/* * Copyright (c) 2015-2017, Texas Instruments Incorporated * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * * Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * * 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. * * * Neither the name of Texas Instruments Incorporated 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. */ /** ============================================================================ * @file MutexP.h * * @brief Mutex module for the RTOS Porting Interface * * The MutexP module allows task to maintain critical region segments. The * MutexP module has two main functions: ::MutexP_lock and ::MutexP_unlock. * * The MutexP module supports recursive calls to the MutexP_lock API by a * single task. The same number of MutexP_unlock calls must be done for the * mutex to be release. Note: the returned key must be provided in the LIFO * order. For example: * @code * uintptr_t key1, key2; * key1 = MutexP_lock(); * key2 = MutexP_lock(); * MutexP_lock(key2); * MutexP_lock(key1); * @endcode * * ============================================================================ */ #ifndef ti_dpl_MutexP__include #define ti_dpl_MutexP__include #ifdef __cplusplus extern "C" { #endif #include #include #include /*! * @brief Number of bytes greater than or equal to the size of any RTOS * MutexP object. * * nortos: 12 * SysBIOS: 40 */ #define MutexP_STRUCT_SIZE (40) /*! * @brief MutexP structure. * * Opaque structure that should be large enough to hold any of the * RTOS specific MutexP objects. */ typedef union MutexP_Struct { uint32_t dummy; /*!< Align object */ char data[MutexP_STRUCT_SIZE]; } MutexP_Struct; /*! * @brief Status codes for MutexP APIs */ typedef enum MutexP_Status { /*! API completed successfully */ MutexP_OK = 0, /*! API failed */ MutexP_FAILURE = -1 } MutexP_Status; /*! * @brief Opaque client reference to an instance of a MutexP * * A MutexP_Handle returned from the ::MutexP_create represents that instance. * and then is used in the other instance based functions (e.g. ::MutexP_lock, * ::MutexP_unlock, etc.). */ typedef void *MutexP_Handle; /*! * @brief Basic MutexP Parameters * * Structure that contains the parameters are passed into ::MutexP_create * when creating a MutexP instance. The ::MutexP_Params_init function should * be used to initialize the fields to default values before the application * sets the fields manually. The MutexP default parameters are noted in * ::MutexP_Params_init. */ typedef struct MutexP_Params { void (*callback)(void); /*!< Callback while waiting for mutex unlock */ } MutexP_Params; /*! * @brief Function to construct a mutex. * * @param handle Pointer to a MutexP_Struct object * * @param params Pointer to the instance configuration parameters. NULL * denotes to use the default parameters (MutexP default * parameters as noted in ::MutexP_Params_init. * * @return A MutexP_Handle on success or a NULL on an error */ extern MutexP_Handle MutexP_construct(MutexP_Struct *handle, MutexP_Params *params); /*! * @brief Function to destruct a mutex object * * @param mutexP Pointer to a MutexP_Struct object that was passed to * MutexP_construct(). * * @return */ extern void MutexP_destruct(MutexP_Struct *mutexP); /*! * @brief Function to create a mutex. * * @param params Pointer to the instance configuration parameters. NULL * denotes to use the default parameters. The MutexP default * parameters are noted in ::MutexP_Params_init. * * @return A MutexP_Handle on success or a NULL on an error */ extern MutexP_Handle MutexP_create(MutexP_Params *params); /*! * @brief Function to delete a mutex. * * @param handle A MutexP_Handle returned from MutexP_create */ extern void MutexP_delete(MutexP_Handle handle); /*! * @brief Initialize params structure to default values. * * The default parameters are: * callback - NULL. * * @param params Pointer to the instance configuration parameters. */ extern void MutexP_Params_init(MutexP_Params *params); /*! * @brief Function to lock a mutex. * * This function can only be called from a Task. It cannot be called from * an interrupt. The lock will block until the mutex is available. * * Users of a mutex should make every attempt to minimize the duration that * that they have it locked. This is to minimize latency. It is recommended * that the users of the mutex do not block while they have the mutex locked. * * This function unlocks the mutex. If the mutex is locked multiple times * by the caller, the same number of unlocks must be called. * * @param handle A MutexP_Handle returned from ::MutexP_create * * @return A key is returned. This key must be passed into ::MutexP_unlock. */ extern uintptr_t MutexP_lock(MutexP_Handle handle); /*! * @brief Function to unlock a mutex * * This function unlocks the mutex. If the mutex is locked multiple times * by the caller, the same number of unlocks must be called. The order of * the keys must be reversed. For example * @code * uintptr_t key1, key2; * key1 = MutexP_lock(); * key2 = MutexP_lock(); * MutexP_lock(key2); * MutexP_lock(key1); * @endcode * * @param handle A MutexP_Handle returned from ::MutexP_create * * @param key Return from ::MutexP_lock. */ extern void MutexP_unlock(MutexP_Handle handle, uintptr_t key); #ifdef __cplusplus } #endif #endif /* ti_dpl_MutexP__include */