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Diffstat (limited to 'nuttx/sched/sem_post.c')
| -rw-r--r-- | nuttx/sched/sem_post.c | 182 |
1 files changed, 0 insertions, 182 deletions
diff --git a/nuttx/sched/sem_post.c b/nuttx/sched/sem_post.c deleted file mode 100644 index 1c694b68c..000000000 --- a/nuttx/sched/sem_post.c +++ /dev/null @@ -1,182 +0,0 @@ -/**************************************************************************** - * sched/sem_post.c - * - * Copyright (C) 2007-2009, 2012 Gregory Nutt. All rights reserved. - * Author: Gregory Nutt <gnutt@nuttx.org> - * - * 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 <limits.h> -#include <semaphore.h> -#include <sched.h> -#include <nuttx/arch.h> - -#include "os_internal.h" -#include "sem_internal.h" - -/**************************************************************************** - * Definitions - ****************************************************************************/ - -/**************************************************************************** - * Private Type Declarations - ****************************************************************************/ - -/**************************************************************************** - * Global Variables - ****************************************************************************/ - -/**************************************************************************** - * Private Variables - ****************************************************************************/ - -/**************************************************************************** - * Private Functions - ****************************************************************************/ - -/**************************************************************************** - * Public Functions - ****************************************************************************/ - -/**************************************************************************** - * Name: sem_post - * - * Description: - * When a task has finished with a semaphore, it will call sem_post(). - * This function unlocks the semaphore referenced by sem by performing the - * semaphore unlock operation on that semaphore. - * - * If the semaphore value resulting from this operation is positive, then - * no tasks were blocked waiting for the semaphore to become unlocked; the - * semaphore is simply incremented. - * - * If the value of the semaphore resulting from this operation is zero, - * then one of the tasks blocked waiting for the semaphore shall be - * allowed to return successfully from its call to sem_wait(). - * - * Parameters: - * sem - Semaphore descriptor - * - * Return Value: - * 0 (OK) or -1 (ERROR) if unsuccessful - * - * Assumptions: - * This function cannot be called from an interrupt handler. - * It assumes the currently executing task is the one that - * is performing the unlock. - * - ****************************************************************************/ - -int sem_post(FAR sem_t *sem) -{ - FAR _TCB *stcb = NULL; - int ret = ERROR; - irqstate_t saved_state; - - /* Make sure we were supplied with a valid semaphore. */ - - if (sem) - { - /* The following operations must be performed with interrupts - * disabled because sem_post() may be called from an interrupt - * handler. - */ - - saved_state = irqsave(); - - /* Perform the semaphore unlock operation. */ - - ASSERT(sem->semcount < SEM_VALUE_MAX); - sem_releaseholder(sem); - sem->semcount++; - -#ifdef CONFIG_PRIORITY_INHERITANCE - /* Don't let any unblocked tasks run until we complete any priority - * restoration steps. Interrupts are disabled, but we do not want - * the head of the read-to-run list to be modified yet. - * - * NOTE: If this sched_lock is called from an interrupt handler, it - * will do nothing. - */ - - sched_lock(); -#endif - /* If the result of of semaphore unlock is non-positive, then - * there must be some task waiting for the semaphore. - */ - - if (sem->semcount <= 0) - { - /* Check if there are any tasks in the waiting for semaphore - * task list that are waiting for this semaphore. This is a - * prioritized list so the first one we encounter is the one - * that we want. - */ - - for (stcb = (FAR _TCB*)g_waitingforsemaphore.head; - (stcb && stcb->waitsem != sem); - stcb = stcb->flink); - - if (stcb) - { - /* It is, let the task take the semaphore */ - - stcb->waitsem = NULL; - - /* Restart the waiting task. */ - - up_unblock_task(stcb); - } - } - - /* Check if we need to drop the priority of any threads holding - * this semaphore. The priority could have been boosted while they - * held the semaphore. - */ - -#ifdef CONFIG_PRIORITY_INHERITANCE - sem_restorebaseprio(stcb, sem); - sched_unlock(); -#endif - ret = OK; - - /* Interrupts may now be enabled. */ - - irqrestore(saved_state); - } - - return ret; -} |