update for the v3+

examples/delayTest.c

@@ -25,7 +25,6 @@
 
 #include <stdio.h>
 #include <unistd.h>
-#include <wiringPi.h>
 
 #include <sys/time.h>
 
@@ -34,17 +33,13 @@
 int main()
 {
   int x ;
-  struct timeval t1, t2 ;
+  struct timeval t1, t2, t3 ;
   int t ;
   int max, min ;
   int del ;
-  int underRuns, overRuns, exactRuns, total ;
+  int underRuns, overRuns, exactRuns, bogusRuns, total ;
   int descheds ;
 
-  if (wiringPiSetup () == -1)
-    return 1 ;
-
-  piHiPri (10) ; sleep (1) ;
 
 // Baseline test
 
@@ -58,21 +53,22 @@ int main()
   {
     underRuns = overRuns = exactRuns = total = 0 ;
     descheds = 0 ;
-    max = del ;
-    min = del ;
+    max =   0 ;
+    min = 999 ;
 
     for (x = 0 ; x < CYCLES ; ++x)
     {
       for (;;)				// Repeat this if we get a delay over 999uS
       {					// -> High probability Linux has deschedulled us
 	gettimeofday (&t1, NULL) ;
-	  delayMicroseconds (del) ;
+	  usleep (del) ;
+//          delayMicroseconds (del) ;
 	gettimeofday (&t2, NULL) ;
 
-	if (t2.tv_usec < t1.tv_usec)	// Counter wrapped
-	  t = (1000000 + t2.tv_usec) - t1.tv_usec;
-	else
-	  t = t2.tv_usec - t1.tv_usec ;
+	timersub (&t2, &t1, &t3) ;
+
+	t = t3.tv_usec ;
+
 	if (t > 999)
 	{
 	  ++descheds ;
@@ -82,25 +78,24 @@ int main()
 	  break ;
       }
 
-      if (t > max)
-      {
-        max = t ;
-	++overRuns ;
-      }
-      else if (t < min)
-      {
-	min = t ;
-	++underRuns ;
-      }
-      else
+      if (t == del)
 	++exactRuns ;
+      else if (t < del)
+	++underRuns ;
+      else if (t > del)
+	++overRuns ;
+
+      if (t > max)
+        max = t ;
+      else if (t < min)
+	min = t ;
 
       total += t ;
     }
     printf ("Delay: %3d. Min: %3d, Max: %3d, Unders: %3d, Overs: %3d, Exacts: %3d, Average: %3d,  Descheds: %2d\n",
 	del, min, max, underRuns, overRuns, exactRuns, total / CYCLES,  descheds) ;
     fflush (stdout) ;
-    delay (1) ;
+    usleep (1000) ;
   }
 
   return 0 ;