Enable MSVC Port to leave the prvProcessSimulatedInterrupts loop when scheduler is stopped (#728)

* allow to leave loop

* add missing brace

* Code review suggestions

Signed-off-by: Gaurav Aggarwal <aggarg@amazon.com>

---------

Signed-off-by: Gaurav Aggarwal <aggarg@amazon.com>
Co-authored-by: Gaurav-Aggarwal-AWS <33462878+aggarg@users.noreply.github.com>
Co-authored-by: Gaurav Aggarwal <aggarg@amazon.com>

portable/MSVC-MingW/port.c

@@ -340,6 +340,9 @@ SYSTEM_INFO xSystemInfo;
         /* Start the first task. */
         ResumeThread( pxThreadState->pvThread );
 
+        /* The scheduler is now running. */
+        xPortRunning = pdTRUE;
+
         /* Handle all simulated interrupts - including yield requests and
         simulated ticks. */
         prvProcessSimulatedInterrupts();
@@ -376,6 +379,8 @@ uint32_t ulSwitchRequired, i;
 ThreadState_t *pxThreadState;
 void *pvObjectList[ 2 ];
 CONTEXT xContext;
+DWORD xWinApiResult;
+const DWORD xTimeoutMilliseconds = 1000;
 
     /* Going to block on the mutex that ensured exclusive access to the simulated
     interrupt objects, and the event that signals that a simulated interrupt
@@ -388,13 +393,16 @@ CONTEXT xContext;
     ulPendingInterrupts |= ( 1 << portINTERRUPT_TICK );
     SetEvent( pvInterruptEvent );
 
-    xPortRunning = pdTRUE;
-
-    for(;;)
+    while( xPortRunning == pdTRUE )
     {
         xInsideInterrupt = pdFALSE;
-        WaitForMultipleObjects( sizeof( pvObjectList ) / sizeof( void * ), pvObjectList, TRUE, INFINITE );
 
+        /* Wait with timeout so that we can exit from this loop when
+         * the scheduler is stopped by calling vPortEndScheduler. */
+        xWinApiResult = WaitForMultipleObjects( sizeof( pvObjectList ) / sizeof( void * ), pvObjectList, TRUE, xTimeoutMilliseconds );
+
+        if( xWinApiResult != WAIT_TIMEOUT )
+        {
             /* Cannot be in a critical section to get here.  Tasks that exit a
             critical section will block on a yield mutex to wait for an interrupt to
             process if an interrupt was set pending while the task was inside the
@@ -488,6 +496,7 @@ CONTEXT xContext;
             SetEvent( pxThreadState->pvYieldEvent );
             ReleaseMutex( pvInterruptEventMutex );
         }
+    }
 }
 /*-----------------------------------------------------------*/