xTaskNotifyAndQueryFromISR / xTaskNotifyAndQueryIndexedFromISR
[RTOS Task Notification API]

task.h

 BaseType_t xTaskNotifyAndQueryFromISR( 
                      TaskHandle_t xTaskToNotify,
                      uint32_t ulValue,
                      eNotifyAction eAction,
                      uint32_t *pulPreviousNotifyValue,
                      BaseType_t *pxHigherPriorityTaskWoken );


 BaseType_t xTaskNotifyAndQueryIndexedFromISR( 
                      TaskHandle_t xTaskToNotify,
                      UBaseType_t uxIndexToNotify
                      uint32_t ulValue,
                      eNotifyAction eAction,
                      uint32_t *pulPreviousNotifyValue,
                      BaseType_t *pxHigherPriorityTaskWoken );

See RTOS Task Notifications for more details.

xTaskNotifyAndQueryIndexedFromISR() performs the same operation as xTaskNotifyIndexedFromISR() with the addition that it also returns the target task's prior notification value (the notification value at the time the function is called rather than at the time the function returns) in the additional pulPreviousNotifyValue parameter.

xTaskNotifyAndQueryFromISR() performs the same operation as xTaskNotifyFromISR() with the addition that it also returns the target task's prior notification value (the notification value at the time the function is called rather than at the time the function returns) in the additional pulPreviousNotifyValue parameter.

Parameters:

xTaskToNotify	The handle of the RTOS task being notified. This is the target task. To obtain a task's handle create the task using xTaskCreate() and make use of the pxCreatedTask parameter, or create the task using xTaskCreateStatic() and store the returned value, or use the task's name in a call to xTaskGetHandle(). The handle of the currently executing RTOS task is returned by the xTaskGetCurrentTaskHandle() API function.
uxIndexToNotify	The index within the target task's array of notification values to which the notification is to be sent. uxIndexToNotify must be less than configTASK_NOTIFICATION_ARRAY_ENTRIES.
ulValue	Used to update the notification value of the target task. See the description of the eAction parameter below.
eAction	An enumerated type that can take one of the values documented in the table below in order to perform the associated action.
pulPreviousNotifyValue	Can be used to pass out the target task's notification value before any bits are modified by the action of xTaskNotifyAndQueryFromISR(). pulPreviousNotifyValue is an optional parameter, and can be set to NULL if it is not required. If pulPreviousNotifyValue is not used then consider using xTaskNotify() in place of xTaskNotifyAndQueryFromISR().
pxHigherPriorityTaskWoken	*pxHigherPriorityTaskWoken must be initialised to pdFALSE (0). xTaskNotifyAndQueryFromISR() will set *pxHigherPriorityTaskWoken to pdTRUE if sending the notification caused a task to unblock, and the unblocked task has a priority higher than the currently running task. If xTaskNotifyAndQueryFromISR() sets this value to pdTRUE then a context switch should be requested before the interrupt is exited. See the example below. pxHigherPriorityTaskWoken is an optional parameter and can be set to NULL.

Returns:

pdPASS is returned in all cases other than when eAction is set to eSetValueWithoutOverwrite and the target task's notification value cannot be updated because the target task already had a notification pending.

Example usage:

void vAnISR( void )

{

/* Must be Initialised to pdFALSE! */

BaseType_t xHigherPriorityTaskWoken = pdFALSE. 

uint32_t ulPreviousValue;



    /* Set bit 8 in the 0th notification value of the task referenced

    by xTask1Handle. Store the task's previous 0th notification value 

    (before bit 8 is set) in ulPreviousValue. */

    xTaskNotifyAndQueryIndexedFromISR( xTask1Handle,

                                       0,

                                       ( 1UL << 8UL ),

                                       eSetBits,

                                       &ulPreviousValue,

                                       &xHigherPriorityTaskWoken );



    /* The task's previous notification value is saved in 

    ulPreviousValue. */



    /* If the task referenced by xTask1Handle was in the Blocked 

    state, waiting for the notification, then it will now have been 

    moved from the Blocked state to the Ready state.  If its priority 

    is higher than the priority of the currently executing task (the 

    task this interrupt interrupted) then xHigherPriorityTaskWoken will 

    have been set to pdTRUE, and passing the variable into a call to 

    portYIELD_FROM_ISR() will result in the interrupt returning directly 

    to the unblocked task.  If xHigherPriorityTaskWoken is still pdFALSE 

    then passing it into portYIELD_FROM_ISR() will have no effect. */



    portYIELD_FROM_ISR( xHigherPriorityTaskWoken );

}