diff options
author | mtm <mtm@FreeBSD.org> | 2004-01-16 10:52:10 +0000 |
---|---|---|
committer | mtm <mtm@FreeBSD.org> | 2004-01-16 10:52:10 +0000 |
commit | e3c786562ff87850be855dfd169fb04002f8419a (patch) | |
tree | bb0ba3c680063e988a19dea0a54d0f940b679804 /share | |
parent | 5af038f21added63f08bd826d3d748c044404156 (diff) | |
download | FreeBSD-src-e3c786562ff87850be855dfd169fb04002f8419a.zip FreeBSD-src-e3c786562ff87850be855dfd169fb04002f8419a.tar.gz |
Add an implementation of pthread_rwlock_timed{rd,wr}lock() to libthr with
attendant documentation.
Diffstat (limited to 'share')
-rw-r--r-- | share/man/man3/Makefile | 2 | ||||
-rw-r--r-- | share/man/man3/pthread_rwlock_timedrdlock.3 | 118 | ||||
-rw-r--r-- | share/man/man3/pthread_rwlock_timedwrlock.3 | 107 |
3 files changed, 227 insertions, 0 deletions
diff --git a/share/man/man3/Makefile b/share/man/man3/Makefile index 8af8e82..05120fe 100644 --- a/share/man/man3/Makefile +++ b/share/man/man3/Makefile @@ -155,6 +155,8 @@ MAN+= pthread.3 \ pthread_rwlock_destroy.3 \ pthread_rwlock_init.3 \ pthread_rwlock_rdlock.3 \ + pthread_rwlock_timedrdlock.3 \ + pthread_rwlock_timedwrlock.3 \ pthread_rwlock_unlock.3 \ pthread_rwlock_wrlock.3 \ pthread_rwlockattr_destroy.3 \ diff --git a/share/man/man3/pthread_rwlock_timedrdlock.3 b/share/man/man3/pthread_rwlock_timedrdlock.3 new file mode 100644 index 0000000..d08ea72 --- /dev/null +++ b/share/man/man3/pthread_rwlock_timedrdlock.3 @@ -0,0 +1,118 @@ +.\" 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. +.\" +.\" $FreeBSD$ +.\" +.Dd January 16, 2004 +.Dt PTHREAD_RWLOCK_TIMEDRDLOCK 3 +.Os +.Sh NAME +.Nm pthread_rwlock_timedrdlock , +.Nd acquire a read-write lock for reading or give up after a specified period +.Sh LIBRARY +.Lb libpthread +.Lb libthr +.Sh SYNOPSIS +.In pthread.h +.Ft int +.Fn pthread_rwlock_timedrdlock "pthread_rwlock_t *rwlock" "const struct timespec *abs_timeout" +.Sh DESCRIPTION +This function acquires a read 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 +.Pp +A thread may hold multiple concurrent read locks. +The +.Fn pthread_rwlock_unlock +function must be called once for each lock acquired. +.Pp +If the thread should be interrupted by a signal, +the +.Fn pthread_rwlock_wrlock +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 a write lock on +.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_timedrdlock +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 EINTR. +.Sh ERRORS +The +.Fn pthread_rwlock_timedrdlock +function will 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_timedrdlock +function may fail if: +.Bl -tag -width Er +.It Bq Er EAGAIN +The read lock could not be +acquired because the maximum number of read locks for +.Fa rwlock +would be exceeded. +.It Bq Er EDEADLK +The calling thread already holds a write lock on +.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_timedwrlock 3 +.Xr pthread_rwlock_unlock 3 , +.Sh STANDARDS +The +.Fn pthread_rwlock_timedrdlock +function is expected to conform to +.St -p1003.1-96 . +.Sh HISTORY +The +.Fn pthread_rwlock_timedrdlock +function first appeared in +.Fx 5.2 . diff --git a/share/man/man3/pthread_rwlock_timedwrlock.3 b/share/man/man3/pthread_rwlock_timedwrlock.3 new file mode 100644 index 0000000..efe45dc --- /dev/null +++ b/share/man/man3/pthread_rwlock_timedwrlock.3 @@ -0,0 +1,107 @@ +.\" 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. +.\" +.\" $FreeBSD$ +.\" +.Dd January 16, 2004 +.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 +.Lb libthr +.Sh SYNOPSIS +.In pthread.h +.Ft int +.Fn pthread_rwlock_timedwrlock "pthread_rwlock_t *rwlock" "const struct timespec *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_wrlock +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 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_timedrwlock +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 . |