/* * Amazon FreeRTOS Common V1.0.0 * Copyright (C) 2018 Amazon.com, Inc. or its affiliates. All Rights Reserved. * * Permission is hereby granted, free of charge, to any person obtaining a copy of * this software and associated documentation files (the "Software"), to deal in * the Software without restriction, including without limitation the rights to * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of * the Software, and to permit persons to whom the Software is furnished to do so, * subject to the following conditions: * * The above copyright notice and this permission notice shall be included in all * copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. * * http://aws.amazon.com/freertos * http://www.FreeRTOS.org */ /** * @file iot_taskpool.h * @brief User-facing functions of the task pool library. */ #ifndef IOT_TASKPOOL_H_ #define IOT_TASKPOOL_H_ /* The config header is always included first. */ #include "iot_config.h" /* Standard includes. */ #include #include #include /* Task pool types. */ #include "types/iot_taskpool_types.h" /*------------------------- Task Pool library functions --------------------------*/ /** * @functionspage{taskpool,task pool library} * - @functionname{taskpool_function_createsystemtaskpool} * - @functionname{taskpool_function_getsystemtaskpool} * - @functionname{taskpool_function_create} * - @functionname{taskpool_function_destroy} * - @functionname{taskpool_function_setmaxthreads} * - @functionname{taskpool_function_createjob} * - @functionname{taskpool_function_createrecyclablejob} * - @functionname{taskpool_function_destroyrecyclablejob} * - @functionname{taskpool_function_recyclejob} * - @functionname{taskpool_function_schedule} * - @functionname{taskpool_function_scheduledeferred} * - @functionname{taskpool_function_getstatus} * - @functionname{taskpool_function_trycancel} * - @functionname{taskpool_function_getjobstoragefromhandle} * - @functionname{taskpool_function_strerror} */ /** * @functionpage{IotTaskPool_CreateSystemTaskPool,taskpool,createsystemtaskpool} * @functionpage{IotTaskPool_GetSystemTaskPool,taskpool,getsystemtaskpool} * @functionpage{IotTaskPool_Create,taskpool,create} * @functionpage{IotTaskPool_Destroy,taskpool,destroy} * @functionpage{IotTaskPool_SetMaxThreads,taskpool,setmaxthreads} * @functionpage{IotTaskPool_CreateJob,taskpool,createjob} * @functionpage{IotTaskPool_CreateRecyclableJob,taskpool,createrecyclablejob} * @functionpage{IotTaskPool_DestroyRecyclableJob,taskpool,destroyrecyclablejob} * @functionpage{IotTaskPool_RecycleJob,taskpool,recyclejob} * @functionpage{IotTaskPool_Schedule,taskpool,schedule} * @functionpage{IotTaskPool_ScheduleDeferred,taskpool,scheduledeferred} * @functionpage{IotTaskPool_GetStatus,taskpool,getstatus} * @functionpage{IotTaskPool_TryCancel,taskpool,trycancel} * @functionpage{IotTaskPool_GetJobStorageFromHandle,taskpool,getjobstoragefromhandle} * @functionpage{IotTaskPool_strerror,taskpool,strerror} */ /** * @brief Creates the one single instance of the system task pool. * * This function should be called once by the application to initialize the one single instance of the system task pool. * An application should initialize the system task pool early in the boot sequence, before initializing any other library * and before posting any jobs. Early initialization it typically easy to accomplish by creating the system task pool * before starting the scheduler. * * This function does not allocate memory to hold the task pool data structures and state, but it * may allocate memory to hold the dependent entities and data structures, e.g. the threads of the task * pool. The system task pool handle is recoverable for later use by calling @ref IotTaskPool_GetSystemTaskPool or * the shortcut @ref IOT_SYSTEM_TASKPOOL. * * @param[in] pInfo A pointer to the task pool initialization data. * * @return One of the following: * - #IOT_TASKPOOL_SUCCESS * - #IOT_TASKPOOL_BAD_PARAMETER * - #IOT_TASKPOOL_NO_MEMORY * * @warning This function should be called only once. Calling this function more that once will result in * undefined behavior. * */ /* @[declare_taskpool_createsystemtaskpool] */ IotTaskPoolError_t IotTaskPool_CreateSystemTaskPool( const IotTaskPoolInfo_t * const pInfo ); /* @[declare_taskpool_createsystemtaskpool] */ /** * @brief Retrieves the one and only instance of a system task pool * * This function retrieves the system task pool created with @ref IotTaskPool_CreateSystemTaskPool, and it is functionally * equivalent to using the shortcut @ref IOT_SYSTEM_TASKPOOL. * * @return The system task pool handle. * * @warning This function should be called after creating the system task pool with @ref IotTaskPool_CreateSystemTaskPool. * Calling this function before creating the system task pool may return a pointer to an uninitialized task pool, NULL, or otherwise * fail with undefined behaviour. * */ /* @[declare_taskpool_getsystemtaskpool] */ IotTaskPool_t IotTaskPool_GetSystemTaskPool( void ); /* @[declare_taskpool_getsystemtaskpool] */ /** * @brief Creates one instance of a task pool. * * This function should be called by the user to initialize one instance of a task * pool. The task pool instance will be created around the storage pointed to by the `pTaskPool` * parameter. This function will create the minimum number of threads requested by the user * through an instance of the #IotTaskPoolInfo_t type specified with the `pInfo` parameter. * This function does not allocate memory to hold the task pool data structures and state, but it * may allocates memory to hold the dependent data structures, e.g. the threads of the task * pool. * * @param[in] pInfo A pointer to the task pool initialization data. * @param[out] pTaskPool A pointer to the task pool handle to be used after initialization. * The pointer `pTaskPool` will hold a valid handle only if (@ref IotTaskPool_Create) * completes successfully. * * @return One of the following: * - #IOT_TASKPOOL_SUCCESS * - #IOT_TASKPOOL_BAD_PARAMETER * - #IOT_TASKPOOL_NO_MEMORY * */ /* @[declare_taskpool_create] */ IotTaskPoolError_t IotTaskPool_Create( const IotTaskPoolInfo_t * const pInfo, IotTaskPool_t * const pTaskPool ); /* @[declare_taskpool_create] */ /** * @brief Destroys a task pool instance and collects all memory associated with a task pool and its * satellite data structures. * * This function should be called to destroy one instance of a task pool previously created with a call * to @ref IotTaskPool_Create or @ref IotTaskPool_CreateSystemTaskPool. * Calling this fuction release all underlying resources. After calling this function, any job scheduled but not yet executed * will be canceled and destroyed. * The `taskPool` instance will no longer be valid after this function returns. * * @param[in] taskPool A handle to the task pool, e.g. as returned by a call to @ref IotTaskPool_Create or * @ref IotTaskPool_CreateSystemTaskPool. The `taskPool` instance will no longer be valid after this function returns. * * @return One of the following: * - #IOT_TASKPOOL_SUCCESS * - #IOT_TASKPOOL_BAD_PARAMETER * */ /* @[declare_taskpool_destroy] */ IotTaskPoolError_t IotTaskPool_Destroy( IotTaskPool_t taskPool ); /* @[declare_taskpool_destroy] */ /** * @brief Sets the maximum number of threads for one instance of a task pool. * * This function sets the maximum number of threads for the task pool * pointed to by `taskPool`. * * If the number of currently active threads in the task pool is greater than `maxThreads`, this * function causes the task pool to shrink the number of active threads. * * @param[in] taskPool A handle to the task pool that must have been previously initialized with * a call to @ref IotTaskPool_Create or @ref IotTaskPool_CreateSystemTaskPool. * @param[in] maxThreads The maximum number of threads for the task pool. * * @return One of the following: * - #IOT_TASKPOOL_SUCCESS * - #IOT_TASKPOOL_BAD_PARAMETER * - #IOT_TASKPOOL_SHUTDOWN_IN_PROGRESS * */ /* @[declare_taskpool_setmaxthreads] */ IotTaskPoolError_t IotTaskPool_SetMaxThreads( IotTaskPool_t taskPool, uint32_t maxThreads ); /* @[declare_taskpool_setmaxthreads] */ /** * @brief Creates a job for the task pool around a user-provided storage. * * This function may allocate memory to hold the state for a job. * * @param[in] userCallback A user-specified callback for the job. * @param[in] pUserContext A user-specified context for the callback. * @param[in] pJobStorage The storage for the job data structure. * @param[out] pJob A pointer to an instance of @ref IotTaskPoolJob_t that will be initialized when this * function returns successfully. This handle can be used to inspect the job status with * @ref IotTaskPool_GetStatus or cancel the job with @ref IotTaskPool_TryCancel, etc.... * * @return One of the following: * - #IOT_TASKPOOL_SUCCESS * - #IOT_TASKPOOL_BAD_PARAMETER * * */ /* @[declare_taskpool_createjob] */ IotTaskPoolError_t IotTaskPool_CreateJob( IotTaskPoolRoutine_t userCallback, void * pUserContext, IotTaskPoolJobStorage_t * const pJobStorage, IotTaskPoolJob_t * const pJob ); /* @[declare_taskpool_createjob] */ /** * brief Creates a job for the task pool by allocating the job dynamically. * * A recyclable job does not need to be allocated twice, but it can rather be reused through * subsequent calls to @ref IotTaskPool_CreateRecyclableJob. * * @param[in] taskPool A handle to the task pool for which to create a recyclable job. * @param[in] userCallback A user-specified callback for the job. * @param[in] pUserContext A user-specified context for the callback. * @param[out] pJob A pointer to an instance of @ref IotTaskPoolJob_t that will be initialized when this * function returns successfully. This handle can be used to inspect the job status with * @ref IotTaskPool_GetStatus or cancel the job with @ref IotTaskPool_TryCancel, etc.... * * @return One of the following: * - #IOT_TASKPOOL_SUCCESS * - #IOT_TASKPOOL_BAD_PARAMETER * - #IOT_TASKPOOL_NO_MEMORY * - #IOT_TASKPOOL_SHUTDOWN_IN_PROGRESS * * @note This function will not allocate memory. //_RB_ Incorrect comment. * * @warning A recyclable job should be recycled with a call to @ref IotTaskPool_RecycleJob rather than destroyed. * */ /* @[declare_taskpool_createrecyclablejob] */ IotTaskPoolError_t IotTaskPool_CreateRecyclableJob( IotTaskPool_t taskPool, IotTaskPoolRoutine_t userCallback, void * pUserContext, IotTaskPoolJob_t * const pJob ); /* @[declare_taskpool_createrecyclablejob] */ /** * @brief This function un-initializes a job. * * This function will destroy a job created with @ref IotTaskPool_CreateRecyclableJob. * A job should not be destroyed twice. A job that was previously scheduled but has not completed yet should not be destroyed, * but rather the application should attempt to cancel it first by calling @ref IotTaskPool_TryCancel. * An attempt to destroy a job that was scheduled but not yet executed or canceled, may result in a * @ref IOT_TASKPOOL_ILLEGAL_OPERATION error. * * @param[in] taskPool A handle to the task pool, e.g. as returned by a call to @ref IotTaskPool_Create or @ref IotTaskPool_CreateSystemTaskPool. * @param[in] job A handle to a job that was create with a call to @ref IotTaskPool_CreateJob. * * @return One of the following: * - #IOT_TASKPOOL_SUCCESS * - #IOT_TASKPOOL_BAD_PARAMETER * - #IOT_TASKPOOL_ILLEGAL_OPERATION * - #IOT_TASKPOOL_SHUTDOWN_IN_PROGRESS * * @warning The task pool will try and prevent destroying jobs that are currently queued for execution, but does * not enforce strict ordering of operations. It is up to the user to make sure @ref IotTaskPool_DestroyRecyclableJob is not called * our of order. * * @warning Calling this function on job that was not previously created with @ref IotTaskPool_CreateRecyclableJob * will result in a @ref IOT_TASKPOOL_ILLEGAL_OPERATION error. * */ /* @[declare_taskpool_destroyrecyclablejob] */ IotTaskPoolError_t IotTaskPool_DestroyRecyclableJob( IotTaskPool_t taskPool, IotTaskPoolJob_t job ); /* @[declare_taskpool_destroyrecyclablejob] */ /** * @brief Recycles a job into the task pool job cache. * * This function will try and recycle the job into the task pool cache. If the cache is full, * the job memory is destroyed as if the user called @ref IotTaskPool_DestroyRecyclableJob. The job should be recycled into * the task pool instance from where it was allocated. * Failure to do so will yield undefined results. A job should not be recycled twice. A job * that was previously scheduled but not completed or canceled cannot be safely recycled. An attempt to do so will result * in an @ref IOT_TASKPOOL_ILLEGAL_OPERATION error. * * @param[in] taskPool A handle to the task pool, e.g. as returned by a call to @ref IotTaskPool_Create. * @param[out] job A pointer to a job that was create with a call to @ref IotTaskPool_CreateJob. * * @return One of the following: * - #IOT_TASKPOOL_SUCCESS * - #IOT_TASKPOOL_BAD_PARAMETER * - #IOT_TASKPOOL_ILLEGAL_OPERATION * - #IOT_TASKPOOL_SHUTDOWN_IN_PROGRESS * * @warning The `taskPool` used in this function should be the same * used to create the job pointed to by `job`, or the results will be undefined. * * @warning Attempting to call this function on a statically allocated job will result in @ref IOT_TASKPOOL_ILLEGAL_OPERATION * error. * * @warning This function should be used to recycle a job in the task pool cache when after the job executed. * Failing to call either this function or @ref IotTaskPool_DestroyRecyclableJob will result is a memory leak. Statically * allocated jobs do not need to be recycled or destroyed. * */ /* @[declare_taskpool_recyclejob] */ IotTaskPoolError_t IotTaskPool_RecycleJob( IotTaskPool_t taskPool, IotTaskPoolJob_t job ); /* @[declare_taskpool_recyclejob] */ /** * @brief This function schedules a job created with @ref IotTaskPool_CreateJob or @ref IotTaskPool_CreateRecyclableJob * against the task pool pointed to by `taskPool`. * * See @ref taskpool_design for a description of the jobs lifetime and interaction with the threads used in the task pool * library. * * @param[in] taskPool A handle to the task pool that must have been previously initialized with. * a call to @ref IotTaskPool_Create. * @param[in] job A job to schedule for execution. This must be first initialized with a call to @ref IotTaskPool_CreateJob. * @param[in] flags Flags to be passed by the user, e.g. to identify the job as high priority by specifying #IOT_TASKPOOL_JOB_HIGH_PRIORITY. * * @return One of the following: * - #IOT_TASKPOOL_SUCCESS * - #IOT_TASKPOOL_BAD_PARAMETER * - #IOT_TASKPOOL_ILLEGAL_OPERATION * - #IOT_TASKPOOL_NO_MEMORY * - #IOT_TASKPOOL_SHUTDOWN_IN_PROGRESS * * * @note This function will not allocate memory, so it is guaranteed to succeed if the paramters are correct and the task pool * was correctly initialized, and not yet destroyed. * * @warning The `taskPool` used in this function should be the same used to create the job pointed to by `job`, or the * results will be undefined. * * Example * @code{c} * // An example of a user context to pass to a callback through a task pool thread. * typedef struct JobUserContext * { * uint32_t counter; * } JobUserContext_t; * * // An example of a user callback to invoke through a task pool thread. * static void ExecutionCb( IotTaskPool_t taskPool, IotTaskPoolJob_t job, void * context ) * { * ( void )taskPool; * ( void )job; * * JobUserContext_t * pUserContext = ( JobUserContext_t * )context; * * pUserContext->counter++; * } * * void TaskPoolExample( ) * { * JobUserContext_t userContext = { 0 }; * IotTaskPoolJob_t job; * IotTaskPool_t taskPool; * * // Configure the task pool to hold at least two threads and three at the maximum. * // Provide proper stack size and priority per the application needs. * * const IotTaskPoolInfo_t tpInfo = { .minThreads = 2, .maxThreads = 3, .stackSize = 512, .priority = 0 }; * * // Create a task pool. * IotTaskPool_Create( &tpInfo, &taskPool ); * * // Statically allocate one job, schedule it. * IotTaskPool_CreateJob( &ExecutionCb, &userContext, &job ); * * IotTaskPoolError_t errorSchedule = IotTaskPool_Schedule( taskPool, &job, 0 ); * * switch ( errorSchedule ) * { * case IOT_TASKPOOL_SUCCESS: * break; * case IOT_TASKPOOL_BAD_PARAMETER: // Invalid parameters, such as a NULL handle, can trigger this error. * case IOT_TASKPOOL_ILLEGAL_OPERATION: // Scheduling a job that was previously scheduled or destroyed could trigger this error. * case IOT_TASKPOOL_NO_MEMORY: // Scheduling a with flag #IOT_TASKPOOL_JOB_HIGH_PRIORITY could trigger this error. * case IOT_TASKPOOL_SHUTDOWN_IN_PROGRESS: // Scheduling a job after trying to destroy the task pool could trigger this error. * // ASSERT * break; * default: * // ASSERT * } * * // * // ... Perform other operations ... * // * * IotTaskPool_Destroy( taskPool ); * } * @endcode */ /* @[declare_taskpool_schedule] */ IotTaskPoolError_t IotTaskPool_Schedule( IotTaskPool_t taskPool, IotTaskPoolJob_t job, uint32_t flags ); /* @[declare_taskpool_schedule] */ /** * @brief This function schedules a job created with @ref IotTaskPool_CreateJob against the task pool * pointed to by `taskPool` to be executed after a user-defined time interval. * * See @ref taskpool_design for a description of the jobs lifetime and interaction with the threads used in the task pool * library. * * @param[in] taskPool A handle to the task pool that must have been previously initialized with. * a call to @ref IotTaskPool_Create. * @param[in] job A job to schedule for execution. This must be first initialized with a call to @ref IotTaskPool_CreateJob. * @param[in] timeMs The time in milliseconds to wait before scheduling the job. * * @return One of the following: * - #IOT_TASKPOOL_SUCCESS * - #IOT_TASKPOOL_BAD_PARAMETER * - #IOT_TASKPOOL_ILLEGAL_OPERATION * - #IOT_TASKPOOL_SHUTDOWN_IN_PROGRESS * * * @note This function will not allocate memory. * * @warning The `taskPool` used in this function should be the same * used to create the job pointed to by `job`, or the results will be undefined. * */ /* @[declare_taskpool_scheduledeferred] */ IotTaskPoolError_t IotTaskPool_ScheduleDeferred( IotTaskPool_t taskPool, IotTaskPoolJob_t job, uint32_t timeMs ); /* @[declare_taskpool_scheduledeferred] */ /** * @brief This function retrieves the current status of a job. * * @param[in] taskPool A handle to the task pool that must have been previously initialized with * a call to @ref IotTaskPool_Create or @ref IotTaskPool_CreateSystemTaskPool. * @param[in] job The job to cancel. * @param[out] pStatus The status of the job at the time of cancellation. * * @return One of the following: * - #IOT_TASKPOOL_SUCCESS * - #IOT_TASKPOOL_BAD_PARAMETER * - #IOT_TASKPOOL_SHUTDOWN_IN_PROGRESS * * @warning This function is not thread safe and the job status returned in `pStatus` may be invalid by the time * the calling thread has a chance to inspect it. */ /* @[declare_taskpool_getstatus] */ IotTaskPoolError_t IotTaskPool_GetStatus( IotTaskPool_t taskPool, IotTaskPoolJob_t job, IotTaskPoolJobStatus_t * const pStatus ); /* @[declare_taskpool_getstatus] */ /** * @brief This function tries to cancel a job that was previously scheduled with @ref IotTaskPool_Schedule. * * A job can be canceled only if it is not yet executing, i.e. if its status is * @ref IOT_TASKPOOL_STATUS_READY or @ref IOT_TASKPOOL_STATUS_SCHEDULED. Calling * @ref IotTaskPool_TryCancel on a job whose status is @ref IOT_TASKPOOL_STATUS_COMPLETED, * or #IOT_TASKPOOL_STATUS_CANCELED will yield a #IOT_TASKPOOL_CANCEL_FAILED return result. * * @param[in] taskPool A handle to the task pool that must have been previously initialized with * a call to @ref IotTaskPool_Create. * @param[in] job The job to cancel. * @param[out] pStatus The status of the job at the time of cancellation. * * @return One of the following: * - #IOT_TASKPOOL_SUCCESS * - #IOT_TASKPOOL_BAD_PARAMETER * - #IOT_TASKPOOL_SHUTDOWN_IN_PROGRESS * - #IOT_TASKPOOL_CANCEL_FAILED * * @warning The `taskPool` used in this function should be the same * used to create the job pointed to by `job`, or the results will be undefined. * */ /* @[declare_taskpool_trycancel] */ IotTaskPoolError_t IotTaskPool_TryCancel( IotTaskPool_t taskPool, IotTaskPoolJob_t job, IotTaskPoolJobStatus_t * const pStatus ); /* @[declare_taskpool_trycancel] */ /** * @brief Returns a pointer to the job storage from an instance of a job handle * of type @ref IotTaskPoolJob_t. This function is guaranteed to succeed for a * valid job handle. * * @param[in] job The job handle. * * @return A pointer to the storage associated with the job handle `job`. * * @warning If the `job` handle used is invalid, the results will be undefined. */ /* @[declare_taskpool_getjobstoragefromhandle] */ IotTaskPoolJobStorage_t * IotTaskPool_GetJobStorageFromHandle( IotTaskPoolJob_t job ); /* @[declare_taskpool_getjobstoragefromhandle] */ /** * @brief Returns a string that describes an @ref IotTaskPoolError_t. * * Like the POSIX's `strerror`, this function returns a string describing a * return code. In this case, the return code is a task pool library error code, * `status`. * * The string returned by this function MUST be treated as read-only: any * attempt to modify its contents may result in a crash. Therefore, this function * is limited to usage in logging. * * @param[in] status The status to describe. * * @return A read-only string that describes `status`. * * @warning The string returned by this function must never be modified. */ /* @[declare_taskpool_strerror] */ const char * IotTaskPool_strerror( IotTaskPoolError_t status ); /* @[declare_taskpool_strerror] */ /** * @brief The maximum number of task pools to be created when using * a memory pool. */ #ifndef IOT_TASKPOOLS #define IOT_TASKPOOLS ( 4 ) #endif /** * @brief The maximum number of jobs to cache. */ #ifndef IOT_TASKPOOL_JOBS_RECYCLE_LIMIT #define IOT_TASKPOOL_JOBS_RECYCLE_LIMIT ( 8UL ) #endif /** * @brief The maximum timeout in milliseconds to wait for a job to be scheduled before waking up a worker thread. * A worker thread that wakes up as a result of a timeout may exit to allow the task pool to fold back to its * minimum number of threads. */ #ifndef IOT_TASKPOOL_JOB_WAIT_TIMEOUT_MS #define IOT_TASKPOOL_JOB_WAIT_TIMEOUT_MS ( 60 * 1000UL ) #endif #endif /* ifndef IOT_TASKPOOL_H_ */