Ticket #4328: patch_top.diff

src/bin/top.c

@@ -443 +443 @@
             refresh = 0;
         }
     }
-    if (iters < 0) {
-        printf("Starting: infinite intervals of %d second%s each\n", 
-               interval,
-               (interval == 1) ? "" : "s");
-    } else {
+    if (iters >= 0) { 
         printf("Starting: %d interval%s of %d second%s each\n", iters, 
                (iters == 1) ? "" : "s", interval,
                (interval == 1) ? "" : "s");
@@ -456 +452 @@
     signal(SIGWINCH, winch_handler);
     
     then = system_time();
+    if (iters < 0) {
+        // You will only have to wait half a second for the first iteration.
+        uinterval = 1 * 1000000 / 2;
+        baseline = gather(NULL, &busy, 0, refresh);
+        elapsed = system_time() - then;
+        if (elapsed < uinterval) {
+            snooze(uinterval - elapsed);
+            elapsed = uinterval;
+        }
+        then = system_time();
+        baseline = gather(&baseline, &busy, elapsed, refresh);
+    } else
+        baseline = gather(NULL, &busy, 0, refresh);
+
     uinterval = interval * 1000000;
-    baseline = gather(NULL, &busy, 0, refresh);
     for (i = 0; iters < 0 || i < iters; i++) {
         elapsed = system_time() - then;
         if (elapsed < uinterval) {