core: introduce grace period

In report mode we break out from select loop immediately after we reach
maximum count of iterations. But we should wait for packets which are still on
the way.

In order to fix the issue we introduce grace period during which we don't send
out more packets but we just wait for responses which might be still on the way.

resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1009051

diff --git a/select.c b/select.c
index 29088fd129fc94f6630663680fa3f2ad22c0ea96..31bfd5fdabd66d5ee701314c317f3d0409ea347b 100644 (file)
--- a/select.c
+++ b/select.c
@@ -45,6 +45,8 @@ static struct timeval intervaltime;
 int display_offset = 0;
 
 
+#define GRACETIME (5 * 1000*1000)
+
 void select_loop(void) {
   fd_set readfd;
   fd_set writefd;
@@ -57,8 +59,12 @@ void select_loop(void) {
   int NumPing = 0;
   int paused = 0;
   struct timeval lasttime, thistime, selecttime;
+  struct timeval startgrace;
   int dt;
   int rv; 
+  int graceperiod = 0;
+
+  memset(&startgrace, 0, sizeof(startgrace));
 
   gettimeofday(&lasttime, NULL);
 
@@ -124,10 +130,24 @@ void select_loop(void) {
           (thistime.tv_sec == lasttime.tv_sec + intervaltime.tv_sec &&
            thistime.tv_usec >= lasttime.tv_usec + intervaltime.tv_usec)) {
          lasttime = thistime;
-         if(NumPing >= MaxPing && (!Interactive || ForceMaxPing))
+
+         if (!graceperiod) {
+           if (NumPing >= MaxPing && (!Interactive || ForceMaxPing)) {
+             graceperiod = 1;
+             startgrace = thistime;
+           }
+
+           /* do not send out batch when we've already initiated grace period */
+           if (!graceperiod && net_send_batch())
+             NumPing++;
+         }
+       }
+
+       if (graceperiod) {
+         dt = (thistime.tv_usec - startgrace.tv_usec) +
+                   1000000 * (thistime.tv_sec - startgrace.tv_sec);
+         if (dt > GRACETIME)
            return;
-         if (net_send_batch())
-           NumPing++;
        }
 
        selecttime.tv_usec = (thistime.tv_usec - lasttime.tv_usec);