Add timer delete completion callback

include/timers.h

@@ -82,6 +82,15 @@ typedef struct tmrTimerControl * TimerHandle_t;
  */
 typedef void (* TimerCallbackFunction_t)( TimerHandle_t xTimer );
 
+/*
+ * Defines the prototype for a callback invoked by the timer daemon when it
+ * processes a timer delete command. The timer remains valid for the duration
+ * of this callback.
+ */
+typedef void (* TimerDeleteCallbackFunction_t)( TimerHandle_t xTimer,
+                                                TimerCallbackFunction_t pxCallbackFunction,
+                                                void * pvTimerID );
+
 /*
  * Defines the prototype to which functions used with the
  * xTimerPendFunctionCallFromISR() function must conform.
@@ -1293,6 +1302,14 @@ void vTimerSetReloadMode( TimerHandle_t xTimer,
  */
 BaseType_t xTimerGetReloadMode( TimerHandle_t xTimer ) PRIVILEGED_FUNCTION;
 
+/**
+ * Registers a callback that is invoked by the timer daemon immediately before
+ * it releases a deleted timer's control block.
+ *
+ * @param pxDeleteCallback The callback to invoke, or NULL to unregister it.
+ */
+void vTimerDeleteCallbackRegister( TimerDeleteCallbackFunction_t pxDeleteCallback ) PRIVILEGED_FUNCTION;
+
 /**
  * UBaseType_t uxTimerGetReloadMode( TimerHandle_t xTimer );
  *

timers.c

@@ -148,6 +148,7 @@
 /* A queue that is used to send commands to the timer service task. */
     PRIVILEGED_DATA static QueueHandle_t xTimerQueue = NULL;
     PRIVILEGED_DATA static TaskHandle_t xTimerTaskHandle = NULL;
+    PRIVILEGED_DATA static TimerDeleteCallbackFunction_t pxTimerDeleteCallback = NULL;
 
 /*-----------------------------------------------------------*/
 
@@ -1047,6 +1048,15 @@
                             break;
 
                         case tmrCOMMAND_DELETE:
+                            /* Notify wrappers while the timer control block and
+                             * its callback context are still valid. */
+                            if( pxTimerDeleteCallback != NULL )
+                            {
+                                pxTimerDeleteCallback( ( TimerHandle_t ) pxTimer,
+                                                       pxTimer->pxCallbackFunction,
+                                                       pxTimer->pvTimerID );
+                            }
+
                             #if ( configSUPPORT_DYNAMIC_ALLOCATION == 1 )
                             {
                                 /* The timer has already been removed from the active list,
@@ -1191,6 +1201,12 @@
     }
 /*-----------------------------------------------------------*/
 
+    void vTimerDeleteCallbackRegister( TimerDeleteCallbackFunction_t pxDeleteCallback )
+    {
+        pxTimerDeleteCallback = pxDeleteCallback;
+    }
+/*-----------------------------------------------------------*/
+
     void * pvTimerGetTimerID( const TimerHandle_t xTimer )
     {
         Timer_t * const pxTimer = xTimer;