Espressif ESP32-S2 Programming Manual page 930

Chapter 2. API Reference
* if( xTimerIsTimerActive( xTimer )
equivalently
→
* {
* // xTimer
* }
* else
* {
* // xTimer
* }
* }
*
Return pdFALSE will be returned if the timer is dormant. A value other than pdFALSE will be returned if
the timer is active.
Parameters
• xTimer: The timer being queried.
TaskHandle_t xTimerGetTimerDaemonTaskHandle(void)
xTimerGetTimerDaemonTaskHandle() is only available if INCLUDE_xTimerGetTimerDaemonTaskHandle
is set to 1 in FreeRTOSConfig.h.
Simply returns the handle of the timer service/daemon task. It it not valid to call xTimerGetTimerDaemon-
TaskHandle() before the scheduler has been started.
BaseType_t xTimerPendFunctionCallFromISR(PendedFunction_t
BaseType_t xTimerPendFunctionCallFromISR( PendedFunction_t xFunctionToPend, void *pvParameter1,
uint32_t ulParameter2, BaseType_t *pxHigherPriorityTaskWoken );
Used from application interrupt service routines to defer the execution of a function to the RTOS daemon task
(the timer service task, hence this function is implemented in timers.c and is prefixed with 'Timer').
Ideally an interrupt service routine (ISR) is kept as short as possible, but sometimes an ISR either has a lot of
processing to do, or needs to perform processing that is not deterministic. In these cases xTimerPendFunc-
tionCallFromISR() can be used to defer processing of a function to the RTOS daemon task.
A mechanism is provided that allows the interrupt to return directly to the task that will subsequently execute the
pended callback function. This allows the callback function to execute contiguously in time with the interrupt
- just as if the callback had executed in the interrupt itself.
Example usage:
*
* // The callback function that will execute
task.
→
* // Note callback functions must
* void vProcessInterface( void *pvParameter1, uint32_t ulParameter2 )
* {
* BaseType_t xInterfaceToService;
*
* // The interface that requires servicing
* // parameter.
* xInterfaceToService
*
* // ...Perform the processing
* }
*
* // An ISR that receives data packets
* void vAnISR( void )
* {
* BaseType_t xInterfaceToService, xHigherPriorityTaskWoken;
Espressif Systems
"if( xTimerIsTimerActive( xTimer ) )"
is active, do something.
is not active, do something
The first parameter
= ( BaseType_t ) ulParameter2;
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!= pdFALSE ) //
else.
*pvParameter1, uint32_t ulParameter2, Base-
Type_t *pxHigherPriorityTaskWoken)
in the context of the
all use this same prototype.
is passed
is not used in
here...
from multiple interfaces
919
(continued from previous page)
or more simply and␣
xFunctionToPend, void
daemon␣
in the second
this case.
(continues on next page)
Release v4.4