- acquire a read/write lock for writing
#include <pthread.h> int
pthread_rwlock_wrlock (pthread_rwlock_t *lock); int
pthread_rwlock_trywrlock (pthread_rwlock_t *lock);
function blocks until a write lock can be acquired against
Fa lock .
function performs the same action, but does not block if the lock
cannot be immediately obtained.
The results are undefined if the calling thread already holds the
lock at the time the call is made.
To prevent writer starvation, writers are favored over readers.
If successful, the
functions will return zero.
Otherwise an error number will be returned
to indicate the error.
function will fail if:
Bq Er EBUSY
The calling thread is not able to acquire the lock without blocking.
functions may fail if:
Bq Er EDEADLK
The calling thread already owns the read/write lock (for reading
Bq Er EINVAL
The value specified by
Bq Er ENOMEM
Insufficient memory exists to initialize the lock (applies to
statically initialized locks only).