78 lines
2.1 KiB
C
78 lines
2.1 KiB
C
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/******************************************************************************
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*
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* Copyright (C) 2015 Google, Inc.
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at:
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*
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******************************************************************************/
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#include "semaphore.h"
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/*-----------------------------------------------------------------------------------*/
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// Creates and returns a new semaphore. The "init_count" argument specifies
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// the initial state of the semaphore, "max_count" specifies the maximum value
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// that can be reached.
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int osi_sem_new(osi_sem_t *sem, uint32_t max_count, uint32_t init_count)
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{
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int ret = -1;
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if (sem) {
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*sem = xSemaphoreCreateCounting(max_count, init_count);
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if ((*sem) != NULL) {
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ret = 0;
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}
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}
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return ret;
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}
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/*-----------------------------------------------------------------------------------*/
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// Give a semaphore
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void osi_sem_give(osi_sem_t *sem)
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{
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xSemaphoreGive(*sem);
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}
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/*
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Blocks the thread while waiting for the semaphore to be
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signaled. If the "timeout" argument is non-zero, the thread should
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only be blocked for the specified time (measured in
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milliseconds).
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*/
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int
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osi_sem_take(osi_sem_t *sem, uint32_t timeout)
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{
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int ret = 0;
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if (timeout == OSI_SEM_MAX_TIMEOUT) {
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if (xSemaphoreTake(*sem, portMAX_DELAY) != pdTRUE) {
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ret = -1;
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}
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} else {
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if (xSemaphoreTake(*sem, timeout / portTICK_PERIOD_MS) != pdTRUE) {
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ret = -2;
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}
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}
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return ret;
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}
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// Deallocates a semaphore
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void osi_sem_free(osi_sem_t *sem)
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{
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vSemaphoreDelete(*sem);
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*sem = NULL;
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}
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