/**************************************************************************** * sched/semaphore/sem_timedwait.c * * SPDX-License-Identifier: Apache-2.0 * * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. The * ASF licenses this file to you under the Apache License, Version 2.0 (the * "License"); you may not use this file except in compliance with the * License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the * License for the specific language governing permissions and limitations * under the License. * ****************************************************************************/ /**************************************************************************** * Included Files ****************************************************************************/ #include #include /**************************************************************************** * Public Functions ****************************************************************************/ /**************************************************************************** * Name: nxsem_timedwait * * Description: * This function will lock the semaphore referenced by sem as in the * sem_wait() function. However, if the semaphore cannot be locked without * waiting for another process or thread to unlock the semaphore by * performing a sem_post() function, this wait will be terminated when the * specified timeout expires. * * The timeout will expire when the absolute time specified by abstime * passes, as measured by the clock on which timeouts are based (that is, * when the value of that clock equals or exceeds abstime), or if the * absolute time specified by abstime has already been passed at the * time of the call. * * This is an internal OS interface. It is functionally equivalent to * sem_wait except that: * * - It is not a cancellation point, and * - It does not modify the errno value. * * Input Parameters: * sem - Semaphore object * abstime - The absolute time to wait until a timeout is declared. * * Returned Value: * This is an internal OS interface and should not be used by applications. * It follows the NuttX internal error return policy: Zero (OK) is * returned on success. A negated errno value is returned on failure. * That may be one of: * * EINVAL The sem argument does not refer to a valid semaphore. Or the * thread would have blocked, and the abstime parameter specified * a nanoseconds field value less than zero or greater than or * equal to 1000 million. * ETIMEDOUT The semaphore could not be locked before the specified timeout * expired. * EDEADLK A deadlock condition was detected. * EINTR A signal interrupted this function. * ****************************************************************************/ int nxsem_timedwait(FAR sem_t *sem, FAR const struct timespec *abstime) { return nxsem_clockwait(sem, CLOCK_REALTIME, abstime); } /**************************************************************************** * Name: nxsem_timedwait_uninterruptible * * Description: * This function is wrapped version of nxsem_timedwait(), which is * uninterruptible and convenient for use. * * Input Parameters: * sem - Semaphore object * abstime - The absolute time to wait until a timeout is declared. * * Returned Value: * EINVAL The sem argument does not refer to a valid semaphore. Or the * thread would have blocked, and the abstime parameter specified * a nanoseconds field value less than zero or greater than or * equal to 1000 million. * ETIMEDOUT The semaphore could not be locked before the specified timeout * expired. * EDEADLK A deadlock condition was detected. * ECANCELED May be returned if the thread is canceled while waiting. * ****************************************************************************/ int nxsem_timedwait_uninterruptible(FAR sem_t *sem, FAR const struct timespec *abstime) { return nxsem_clockwait_uninterruptible(sem, CLOCK_REALTIME, abstime); }