl-de543b05c87d79a9313991810e9ee8ecdaad8f19.tar.gz musl-de543b05c87d79a9313991810e9ee8ecdaad8f19.tar.bz2 musl-de543b05c87d79a9313991810e9ee8ecdaad8f19.tar.xz musl-de543b05c87d79a9313991810e9ee8ecdaad8f19.zip | |
fix excessive/insufficient wakes in __vm_unlock
there is no need to send a wake when the lock count does not hit zero,
but when it does, all waiters must be woken (since all with the same
sign are eligible to obtain the lock).
Diffstat (limited to 'src')
| -rw-r--r-- | src/thread/pthread_barrier_wait.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/src/thread/pthread_barrier_wait.c b/src/thread/pthread_barrier_wait.c index 71f7b5fe..6052925a 100644 --- a/src/thread/pthread_barrier_wait.c +++ b/src/thread/pthread_barrier_wait.c @@ -13,9 +13,9 @@ void __vm_lock(int inc) void __vm_unlock(void) { - if (vmlock[0]>0) a_dec(vmlock); - else a_inc(vmlock); - if (vmlock[1]) __wake(vmlock, 1, 1); + int inc = vmlock[0]>0 ? -1 : 1; + if (a_fetch_add(vmlock, inc)==-inc && vmlock[1]) + __wake(vmlock, -1, 1); } static int pshared_barrier_wait(pthread_barrier_t *b) |