[Olsr-dev] olsr strange behaving / nearly no outgoing packets [partly solved]

[Lars Kruse]

Hi,

> > Besides this approach I don't see any other options for further
> > investigations. Or what would you say?
> 
> Maybe we could just add a new variable and calculate the return value in 
> two steps. Most compilers should optimize the variable away anyways.
> 
> uint32_t ms;
> 
> ....
> 
> t = (tv.tv_sec  - first_tv.tv_sec)  * 1000;
> ms = (tv.tv_usec - first_tv.tv_usec) / 1000;
> 
> return t + ms;
> }
> 
> Does this help ?

Almost - but thanks for the hint!


The following patch fixes it:

--- olsrd-0.6.2.orig/src/scheduler.c	2012-08-13 14:59:43.000000000 +0200
+++ olsrd-0.6.2/src/scheduler.c	2012-08-13 15:00:46.000000000 +0200
@@ -87,7 +87,7 @@ static uint32_t
 olsr_times(void)
 {
   struct timeval tv;
-  uint32_t t;
+  volatile uint32_t t, ms;
 
   if (gettimeofday(&tv, NULL) != 0) {
     olsr_exit("OS clock is not working, have to shut down OLSR", 1);
@@ -114,7 +114,9 @@ olsr_times(void)
     return t;
   }
   last_tv = tv;
-  return (tv.tv_sec - first_tv.tv_sec) * 1000 + (tv.tv_usec -
first_tv.tv_usec) / 1000;
+  t = (tv.tv_sec - first_tv.tv_sec) * 1000;
+  ms = (tv.tv_usec - first_tv.tv_usec) / 1000;
+  return t + ms;
 }
 
 /**



It seems that the "volatile" keyword prevents the compiler from doing evil
things. This is ugly! :(

cheers,
Lars