EBIKE-FreeRTOS/Common/Full/dynamic.c
2024-04-14 18:38:39 +08:00

575 lines
21 KiB
C

/*
* FreeRTOS V202212.00
* Copyright (C) 2020 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.
*
* https://www.FreeRTOS.org
* https://github.com/FreeRTOS
*
*/
/**
* The first test creates three tasks - two counter tasks (one continuous count
* and one limited count) and one controller. A "count" variable is shared
* between all three tasks. The two counter tasks should never be in a "ready"
* state at the same time. The controller task runs at the same priority as
* the continuous count task, and at a lower priority than the limited count
* task.
*
* One counter task loops indefinitely, incrementing the shared count variable
* on each iteration. To ensure it has exclusive access to the variable it
* raises it's priority above that of the controller task before each
* increment, lowering it again to it's original priority before starting the
* next iteration.
*
* The other counter task increments the shared count variable on each
* iteration of it's loop until the count has reached a limit of 0xff - at
* which point it suspends itself. It will not start a new loop until the
* controller task has made it "ready" again by calling vTaskResume ().
* This second counter task operates at a higher priority than controller
* task so does not need to worry about mutual exclusion of the counter
* variable.
*
* The controller task is in two sections. The first section controls and
* monitors the continuous count task. When this section is operational the
* limited count task is suspended. Likewise, the second section controls
* and monitors the limited count task. When this section is operational the
* continuous count task is suspended.
*
* In the first section the controller task first takes a copy of the shared
* count variable. To ensure mutual exclusion on the count variable it
* suspends the continuous count task, resuming it again when the copy has been
* taken. The controller task then sleeps for a fixed period - during which
* the continuous count task will execute and increment the shared variable.
* When the controller task wakes it checks that the continuous count task
* has executed by comparing the copy of the shared variable with its current
* value. This time, to ensure mutual exclusion, the scheduler itself is
* suspended with a call to vTaskSuspendAll (). This is for demonstration
* purposes only and is not a recommended technique due to its inefficiency.
*
* After a fixed number of iterations the controller task suspends the
* continuous count task, and moves on to its second section.
*
* At the start of the second section the shared variable is cleared to zero.
* The limited count task is then woken from it's suspension by a call to
* vTaskResume (). As this counter task operates at a higher priority than
* the controller task the controller task should not run again until the
* shared variable has been counted up to the limited value causing the counter
* task to suspend itself. The next line after vTaskResume () is therefore
* a check on the shared variable to ensure everything is as expected.
*
*
* The second test consists of a couple of very simple tasks that post onto a
* queue while the scheduler is suspended. This test was added to test parts
* of the scheduler not exercised by the first test.
*
*
* The final set of two tasks implements a third test. This simply raises the
* priority of a task while the scheduler is suspended. Again this test was
* added to exercise parts of the code not covered by the first test.
*
* \page Priorities dynamic.c
* \ingroup DemoFiles
* <HR>
*/
/*
* Changes from V2.0.0
*
+ Delay periods are now specified using variables and constants of
+ TickType_t rather than unsigned long.
+ Added a second, simple test that uses the functions
+ vQueueReceiveWhenSuspendedTask() and vQueueSendWhenSuspendedTask().
+
+ Changes from V3.1.1
+
+ Added a third simple test that uses the vTaskPrioritySet() function
+ while the scheduler is suspended.
+ Modified the controller task slightly to test the calling of
+ vTaskResumeAll() while the scheduler is suspended.
*/
#include <stdlib.h>
/* Scheduler include files. */
#include "FreeRTOS.h"
#include "task.h"
#include "semphr.h"
/* Demo app include files. */
#include "dynamic.h"
#include "print.h"
/* Function that implements the "limited count" task as described above. */
static void vLimitedIncrementTask( void * pvParameters );
/* Function that implements the "continuous count" task as described above. */
static void vContinuousIncrementTask( void * pvParameters );
/* Function that implements the controller task as described above. */
static void vCounterControlTask( void * pvParameters );
/* The simple test functions that check sending and receiving while the
* scheduler is suspended. */
static void vQueueReceiveWhenSuspendedTask( void * pvParameters );
static void vQueueSendWhenSuspendedTask( void * pvParameters );
/* The simple test functions that check raising and lowering of task priorities
* while the scheduler is suspended. */
static void prvChangePriorityWhenSuspendedTask( void * pvParameters );
static void prvChangePriorityHelperTask( void * pvParameters );
/* Demo task specific constants. */
#define priSTACK_SIZE ( ( unsigned short ) configMINIMAL_STACK_SIZE )
#define priSLEEP_TIME ( ( TickType_t ) 50 )
#define priLOOPS ( 5 )
#define priMAX_COUNT ( ( unsigned long ) 0xff )
#define priNO_BLOCK ( ( TickType_t ) 0 )
#define priSUSPENDED_QUEUE_LENGTH ( 1 )
/*-----------------------------------------------------------*/
/* Handles to the two counter tasks. These could be passed in as parameters
* to the controller task to prevent them having to be file scope. */
static TaskHandle_t xContinuousIncrementHandle, xLimitedIncrementHandle, xChangePriorityWhenSuspendedHandle;
/* The shared counter variable. This is passed in as a parameter to the two
* counter variables for demonstration purposes. */
static unsigned long ulCounter;
/* Variable used in a similar way by the test that checks the raising and
* lowering of task priorities while the scheduler is suspended. */
static unsigned long ulPrioritySetCounter;
/* Variables used to check that the tasks are still operating without error.
* Each complete iteration of the controller task increments this variable
* provided no errors have been found. The variable maintaining the same value
* is therefore indication of an error. */
static unsigned short usCheckVariable = ( unsigned short ) 0;
static portBASE_TYPE xSuspendedQueueSendError = pdFALSE;
static portBASE_TYPE xSuspendedQueueReceiveError = pdFALSE;
static portBASE_TYPE xPriorityRaiseWhenSuspendedError = pdFALSE;
/* Queue used by the second test. */
QueueHandle_t xSuspendedTestQueue;
/*-----------------------------------------------------------*/
/*
* Start the seven tasks as described at the top of the file.
* Note that the limited count task is given a higher priority.
*/
void vStartDynamicPriorityTasks( void )
{
xSuspendedTestQueue = xQueueCreate( priSUSPENDED_QUEUE_LENGTH, sizeof( unsigned long ) );
xTaskCreate( vContinuousIncrementTask, "CONT_INC", priSTACK_SIZE, ( void * ) &ulCounter, tskIDLE_PRIORITY, &xContinuousIncrementHandle );
xTaskCreate( vLimitedIncrementTask, "LIM_INC", priSTACK_SIZE, ( void * ) &ulCounter, tskIDLE_PRIORITY + 1, &xLimitedIncrementHandle );
xTaskCreate( vCounterControlTask, "C_CTRL", priSTACK_SIZE, NULL, tskIDLE_PRIORITY, NULL );
xTaskCreate( vQueueSendWhenSuspendedTask, "SUSP_SEND", priSTACK_SIZE, NULL, tskIDLE_PRIORITY, NULL );
xTaskCreate( vQueueReceiveWhenSuspendedTask, "SUSP_RECV", priSTACK_SIZE, NULL, tskIDLE_PRIORITY, NULL );
xTaskCreate( prvChangePriorityWhenSuspendedTask, "1st_P_CHANGE", priSTACK_SIZE, NULL, tskIDLE_PRIORITY + 1, NULL );
xTaskCreate( prvChangePriorityHelperTask, "2nd_P_CHANGE", priSTACK_SIZE, NULL, tskIDLE_PRIORITY, &xChangePriorityWhenSuspendedHandle );
}
/*-----------------------------------------------------------*/
/*
* Just loops around incrementing the shared variable until the limit has been
* reached. Once the limit has been reached it suspends itself.
*/
static void vLimitedIncrementTask( void * pvParameters )
{
unsigned long * pulCounter;
/* Take a pointer to the shared variable from the parameters passed into
* the task. */
pulCounter = ( unsigned long * ) pvParameters;
/* This will run before the control task, so the first thing it does is
* suspend - the control task will resume it when ready. */
vTaskSuspend( NULL );
for( ; ; )
{
/* Just count up to a value then suspend. */
( *pulCounter )++;
if( *pulCounter >= priMAX_COUNT )
{
vTaskSuspend( NULL );
}
}
}
/*-----------------------------------------------------------*/
/*
* Just keep counting the shared variable up. The control task will suspend
* this task when it wants.
*/
static void vContinuousIncrementTask( void * pvParameters )
{
unsigned long * pulCounter;
unsigned portBASE_TYPE uxOurPriority;
/* Take a pointer to the shared variable from the parameters passed into
* the task. */
pulCounter = ( unsigned long * ) pvParameters;
/* Query our priority so we can raise it when exclusive access to the
* shared variable is required. */
uxOurPriority = uxTaskPriorityGet( NULL );
for( ; ; )
{
/* Raise our priority above the controller task to ensure a context
* switch does not occur while we are accessing this variable. */
vTaskPrioritySet( NULL, uxOurPriority + 1 );
( *pulCounter )++;
vTaskPrioritySet( NULL, uxOurPriority );
#if configUSE_PREEMPTION == 0
taskYIELD();
#endif
}
}
/*-----------------------------------------------------------*/
/*
* Controller task as described above.
*/
static void vCounterControlTask( void * pvParameters )
{
unsigned long ulLastCounter;
short sLoops;
short sError = pdFALSE;
const char * const pcTaskStartMsg = "Priority manipulation tasks started.\r\n";
const char * const pcTaskFailMsg = "Priority manipulation Task Failed\r\n";
/* Just to stop warning messages. */
( void ) pvParameters;
/* Queue a message for printing to say the task has started. */
vPrintDisplayMessage( &pcTaskStartMsg );
for( ; ; )
{
/* Start with the counter at zero. */
ulCounter = ( unsigned long ) 0;
/* First section : */
/* Check the continuous count task is running. */
for( sLoops = 0; sLoops < priLOOPS; sLoops++ )
{
/* Suspend the continuous count task so we can take a mirror of the
* shared variable without risk of corruption. */
vTaskSuspend( xContinuousIncrementHandle );
ulLastCounter = ulCounter;
vTaskResume( xContinuousIncrementHandle );
/* Now delay to ensure the other task has processor time. */
vTaskDelay( priSLEEP_TIME );
/* Check the shared variable again. This time to ensure mutual
* exclusion the whole scheduler will be locked. This is just for
* demo purposes! */
vTaskSuspendAll();
{
if( ulLastCounter == ulCounter )
{
/* The shared variable has not changed. There is a problem
* with the continuous count task so flag an error. */
sError = pdTRUE;
xTaskResumeAll();
vPrintDisplayMessage( &pcTaskFailMsg );
vTaskSuspendAll();
}
}
xTaskResumeAll();
}
/* Second section: */
/* Suspend the continuous counter task so it stops accessing the shared variable. */
vTaskSuspend( xContinuousIncrementHandle );
/* Reset the variable. */
ulCounter = ( unsigned long ) 0;
/* Resume the limited count task which has a higher priority than us.
* We should therefore not return from this call until the limited count
* task has suspended itself with a known value in the counter variable.
* The scheduler suspension is not necessary but is included for test
* purposes. */
vTaskSuspendAll();
vTaskResume( xLimitedIncrementHandle );
xTaskResumeAll();
/* Does the counter variable have the expected value? */
if( ulCounter != priMAX_COUNT )
{
sError = pdTRUE;
vPrintDisplayMessage( &pcTaskFailMsg );
}
if( sError == pdFALSE )
{
/* If no errors have occurred then increment the check variable. */
portENTER_CRITICAL();
usCheckVariable++;
portEXIT_CRITICAL();
}
#if configUSE_PREEMPTION == 0
taskYIELD();
#endif
/* Resume the continuous count task and do it all again. */
vTaskResume( xContinuousIncrementHandle );
}
}
/*-----------------------------------------------------------*/
static void vQueueSendWhenSuspendedTask( void * pvParameters )
{
static unsigned long ulValueToSend = ( unsigned long ) 0;
const char * const pcTaskStartMsg = "Queue send while suspended task started.\r\n";
const char * const pcTaskFailMsg = "Queue send while suspended failed.\r\n";
/* Just to stop warning messages. */
( void ) pvParameters;
/* Queue a message for printing to say the task has started. */
vPrintDisplayMessage( &pcTaskStartMsg );
for( ; ; )
{
vTaskSuspendAll();
{
/* We must not block while the scheduler is suspended! */
if( xQueueSend( xSuspendedTestQueue, ( void * ) &ulValueToSend, priNO_BLOCK ) != pdTRUE )
{
if( xSuspendedQueueSendError == pdFALSE )
{
xTaskResumeAll();
vPrintDisplayMessage( &pcTaskFailMsg );
vTaskSuspendAll();
}
xSuspendedQueueSendError = pdTRUE;
}
}
xTaskResumeAll();
vTaskDelay( priSLEEP_TIME );
++ulValueToSend;
}
}
/*-----------------------------------------------------------*/
static void vQueueReceiveWhenSuspendedTask( void * pvParameters )
{
static unsigned long ulExpectedValue = ( unsigned long ) 0, ulReceivedValue;
const char * const pcTaskStartMsg = "Queue receive while suspended task started.\r\n";
const char * const pcTaskFailMsg = "Queue receive while suspended failed.\r\n";
portBASE_TYPE xGotValue;
/* Just to stop warning messages. */
( void ) pvParameters;
/* Queue a message for printing to say the task has started. */
vPrintDisplayMessage( &pcTaskStartMsg );
for( ; ; )
{
do
{
/* Suspending the scheduler here is fairly pointless and
* undesirable for a normal application. It is done here purely
* to test the scheduler. The inner xTaskResumeAll() should
* never return pdTRUE as the scheduler is still locked by the
* outer call. */
vTaskSuspendAll();
{
vTaskSuspendAll();
{
xGotValue = xQueueReceive( xSuspendedTestQueue, ( void * ) &ulReceivedValue, priNO_BLOCK );
}
if( xTaskResumeAll() )
{
xSuspendedQueueReceiveError = pdTRUE;
}
}
xTaskResumeAll();
#if configUSE_PREEMPTION == 0
taskYIELD();
#endif
} while( xGotValue == pdFALSE );
if( ulReceivedValue != ulExpectedValue )
{
if( xSuspendedQueueReceiveError == pdFALSE )
{
vPrintDisplayMessage( &pcTaskFailMsg );
}
xSuspendedQueueReceiveError = pdTRUE;
}
++ulExpectedValue;
}
}
/*-----------------------------------------------------------*/
static void prvChangePriorityWhenSuspendedTask( void * pvParameters )
{
const char * const pcTaskStartMsg = "Priority change when suspended task started.\r\n";
const char * const pcTaskFailMsg = "Priority change when suspended task failed.\r\n";
/* Just to stop warning messages. */
( void ) pvParameters;
/* Queue a message for printing to say the task has started. */
vPrintDisplayMessage( &pcTaskStartMsg );
for( ; ; )
{
/* Start with the counter at 0 so we know what the counter should be
* when we check it next. */
ulPrioritySetCounter = ( unsigned long ) 0;
/* Resume the helper task. At this time it has a priority lower than
* ours so no context switch should occur. */
vTaskResume( xChangePriorityWhenSuspendedHandle );
/* Check to ensure the task just resumed has not executed. */
portENTER_CRITICAL();
{
if( ulPrioritySetCounter != ( unsigned long ) 0 )
{
xPriorityRaiseWhenSuspendedError = pdTRUE;
vPrintDisplayMessage( &pcTaskFailMsg );
}
}
portEXIT_CRITICAL();
/* Now try raising the priority while the scheduler is suspended. */
vTaskSuspendAll();
{
vTaskPrioritySet( xChangePriorityWhenSuspendedHandle, ( configMAX_PRIORITIES - 1 ) );
/* Again, even though the helper task has a priority greater than
* ours, it should not have executed yet because the scheduler is
* suspended. */
portENTER_CRITICAL();
{
if( ulPrioritySetCounter != ( unsigned long ) 0 )
{
xPriorityRaiseWhenSuspendedError = pdTRUE;
vPrintDisplayMessage( &pcTaskFailMsg );
}
}
portEXIT_CRITICAL();
}
xTaskResumeAll();
/* Now the scheduler has been resumed the helper task should
* immediately preempt us and execute. When it executes it will increment
* the ulPrioritySetCounter exactly once before suspending itself.
*
* We should now always find the counter set to 1. */
portENTER_CRITICAL();
{
if( ulPrioritySetCounter != ( unsigned long ) 1 )
{
xPriorityRaiseWhenSuspendedError = pdTRUE;
vPrintDisplayMessage( &pcTaskFailMsg );
}
}
portEXIT_CRITICAL();
/* Delay until we try this again. */
vTaskDelay( priSLEEP_TIME * 2 );
/* Set the priority of the helper task back ready for the next
* execution of this task. */
vTaskSuspendAll();
vTaskPrioritySet( xChangePriorityWhenSuspendedHandle, tskIDLE_PRIORITY );
xTaskResumeAll();
}
}
/*-----------------------------------------------------------*/
static void prvChangePriorityHelperTask( void * pvParameters )
{
/* Just to stop warning messages. */
( void ) pvParameters;
for( ; ; )
{
/* This is the helper task for prvChangePriorityWhenSuspendedTask().
* It has it's priority raised and lowered. When it runs it simply
* increments the counter then suspends itself again. This allows
* prvChangePriorityWhenSuspendedTask() to know how many times it has
* executed. */
ulPrioritySetCounter++;
vTaskSuspend( NULL );
}
}
/*-----------------------------------------------------------*/
/* Called to check that all the created tasks are still running without error. */
portBASE_TYPE xAreDynamicPriorityTasksStillRunning( void )
{
/* Keep a history of the check variables so we know if it has been incremented
* since the last call. */
static unsigned short usLastTaskCheck = ( unsigned short ) 0;
portBASE_TYPE xReturn = pdTRUE;
/* Check the tasks are still running by ensuring the check variable
* is still incrementing. */
if( usCheckVariable == usLastTaskCheck )
{
/* The check has not incremented so an error exists. */
xReturn = pdFALSE;
}
if( xSuspendedQueueSendError == pdTRUE )
{
xReturn = pdFALSE;
}
if( xSuspendedQueueReceiveError == pdTRUE )
{
xReturn = pdFALSE;
}
if( xPriorityRaiseWhenSuspendedError == pdTRUE )
{
xReturn = pdFALSE;
}
usLastTaskCheck = usCheckVariable;
return xReturn;
}