Author: toad
Date: 2008-02-28 16:41:08 +0000 (Thu, 28 Feb 2008)
New Revision: 18205
Modified:
trunk/freenet/src/freenet/io/xfer/PacketThrottle.java
Log:
Shrink the window if we don't use all of it.
Modified: trunk/freenet/src/freenet/io/xfer/PacketThrottle.java
===================================================================
--- trunk/freenet/src/freenet/io/xfer/PacketThrottle.java 2008-02-28
16:12:52 UTC (rev 18204)
+++ trunk/freenet/src/freenet/io/xfer/PacketThrottle.java 2008-02-28
16:41:08 UTC (rev 18205)
@@ -50,6 +50,12 @@
private boolean slowStart = true;
/** Total packets in flight, including waiting for bandwidth from the
central throttle. */
private int _packetsInFlight;
+ /** Incremented on each send */
+ private long _packetSeq;
+ /** Last time (seqno) the window was full */
+ private long _packetSeqWindowFull;
+ /** Last time (seqno) we checked whether the window was full, or
dropped a packet. */
+ private long _packetSeqWindowFullChecked;
/**
* Create a PacketThrottle for a given peer.
@@ -83,10 +89,25 @@
slowStart = false;
if(Logger.shouldLog(Logger.MINOR, this))
Logger.minor(this, "notifyOfPacketLost(): "+this);
+ _packetSeqWindowFullChecked = _packetSeq;
}
public synchronized void notifyOfPacketAcknowledged() {
_totalPackets++;
+ // If we didn't use the whole window, shrink the window a bit.
+ // This is similar but not identical to RFC2861
+ // See [freenet-dev] Major weakness in our current link-level
congestion control
+ int windowSize = (int)getWindowSize();
+ if(_packetSeqWindowFullChecked + windowSize < _packetSeq) {
+ if(_packetSeqWindowFull < _packetSeqWindowFullChecked) {
+ // We haven't used the full window once since we last
checked.
+ _packetSeqWindowFull *= PACKET_DROP_DECREASE_MULTIPLE;
+ _packetSeqWindowFullChecked += windowSize;
+ return;
+ }
+ _packetSeqWindowFullChecked += windowSize;
+ }
+
if(slowStart) {
_simulatedWindowSize += _simulatedWindowSize /
SLOW_START_DIVISOR;
} else {
@@ -150,6 +171,10 @@
int windowSize = (int) getWindowSize();
if(_packetsInFlight < windowSize) {
_packetsInFlight++;
+ _packetSeq++;
+ if(windowSize == _packetsInFlight) {
+ _packetSeqWindowFull =
_packetSeq;
+ }
break;
}
try {
