34. 启动任务调度器
1. 开启任务调度器
vTaskStartScheduler()
void vTaskStartScheduler( void )
if ( configSUPPORT_STATIC_ALLOCATION == 1 )
{
/* The Idle task is being created using dynamically allocated RAM. */
//创建空闲任务
xReturn = xTaskCreate( prvIdleTask,
configIDLE_TASK_NAME, //"IDLE"
configMINIMAL_STACK_SIZE, //128 word
( void * ) NULL,
/* In effect ( tskIDLE_PRIORITY | portPRIVILEGE_BIT ), but tskIDLE_PRIORITY is zero. */
portPRIVILEGE_BIT, //#define portPRIVILEGE_BIT ( ( UBaseType_t ) 0x00 )
&xIdleTaskHandle ); // static TaskHandle_t xIdleTaskHandle = NULL;
#if ( configUSE_TIMERS == 1 )
{
if( xReturn == pdPASS )
{
//创建软件定时器任务
xReturn = xTimerCreateTimerTask();
}
}
#endif /* configUSE_TIMERS */
if( xReturn == pdPASS )
{
/* Interrupts are turned off here, to ensure a tick does not occur
* before or during the call to xPortStartScheduler(). The stacks of
* the created tasks contain a status word with interrupts switched on
* so interrupts will automatically get re-enabled when the first task
* starts to run. */
portDISABLE_INTERRUPTS();
xNextTaskUnblockTime = portMAX_DELAY;// #define portMAX_DELAY ( TickType_t ) 0xffffffffUL
xSchedulerRunning = pdTRUE;
xTickCount = ( TickType_t ) configINITIAL_TICK_COUNT; // #define configINITIAL_TICK_COUNT 0
if( xPortStartScheduler() != pdFALSE )
{
/* Should not reach here as if the scheduler is running the
* function will not return. */
}
}
} BaseType_t xTimerCreateTimerTask( void )
{
BaseType_t xReturn = pdFAIL;