revert mutex "optimization" that turned out to be worse

diff --git a/src/thread/pthread_mutex_trylock.c b/src/thread/pthread_mutex_trylock.c
index 232e172..50a815a 100644 (file)
--- a/src/thread/pthread_mutex_trylock.c
+++ b/src/thread/pthread_mutex_trylock.c
@@ -7,7 +7,7 @@ int pthread_mutex_trylock(pthread_mutex_t *m)
        pthread_t self;
 
        if (m->_m_type == PTHREAD_MUTEX_NORMAL)
-               return (m->_m_lock || a_swap(&m->_m_lock, 1)) ? EBUSY : 0;
+               return -a_swap(&m->_m_lock, 1) & EBUSY;
 
        self = pthread_self();
        tid = self->tid | 0x80000000;