ACS ACR89U-A1 User Manual download pdf (Page 70)

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ACR89U-A1 Application Programming Interface

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6.4.4. vTaskSuspendAll

This function suspends all real time kernel activity while keeping interrupts (including the kernel tick)

enabled. After calling vTaskSuspendAll () the calling task will continue to execute without the risk of

being swapped out until a call to xTaskResumeAll ( ) has been made. API functions that have the

potential to cause a context switch (for example, vTaskDelayUntill ( ), xQueueSend ( ), etc.) must

not be called while the scheduler is suspended.

[task.h]

void vTaskSuspendAll( void );

Example usage:

void vTask1( void * pvParameters )

{

for( ;; )

{

// Task code goes here.

// ...

// At some point the task wants to perform a long operation during

// which it does not want to get swapped out. It cannot use

// taskENTER_CRITICAL ()/taskEXIT_CRITICAL () as the length of the

// operation may cause interrupts to be missed - including the

// ticks.

// Prevent the real time kernel swapping out the task.

vTaskSuspendAll ();

// Perform the operation here. There is no need to use critical

// sections as we have all the microcontroller processing time.

// During this time interrupts will still operate and the kernel

// tick count will be maintained.

// ...

// The operation is complete. Restart the kernel.

xTaskResumeAll ();

}

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ACS ACR89U-A1 User Manual Page 70