add Timer::GetDelayLeft

src/simulator/timer.cc

@@ -57,7 +57,25 @@ Timer::GetDelay (void) const
 {
   return m_delay;
 }
-
+Time
+Timer::GetDelayLeft (void) const
+{
+  switch (GetState ()) {
+  case Timer::RUNNING:
+    return Simulator::GetDelayLeft (m_event);
+    break;
+  case Timer::EXPIRED:
+    return TimeStep (0);
+    break;
+  case Timer::SUSPENDED:
+    return m_delayLeft;
+    break;
+  default:
+    NS_ASSERT (false);
+    return TimeStep (0);
+    break;
+  }
+}
 
 void 
 Timer::Cancel (void)

src/simulator/timer.h

@@ -177,6 +177,12 @@ public:
    * \returns the currently-configured delay for the next Schedule.
    */
   Time GetDelay (void) const;
+  /**
+   * \returns the amount of time left until this timer expires.
+   *
+   * This method returns zero if the timer is in EXPIRED state.
+   */
+  Time GetDelayLeft (void) const;
   /**
    * Cancel the currently-running event if there is one. Do nothing
    * otherwise.