From cccc549ced940c85039c8ce263c8bb571f244afd Mon Sep 17 00:00:00 2001 From: Mike Frysinger Date: Tue, 31 Jan 2006 05:05:15 +0000 Subject: initial import of latest linuxthreads --- libpthread/linuxthreads/barrier.c | 128 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 128 insertions(+) create mode 100644 libpthread/linuxthreads/barrier.c (limited to 'libpthread/linuxthreads/barrier.c') diff --git a/libpthread/linuxthreads/barrier.c b/libpthread/linuxthreads/barrier.c new file mode 100644 index 000000000..37d997cfc --- /dev/null +++ b/libpthread/linuxthreads/barrier.c @@ -0,0 +1,128 @@ +/* POSIX barrier implementation for LinuxThreads. + Copyright (C) 2000, 2003 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Kaz Kylheku , 2000. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public License as + published by the Free Software Foundation; either version 2.1 of the + License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; see the file COPYING.LIB. If not, + write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, + Boston, MA 02111-1307, USA. */ + +#include +#include "pthread.h" +#include "internals.h" +#include "spinlock.h" +#include "queue.h" +#include "restart.h" + +int +pthread_barrier_wait(pthread_barrier_t *barrier) +{ + pthread_descr self = thread_self(); + pthread_descr temp_wake_queue, th; + int result = 0; + + __pthread_lock(&barrier->__ba_lock, self); + + /* If the required number of threads have achieved rendezvous... */ + if (barrier->__ba_present >= barrier->__ba_required - 1) + { + /* ... then this last caller shall be the serial thread */ + result = PTHREAD_BARRIER_SERIAL_THREAD; + /* Copy and clear wait queue and reset barrier. */ + temp_wake_queue = barrier->__ba_waiting; + barrier->__ba_waiting = NULL; + barrier->__ba_present = 0; + } + else + { + result = 0; + barrier->__ba_present++; + enqueue(&barrier->__ba_waiting, self); + } + + __pthread_unlock(&barrier->__ba_lock); + + if (result == 0) + { + /* Non-serial threads have to suspend */ + suspend(self); + /* We don't bother dealing with cancellation because the POSIX + spec for barriers doesn't mention that pthread_barrier_wait + is a cancellation point. */ + } + else + { + /* Serial thread wakes up all others. */ + while ((th = dequeue(&temp_wake_queue)) != NULL) + restart(th); + } + + return result; +} + +int +pthread_barrier_init(pthread_barrier_t *barrier, + const pthread_barrierattr_t *attr, + unsigned int count) +{ + if (count == 0) + return EINVAL; + + __pthread_init_lock(&barrier->__ba_lock); + barrier->__ba_required = count; + barrier->__ba_present = 0; + barrier->__ba_waiting = NULL; + return 0; +} + +int +pthread_barrier_destroy(pthread_barrier_t *barrier) +{ + if (barrier->__ba_waiting != NULL) return EBUSY; + return 0; +} + +int +pthread_barrierattr_init(pthread_barrierattr_t *attr) +{ + attr->__pshared = PTHREAD_PROCESS_PRIVATE; + return 0; +} + +int +pthread_barrierattr_destroy(pthread_barrierattr_t *attr) +{ + return 0; +} + +int +__pthread_barrierattr_getpshared(const pthread_barrierattr_t *attr, + int *pshared) +{ + *pshared = PTHREAD_PROCESS_PRIVATE; + return 0; +} + +int +pthread_barrierattr_setpshared(pthread_barrierattr_t *attr, int pshared) +{ + if (pshared != PTHREAD_PROCESS_PRIVATE && pshared != PTHREAD_PROCESS_SHARED) + return EINVAL; + + /* For now it is not possible to shared a conditional variable. */ + if (pshared != PTHREAD_PROCESS_PRIVATE) + return ENOSYS; + + return 0; +} -- cgit v1.2.3