diff options
Diffstat (limited to 'nuttx/sched/sem_trywait.c')
-rw-r--r-- | nuttx/sched/sem_trywait.c | 142 |
1 files changed, 0 insertions, 142 deletions
diff --git a/nuttx/sched/sem_trywait.c b/nuttx/sched/sem_trywait.c deleted file mode 100644 index cbd8dae69..000000000 --- a/nuttx/sched/sem_trywait.c +++ /dev/null @@ -1,142 +0,0 @@ -/**************************************************************************** - * sched/sem_trywait.c - * - * Copyright (C) 2007-2009 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 <stdbool.h> -#include <semaphore.h> -#include <sched.h> -#include <errno.h> -#include <nuttx/arch.h> - -#include "os_internal.h" -#include "sem_internal.h" - -/**************************************************************************** - * Pre-processor Definitions - ****************************************************************************/ - -/**************************************************************************** - * Private Type Declarations - ****************************************************************************/ - -/**************************************************************************** - * Global Variables - ****************************************************************************/ - -/**************************************************************************** - * Private Variables - ****************************************************************************/ - -/**************************************************************************** - * Private Functions - ****************************************************************************/ - -/**************************************************************************** - * Public Functions - ****************************************************************************/ - -/**************************************************************************** - * Name: sem_trywait - * - * Description: - * This function locks the specified semaphore only if the semaphore is - * currently not locked. Otherwise, it locks the semaphore. In either - * case, the call returns without blocking. - * - * Parameters: - * sem - the semaphore descriptor - * - * Return Value: - * 0 (OK) or -1 (ERROR) if unsuccessful. If this function returns -1 - * (ERROR),then the cause of the failure will be reported in "errno" as: - * - * EINVAL: Invalid attempt to get the semaphore - * EAGAIN: The semaphore is not available. - * - * Assumptions: - * - ****************************************************************************/ - -int sem_trywait(FAR sem_t *sem) -{ - FAR _TCB *rtcb = (FAR _TCB*)g_readytorun.head; - irqstate_t saved_state; - int ret = ERROR; - - /* This API should not be called from interrupt handlers */ - - DEBUGASSERT(up_interrupt_context() == false) - - /* Assume any errors reported are due to invalid arguments. */ - - set_errno(EINVAL); - - if (sem) - { - /* The following operations must be performed with interrupts disabled - * because sem_post() may be called from an interrupt handler. - */ - - saved_state = irqsave(); - - /* Any further errors could only be occurred because the semaphore - * is not available. - */ - - set_errno(EAGAIN); - - /* If the semaphore is available, give it to the requesting task */ - - if (sem->semcount > 0) - { - /* It is, let the task take the semaphore */ - - sem->semcount--; - rtcb->waitsem = NULL; - ret = OK; - } - - /* Interrupts may now be enabled. */ - - irqrestore(saved_state); - } - - return ret; -} |