uc-sdk
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task. h
portBASE_TYPE xTaskCreate( pdTASK_CODE pvTaskCode, const char * const pcName, unsigned short usStackDepth, void *pvParameters, unsigned portBASE_TYPE uxPriority, xTaskHandle *pvCreatedTask );
Create a new task and add it to the list of tasks that are ready to run.
xTaskCreate() can only be used to create a task that has unrestricted access to the entire microcontroller memory map. Systems that include MPU support can alternatively create an MPU constrained task using xTaskCreateRestricted().
pvTaskCode | Pointer to the task entry function. Tasks must be implemented to never return (i.e. continuous loop). |
pcName | A descriptive name for the task. This is mainly used to facilitate debugging. Max length defined by tskMAX_TASK_NAME_LEN - default is 16. |
usStackDepth | The size of the task stack specified as the number of variables the stack can hold - not the number of bytes. For example, if the stack is 16 bits wide and usStackDepth is defined as 100, 200 bytes will be allocated for stack storage. |
pvParameters | Pointer that will be used as the parameter for the task being created. |
uxPriority | The priority at which the task should run. Systems that include MPU support can optionally create tasks in a privileged (system) mode by setting bit portPRIVILEGE_BIT of the priority parameter. For example, to create a privileged task at priority 2 the uxPriority parameter should be set to ( 2 | portPRIVILEGE_BIT ). |
pvCreatedTask | Used to pass back a handle by which the created task can be referenced. |
Example usage:
Task to be created. void vTaskCode( void * pvParameters ) { for( ;; ) { Task code goes here. } }
Function that creates a task. void vOtherFunction( void ) { static unsigned char ucParameterToPass; xTaskHandle xHandle;
Create the task, storing the handle. Note that the passed parameter ucParameterToPass must exist for the lifetime of the task, so in this case is declared static. If it was just an an automatic stack variable it might no longer exist, or at least have been corrupted, by the time the new task attempts to access it. xTaskCreate( vTaskCode, "NAME", STACK_SIZE, &ucParameterToPass, tskIDLE_PRIORITY, &xHandle );
Use the handle to delete the task. vTaskDelete( xHandle ); }