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600 lines
28 KiB
C
600 lines
28 KiB
C
/*
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* FreeRTOS Kernel V10.2.1
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* Copyright (C) 2017 Amazon.com, Inc. or its affiliates. All Rights Reserved.
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy of
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* this software and associated documentation files (the "Software"), to deal in
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* the Software without restriction, including without limitation the rights to
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* use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
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* the Software, and to permit persons to whom the Software is furnished to do so,
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* subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in all
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* copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
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* FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
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* COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
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* IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
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* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
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*
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* http://www.FreeRTOS.org
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* http://aws.amazon.com/freertos
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*
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* 1 tab == 4 spaces!
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*/
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//_RB_ Add link to docs here.
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/* Kernel includes. */
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#include "FreeRTOS.h"
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#include "task.h"
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/* Standard includes. */
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#include <stdio.h>
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/* IoT SDK includes. */
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#include "iot_taskpool.h"
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/* The priority at which that tasks in the task pool (the worker tasks) get
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created. */
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#define tpTASK_POOL_WORKER_PRIORITY 1
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/* The number of jobs created in the example functions that create more than
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one job. */
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#define tpJOBS_TO_CREATE 5
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/*
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* Prototypes for the functions that demonstrate the task pool API.
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* See the implementation of the prvTaskPoolDemoTask() function within this file
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* for a description of the individual functions. A configASSERT() is hit if
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* any of the demos encounter any unexpected behaviour.
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*/
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static void prvExample_BasicSingleJob( void );
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static void prvExample_DeferredJobAndCancellingJobs( void );
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static void prvExample_BasicRecyclableJob( void );
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static void prvExample_ReuseRecyclableJobFromLowPriorityTask( void );
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static void prvExample_ReuseRecyclableJobFromHighPriorityTask( void );
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/*
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* Prototypes of the callback functions used in the examples. The callback
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* simply sends a signal (in the form of a direct task notification) to the
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* prvTaskPoolDemoTask() task to let the task know that the callback execute.
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* The handle of the prvTaskPoolDemoTask() task is not accessed directly, but
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* instead passed into the task pool job as the job's context.
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*/
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static void prvSimpleTaskNotifyCallback( IotTaskPool_t pTaskPool, IotTaskPoolJob_t pJob, void *pUserContext );
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/*
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* The task used to demonstrate the task pool API. This task just loops through
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* each demo in turn.
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*/
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static void prvTaskPoolDemoTask( void *pvParameters );
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/*-----------------------------------------------------------*/
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/* Parameters used to create the system task pool - see TBD for more information
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as the task pool used in this example is a slimmed down version of the full
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library - the slimmed down version being intended specifically for FreeRTOS
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kernel use cases. */
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static const IotTaskPoolInfo_t xTaskPoolParameters = {
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/* Minimum number of threads in a task pool.
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Note the slimmed down version of the task
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pool used by this library does not autoscale
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the number of tasks in the pool so in this
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case this sets the number of tasks in the
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pool. */
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2,
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/* Maximum number of threads in a task pool.
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Note the slimmed down version of the task
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pool used by this library does not autoscale
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the number of tasks in the pool so in this
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case this parameter is just ignored. */
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2,
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/* Stack size for every task pool thread - in
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bytes, hence multiplying by the number of bytes
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in a word as configMINIMAL_STACK_SIZE is
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specified in words. */
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configMINIMAL_STACK_SIZE * sizeof( portSTACK_TYPE ),
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/* Priority for every task pool thread. */
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tpTASK_POOL_WORKER_PRIORITY,
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};
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/*-----------------------------------------------------------*/
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void vStartSimpleTaskPoolDemo( void )
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{
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/* This example uses a single application task, which in turn is used to
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create and send jobs to task pool tasks. */
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xTaskCreate( prvTaskPoolDemoTask, /* Function that implements the task. */
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"PoolDemo", /* Text name for the task - only used for debugging. */
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configMINIMAL_STACK_SIZE, /* Size of stack (in words, not bytes) to allocate for the task. */
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NULL, /* Task parameter - not used in this case. */
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tskIDLE_PRIORITY, /* Task priority, must be between 0 and configMAX_PRIORITIES - 1. */
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NULL ); /* Used to pass out a handle to the created tsak - not used in this case. */
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}
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/*-----------------------------------------------------------*/
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static void prvTaskPoolDemoTask( void *pvParameters )
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{
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IotTaskPoolError_t xResult;
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uint32_t ulLoops = 0;
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/* Remove compiler warnings about unused parameters. */
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( void ) pvParameters;
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/* The task pool must be created before it can be used. The system task
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pool is the task pool managed by the task pool library itself - the storage
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used by the task pool is provided by the library. */
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xResult = IotTaskPool_CreateSystemTaskPool( &xTaskPoolParameters );
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configASSERT( xResult == IOT_TASKPOOL_SUCCESS );
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/* Attempting to create the task pool again should then appear to succeed
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(in case it is initialised by more than one library), but have no effect. */
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xResult = IotTaskPool_CreateSystemTaskPool( &xTaskPoolParameters );
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configASSERT( xResult == IOT_TASKPOOL_SUCCESS );
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for( ;; )
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{
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/* Demonstrate the most basic use case where a non persistent job is
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created and scheduled to run immediately. The task pool worker tasks
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(in which the job callback function executes) have a priority above the
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priority of this task so the job's callback executes as soon as it is
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scheduled. */
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prvExample_BasicSingleJob();
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/* Demonstrate a job being scheduled to run at some time in the
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future, and how a job scheduled to run in the future can be cancelled if
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it has not yet started executing. */
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prvExample_DeferredJobAndCancellingJobs();
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/* Demonstrate the most basic use of a recyclable job. This is similar
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to prvExample_BasicSingleJob() but using a recyclable job. Creating a
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recyclable job will re-use a previously created and now spare job from
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the task pool's job cache if one is available, or otherwise dynamically
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create a new job if a spare job is not available in the cache but space
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remains in the cache. */
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prvExample_BasicRecyclableJob();
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/* Demonstrate multiple recyclable jobs being created, used, and then
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re-used. In this the task pool worker tasks (in which the job callback
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functions execute) have a priority above the priority of this task so
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the job's callback functions execute as soon as they are scheduled. */
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prvExample_ReuseRecyclableJobFromLowPriorityTask();
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/* Again demonstrate multiple recyclable jobs being used, but this time
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the priority of the task pool worker tasks (in which the job callback
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functions execute) are lower than the priority of this task so the job's
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callback functions don't execute until this task enteres the blocked
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state. */
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prvExample_ReuseRecyclableJobFromHighPriorityTask();
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ulLoops++;
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if( ( ulLoops % 10UL ) == 0 )
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{
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printf( "prvTaskPoolDemoTask() performed %u iterations without hitting an assert.\r\n", ulLoops );
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fflush( stdout );
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}
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}
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}
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/*-----------------------------------------------------------*/
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static void prvSimpleTaskNotifyCallback( IotTaskPool_t pTaskPool, IotTaskPoolJob_t pJob, void *pUserContext )
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{
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/* The jobs context is the handle of the task to which a notification should
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be sent. */
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TaskHandle_t xTaskToNotify = ( TaskHandle_t ) pUserContext;
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/* Remove warnings about unused parameters. */
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( void ) pTaskPool;
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( void ) pJob;
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/* Notify the task that created this job. */
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xTaskNotifyGive( xTaskToNotify );
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}
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/*-----------------------------------------------------------*/
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static void prvExample_BasicSingleJob( void )
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{
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IotTaskPoolJobStorage_t xJobStorage;
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IotTaskPoolJob_t xJob;
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IotTaskPoolError_t xResult;
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uint32_t ulReturn;
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const uint32_t ulNoFlags = 0UL;
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const TickType_t xNoDelay = ( TickType_t ) 0;
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size_t xFreeHeapBeforeCreatingJob = xPortGetFreeHeapSize();
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IotTaskPoolJobStatus_t xJobStatus;
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/* Don't expect any notifications to be pending yet. */
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configASSERT( ulTaskNotifyTake( pdTRUE, 0 ) == 0 );
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/* Create and schedule a job using the handle of this task as the job's
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context and the function that sends a notification to the task handle as
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the jobs callback function. This is not a recyclable job so the storage
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required to hold information about the job is provided by this task - in
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this case the storage is on the stack of this task so no memory is allocated
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dynamically but the stack frame must remain in scope for the lifetime of
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the job. */
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xResult = IotTaskPool_CreateJob( prvSimpleTaskNotifyCallback, /* Callback function. */
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( void * ) xTaskGetCurrentTaskHandle(), /* Job context. */
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&xJobStorage,
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&xJob );
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configASSERT( xResult == IOT_TASKPOOL_SUCCESS );
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/* The job has been created but not scheduled so is now ready. */
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IotTaskPool_GetStatus( NULL, xJob, &xJobStatus );
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configASSERT( xJobStatus == IOT_TASKPOOL_STATUS_READY );
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/* This is not a persistent (recyclable) job and its storage is on the
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stack of this function, so the amount of heap space available should not
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have chanced since entering this function. */
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configASSERT( xFreeHeapBeforeCreatingJob == xPortGetFreeHeapSize() );
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/* In the full task pool implementation the first parameter is used to
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pass the handle of the task pool to schedule. The lean task pool
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implementation used in this demo only supports a single task pool, which
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is created internally within the library, so the first parameter is NULL. */
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xResult = IotTaskPool_Schedule( NULL, xJob, ulNoFlags );
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configASSERT( xResult == IOT_TASKPOOL_SUCCESS );
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/* Look for the notification coming from the job's callback function. The
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priority of the task pool worker task that executes the callback is higher
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than the priority of this task so a block time is not needed - the task pool
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worker task pre-empts this task and sends the notification (from the job's
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callback) as soon as the job is scheduled. */
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ulReturn = ulTaskNotifyTake( pdTRUE, xNoDelay );
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configASSERT( ulReturn );
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/* The job's callback has executed so the job has now completed. */
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IotTaskPool_GetStatus( NULL, xJob, &xJobStatus );
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configASSERT( xJobStatus == IOT_TASKPOOL_STATUS_COMPLETED );
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}
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/*-----------------------------------------------------------*/
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static void prvExample_DeferredJobAndCancellingJobs( void )
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{
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IotTaskPoolJobStorage_t xJobStorage;
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IotTaskPoolJob_t xJob;
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IotTaskPoolError_t xResult;
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uint32_t ulReturn;
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const uint32_t ulShortDelay_ms = 100UL;
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const TickType_t xNoDelay = ( TickType_t ) 0, xAllowableMargin = ( TickType_t ) 5; /* Large margin for Windows port, which is not real time. */
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TickType_t xTimeBefore, xElapsedTime, xShortDelay_ticks;
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size_t xFreeHeapBeforeCreatingJob = xPortGetFreeHeapSize();
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IotTaskPoolJobStatus_t xJobStatus;
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/* Don't expect any notifications to be pending yet. */
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configASSERT( ulTaskNotifyTake( pdTRUE, 0 ) == 0 );
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/* Create a job using the handle of this task as the job's context and the
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function that sends a notification to the task handle as the jobs callback
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function. The job is created using storage allocated on the stack of this
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function - so no memory is allocated. */
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xResult = IotTaskPool_CreateJob( prvSimpleTaskNotifyCallback, /* Callback function. */
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( void * ) xTaskGetCurrentTaskHandle(), /* Job context. */
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&xJobStorage,
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&xJob );
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configASSERT( xResult == IOT_TASKPOOL_SUCCESS );
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/* The job has been created but not scheduled so is now ready. */
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IotTaskPool_GetStatus( NULL, xJob, &xJobStatus );
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configASSERT( xJobStatus == IOT_TASKPOOL_STATUS_READY );
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/* This is not a persistent (recyclable) job and its storage is on the
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stack of this function, so the amount of heap space available should not
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have chanced since entering this function. */
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configASSERT( xFreeHeapBeforeCreatingJob == xPortGetFreeHeapSize() );
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/* Schedule the job to run its callback in xShortDelay_ms milliseconds time.
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In the full task pool implementation the first parameter is used to pass the
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handle of the task pool to schedule. The lean task pool implementation used
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in this demo only supports a single task pool, which is created internally
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within the library, so the first parameter is NULL. */
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xResult = IotTaskPool_ScheduleDeferred( NULL, xJob, ulShortDelay_ms );
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configASSERT( xResult == IOT_TASKPOOL_SUCCESS );
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/* The scheduled job should not have executed yet, so don't expect any
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notifications and expect the job's status to be 'deferred'. */
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ulReturn = ulTaskNotifyTake( pdTRUE, xNoDelay );
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configASSERT( ulReturn == 0 );
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IotTaskPool_GetStatus( NULL, xJob, &xJobStatus );
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configASSERT( xJobStatus == IOT_TASKPOOL_STATUS_DEFERRED );
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/* As the job has not yet been executed it can be stopped. */
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xResult = IotTaskPool_TryCancel( NULL, xJob, &xJobStatus );
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configASSERT( xResult == IOT_TASKPOOL_SUCCESS );
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IotTaskPool_GetStatus( NULL, xJob, &xJobStatus );
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configASSERT( xJobStatus == IOT_TASKPOOL_STATUS_CANCELED );
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/* Schedule the job again, and this time wait until its callback is
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executed (the callback function sends a notification to this task) to see
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that it executes at the right time. */
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xTimeBefore = xTaskGetTickCount();
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xResult = IotTaskPool_ScheduleDeferred( NULL, xJob, ulShortDelay_ms );
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configASSERT( xResult == IOT_TASKPOOL_SUCCESS );
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/* Wait twice the deferred execution time to ensure the callback is executed
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before the call below times out. */
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ulReturn = ulTaskNotifyTake( pdTRUE, pdMS_TO_TICKS( ulShortDelay_ms * 2UL ) );
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xElapsedTime = xTaskGetTickCount() - xTimeBefore;
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/* A single notification should not have been received... */
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configASSERT( ulReturn == 1 );
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/* ...and the time since scheduling the job should be greater than or
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equal to the deferred execution time - which is converted to ticks for
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comparison. */
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xShortDelay_ticks = pdMS_TO_TICKS( ulShortDelay_ms );
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configASSERT( ( xElapsedTime >= xShortDelay_ticks ) && ( xElapsedTime < ( xShortDelay_ticks + xAllowableMargin ) ) );
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}
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/*-----------------------------------------------------------*/
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static void prvExample_BasicRecyclableJob( void )
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{
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IotTaskPoolJob_t xJob;
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IotTaskPoolError_t xResult;
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uint32_t ulReturn;
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const uint32_t ulNoFlags = 0UL;
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const TickType_t xNoDelay = ( TickType_t ) 0;
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size_t xFreeHeapBeforeCreatingJob = xPortGetFreeHeapSize();
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/* Don't expect any notifications to be pending yet. */
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configASSERT( ulTaskNotifyTake( pdTRUE, 0 ) == 0 );
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/* Create and schedule a job using the handle of this task as the job's
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context and the function that sends a notification to the task handle as
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the jobs callback function. The job is created as a recyclable job and in
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this case the memory used to hold the job status is allocated inside the
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create function. As the job is persistent it can be used multiple times,
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as demonstrated in other examples within this demo. In the full task pool
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implementation the first parameter is used to pass the handle of the task
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pool this recyclable job is to be associated with. In the lean
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implementation of the task pool used by this demo there is only one task
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pool (the system task pool created within the task pool library) so the
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first parameter is NULL. */
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xResult = IotTaskPool_CreateRecyclableJob( NULL,
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prvSimpleTaskNotifyCallback,
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(void * ) xTaskGetCurrentTaskHandle(),
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&xJob );
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configASSERT( xResult == IOT_TASKPOOL_SUCCESS );
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/* This recyclable job is persistent, and in this case created dynamically,
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so expect there to be less heap space then when entering the function. */
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configASSERT( xPortGetFreeHeapSize() < xFreeHeapBeforeCreatingJob );
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/* In the full task pool implementation the first parameter is used to
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pass the handle of the task pool to schedule. The lean task pool
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implementation used in this demo only supports a single task pool, which
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is created internally within the library, so the first parameter is NULL. */
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xResult = IotTaskPool_Schedule( NULL, xJob, ulNoFlags );
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configASSERT( xResult == IOT_TASKPOOL_SUCCESS );
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/* Look for the notification coming from the job's callback function. The
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priority of the task pool worker task that executes the callback is higher
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than the priority of this task so a block time is not needed - the task pool
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worker task pre-empts this task and sends the notification (from the job's
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callback) as soon as the job is scheduled. */
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ulReturn = ulTaskNotifyTake( pdTRUE, xNoDelay );
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configASSERT( ulReturn );
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/* Clean up recyclable job. In the full implementation of the task pool
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the first parameter is used to pass a handle to the task pool the job is
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associated with. In the lean implementation of the task pool used by this
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demo there is only one task pool (the system task pool created in the
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task pool library itself) so the first parameter is NULL. */
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IotTaskPool_DestroyRecyclableJob( NULL, xJob );
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/* Once the job has been deleted the memory used to hold the job is
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returned, so the available heap should be exactly as when entering this
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function. */
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configASSERT( xPortGetFreeHeapSize() == xFreeHeapBeforeCreatingJob );
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}
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/*-----------------------------------------------------------*/
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static void prvExample_ReuseRecyclableJobFromLowPriorityTask( void )
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{
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IotTaskPoolError_t xResult;
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uint32_t x, xIndex, ulNotificationValue;
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const uint32_t ulNoFlags = 0UL;
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IotTaskPoolJob_t xJobs[ tpJOBS_TO_CREATE ];
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size_t xFreeHeapBeforeCreatingJob = xPortGetFreeHeapSize();
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IotTaskPoolJobStatus_t xJobStatus;
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/* Don't expect any notifications to be pending yet. */
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configASSERT( ulTaskNotifyTake( pdTRUE, 0 ) == 0 );
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/* Create tpJOBS_TO_CREATE jobs using the handle of this task as the job's
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context and the function that sends a notification to the task handle as
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the jobs callback function. The jobs are created as a recyclable job and
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in this case the memory to store the job information is allocated within
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the create function as at this time there are no recyclable jobs in the
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task pool jobs cache. As the jobs are persistent they can be used multiple
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times. In the full task pool implementation the first parameter is used to
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pass the handle of the task pool this recyclable job is to be associated
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with. In the lean implementation of the task pool used by this demo there
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is only one task pool (the system task pool created within the task pool
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library) so the first parameter is NULL. */
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for( x = 0; x < tpJOBS_TO_CREATE; x++ )
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{
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xResult = IotTaskPool_CreateRecyclableJob( NULL,
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prvSimpleTaskNotifyCallback,
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(void * ) xTaskGetCurrentTaskHandle(),
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&( xJobs[ x ] ) );
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configASSERT( xResult == IOT_TASKPOOL_SUCCESS );
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/* The job has been created but not scheduled so is now ready. */
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IotTaskPool_GetStatus( NULL, xJobs[ x ], &xJobStatus );
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configASSERT( xJobStatus == IOT_TASKPOOL_STATUS_READY );
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}
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/* Demonstrate that the jobs can be recycled by performing twice the number
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of iterations of scheduling jobs than there actually are created jobs. This
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works because the task pool task priorities are above the priority of this
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task, so the tasks that run the jobs pre-empt this task as soon as a job is
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ready. */
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for( x = 0; x < ( tpJOBS_TO_CREATE * 2UL ); x++ )
|
|
{
|
|
/* Make sure array index does not go out of bounds. */
|
|
xIndex = x % tpJOBS_TO_CREATE;
|
|
|
|
xResult = IotTaskPool_Schedule( NULL, xJobs[ xIndex ], ulNoFlags );
|
|
configASSERT( xResult == IOT_TASKPOOL_SUCCESS );
|
|
|
|
/* The priority of the task pool task(s) is higher than the priority
|
|
of this task, so the job's callback function should have already
|
|
executed, sending a notification to this task, and incrementing this
|
|
task's notification value. */
|
|
xTaskNotifyWait( 0UL, /* Don't clear any bits on entry. */
|
|
0UL, /* Don't clear any bits on exit. */
|
|
&ulNotificationValue, /* Obtain the notification value. */
|
|
0UL ); /* No block time, return immediately. */
|
|
configASSERT( ulNotificationValue == ( x + 1 ) );
|
|
|
|
/* The job's callback has executed so the job is now completed. */
|
|
IotTaskPool_GetStatus( NULL, xJobs[ xIndex ], &xJobStatus );
|
|
configASSERT( xJobStatus == IOT_TASKPOOL_STATUS_COMPLETED );
|
|
|
|
/* To leave the list of jobs empty we can stop re-creating jobs half
|
|
way through iterations of this loop. */
|
|
if( x < tpJOBS_TO_CREATE )
|
|
{
|
|
/* Recycle the job so it can be used again. In the full task pool
|
|
implementation the first parameter is used to pass the handle of the
|
|
task pool this job will be associated with. In this lean task pool
|
|
implementation only the system task pool exists (the task pool created
|
|
internally to the task pool library) so the first parameter is just
|
|
passed as NULL. *//*_RB_ Why not recycle it automatically? */
|
|
IotTaskPool_RecycleJob( NULL, xJobs[ xIndex ] );
|
|
xResult = IotTaskPool_CreateRecyclableJob( NULL,
|
|
prvSimpleTaskNotifyCallback,
|
|
(void * ) xTaskGetCurrentTaskHandle(),
|
|
&( xJobs[ xIndex ] ) );
|
|
configASSERT( xResult == IOT_TASKPOOL_SUCCESS );
|
|
}
|
|
}
|
|
|
|
/* Clear all the notification value bits again. */
|
|
xTaskNotifyWait( portMAX_DELAY, /* Clear all bits on entry - portMAX_DELAY is used as it is a portable way of having all bits set. */
|
|
0UL, /* Don't clear any bits on exit. */
|
|
NULL, /* Don't need the notification value this time. */
|
|
0UL ); /* No block time, return immediately. */
|
|
configASSERT( ulTaskNotifyTake( pdTRUE, 0 ) == 0 );
|
|
|
|
/* Clean up all the recyclable job. In the full implementation of the task
|
|
pool the first parameter is used to pass a handle to the task pool the job
|
|
is associated with. In the lean implementation of the task pool used by
|
|
this demo there is only one task pool (the system task pool created in the
|
|
task pool library itself) so the first parameter is NULL. */
|
|
for( x = 0; x < tpJOBS_TO_CREATE; x++ )
|
|
{
|
|
xResult = IotTaskPool_DestroyRecyclableJob( NULL, xJobs[ x ] );
|
|
configASSERT( xResult == IOT_TASKPOOL_SUCCESS );
|
|
}
|
|
|
|
/* Once the job has been deleted the memory used to hold the job is
|
|
returned, so the available heap should be exactly as when entering this
|
|
function. */
|
|
configASSERT( xPortGetFreeHeapSize() == xFreeHeapBeforeCreatingJob );
|
|
}
|
|
/*-----------------------------------------------------------*/
|
|
|
|
static void prvExample_ReuseRecyclableJobFromHighPriorityTask( void )
|
|
{
|
|
IotTaskPoolError_t xResult;
|
|
uint32_t x, ulNotificationValue;
|
|
const uint32_t ulNoFlags = 0UL;
|
|
IotTaskPoolJob_t xJobs[ tpJOBS_TO_CREATE ];
|
|
IotTaskPoolJobStorage_t xJobStorage[ tpJOBS_TO_CREATE ];
|
|
size_t xFreeHeapBeforeCreatingJob = xPortGetFreeHeapSize();
|
|
TickType_t xShortDelay = pdMS_TO_TICKS( 150 );
|
|
IotTaskPoolJobStatus_t xJobStatus;
|
|
|
|
/* Don't expect any notifications to be pending yet. */
|
|
configASSERT( ulTaskNotifyTake( pdTRUE, 0 ) == 0 );
|
|
|
|
/* prvExample_ReuseRecyclableJobFromLowPriorityTask() executes in a task
|
|
that has a lower [task] priority than the task pool's worker tasks.
|
|
Therefore a talk pool worker preempts the task that calls
|
|
prvExample_ReuseRecyclableJobFromHighPriorityTask() as soon as the job is
|
|
scheduled. prvExample_ReuseRecyclableJobFromHighPriorityTask() reverses the
|
|
priorities - prvExample_ReuseRecyclableJobFromHighPriorityTask() raises its
|
|
priority to above the task pool's worker tasks, so the worker tasks do not
|
|
execute until the calling task enters the blocked state. First raise the
|
|
priority - passing NULL means raise the priority of the calling task. */
|
|
vTaskPrioritySet( NULL, tpTASK_POOL_WORKER_PRIORITY + 1 );
|
|
|
|
/* Create tpJOBS_TO_CREATE jobs using the handle of this task as the job's
|
|
context and the function that sends a notification to the task handle as
|
|
the jobs callback function. */
|
|
for( x = 0; x < tpJOBS_TO_CREATE; x++ )
|
|
{
|
|
xResult = IotTaskPool_CreateJob( prvSimpleTaskNotifyCallback, /* Callback function. */
|
|
( void * ) xTaskGetCurrentTaskHandle(), /* Job context. */
|
|
&( xJobStorage[ x ] ),
|
|
&( xJobs[ x ] ) );
|
|
configASSERT( xResult == IOT_TASKPOOL_SUCCESS );
|
|
|
|
/* This is not a persistent (recyclable) job and its storage is on the
|
|
stack of this function, so the amount of heap space available should not
|
|
have chanced since entering this function. */
|
|
configASSERT( xFreeHeapBeforeCreatingJob == xPortGetFreeHeapSize() );
|
|
}
|
|
|
|
for( x = 0; x < tpJOBS_TO_CREATE; x++ )
|
|
{
|
|
/* Schedule the next job. */
|
|
xResult = IotTaskPool_Schedule( NULL, xJobs[ x ], ulNoFlags );
|
|
configASSERT( xResult == IOT_TASKPOOL_SUCCESS );
|
|
|
|
/* Although scheduled, the job's callback has not executed, so the job
|
|
reports itself as scheduled. */
|
|
IotTaskPool_GetStatus( NULL, xJobs[ x ], &xJobStatus );
|
|
configASSERT( xJobStatus == IOT_TASKPOOL_STATUS_SCHEDULED );
|
|
|
|
/* The priority of the task pool task(s) is lower than the priority
|
|
of this task, so the job's callback function should not have executed
|
|
yes, so don't expect the notification value for this task to have
|
|
changed. */
|
|
xTaskNotifyWait( 0UL, /* Don't clear any bits on entry. */
|
|
0UL, /* Don't clear any bits on exit. */
|
|
&ulNotificationValue, /* Obtain the notification value. */
|
|
0UL ); /* No block time, return immediately. */
|
|
configASSERT( ulNotificationValue == 0 );
|
|
}
|
|
|
|
/* At this point there are tpJOBS_TO_CREATE scheduled, but none have executed
|
|
their callbacks because the priority of this task is higher than the
|
|
priority of the task pool worker threads. When this task blocks to wait for
|
|
a notification a worker thread will be able to executes - but as soon as its
|
|
callback function sends a notification to this task this task will
|
|
preempt it (because it has a higher priority) so this task only expects to
|
|
receive one notification at a time. */
|
|
for( x = 0; x < tpJOBS_TO_CREATE; x++ )
|
|
{
|
|
xTaskNotifyWait( 0UL, /* Don't clear any bits on entry. */
|
|
0UL, /* Don't clear any bits on exit. */
|
|
&ulNotificationValue, /* Obtain the notification value. */
|
|
xShortDelay ); /* Short delay to allow a task pool worker to execute. */
|
|
configASSERT( ulNotificationValue == ( x + 1 ) );
|
|
}
|
|
|
|
/* All the scheduled jobs have now executed, so waiting for another
|
|
notification should timeout without the notification value changing. */
|
|
xTaskNotifyWait( 0UL, /* Don't clear any bits on entry. */
|
|
0UL, /* Don't clear any bits on exit. */
|
|
&ulNotificationValue, /* Obtain the notification value. */
|
|
xShortDelay ); /* Short delay to allow a task pool worker to execute. */
|
|
configASSERT( ulNotificationValue == x );
|
|
|
|
/* Reset the priority of this task and clear the notifications ready for the
|
|
next example. */
|
|
vTaskPrioritySet( NULL, tskIDLE_PRIORITY );
|
|
xTaskNotifyWait( portMAX_DELAY, /* Clear all bits on entry - portMAX_DELAY is used as it is a portable way of having all bits set. */
|
|
0UL, /* Don't clear any bits on exit. */
|
|
NULL, /* Don't need the notification value this time. */
|
|
0UL ); /* No block time, return immediately. */
|
|
}
|
|
/*-----------------------------------------------------------*/
|
|
|