ado_rwlock_rdlock()

Acquire a shared read lock on a read-write lock

Synopsis:

#include <audio_driver.h>

ado_rwlock_rdlock( pthread_rwlock_t *rwl);

Arguments:

rwl: A pointer to the pthread_rwlock_t structure for the read-write lock.

Description:

This macro acquires a shared read lock on the given read-write lock.

The ado_rwlock_rdlock macro() is defined as pthread_rwlock_rdlock(), or ado_rwlock_rdlock_debug() if ADO_RWLOCK_DEBUG and ADO_DEBUG are defined. The debug version uses ado_debug() to display a message to help you locate a locking problem in the driver.

For more information, see “Debugging an audio driver” in the Organization of a Driver chapter.

Returns:

Same as pthread_rwlock_rdlock():

EOK: Success.
EAGAIN: On the first use of statically initialized read-write lock, insufficient system resources existed to initialize the read-write lock.
EDEADLK: The calling thread already has an exclusive lock for rwl.
EFAULT: A fault occurred when the kernel tried to access rwl.
EINVAL: The read-write lock rwl is invalid.

Classification:

QNX Neutrino

Safety:
Cancellation point	No
Interrupt handler	No
Signal handler	No
Thread	Yes