/* * Copyright (c) 2018 Intel Corporation * * SPDX-License-Identifier: Apache-2.0 */ #include #include /** * @brief Destroy semaphore. * * see IEEE 1003.1 */ int sem_destroy(sem_t *semaphore) { if (semaphore == NULL) { errno = EINVAL; return -1; } if (k_sem_count_get(semaphore)) { errno = EBUSY; return -1; } k_sem_reset(semaphore); return 0; } /** * @brief Get value of semaphore. * * See IEEE 1003.1 */ int sem_getvalue(sem_t *semaphore, int *value) { if (semaphore == NULL) { errno = EINVAL; return -1; } *value = (int) k_sem_count_get(semaphore); return 0; } /** * @brief Initialize semaphore. * * See IEEE 1003.1 */ int sem_init(sem_t *semaphore, int pshared, unsigned int value) { if (value > CONFIG_SEM_VALUE_MAX) { errno = EINVAL; return -1; } /* * Zephyr has no concept of process, so only thread shared * semaphore makes sense in here. */ __ASSERT(pshared == 0, "pshared should be 0"); k_sem_init(semaphore, value, CONFIG_SEM_VALUE_MAX); return 0; } /** * @brief Unlock a semaphore. * * See IEEE 1003.1 */ int sem_post(sem_t *semaphore) { if (semaphore == NULL) { errno = EINVAL; return -1; } k_sem_give(semaphore); return 0; } /** * @brief Try time limited locking a semaphore. * * See IEEE 1003.1 */ int sem_timedwait(sem_t *semaphore, struct timespec *abstime) { int32_t timeout; struct timespec current; int64_t current_ms, abstime_ms; __ASSERT(abstime, "abstime pointer NULL"); if ((abstime->tv_sec < 0) || (abstime->tv_nsec >= NSEC_PER_SEC)) { errno = EINVAL; return -1; } if (clock_gettime(CLOCK_REALTIME, ¤t) < 0) { return -1; } abstime_ms = (int64_t)_ts_to_ms(abstime); current_ms = (int64_t)_ts_to_ms(¤t); if (abstime_ms <= current_ms) { timeout = 0; } else { timeout = (int32_t)(abstime_ms - current_ms); } if (k_sem_take(semaphore, K_MSEC(timeout))) { errno = ETIMEDOUT; return -1; } return 0; } /** * @brief Lock a semaphore if not taken. * * See IEEE 1003.1 */ int sem_trywait(sem_t *semaphore) { if (k_sem_take(semaphore, K_NO_WAIT) == -EBUSY) { errno = EAGAIN; return -1; } else { return 0; } } /** * @brief Lock a semaphore. * * See IEEE 1003.1 */ int sem_wait(sem_t *semaphore) { /* With K_FOREVER, may return only success. */ (void)k_sem_take(semaphore, K_FOREVER); return 0; }