diff options
| author | Ted Unangst <tedu@cvs.openbsd.org> | 2010-04-12 01:54:24 +0000 |
|---|---|---|
| committer | Ted Unangst <tedu@cvs.openbsd.org> | 2010-04-12 01:54:24 +0000 |
| commit | 41c1a3e3e6683fe9b4edf023cd5a862fd79746b0 (patch) | |
| tree | efce53ab5ec5de44259e6fae7768cc9358cbce71 /lib/libpthread/man/pthread_rwlock_rdlock.3 | |
| parent | 46975a2a516f3489a5273d971ef327e5c5fd681e (diff) | |
Add support for pthread_rwlock_timed locks.
from brad. ok kurt, who's too busy to commit
Diffstat (limited to 'lib/libpthread/man/pthread_rwlock_rdlock.3')
| -rw-r--r-- | lib/libpthread/man/pthread_rwlock_rdlock.3 | 40 |
1 files changed, 32 insertions, 8 deletions
diff --git a/lib/libpthread/man/pthread_rwlock_rdlock.3 b/lib/libpthread/man/pthread_rwlock_rdlock.3 index 2102c6a74a9..5be678b7675 100644 --- a/lib/libpthread/man/pthread_rwlock_rdlock.3 +++ b/lib/libpthread/man/pthread_rwlock_rdlock.3 @@ -1,4 +1,4 @@ -.\" $OpenBSD: pthread_rwlock_rdlock.3,v 1.8 2007/05/31 19:19:37 jmc Exp $ +.\" $OpenBSD: pthread_rwlock_rdlock.3,v 1.9 2010/04/12 01:54:23 tedu Exp $ .\" Copyright (c) 1998 Alex Nash .\" All rights reserved. .\" @@ -25,11 +25,12 @@ .\" .\" $FreeBSD: pthread_rwlock_rdlock.3,v 1.2 1999/08/28 00:03:09 peter Exp $ .\" -.Dd $Mdocdate: May 31 2007 $ +.Dd $Mdocdate: April 12 2010 $ .Dt PTHREAD_RWLOCK_RDLOCK 3 .Os .Sh NAME .Nm pthread_rwlock_rdlock , +.Nm pthread_rwlock_timedrdlock , .Nm pthread_rwlock_tryrdlock .Nd acquire a read/write lock for reading .Sh SYNOPSIS @@ -37,6 +38,8 @@ .Ft int .Fn pthread_rwlock_rdlock "pthread_rwlock_t *lock" .Ft int +.Fn pthread_rwlock_timedrdlock "pthread_rwlock_t *lock" "const struct timespec *abstime" +.Ft int .Fn pthread_rwlock_tryrdlock "pthread_rwlock_t *lock" .Sh DESCRIPTION The @@ -51,10 +54,18 @@ If the read lock cannot be immediately acquired, the calling thread blocks until it can acquire the lock. .Pp The +.Fn pthread_rwlock_timedrdlock +function performs the same action, +but will not wait beyond +.Fa abstime +to obtain the lock before returning. +.Pp +The .Fn pthread_rwlock_tryrdlock -function performs the same action, but does not block if the lock -cannot be immediately obtained (i.e., the lock is held for writing -or there are waiting writers). +function performs the same action as +.Fn pthread_rwlock_rdlock , +but does not block if the lock cannot be immediately obtained +(i.e., the lock is held for writing or there are writers waiting). .Pp A thread may hold multiple concurrent read locks. If so, @@ -67,7 +78,8 @@ a write lock are undefined. To prevent writer starvation, writers are favored over readers. .Sh RETURN VALUES If successful, the -.Fn pthread_rwlock_rdlock +.Fn pthread_rwlock_rdlock , +.Fn pthread_rwlock_timedrdlock , and .Fn pthread_rwlock_tryrdlock functions will return zero. @@ -83,7 +95,18 @@ was blocked on it. .El .Pp The -.Fn pthread_rwlock_rdlock +.Fn pthread_rwlock_timedrdlock +function will fail if: +.Bl -tag -width Er +.It Bq Er ETIMEDOUT +The time specified by +.Fa abstime +was reached before the lock could be obtained. +.El +.Pp +The +.Fn pthread_rwlock_rdlock , +.Fn pthread_rwlock_timedrdlock , and .Fn pthread_rwlock_tryrdlock functions may fail if: @@ -112,7 +135,8 @@ statically initialized locks only). .Xr pthread_rwlock_wrlock 3 .Sh STANDARDS The -.Fn pthread_rwlock_rdlock +.Fn pthread_rwlock_rdlock , +.Fn pthread_rwlock_timedrdlock , and .Fn pthread_rwlock_tryrdlock functions are expected to conform to |