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Diffstat (limited to 'thirdparty/nRF5_SDK_15.0.0_a53641a/components/libraries/mutex')
-rw-r--r-- | thirdparty/nRF5_SDK_15.0.0_a53641a/components/libraries/mutex/nrf_mtx.h | 159 |
1 files changed, 159 insertions, 0 deletions
diff --git a/thirdparty/nRF5_SDK_15.0.0_a53641a/components/libraries/mutex/nrf_mtx.h b/thirdparty/nRF5_SDK_15.0.0_a53641a/components/libraries/mutex/nrf_mtx.h new file mode 100644 index 0000000..2e1b553 --- /dev/null +++ b/thirdparty/nRF5_SDK_15.0.0_a53641a/components/libraries/mutex/nrf_mtx.h @@ -0,0 +1,159 @@ +/** + * Copyright (c) 2015 - 2018, Nordic Semiconductor ASA + * + * All rights reserved. + * + * 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, except as embedded into a Nordic + * Semiconductor ASA integrated circuit in a product or a software update for + * such product, 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 of Nordic Semiconductor ASA nor the names of its + * contributors may be used to endorse or promote products derived from this + * software without specific prior written permission. + * + * 4. This software, with or without modification, must only be used with a + * Nordic Semiconductor ASA integrated circuit. + * + * 5. Any software provided in binary form under this license must not be reverse + * engineered, decompiled, modified and/or disassembled. + * + * THIS SOFTWARE IS PROVIDED BY NORDIC SEMICONDUCTOR ASA "AS IS" AND ANY EXPRESS + * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES + * OF MERCHANTABILITY, NONINFRINGEMENT, AND FITNESS FOR A PARTICULAR PURPOSE ARE + * DISCLAIMED. IN NO EVENT SHALL NORDIC SEMICONDUCTOR ASA 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. + * + */ +/** @file + * @defgroup nrf_mtx nRF Mutex + * @{ + * @ingroup app_common + * @brief Mutex used for protecting resources. + * + * This module provides a mutex that can be used to ensure only one context may enter a critical + * section holding the lock. + */ +#ifndef NRF_MTX_H__ +#define NRF_MTX_H__ + +#include <stdint.h> +#include <stdbool.h> +#include "nrf.h" +#include "nrf_atomic.h" +#include "nrf_assert.h" + +#define NRF_MTX_LOCKED 1 +#define NRF_MTX_UNLOCKED 0 + +/** + * @brief Mutex data type. + * + * All fields in this struct are internal, and should never be modified outside of the nrf_mtx_* + * functions. + */ +typedef nrf_atomic_u32_t nrf_mtx_t; + +/** + * @brief Initialize mutex. + * + * This function _must_ be called before nrf_mtx_trylock() and nrf_mtx_unlock() functions. + * + * @param[in, out] p_mtx The mutex to be initialized. + */ +__STATIC_INLINE void nrf_mtx_init(nrf_mtx_t * p_mtx); + + +/** + * @brief Destroy mutex. + * + * This function can be used in abort scenarios or when the mutex is no longer to be used. + * + * @param[in] p_mtx The mutex to be destroy. + */ +__STATIC_INLINE void nrf_mtx_destroy(nrf_mtx_t * p_mtx); + +/** + * @brief Try to lock a mutex. + * + * If the mutex is already held by another context, this function will return immediately. + * + * @param[in, out] p_mtx The mutex to be locked. + * @return true if lock was acquired, false if not + */ +__STATIC_INLINE bool nrf_mtx_trylock(nrf_mtx_t * p_mtx); + +/** + * @brief Unlock a mutex. + * + * This function _must_ only be called when holding the lock. Unlocking a mutex which you do not + * hold will give undefined behavior. + * + * @note Unlock must happen from the same context as the one used to lock the mutex. + * + * @param[in, out] p_mtx The mutex to be unlocked. + */ +__STATIC_INLINE void nrf_mtx_unlock(nrf_mtx_t * p_mtx); + +#ifndef SUPPRESS_INLINE_IMPLEMENTATION + +__STATIC_INLINE void nrf_mtx_init(nrf_mtx_t * p_mtx) +{ + ASSERT(p_mtx != NULL); + + *p_mtx = NRF_MTX_UNLOCKED; + __DMB(); +} + +__STATIC_INLINE void nrf_mtx_destroy(nrf_mtx_t * p_mtx) +{ + ASSERT(p_mtx != NULL); + + // Add memory barrier to ensure that any memory operations protected by the mutex complete + // before the mutex is destroyed. + __DMB(); + + *p_mtx = NRF_MTX_UNLOCKED; +} + +__STATIC_INLINE bool nrf_mtx_trylock(nrf_mtx_t * p_mtx) +{ + ASSERT(p_mtx != NULL); + + uint32_t old_val = nrf_atomic_u32_fetch_store(p_mtx, NRF_MTX_LOCKED); + + // Add memory barrier to ensure that the mutex is locked before any memory operations protected + // by the mutex are started. + __DMB(); + + return (old_val == NRF_MTX_UNLOCKED); +} + +__STATIC_INLINE void nrf_mtx_unlock(nrf_mtx_t * p_mtx) +{ + ASSERT(p_mtx != NULL); + ASSERT(*p_mtx == NRF_MTX_LOCKED); + + // Add memory barrier to ensure that any memory operations protected by the mutex complete + // before the mutex is unlocked. + __DMB(); + + *p_mtx = NRF_MTX_UNLOCKED; +} + +#endif //SUPPRESS_INLINE_IMPLEMENTATION + +#endif // NRF_MTX_H__ +/** @} */ |