From: richardbarry <richardbarry@1d2547de-c912-0410-9cb9-b8ca96c0e9e2>
Date: Sun, 18 Nov 2012 09:13:39 +0000 (+0000)
Subject: Move the call that sets xTimeNow inside the loop that drains the timer queue to ensur... 
X-Git-Tag: V7.4.0~19
X-Git-Url: https://git.sur5r.net/?a=commitdiff_plain;h=2d0dfbe32e1d3ee41f64f6a29261122e946e7b2b;p=freertos

Move the call that sets xTimeNow inside the loop that drains the timer queue to ensure higher priority tasks that pre-empt the timer daemon cannot post messages that appear to be in the future to the daemon task.

git-svn-id: https://svn.code.sf.net/p/freertos/code/trunk@1812 1d2547de-c912-0410-9cb9-b8ca96c0e9e2
---

diff --git a/FreeRTOS/Source/timers.c b/FreeRTOS/Source/timers.c
index e68cc0341..bc4ef062d 100644
--- a/FreeRTOS/Source/timers.c
+++ b/FreeRTOS/Source/timers.c
@@ -512,10 +512,6 @@ xTIMER *pxTimer;
 portBASE_TYPE xTimerListsWereSwitched, xResult;
 portTickType xTimeNow;
 
-	/* In this case the xTimerListsWereSwitched parameter is not used, but it
-	must be present in the function call. */
-	xTimeNow = prvSampleTimeNow( &xTimerListsWereSwitched );
-
 	while( xQueueReceive( xTimerQueue, &xMessage, tmrNO_DELAY ) != pdFAIL )
 	{
 		pxTimer = xMessage.pxTimer;
@@ -528,6 +524,14 @@ portTickType xTimeNow;
 
 		traceTIMER_COMMAND_RECEIVED( pxTimer, xMessage.xMessageID, xMessage.xMessageValue );
 
+		/* In this case the xTimerListsWereSwitched parameter is not used, but 
+		it must be present in the function call.  prvSampleTimeNow() must be 
+		called after the message is received from xTimerQueue so there is no 
+		possibility of a higher priority task adding a message to the message
+		queue with a time that is ahead of the timer daemon task (because it
+		pre-empted the timer daemon task after the xTimeNow value was set). */
+		xTimeNow = prvSampleTimeNow( &xTimerListsWereSwitched );
+
 		switch( xMessage.xMessageID )
 		{
 			case tmrCOMMAND_START :
@@ -680,3 +684,6 @@ xTIMER *pxTimer = ( xTIMER * ) xTimer;
 to include software timer functionality.  If you want to include software timer
 functionality then ensure configUSE_TIMERS is set to 1 in FreeRTOSConfig.h. */
 #endif /* configUSE_TIMERS == 1 */
+
+
+