Sun Microsystems, Inc. gratefully acknowledges The Open Group for
permission to reproduce portions of its copyrighted documentation.
Original documentation from The Open Group can be obtained online at
http://www.opengroup.org/bookstore/.
The Institute of Electrical and Electronics Engineers and The Open
Group, have given us permission to reprint portions of their
documentation.
In the following statement, the phrase ``this text'' refers to portions
of the system documentation.
Portions of this text are reprinted and reproduced in electronic form
in the SunOS Reference Manual, from IEEE Std 1003.1, 2004 Edition,
Standard for Information Technology -- Portable Operating System
Interface (POSIX), The Open Group Base Specifications Issue 6,
Copyright (C) 2001-2004 by the Institute of Electrical and Electronics
Engineers, Inc and The Open Group. In the event of any discrepancy
between these versions and the original IEEE and The Open Group
Standard, the original IEEE and The Open Group Standard is the referee
document. The original Standard can be obtained online at
http://www.opengroup.org/unix/online.html.
This notice shall appear on any product containing this material.
The contents of this file are subject to the terms of the
Common Development and Distribution License (the "License").
You may not use this file except in compliance with the License.
You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
or http://www.opensolaris.org/os/licensing.
See the License for the specific language governing permissions
and limitations under the License.
When distributing Covered Code, include this CDDL HEADER in each
file and include the License file at usr/src/OPENSOLARIS.LICENSE.
If applicable, add the following below this CDDL HEADER, with the
fields enclosed by brackets "[]" replaced with your own identifying
information: Portions Copyright [yyyy] [name of copyright owner]
Copyright (c) 2001, The IEEE and The Open Group. All Rights Reserved.
Portions Copyright (c) 2004, Sun Microsystems, Inc. All Rights Reserved.
cc -mt [ flag... ] file... [ library... ] #include <pthread.h> #include <time.h> int pthread_rwlock_timedwrlock(pthread_rwlock_t *restrict rwlock, const struct timespec *restrict abs_timeout);
int pthread_rwlock_reltimedwrlock_np(pthread_rwlock_t *restrict rwlock, const struct timespec *restrict rel_timeout);
The pthread_rwlock_timedwrlock() function applies a write lock to the read-write lock referenced by rwlock as in the pthread_rwlock_wrlock(3C) function. If the lock cannot be acquired without waiting for other threads to unlock the lock, this wait will be terminated when the specified timeout expires. The timeout expires when the absolute time specified by abs_timeout passes, as measured by the CLOCK_REALTIME clock (that is, when the value of that clock equals or exceeds abs_timeout), or if the absolute time specified by abs_timeout has already been passed at the time of the call.
The pthread_rwlock_reltimedwrlock_np() function is identical to the pthread_rwlock_timedwrlock() function, except that the timeout is specified as a relative time interval. The timeout expires when the time interval specified by rel_timeout passes, as measured by the CLOCK_REALTIME clock, or if the time interval specified by rel_timeout is negative at the time of the call.
The resolution of the timeout is the resolution of the CLOCK_REALTIME clock. The timespec data type is defined in the <time.h> header. Under no circumstances does either function fail with a timeout if the lock can be acquired immediately. The validity of the abs_timeout parameter need not be checked if the lock can be immediately acquired.
If a signal that causes a signal handler to be executed is delivered to a thread blocked on a read- write lock with a call to pthread_rwlock_timedwrlock() or pthread_rwlock_reltimedwrlock_np(), upon return from the signal handler the thread resumes waiting for the lock as if it was not interrupted.
The calling thread can deadlock if at the time the call is made it holds the read-write lock. The results are undefined if this function is called with an uninitialized read-write lock.
The pthread_rwlock_timedwrlock() and pthread_rwlock_reltimedwrlock_np() functions return 0 if the lock for writing on the read-write lock object referenced by rwlock is acquired. Otherwise, an error number is returned to indicate the error.
The pthread_rwlock_timedwrlock() and pthread_rwlock_reltimedwrlock_np() functions will fail if: ETIMEDOUT
The lock could not be acquired before the specified timeout expired.
The pthread_rwlock_timedwrlock() and pthread_rwlock_reltimedwrlock_np() functions may fail if: EDEADLK
The calling thread already holds the rwlock.
The value specified by rwlock does not refer to an initialized read-write lock object, or the timeout nanosecond value is less than zero or greater than or equal to 1,000 million.
See attributes(7) for descriptions of the following attributes:
| ATTRIBUTE TYPE ATTRIBUTE VALUE |
| Interface Stability See below. |
| MT-Level MT-Safe |
The pthread_rwlock_timedwrlock() function is Standard. The pthread_rwlock_reltimedwrlock_np() function is Stable.
pthread_rwlock_destroy (3C), pthread_rwlock_rdlock (3C), pthread_rwlock_timedrdlock (3C), pthread_rwlock_trywrlock (3C), pthread_rwlock_unlock (3C), pthread_rwlock_wrlock (3C), attributes (7), standards (7)