191 lines
6.4 KiB
C
191 lines
6.4 KiB
C
/*
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* FreeRTOS Kernel V10.3.0
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* Copyright (C) 2020 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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/**
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* Create a single persistent task which periodically dynamically creates another
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* two tasks. The original task is called the creator task, the two tasks it
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* creates are called suicidal tasks.
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*
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* One of the created suicidal tasks kill one other suicidal task before killing
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* itself - leaving just the original task remaining.
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*
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* The creator task must be spawned after all of the other demo application tasks
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* as it keeps a check on the number of tasks under the scheduler control. The
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* number of tasks it expects to see running should never be greater than the
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* number of tasks that were in existence when the creator task was spawned, plus
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* one set of four suicidal tasks. If this number is exceeded an error is flagged.
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*
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* \page DeathC death.c
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* \ingroup DemoFiles
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* <HR>
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*/
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#include <stdlib.h>
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/* Scheduler include files. */
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#include "FreeRTOS.h"
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#include "task.h"
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/* Demo program include files. */
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#include "death.h"
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#define deathSTACK_SIZE (configMINIMAL_STACK_SIZE + 60)
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/* The task originally created which is responsible for periodically dynamically
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creating another four tasks. */
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static portTASK_FUNCTION_PROTO(vCreateTasks, pvParameters);
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/* The task function of the dynamically created tasks. */
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static portTASK_FUNCTION_PROTO(vSuicidalTask, pvParameters);
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/* A variable which is incremented every time the dynamic tasks are created. This
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is used to check that the task is still running. */
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static volatile uint16_t usCreationCount = 0;
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/* Used to store the number of tasks that were originally running so the creator
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task can tell if any of the suicidal tasks have failed to die.
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*/
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static volatile UBaseType_t uxTasksRunningAtStart = 0;
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/* When a task deletes itself, it stack and TCB are cleaned up by the Idle task.
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Under heavy load the idle task might not get much processing time, so it would
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be legitimate for several tasks to remain undeleted for a short period. There
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may also be a few other unexpected tasks if, for example, the tasks that test
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static allocation are also being used. */
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static const UBaseType_t uxMaxNumberOfExtraTasksRunning = 3;
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/* Used to store a handle to the task that should be killed by a suicidal task,
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before it kills itself. */
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TaskHandle_t xCreatedTask;
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/*-----------------------------------------------------------*/
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void vCreateSuicidalTasks(UBaseType_t uxPriority)
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{
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xTaskCreate(vCreateTasks, "CREATOR", deathSTACK_SIZE, (void *)NULL,
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uxPriority, NULL);
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}
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/*-----------------------------------------------------------*/
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static portTASK_FUNCTION(vSuicidalTask, pvParameters)
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{
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volatile long l1, l2;
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TaskHandle_t xTaskToKill;
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const TickType_t xDelay = pdMS_TO_TICKS((TickType_t)200);
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/* Test deletion of a task's secure context, if any. */
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portALLOCATE_SECURE_CONTEXT(configMINIMAL_SECURE_STACK_SIZE);
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if (pvParameters != NULL) {
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/* This task is periodically created four times. Two created tasks are
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passed a handle to the other task so it can kill it before killing itself.
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The other task is passed in null. */
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xTaskToKill = *(TaskHandle_t *)pvParameters;
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} else {
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xTaskToKill = NULL;
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}
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for (;;) {
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/* Do something random just to use some stack and registers. */
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l1 = 2;
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l2 = 89;
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l2 *= l1;
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vTaskDelay(xDelay);
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if (xTaskToKill != NULL) {
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/* Make sure the other task has a go before we delete it. */
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vTaskDelay((TickType_t)0);
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/* Kill the other task that was created by vCreateTasks(). */
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vTaskDelete(xTaskToKill);
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/* Kill ourselves. */
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vTaskDelete(NULL);
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}
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}
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} /*lint !e818 !e550 Function prototype must be as per standard for task functions. */
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/*-----------------------------------------------------------*/
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static portTASK_FUNCTION(vCreateTasks, pvParameters)
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{
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const TickType_t xDelay = pdMS_TO_TICKS((TickType_t)1000);
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UBaseType_t uxPriority;
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/* Remove compiler warning about unused parameter. */
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(void)pvParameters;
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/* Delay at the start to ensure tasks created by other demos have been
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created before storing the current number of tasks. */
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vTaskDelay(xDelay);
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uxTasksRunningAtStart = (UBaseType_t)uxTaskGetNumberOfTasks();
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uxPriority = uxTaskPriorityGet(NULL);
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for (;;) {
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/* Just loop round, delaying then creating the four suicidal tasks. */
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vTaskDelay(xDelay);
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xCreatedTask = NULL;
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xTaskCreate(vSuicidalTask, "SUICID1", configMINIMAL_STACK_SIZE,
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NULL, uxPriority, &xCreatedTask);
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xTaskCreate(vSuicidalTask, "SUICID2", configMINIMAL_STACK_SIZE,
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&xCreatedTask, uxPriority, NULL);
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++usCreationCount;
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}
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}
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/*-----------------------------------------------------------*/
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/* This is called to check that the creator task is still running and that there
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are not any more than four extra tasks. */
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BaseType_t xIsCreateTaskStillRunning(void)
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{
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static uint16_t usLastCreationCount = 0xfff;
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BaseType_t xReturn = pdTRUE;
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static UBaseType_t uxTasksRunningNow;
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if (usLastCreationCount == usCreationCount) {
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xReturn = pdFALSE;
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} else {
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usLastCreationCount = usCreationCount;
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}
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uxTasksRunningNow = (UBaseType_t)uxTaskGetNumberOfTasks();
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if (uxTasksRunningNow < uxTasksRunningAtStart) {
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xReturn = pdFALSE;
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} else if ((uxTasksRunningNow - uxTasksRunningAtStart) >
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uxMaxNumberOfExtraTasksRunning) {
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xReturn = pdFALSE;
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} else {
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/* Everything is okay. */
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}
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return xReturn;
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}
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