Acquire an exclusive write lock on a read-write lock
#include <pthread.h> int pthread_rwlock_wrlock( pthread_rwlock_t* rwl );
- A pointer to a pthread_rwlock_t object that you want to lock for writing.
Use the -l c option to qcc to link against this library. This library is usually included automatically.
The pthread_rwlock_wrlock() function acquires an exclusive lock on the read-write lock referenced by rwl. If the read-write lock is already shared-locked by any thread (including the calling thread) or exclusively-locked by any thread (other than the calling thread), the calling thread blocks until all shared locks and exclusive locks are released.
If a signal is delivered to a thread waiting to lock a read-write lock, it resumes waiting for the lock after returning from the signal handler.
- On the first use of a statically initialized read-write lock, insufficient system resources existed to initialize the read-write lock.
- The calling thread already has an exclusive lock for rwl.
- A fault occurred when the kernel tried to access rwl.
- The read-write lock rwl is invalid.