Support reset kernel state for restarting scheduler (#944)

* Adding the following functions to reset kernel state. These functions are only required for application which 
needs to restart the scheduler.
 - void vTaskResetState( void )
 - void vTimerResetState( void )
 - void vPortHeapResetState( void )
 - void vCoRoutineResetState( void )

---------

Signed-off-by: Gaurav Aggarwal <aggarg@amazon.com>
Co-authored-by: Chris Morgan <cmorgan@boston-engineering.com>
Co-authored-by: Soren Ptak <ptaksoren@gmail.com>
Co-authored-by: Rahul Kar <118818625+kar-rahul-aws@users.noreply.github.com>
Co-authored-by: Gaurav Aggarwal <aggarg@amazon.com>
Co-authored-by: Gaurav-Aggarwal-AWS <33462878+aggarg@users.noreply.github.com>

croutine.c

@@ -52,8 +52,10 @@
 
 /* Other file private variables. --------------------------------*/
     CRCB_t * pxCurrentCoRoutine = NULL;
-    static UBaseType_t uxTopCoRoutineReadyPriority = 0;
+    static UBaseType_t uxTopCoRoutineReadyPriority = ( UBaseType_t ) 0U;
-    static TickType_t xCoRoutineTickCount = 0, xLastTickCount = 0, xPassedTicks = 0;
+    static TickType_t xCoRoutineTickCount = ( TickType_t ) 0U;
+    static TickType_t xLastTickCount = ( TickType_t ) 0U;
+    static TickType_t xPassedTicks = ( TickType_t ) 0U;
 
 /* The initial state of the co-routine when it is created. */
     #define corINITIAL_STATE    ( 0 )
@@ -378,5 +380,26 @@
 
         return xReturn;
     }
+/*-----------------------------------------------------------*/
+
+/*
+ * Reset state in this file. This state is normally initialized at start up.
+ * This function must be called by the application before restarting the
+ * scheduler.
+ */
+    void vCoRoutineResetState( void )
+    {
+        /* Lists for ready and blocked co-routines. */
+        pxDelayedCoRoutineList = NULL;
+        pxOverflowDelayedCoRoutineList = NULL;
+
+        /* Other file private variables. */
+        pxCurrentCoRoutine = NULL;
+        uxTopCoRoutineReadyPriority = ( UBaseType_t ) 0U;
+        xCoRoutineTickCount = ( TickType_t ) 0U;
+        xLastTickCount = ( TickType_t ) 0U;
+        xPassedTicks = ( TickType_t ) 0U;
+    }
+/*-----------------------------------------------------------*/
 
 #endif /* configUSE_CO_ROUTINES == 0 */

include/croutine.h

@@ -746,6 +746,13 @@ void vCoRoutineAddToDelayedList( TickType_t xTicksToDelay,
  */
 BaseType_t xCoRoutineRemoveFromEventList( const List_t * pxEventList );
 
+
+/*
+ * This function resets the internal state of the coroutine module. It must be
+ * called by the application before restarting the scheduler.
+ */
+void vCoRoutineResetState( void ) PRIVILEGED_FUNCTION;
+
 /* *INDENT-OFF* */
 #ifdef __cplusplus
     }

include/portable.h

@@ -194,6 +194,12 @@ size_t xPortGetMinimumEverFreeHeapSize( void ) PRIVILEGED_FUNCTION;
     #define vPortFreeStack       vPortFree
 #endif
 
+/*
+ * This function resets the internal state of the heap module. It must be called
+ * by the application before restarting the scheduler.
+ */
+void vPortHeapResetState( void ) PRIVILEGED_FUNCTION;
+
 #if ( configUSE_MALLOC_FAILED_HOOK == 1 )
 
 /**

include/task.h

@@ -3438,6 +3438,20 @@ BaseType_t xTaskCheckForTimeOut( TimeOut_t * const pxTimeOut,
  */
 BaseType_t xTaskCatchUpTicks( TickType_t xTicksToCatchUp ) PRIVILEGED_FUNCTION;
 
+/**
+ * task.h
+ * @code{c}
+ * void vTaskResetState( void );
+ * @endcode
+ *
+ * This function resets the internal state of the task. It must be called by the
+ * application before restarting the scheduler.
+ *
+ * \defgroup vTaskResetState vTaskResetState
+ * \ingroup SchedulerControl
+ */
+void vTaskResetState( void ) PRIVILEGED_FUNCTION;
+
 
 /*-----------------------------------------------------------
 * SCHEDULER INTERNALS AVAILABLE FOR PORTING PURPOSES

include/timers.h

@@ -1417,6 +1417,12 @@ BaseType_t xTimerGenericCommandFromISR( TimerHandle_t xTimer,
 
 #endif
 
+/*
+ * This function resets the internal state of the timer module. It must be called
+ * by the application before restarting the scheduler.
+ */
+void vTimerResetState( void ) PRIVILEGED_FUNCTION;
+
 /* *INDENT-OFF* */
 #ifdef __cplusplus
     }

portable/MemMang/heap_1.c

@@ -64,7 +64,7 @@
 #endif /* configAPPLICATION_ALLOCATED_HEAP */
 
 /* Index into the ucHeap array. */
-static size_t xNextFreeByte = ( size_t ) 0;
+static size_t xNextFreeByte = ( size_t ) 0U;
 
 /*-----------------------------------------------------------*/
 
@@ -150,3 +150,16 @@ size_t xPortGetFreeHeapSize( void )
 {
     return( configADJUSTED_HEAP_SIZE - xNextFreeByte );
 }
+
+/*-----------------------------------------------------------*/
+
+/*
+ * Reset the state in this file. This state is normally initialized at start up.
+ * This function must be called by the application before restarting the
+ * scheduler.
+ */
+void vPortHeapResetState( void )
+{
+    xNextFreeByte = ( size_t ) 0U;
+}
+/*-----------------------------------------------------------*/

portable/MemMang/heap_2.c

@@ -113,6 +113,9 @@ PRIVILEGED_DATA static BlockLink_t xStart, xEnd;
  * fragmentation. */
 PRIVILEGED_DATA static size_t xFreeBytesRemaining = configADJUSTED_HEAP_SIZE;
 
+/* Indicates whether the heap has been initialised or not. */
+PRIVILEGED_DATA static BaseType_t xHeapHasBeenInitialised = pdFALSE;
+
 /*-----------------------------------------------------------*/
 
 /*
@@ -155,7 +158,6 @@ void * pvPortMalloc( size_t xWantedSize )
     BlockLink_t * pxBlock;
     BlockLink_t * pxPreviousBlock;
     BlockLink_t * pxNewBlockLink;
-    PRIVILEGED_DATA static BaseType_t xHeapHasBeenInitialised = pdFALSE;
     void * pvReturn = NULL;
     size_t xAdditionalRequiredSize;
 
@@ -384,3 +386,16 @@ static void prvHeapInit( void ) /* PRIVILEGED_FUNCTION */
     pxFirstFreeBlock->pxNextFreeBlock = &xEnd;
 }
 /*-----------------------------------------------------------*/
+
+/*
+ * Reset the state in this file. This state is normally initialized at start up.
+ * This function must be called by the application before restarting the
+ * scheduler.
+ */
+void vPortHeapResetState( void )
+{
+    xFreeBytesRemaining = configADJUSTED_HEAP_SIZE;
+
+    xHeapHasBeenInitialised = pdFALSE;
+}
+/*-----------------------------------------------------------*/

portable/MemMang/heap_3.c

@@ -92,3 +92,15 @@ void vPortFree( void * pv )
         ( void ) xTaskResumeAll();
     }
 }
+/*-----------------------------------------------------------*/
+
+/*
+ * Reset the state in this file. This state is normally initialized at start up.
+ * This function must be called by the application before restarting the
+ * scheduler.
+ */
+void vPortHeapResetState( void )
+{
+    /* No state needs to be re-initialised in heap_3. */
+}
+/*-----------------------------------------------------------*/

portable/MemMang/heap_4.c

@@ -163,10 +163,10 @@ PRIVILEGED_DATA static BlockLink_t * pxEnd = NULL;
 
 /* Keeps track of the number of calls to allocate and free memory as well as the
  * number of free bytes remaining, but says nothing about fragmentation. */
-PRIVILEGED_DATA static size_t xFreeBytesRemaining = 0U;
+PRIVILEGED_DATA static size_t xFreeBytesRemaining = ( size_t ) 0U;
-PRIVILEGED_DATA static size_t xMinimumEverFreeBytesRemaining = 0U;
+PRIVILEGED_DATA static size_t xMinimumEverFreeBytesRemaining = ( size_t ) 0U;
-PRIVILEGED_DATA static size_t xNumberOfSuccessfulAllocations = 0;
+PRIVILEGED_DATA static size_t xNumberOfSuccessfulAllocations = ( size_t ) 0U;
-PRIVILEGED_DATA static size_t xNumberOfSuccessfulFrees = 0;
+PRIVILEGED_DATA static size_t xNumberOfSuccessfulFrees = ( size_t ) 0U;
 
 /*-----------------------------------------------------------*/
 
@@ -608,3 +608,19 @@ void vPortGetHeapStats( HeapStats_t * pxHeapStats )
     taskEXIT_CRITICAL();
 }
 /*-----------------------------------------------------------*/
+
+/*
+ * Reset the state in this file. This state is normally initialized at start up.
+ * This function must be called by the application before restarting the
+ * scheduler.
+ */
+void vPortHeapResetState( void )
+{
+    pxEnd = NULL;
+
+    xFreeBytesRemaining = ( size_t ) 0U;
+    xMinimumEverFreeBytesRemaining = ( size_t ) 0U;
+    xNumberOfSuccessfulAllocations = ( size_t ) 0U;
+    xNumberOfSuccessfulFrees = ( size_t ) 0U;
+}
+/*-----------------------------------------------------------*/

portable/MemMang/heap_5.c

@@ -187,10 +187,10 @@ PRIVILEGED_DATA static BlockLink_t * pxEnd = NULL;
 
 /* Keeps track of the number of calls to allocate and free memory as well as the
  * number of free bytes remaining, but says nothing about fragmentation. */
-PRIVILEGED_DATA static size_t xFreeBytesRemaining = 0U;
+PRIVILEGED_DATA static size_t xFreeBytesRemaining = ( size_t ) 0U;
-PRIVILEGED_DATA static size_t xMinimumEverFreeBytesRemaining = 0U;
+PRIVILEGED_DATA static size_t xMinimumEverFreeBytesRemaining = ( size_t ) 0U;
-PRIVILEGED_DATA static size_t xNumberOfSuccessfulAllocations = 0;
+PRIVILEGED_DATA static size_t xNumberOfSuccessfulAllocations = ( size_t ) 0U;
-PRIVILEGED_DATA static size_t xNumberOfSuccessfulFrees = 0;
+PRIVILEGED_DATA static size_t xNumberOfSuccessfulFrees = ( size_t ) 0U;
 
 #if ( configENABLE_HEAP_PROTECTOR == 1 )
 
@@ -707,3 +707,24 @@ void vPortGetHeapStats( HeapStats_t * pxHeapStats )
     taskEXIT_CRITICAL();
 }
 /*-----------------------------------------------------------*/
+
+/*
+ * Reset the state in this file. This state is normally initialized at start up.
+ * This function must be called by the application before restarting the
+ * scheduler.
+ */
+void vPortHeapResetState( void )
+{
+    pxEnd = NULL;
+
+    xFreeBytesRemaining = ( size_t ) 0U;
+    xMinimumEverFreeBytesRemaining = ( size_t ) 0U;
+    xNumberOfSuccessfulAllocations = ( size_t ) 0U;
+    xNumberOfSuccessfulFrees = ( size_t ) 0U;
+
+    #if ( configENABLE_HEAP_PROTECTOR == 1 )
+        pucHeapHighAddress = NULL;
+        pucHeapLowAddress = NULL;
+    #endif /* #if ( configENABLE_HEAP_PROTECTOR == 1 ) */
+}
+/*-----------------------------------------------------------*/

tasks.c

@@ -8694,3 +8694,61 @@ static void prvAddCurrentTaskToDelayedList( TickType_t xTicksToWait,
 
 #endif /* #if ( ( configSUPPORT_STATIC_ALLOCATION == 1 ) && ( configKERNEL_PROVIDED_STATIC_MEMORY == 1 ) && ( portUSING_MPU_WRAPPERS == 0 ) ) */
 /*-----------------------------------------------------------*/
+
+/*
+ * Reset the state in this file. This state is normally initialized at start up.
+ * This function must be called by the application before restarting the
+ * scheduler.
+ */
+void vTaskResetState( void )
+{
+    BaseType_t xCoreID;
+
+    /* Task control block. */
+    #if ( configNUMBER_OF_CORES == 1 )
+    {
+        pxCurrentTCB = NULL;
+    }
+    #endif /* #if ( configNUMBER_OF_CORES == 1 ) */
+
+    #if ( INCLUDE_vTaskDelete == 1 )
+    {
+        uxDeletedTasksWaitingCleanUp = ( UBaseType_t ) 0U;
+    }
+    #endif /* #if ( INCLUDE_vTaskDelete == 1 ) */
+
+    #if ( configUSE_POSIX_ERRNO == 1 )
+    {
+        FreeRTOS_errno = 0;
+    }
+    #endif /* #if ( configUSE_POSIX_ERRNO == 1 ) */
+
+    /* Other file private variables. */
+    uxCurrentNumberOfTasks = ( UBaseType_t ) 0U;
+    xTickCount = ( TickType_t ) configINITIAL_TICK_COUNT;
+    uxTopReadyPriority = tskIDLE_PRIORITY;
+    xSchedulerRunning = pdFALSE;
+    xPendedTicks = ( TickType_t ) 0U;
+
+    for( xCoreID = 0; xCoreID < configNUMBER_OF_CORES; xCoreID++ )
+    {
+        xYieldPendings[ xCoreID ] = pdFALSE;
+    }
+
+    xNumOfOverflows = ( BaseType_t ) 0;
+    uxTaskNumber = ( UBaseType_t ) 0U;
+    xNextTaskUnblockTime = ( TickType_t ) 0U;
+
+    uxSchedulerSuspended = ( UBaseType_t ) 0U;
+
+    #if ( configGENERATE_RUN_TIME_STATS == 1 )
+    {
+        for( xCoreID = 0; xCoreID < configNUMBER_OF_CORES; xCoreID++ )
+        {
+            ulTaskSwitchedInTime[ xCoreID ] = 0U;
+            ulTotalRunTime[ xCoreID ] = 0U;
+        }
+    }
+    #endif /* #if ( configGENERATE_RUN_TIME_STATS == 1 ) */
+}
+/*-----------------------------------------------------------*/

timers.c

@@ -1322,6 +1322,18 @@
     #endif /* configUSE_TRACE_FACILITY */
 /*-----------------------------------------------------------*/
 
+/*
+ * Reset the state in this file. This state is normally initialized at start up.
+ * This function must be called by the application before restarting the
+ * scheduler.
+ */
+    void vTimerResetState( void )
+    {
+        xTimerQueue = NULL;
+        xTimerTaskHandle = NULL;
+    }
+/*-----------------------------------------------------------*/
+
 /* This entire source file will be skipped if the application is not configured
  * to include software timer functionality.  If you want to include software timer
  * functionality then ensure configUSE_TIMERS is set to 1 in FreeRTOSConfig.h. */