freebsd-skq/share/man/man3/pthread_mutex_timedlock.3
Pedro F. Giffuni b6413b6db8 POSIX compliance improvements in the pthread(3) functions.
This basically adds makes use of the C99 restrict keyword, and also
adds some 'const's to four threading functions: pthread_mutexattr_gettype(),
pthread_mutexattr_getprioceiling(), pthread_mutexattr_getprotocol(), and
pthread_mutex_getprioceiling. The changes are in accordance to POSIX/SUSv4-2018.

Hinted by:	DragonFlyBSD

Relnotes:	yes
MFC after:	1 month
Differential Revision:	D16722
2018-08-18 01:05:38 +00:00

116 lines
3.5 KiB
Groff

.\" Copyright (c) 2003 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.
.\"
.\" $FreeBSD$
.\"
.Dd August 17, 2018
.Dt PTHREAD_MUTEX_TIMEDLOCK 3
.Os
.Sh NAME
.Nm pthread_mutex_timedlock
.Nd lock a mutex without blocking indefinitely
.Sh LIBRARY
.Lb libpthread
.Sh SYNOPSIS
.In pthread.h
.In time.h
.Ft int
.Fn pthread_mutex_timedlock "pthread_mutex_t *restrict mutex" "const struct timespec *restrict abs_timeout"
.Sh DESCRIPTION
The
.Fn pthread_mutex_timedlock
function will lock
.Fa mutex .
If it is already locked the calling thread will block until
the mutex becomes available or
the timeout,
specified by abs_timeout,
expires.
The time of the timeout is an absolute time and
is not relative to the current time.
.Sh RETURN VALUES
If successful,
.Fn pthread_mutex_timedlock
will return zero, otherwise an error number will be returned to
indicate the error.
.Sh ERRORS
The
.Fn pthread_mutex_timedlock
function will fail if:
.Bl -tag -width Er
.It Bq "Er ENOTRECOVERABLE"
The
.Fa mutex
was created with the protocol attribute having the
value PTHREAD_PRIO_PROTECT and
the calling thread's priority is higher than the
mutex's current priority ceiling.
.It Bq Er EINVAL
The process or thread would have blocked, and
.Fa abs_timeout
specified a nanosecond value less than zero or
greater than or equal to 1 billion.
.It Bq Er EINVAL
The
.Fa mutex
parameter is invalid.
.It Bq Er ETIMEDOUT
The
.Fa mutex
could not be locked before the timeout expired.
.It Bq Er EAGAIN
The
.Fa mutex
could not be acquired because the
maximum number of recursive locks for the
.Fa mutex
has been exceeded.
.It Bq Er EDEADLK
The current thread already owns the
.Fa mutex .
.It Bq Er EOWNERDEAD
The argument
.Fa mutex
points to a robust mutex and the previous owning thread terminated
while holding the mutex lock.
The lock was granted to the caller and it is up to the new owner
to make the state consistent.
.It Bq Er ENOTRECOVERABLE
The state protected by the
.Fa mutex
is not recoverable.
.El
.Sh SEE ALSO
.Xr pthread_mutex_consistent 3 ,
.Xr pthread_mutex_destroy 3 ,
.Xr pthread_mutex_init 3 ,
.Xr pthread_mutex_lock 3 ,
.Xr pthread_mutex_trylock 3 ,
.Xr pthread_mutex_unlock 3
.Sh STANDARDS
The
.Fn pthread_mutex_timedlock
function is expected to conform to
.St -p1003.1-96 .