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: #1009051

mtr-introduce-grace-period.patch

@@ -0,0 +1,74 @@
+From 6ce1601b27fdd95b44ed65d7fd83604860276d63 Mon Sep 17 00:00:00 2001
+From: Michal Sekletar <sekletar.m@gmail.com>
+Date: Tue, 17 Sep 2013 16:11:20 +0200
+Subject: [PATCH] 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
+---
+ select.c | 26 +++++++++++++++++++++++---
+ 1 file changed, 23 insertions(+), 3 deletions(-)
+
+diff --git a/select.c b/select.c
+index 29088fd..31bfd5f 100644
+--- 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);
+-- 
+1.8.3.1
+

mtr.spec

@@ -19,6 +19,7 @@ Patch1: mtr-crash-in-xml-mode.patch
 Patch2: mtr-xml-format-fixes.patch
 Patch3: mtr-default-hostname.patch
 Patch4: mtr-ipv6-on-ipv4-only.patch
+Patch5: mtr-introduce-grace-period.patch
 
 BuildRequires: ncurses-devel gtk2-devel desktop-file-utils
 BuildRequires: autoconf automake libtool
@@ -45,6 +46,7 @@ diagnostic tool.
 %patch2 -p1
 %patch3 -p1
 %patch4 -p1
+%patch5 -p1
 
 %build
 export CFLAGS="%{optflags} -fPIE"
@@ -92,6 +94,7 @@ desktop-file-install \
 * Tue Oct  1 2013 Michal Sekletar <msekleta@redhat.com> - 2:0.85-4
 - migrate from consolehelper to policykit (#502750)
 - specfile cleanup
+- introduce grace period (#1009051)
 
 * Sat Sep 14 2013 Michal Sekletar <msekleta@redhat.com> - 2:0.85-3
 - enable hardened build