Acquire an exclusive write lock on a read-write lock
#include <pthread.h> int pthread_rwlock_wrlock( pthread_rwlock_t* rwl );
libc
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.
See An example of synchronization in the Processes and Threads chapter of Getting Started with QNX Neutrino.
Safety: | |
---|---|
Cancellation point | Yes |
Interrupt handler | No |
Signal handler | Yes |
Thread | Yes |