NAME

pthread_rwlock_timedwrlock —

acquire a read-write lock for writing or give up after a specified period

LIBRARY

POSIX Threads Library (libpthread, -lpthread)

SYNOPSIS

#include <pthread.h>

int
pthread_rwlock_timedwrlock(pthread_rwlock_t *restrict rwlock, const struct timespec *restrict abs_timeout);

DESCRIPTION

This function acquires a write lock on the read-write lock rwlock. However, if the lock cannot be acquired without waiting for another thread to unlock the lock, this wait shall be terminated when abs_timeout expires.

If the thread should be interrupted by a signal, the pthread_rwlock_timedwrlock() function will be automatically restarted after the thread returns from the signal handler.

The calling thread may deadlock if at the time the call is made it holds rwlock. The results are undefined if this function is called with an uninitialized read-write lock.

IMPLEMENTATION NOTES

To prevent writer starvation, writers are favored over readers.

RETURN VALUES

If successful, the pthread_rwlock_timedwrlock() function will return zero. Otherwise, an error number will be returned to indicate the error.

This function shall not return an error code of EINTR.

ERRORS

The pthread_rwlock_timedwrlock() function shall fail if:

[ETIMEDOUT]: The lock could not be acquired before the specified timeout expired.

The pthread_rwlock_timedwrlock() function may fail if:

[EDEADLK]: The calling thread already holds rwlock.
[EINVAL]: The value specified by rwlock does not refer to an initialized read-write lock object, or the abs_timeout nanosecond value is less than zero or greater than or equal to 1 billion.

STANDARDS

The pthread_rwlock_timedwrlock() function is expected to conform to ISO/IEC 9945-1:1996 (“POSIX.1”).

HISTORY

The pthread_rwlock_timedwrlock() function first appeared in FreeBSD 5.2.