Tries to obtain a write lock on rw_lock. If another thread currently holds a read or write lock on rw_lock, it immediately returns false. Otherwise it locks rw_lock and returns true.
true if rw_lock could be locked
Tries to obtain a write lock on rw_lock. If another thread currently holds a read or write lock on rw_lock, it immediately returns false. Otherwise it locks rw_lock and returns true.