[Udt-java-commits] SF.net SVN: udt-java:[22] udt-java/trunk/src
Status: Alpha
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[Udt-java-commits] SF.net SVN: udt-java:[22] udt-java/trunk/src
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From: <bsc...@us...> - 2010-04-21 20:36:43
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Revision: 22
http://udt-java.svn.sourceforge.net/udt-java/?rev=22&view=rev
Author: bschuller
Date: 2010-04-21 20:36:36 +0000 (Wed, 21 Apr 2010)
Log Message:
-----------
Modified Paths:
--------------
udt-java/trunk/src/main/java/udt/UDTCongestionControl.java
udt-java/trunk/src/main/java/udt/UDTSender.java
udt-java/trunk/src/main/java/udt/receiver/PacketPairWindow.java
udt-java/trunk/src/main/java/udt/sender/SenderLossList.java
udt-java/trunk/src/test/java/udt/performance/TestUDTLargeData.java
Modified: udt-java/trunk/src/main/java/udt/UDTCongestionControl.java
===================================================================
--- udt-java/trunk/src/main/java/udt/UDTCongestionControl.java 2010-04-21 15:45:00 UTC (rev 21)
+++ udt-java/trunk/src/main/java/udt/UDTCongestionControl.java 2010-04-21 20:36:36 UTC (rev 22)
@@ -7,62 +7,61 @@
import udt.util.UDTStatistics;
import udt.util.Util;
+/**
+ * default UDT congestion control.<br/>
+ *
+ * The algorithm is adapted from the C++ reference implementation.
+ */
public class UDTCongestionControl implements CongestionControl {
private static final Logger logger=Logger.getLogger(UDTCongestionControl.class.getName());
private final UDTSession session;
-
+
private final UDTStatistics statistics;
-
+
//round trip time in microseconds
private long roundTripTime=2*Util.getSYNTime();
-
+
//rate in packets per second
private long packetArrivalRate=0;
-
+
//link capacity in packets per second
private long estimatedLinkCapacity=0;
-
- long maxControlWindowSize=128;
// Packet sending period = packet send interval, in microseconds
private double packetSendingPeriod=1;
+
// Congestion window size, in packets
private long congestionWindowSize=16;
-
- //number of packets to be increased in the next SYN period
- private double numOfIncreasingPacket;
-
+
//last rate increase time (microsecond value)
long lastRateIncreaseTime=Util.getCurrentTime();
-
+
/*if in slow start phase*/
boolean slowStartPhase=true;
-
+
/*last ACKed seq no*/
long lastAckSeqNumber=-1;
-
+
/*max packet seq. no. sent out when last decrease happened*/
private long lastDecreaseSeqNo;
- //value of packetSendPeriod when last decrease happened
- long lastDecreasePeriod;
-
//NAK counter
- long nACKCount=1;
-
+ private long nACKCount=1;
+
//number of decreases in a congestion epoch
long decCount=1;
-
+
//random threshold on decrease by number of loss events
long decreaseRandom=1;
-
+
//average number of NAKs per congestion
long averageNACKNum;
- boolean loss=false;
-
+ //this flag avoids immediate rate increase after a NAK
+ private boolean loss=false;
+
public UDTCongestionControl(UDTSession session){
this.session=session;
this.statistics=session.getStatistics();
@@ -108,7 +107,7 @@
public double getSendInterval(){
return packetSendingPeriod;
}
-
+
/**
* congestionWindowSize
* @return
@@ -125,7 +124,7 @@
if(slowStartPhase){
congestionWindowSize+=ackSeqno-lastAckSeqNumber;
lastAckSeqNumber = ackSeqno;
-
+
//but not beyond a maximum size
if(congestionWindowSize>session.getFlowWindowSize()){
System.out.println("slow start ends on ACK");
@@ -137,7 +136,7 @@
packetSendingPeriod=(double)congestionWindowSize/(roundTripTime+Util.getSYNTimeD());
}
}
-
+
}else{
//1.if it is not in slow start phase,set the congestion window size
//to the product of packet arrival rate and(rtt +SYN)
@@ -148,51 +147,51 @@
}
}
- //no rate increase in slow start
+ //no rate increase during slow start
if(slowStartPhase)return;
-
+
+ //no rate increase "immediately" after a NAK
if(loss){
loss=false;
return;
}
-
- //4.compute the number of sent packets to be increase in the next SYN period
- //and update the send intervall
- numOfIncreasingPacket=computeNumOfIncreasingPacket();
-
- //4.update the send period :
+
+ //4. compute the increase in sent packets for the next SYN period
+ double numOfIncreasingPacket=computeNumOfIncreasingPacket();
+
+ //5. update the send period
double factor=Util.getSYNTimeD()/(packetSendingPeriod*numOfIncreasingPacket+Util.getSYNTimeD());
packetSendingPeriod=factor*packetSendingPeriod;
//packetSendingPeriod=0.995*packetSendingPeriod;
//System.out.println("dec snd factor "+factor+" to "+packetSendingPeriod);
-
+
statistics.setSendPeriod(packetSendingPeriod);
}
private final long PS=UDPEndPoint.DATAGRAM_SIZE;
private final double BetaDivPS=0.0000015/PS;
-
+
//see spec page 16
private double computeNumOfIncreasingPacket (){
- //link capacity and sending speed, in packets per second
- double B=estimatedLinkCapacity;
- double C=1000000.0/packetSendingPeriod;
-
- if(B<=C)return 1.0/UDPEndPoint.DATAGRAM_SIZE;
-
- double exp=Math.ceil(Math.log10((B-C)*PS*8));
- double power10 = Math.pow( 10.0, exp)* BetaDivPS;
- double inc = Math.max(power10, 1/PS);
- return inc;
+ //difference in link capacity and sending speed, in packets per second
+ double remaining=estimatedLinkCapacity-1000000.0/packetSendingPeriod;
+
+ if(remaining<=0){
+ return 1.0/UDPEndPoint.DATAGRAM_SIZE;
+ }
+ else{
+ double exp=Math.ceil(Math.log10(remaining*PS*8));
+ double power10 = Math.pow( 10.0, exp)* BetaDivPS;
+ return Math.max(power10, 1/PS);
+ }
}
-
+
/* (non-Javadoc)
* @see udt.CongestionControl#onNAK(java.util.List)
*/
public void onNAK(List<Integer>lossInfo){
loss=true;
- long firstBiggestlossSeqNo=lossInfo.get(lossInfo.size()-1);
-
+ long firstBiggestlossSeqNo=lossInfo.get(0);
nACKCount++;
/*1) If it is in slow start phase, set inter-packet interval to
1/recvrate. Slow start ends. Stop. */
@@ -206,12 +205,10 @@
slowStartPhase = false;
return;
}
-
+
long currentMaxSequenceNumber=session.getSocket().getSender().getCurrentSequenceNumber();
-
// 2)If this NAK starts a new congestion epoch
if(firstBiggestlossSeqNo>lastDecreaseSeqNo){
-
// -increase inter-packet interval
packetSendingPeriod = Math.ceil(packetSendingPeriod*1.125);
// -Update AvgNAKNum(the average number of NAKs per congestion)
@@ -224,20 +221,19 @@
// -Update LastDecSeq
lastDecreaseSeqNo = currentMaxSequenceNumber;
// -Stop.
- statistics.setSendPeriod(packetSendingPeriod);
}
-
//* 3) If DecCount <= 5, and NAKCount == DecCount * DecRandom:
- if(decCount<=5 && nACKCount==decCount*decreaseRandom){
+ else if(decCount<=5 && nACKCount==decCount*decreaseRandom){
// a. Update SND period: SND = SND * 1.125;
packetSendingPeriod = Math.ceil(packetSendingPeriod*1.125);
// b. Increase DecCount by 1;
decCount++;
// c. Record the current largest sent sequence number (LastDecSeq).
lastDecreaseSeqNo= currentMaxSequenceNumber;
- statistics.setSendPeriod(packetSendingPeriod);
- return;
}
+
+ statistics.setSendPeriod(packetSendingPeriod);
+ return;
}
/* (non-Javadoc)
Modified: udt-java/trunk/src/main/java/udt/UDTSender.java
===================================================================
--- udt-java/trunk/src/main/java/udt/UDTSender.java 2010-04-21 15:45:00 UTC (rev 21)
+++ udt-java/trunk/src/main/java/udt/UDTSender.java 2010-04-21 20:36:36 UTC (rev 22)
@@ -253,10 +253,10 @@
statistics.incNumberOfNAKReceived();
statistics.storeParameters();
- //if(logger.isLoggable(Level.FINER)){
- System.out.println("NAK for "+nak.getDecodedLossInfo().size()+" packets lost, "
+ if(logger.isLoggable(Level.FINER)){
+ logger.finer("NAK for "+nak.getDecodedLossInfo().size()+" packets lost, "
+"set send period to "+session.getCongestionControl().getSendInterval());
- //}
+ }
return;
}
@@ -315,12 +315,9 @@
if(unAcknowledged<session.getCongestionControl().getCongestionWindowSize()
&& unAcknowledged<session.getFlowWindowSize()){
-// if(lastSentTime>0 && Util.getCurrentTime()-lastSentTime<snd){
-// statistics.incNumberOfCCSlowDownEvents();
-// return;
-// }
+
if(sendQueue.size()==0){
- Thread.yield();
+ //Thread.yield();
return;
}
DataPacket dp=sendQueue.poll(20,TimeUnit.MILLISECONDS);
@@ -340,10 +337,12 @@
//wait
double snd=session.getCongestionControl().getSendInterval();
long passed=Util.getCurrentTime()-iterationStart;
+ int x=0;
while(snd-passed>0){
- //busy wait, but we cannot wait with microsecond precision
+ if(x++==0)statistics.incNumberOfCCSlowDownEvents();
+ //we cannot wait with microsecond precision
if(snd-passed>750)Thread.sleep(1);
- statistics.incNumberOfCCSlowDownEvents();
+ else Thread.yield();
passed=Util.getCurrentTime()-iterationStart;
}
@@ -394,8 +393,9 @@
return largestSentSequenceNumber>=sequenceNumber;
}
+
boolean haveLostPackets(){
- return senderLossList.isEmpty();
+ return !senderLossList.isEmpty();
}
/**
Modified: udt-java/trunk/src/main/java/udt/receiver/PacketPairWindow.java
===================================================================
--- udt-java/trunk/src/main/java/udt/receiver/PacketPairWindow.java 2010-04-21 15:45:00 UTC (rev 21)
+++ udt-java/trunk/src/main/java/udt/receiver/PacketPairWindow.java 2010-04-21 20:36:36 UTC (rev 22)
@@ -79,7 +79,6 @@
}
}
double res=total/count;
- //System.out.println("median: "+median+" filtered "+res);
return res;
}
Modified: udt-java/trunk/src/main/java/udt/sender/SenderLossList.java
===================================================================
--- udt-java/trunk/src/main/java/udt/sender/SenderLossList.java 2010-04-21 15:45:00 UTC (rev 21)
+++ udt-java/trunk/src/main/java/udt/sender/SenderLossList.java 2010-04-21 20:36:36 UTC (rev 22)
@@ -31,7 +31,6 @@
*********************************************************************************/
package udt.sender;
-import java.util.Iterator;
import java.util.concurrent.PriorityBlockingQueue;
/**
Modified: udt-java/trunk/src/test/java/udt/performance/TestUDTLargeData.java
===================================================================
--- udt-java/trunk/src/test/java/udt/performance/TestUDTLargeData.java 2010-04-21 15:45:00 UTC (rev 21)
+++ udt-java/trunk/src/test/java/udt/performance/TestUDTLargeData.java 2010-04-21 20:36:36 UTC (rev 22)
@@ -20,7 +20,7 @@
boolean running=false;
//how many
- int num_packets=200;
+ int num_packets=100;
//how large is a single packet
int size=1*1024*1024;
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