try to acquire the mutex, without waiting
int __sched mutex_trylock (
|struct mutex * lock|
the mutex to be acquired
Try to acquire the mutex atomically. Returns 1 if the mutex
has been acquired successfully, and 0 on contention.
this function follows the
spin_trylock convention, so
it is negated from the
down_trylock return values! Be careful
about this when converting semaphore users to mutexes.
This function must not be used in interrupt context. The
mutex must be released by the same task that acquired it.