mirror of
https://git.hardenedbsd.org/hardenedbsd/HardenedBSD.git
synced 2024-12-26 04:54:07 +01:00
107 lines
3.4 KiB
Groff
107 lines
3.4 KiB
Groff
.\" Copyright (c) 2004 Michael Telahun Makonnen
|
|
.\" All rights reserved.
|
|
.\"
|
|
.\" Redistribution and use in source and binary forms, with or without
|
|
.\" modification, are permitted provided that the following conditions
|
|
.\" are met:
|
|
.\" 1. Redistributions of source code must retain the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer.
|
|
.\" 2. Redistributions in binary form must reproduce the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer in the
|
|
.\" documentation and/or other materials provided with the distribution.
|
|
.\"
|
|
.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
|
|
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
|
|
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
.\" SUCH DAMAGE.
|
|
.\"
|
|
.Dd August 17, 2018
|
|
.Dt PTHREAD_RWLOCK_TIMEDWRLOCK 3
|
|
.Os
|
|
.Sh NAME
|
|
.Nm pthread_rwlock_timedwrlock
|
|
.Nd "acquire a read-write lock for writing or give up after a specified period"
|
|
.Sh LIBRARY
|
|
.Lb libpthread
|
|
.Sh SYNOPSIS
|
|
.In pthread.h
|
|
.Ft int
|
|
.Fn pthread_rwlock_timedwrlock "pthread_rwlock_t *restrict rwlock" "const struct timespec *restrict abs_timeout"
|
|
.Sh DESCRIPTION
|
|
This function acquires a write lock on the read-write lock
|
|
.Fa rwlock .
|
|
However, if the lock cannot be
|
|
acquired without waiting for another thread to
|
|
unlock the lock,
|
|
this wait shall be terminated when
|
|
.Fa abs_timeout
|
|
expires.
|
|
.Pp
|
|
If the thread should be interrupted by a signal,
|
|
the
|
|
.Fn pthread_rwlock_timedwrlock
|
|
function will be automatically restarted after the thread returns from
|
|
the signal handler.
|
|
.Pp
|
|
The calling thread may deadlock if
|
|
at the time the call is made it holds
|
|
.Fa rwlock .
|
|
The results are undefined if this function is called with
|
|
an uninitialized read-write lock.
|
|
.Sh IMPLEMENTATION NOTES
|
|
To prevent writer starvation, writers are favored over readers.
|
|
.Sh RETURN VALUES
|
|
If successful, the
|
|
.Fn pthread_rwlock_timedwrlock
|
|
function will return zero.
|
|
Otherwise, an error number will be returned to indicate the error.
|
|
.Pp
|
|
This function shall not return an error code of
|
|
.Er EINTR .
|
|
.Sh ERRORS
|
|
The
|
|
.Fn pthread_rwlock_timedwrlock
|
|
function shall fail if:
|
|
.Bl -tag -width Er
|
|
.It Bq Er ETIMEDOUT
|
|
The lock could not be acquired before the specified timeout expired.
|
|
.El
|
|
.Pp
|
|
The
|
|
.Fn pthread_rwlock_timedwrlock
|
|
function may fail if:
|
|
.Bl -tag -width Er
|
|
.It Bq Er EDEADLK
|
|
The calling thread already holds
|
|
.Fa rwlock .
|
|
.It Bq Er EINVAL
|
|
The value specified by
|
|
.Fa rwlock
|
|
does not refer to an initialized read-write lock object,
|
|
or the
|
|
.Fa abs_timeout
|
|
nanosecond value is less than zero or
|
|
greater than or equal to 1 billion.
|
|
.El
|
|
.Sh SEE ALSO
|
|
.Xr pthread_rwlock_init 3 ,
|
|
.Xr pthread_rwlock_timedrdlock 3 ,
|
|
.Xr pthread_rwlock_unlock 3
|
|
.Sh STANDARDS
|
|
The
|
|
.Fn pthread_rwlock_timedwrlock
|
|
function is expected to conform to
|
|
.St -p1003.1-96 .
|
|
.Sh HISTORY
|
|
The
|
|
.Fn pthread_rwlock_timedwrlock
|
|
function first appeared in
|
|
.Fx 5.2 .
|