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author | patacongo <patacongo@7fd9a85b-ad96-42d3-883c-3090e2eb8679> | 2011-12-19 19:24:09 +0000 |
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committer | patacongo <patacongo@7fd9a85b-ad96-42d3-883c-3090e2eb8679> | 2011-12-19 19:24:09 +0000 |
commit | add995c32e86f9de8fa8fc05172435332c25a895 (patch) | |
tree | 0191fde92a5c4dcd55a24b2aa760fa4c88713242 /nuttx/sched/pthread_condbroadcast.c | |
download | px4-firmware-add995c32e86f9de8fa8fc05172435332c25a895.tar.gz px4-firmware-add995c32e86f9de8fa8fc05172435332c25a895.tar.bz2 px4-firmware-add995c32e86f9de8fa8fc05172435332c25a895.zip |
Completes coding of the PWM module
git-svn-id: https://nuttx.svn.sourceforge.net/svnroot/nuttx/trunk@4200 7fd9a85b-ad96-42d3-883c-3090e2eb8679
Diffstat (limited to 'nuttx/sched/pthread_condbroadcast.c')
-rw-r--r-- | nuttx/sched/pthread_condbroadcast.c | 144 |
1 files changed, 144 insertions, 0 deletions
diff --git a/nuttx/sched/pthread_condbroadcast.c b/nuttx/sched/pthread_condbroadcast.c new file mode 100644 index 000000000..5b69ea428 --- /dev/null +++ b/nuttx/sched/pthread_condbroadcast.c @@ -0,0 +1,144 @@ +/**************************************************************************** + * sched/pthread_condbroadcast.c + * + * Copyright (C) 2007-2009 Gregory Nutt. All rights reserved. + * Author: Gregory Nutt <spudmonkey@racsa.co.cr> + * + * 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. + * 3. Neither the name NuttX nor the names of its contributors may be + * used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 + * COPYRIGHT OWNER 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. + * + ****************************************************************************/ + +/**************************************************************************** + * Included Files + ****************************************************************************/ + +#include <nuttx/config.h> + +#include <pthread.h> +#include <sched.h> +#include <errno.h> +#include <debug.h> + +#include "pthread_internal.h" + +/**************************************************************************** + * Definitions + ****************************************************************************/ + +/**************************************************************************** + * Private Type Declarations + ****************************************************************************/ + +/**************************************************************************** + * Global Variables + ****************************************************************************/ + +/**************************************************************************** + * Private Variables + ****************************************************************************/ + +/**************************************************************************** + * Private Functions + ****************************************************************************/ + +/**************************************************************************** + * Public Functions + ****************************************************************************/ + +/**************************************************************************** + * Function: pthread_cond_broadcast + * + * Description: + * A thread broadcast on a condition variable. + * + * Parameters: + * None + * + * Return Value: + * None + * + * Assumptions: + * + ****************************************************************************/ + +int pthread_cond_broadcast(FAR pthread_cond_t *cond) +{ + int ret = OK; + int sval; + + sdbg("cond=0x%p\n", cond); + + if (!cond) + { + ret = EINVAL; + } + else + { + /* Disable pre-emption until all of the waiting threads have + * been restarted. This is necessary to assure that the sval + * behaves as expected in the following while loop + */ + + sched_lock(); + + /* Get the current value of the semaphore */ + + if (sem_getvalue((sem_t*)&cond->sem, &sval) != OK) + ret = EINVAL; + + else + { + /* Loop until all of the waiting threads have been restarted. */ + + while (sval < 0) + { + /* If the value is less than zero (meaning that one or more + * thread is waiting), then post the condition semaphore. + * Only the highest priority waiting thread will get to execute + */ + + ret = pthread_givesemaphore((sem_t*)&cond->sem); + + /* Increment the semaphore count (as was done by the + * above post). + */ + + sval++; + } + } + + /* Now we can let the restarted threads run */ + + sched_unlock(); + } + + sdbg("Returning %d\n", ret); + return ret; +} + + |