From e7df295f457c473ae76ae4d266f17176a5b31a28 Mon Sep 17 00:00:00 2001
From: Keith Winstein <keithw@mit.edu>
Date: Wed, 10 Aug 2011 00:13:22 -0400
Subject: [PATCH] Variable wait time

---
 networktransport.cpp | 17 ++++++++++-------
 networktransport.hpp |  2 +-
 ntester.cpp          |  8 ++------
 3 files changed, 13 insertions(+), 14 deletions(-)

diff --git a/networktransport.cpp b/networktransport.cpp
index 4c2779b..d639dd5 100644
--- a/networktransport.cpp
+++ b/networktransport.cpp
@@ -49,19 +49,22 @@ Transport<MyState, RemoteState>::Transport( MyState &initial_state, RemoteState
 }
 
 template <class MyState, class RemoteState>
-void Transport<MyState, RemoteState>::tick( void )
+int Transport<MyState, RemoteState>::tick( void )
 {
-  /* Update assumed receiver state */
-  update_assumed_receiver_state();
-
-  /* Cut out common prefix of all states */
-  rationalize_states();
-
   /* Determine if a new diff or empty ack needs to be sent */
   if ( timestamp() - sent_states.back().timestamp >= int64_t( SEND_INTERVAL ) ) {
+    /* Update assumed receiver state */
+    update_assumed_receiver_state();
+
+    /* Cut out common prefix of all states */
+    rationalize_states();
+
     /* Send diffs or ack */
     send_to_receiver();
   }
+
+  int64_t wait = int64_t( sent_states.back().timestamp + SEND_INTERVAL ) - timestamp();
+  return wait;
 }
 
 template <class MyState, class RemoteState>
diff --git a/networktransport.hpp b/networktransport.hpp
index 0a32d0f..464999e 100644
--- a/networktransport.hpp
+++ b/networktransport.hpp
@@ -87,7 +87,7 @@ namespace Network {
     Transport( MyState &initial_state, RemoteState &initial_remote,
 	       const char *key_str, const char *ip, int port );
 
-    void tick( void );
+    int tick( void );
 
     void recv( void );
 
diff --git a/ntester.cpp b/ntester.cpp
index 6294ea9..63555e2 100644
--- a/ntester.cpp
+++ b/ntester.cpp
@@ -43,9 +43,7 @@ int main( int argc, char *argv[] )
     uint64_t last_num = n->get_remote_state_num();
     while ( true ) {
       try {
-	n->tick();
-
-	if ( poll( &my_pollfd, 1, 5 ) < 0 ) {
+	if ( poll( &my_pollfd, 1, n->tick() ) < 0 ) {
 	  perror( "poll" );
 	  exit( 1 );
 	}
@@ -94,9 +92,7 @@ int main( int argc, char *argv[] )
 
     while( true ) {
       try {
-	n->tick();
-
-	if ( poll( fds, 2, 5 ) < 0 ) {
+	if ( poll( fds, 2, n->tick() ) < 0 ) {
 	  perror( "poll" );
 	}