From: Sascha Wildner Date: Tue, 25 Dec 2012 19:37:29 +0000 (+0100) Subject: libpthread: Add sem_timedwait(). X-Git-Tag: v3.4.0rc~623 X-Git-Url: https://gitweb.dragonflybsd.org/~tuxillo/dragonfly.git/commitdiff_plain/775923a8d67ea35ff5fb2fc616d36ae4acd5e4ff libpthread: Add sem_timedwait(). It was commented out and I'm not sure why. It needed a bit of adjustment to properly check the nanoseconds field but with that, it passes all eleven tests of the Open POSIX Test Suite. Other people (thesjg, vsrinivas) have tested and used it too in the past. While here, also add a manual page (taken from FreeBSD). In-discussion-with: vsrinivas --- diff --git a/lib/libc/gen/_pthread_stubs.c b/lib/libc/gen/_pthread_stubs.c index 2d81c6bf20..749c181fcc 100644 --- a/lib/libc/gen/_pthread_stubs.c +++ b/lib/libc/gen/_pthread_stubs.c @@ -168,6 +168,7 @@ WR(stub_zero, sem_init); WR(stub_zero, sem_open); WR(stub_zero, sem_post); WR(stub_zero, sem_trywait); +WR(stub_zero, sem_timedwait); WR(stub_zero, sem_unlink); WR(stub_zero, sem_wait); diff --git a/lib/libpthread/Makefile b/lib/libpthread/Makefile index e2df584dbc..213ae85a93 100644 --- a/lib/libpthread/Makefile +++ b/lib/libpthread/Makefile @@ -74,6 +74,7 @@ MAN+= \ sem_init.3 \ sem_open.3 \ sem_post.3 \ + sem_timedwait.3 \ sem_wait.3 \ sigwait.3 diff --git a/lib/libpthread/sem_timedwait.3 b/lib/libpthread/sem_timedwait.3 new file mode 100644 index 0000000000..2c6c788369 --- /dev/null +++ b/lib/libpthread/sem_timedwait.3 @@ -0,0 +1,119 @@ +.\" Copyright (c) 2008, David Xu +.\" 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. +.\" +.\" Portions of this text are reprinted and reproduced in electronic form +.\" 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 this version 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. +.\" +.\" $FreeBSD: src/lib/libc/gen/sem_timedwait.3,v 1.6 2012/11/17 01:49:25 svnexp Exp $ +.\" +.Dd December 25, 2012 +.Dt SEM_TIMEDWAIT 3 +.Os +.Sh NAME +.Nm sem_timedwait +.Nd "lock a semaphore" +.Sh LIBRARY +.Lb libpthread +.Sh SYNOPSIS +.In semaphore.h +.Ft int +.Fn sem_timedwait "sem_t *sem" "const struct timespec *abs_timeout" +.Sh DESCRIPTION +The +.Fn sem_timedwait +function locks the semaphore referenced by +.Fa sem , +as in the +.Xr sem_wait 3 +function. +However, if the semaphore cannot be locked without waiting for +another process or thread to unlock the semaphore by performing +a +.Xr sem_post 3 +function, this wait will be terminated when the specified timeout expires. +.Pp +The timeout will expire when the absolute time specified by +.Fa abs_timeout +passes, as measured by the clock on which timeouts are based (that is, +when the value of that clock equals or exceeds +.Fa abs_timeout ) , +or if the +absolute time specified by +.Fa abs_timeout +has already been passed at the time of the call. +.Pp +Note that the timeout is based on the +.Dv CLOCK_REALTIME +clock. +.Pp +The validity of the +.Fa abs_timeout +is not checked if the semaphore can be locked immediately. +.Sh RETURN VALUES +The +.Fn sem_timedwait +function returns zero if the calling process successfully performed the +semaphore lock operation on the semaphore designated by +.Fa sem . +If the call was unsuccessful, the state of the semaphore is unchanged, +and the function returns a value of \-1 and sets the global variable +.Va errno +to indicate the error. +.Sh ERRORS +The +.Fn sem_timedwait +function will fail if: +.Bl -tag -width Er +.It Bq Er EINVAL +The +.Fa sem +argument does not refer to a valid semaphore, or the process or thread would +have blocked, and the +.Fa abs_timeout +parameter specified a nanoseconds field value less than zero or greater than +or equal to 1000 million. +.It Bq Er ETIMEDOUT +The semaphore could not be locked before the specified timeout expired. +.It Bq Er EINTR +A signal interrupted this function. +.El +.Sh SEE ALSO +.Xr sem_post 3 , +.Xr sem_trywait 3 , +.Xr sem_wait 3 +.Sh STANDARDS +The +.Fn sem_timedwait +function conforms to +.St -p1003.1-2004 . +.Sh HISTORY +The function first appeared in +.Fx 5.0 . diff --git a/lib/libthread_xu/thread/thr_sem.c b/lib/libthread_xu/thread/thr_sem.c index 83768a1d00..09606b4077 100644 --- a/lib/libthread_xu/thread/thr_sem.c +++ b/lib/libthread_xu/thread/thr_sem.c @@ -185,7 +185,6 @@ _sem_wait(sem_t *sem) return (-1); } -#if 0 int _sem_timedwait(sem_t * __restrict sem, struct timespec * __restrict abstime) { @@ -208,7 +207,8 @@ _sem_timedwait(sem_t * __restrict sem, struct timespec * __restrict abstime) if (atomic_cmpset_acq_int(&(*sem)->count, val, val - 1)) return (0); } - if (abstime == NULL) { + if (abstime == NULL || + abstime->tv_nsec >= 1000000000 || abstime->tv_nsec < 0) { errno = EINVAL; return (-1); } @@ -222,7 +222,6 @@ _sem_timedwait(sem_t * __restrict sem, struct timespec * __restrict abstime) errno = retval; return (-1); } -#endif int _sem_post(sem_t *sem) @@ -269,9 +268,7 @@ __strong_reference(_sem_getvalue, sem_getvalue); __strong_reference(_sem_init, sem_init); __strong_reference(_sem_trywait, sem_trywait); __strong_reference(_sem_wait, sem_wait); -#if 0 __strong_reference(_sem_timedwait, sem_timedwait); -#endif __strong_reference(_sem_post, sem_post); __strong_reference(_sem_open, sem_open); __strong_reference(_sem_close, sem_close); diff --git a/sys/sys/semaphore.h b/sys/sys/semaphore.h index c80ad398da..b2373058a9 100644 --- a/sys/sys/semaphore.h +++ b/sys/sys/semaphore.h @@ -35,10 +35,10 @@ * SUCH DAMAGE. * * $FreeBSD: src/sys/posix4/semaphore.h,v 1.6 2000/01/20 07:55:42 jasone Exp $ - * $DragonFly: src/sys/sys/semaphore.h,v 1.3 2003/08/27 06:30:04 rob Exp $ */ #include +#include #include #ifdef _P1003_1B_INCLUDE_MAYBES @@ -64,6 +64,7 @@ int sem_close (sem_t *); int sem_unlink (const char *); int sem_wait (sem_t *); int sem_trywait (sem_t *); +int sem_timedwait (sem_t * __restrict, struct timespec * __restrict); int sem_post (sem_t *); int sem_getvalue (sem_t *, int *); __END_DECLS