bboss.org.jgroups.protocols.UNICAST2 Maven / Gradle / Ivy
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package bboss.org.jgroups.protocols;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.Vector;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
import java.util.concurrent.Future;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;
import bboss.org.jgroups.Address;
import bboss.org.jgroups.Event;
import bboss.org.jgroups.Global;
import bboss.org.jgroups.Header;
import bboss.org.jgroups.Message;
import bboss.org.jgroups.View;
import bboss.org.jgroups.annotations.Experimental;
import bboss.org.jgroups.annotations.MBean;
import bboss.org.jgroups.annotations.ManagedAttribute;
import bboss.org.jgroups.annotations.ManagedOperation;
import bboss.org.jgroups.annotations.Property;
import bboss.org.jgroups.annotations.Unsupported;
import bboss.org.jgroups.conf.PropertyConverters;
import bboss.org.jgroups.stack.AckSenderWindow;
import bboss.org.jgroups.stack.NakReceiverWindow;
import bboss.org.jgroups.stack.Protocol;
import bboss.org.jgroups.stack.Retransmitter;
import bboss.org.jgroups.util.AgeOutCache;
import bboss.org.jgroups.util.TimeScheduler;
/**
* Reliable unicast layer. Implemented with negative acks. Every sender keeps its messages in an AckSenderWindow. A
* receiver stores incoming messages in a NakReceiverWindow, and asks the sender for retransmission if a gap is
* detected. Every now and then (stable_interval), a timer task sends a STABLE message to all senders, including the
* highest received and delivered seqnos. A sender purges messages lower than highest delivered and asks the STABLE
* sender for messages it might have missed (smaller than highest received). A STABLE message can also be sent when
* a receiver has received more than max_bytes from a given sender.
* The advantage of this protocol over {@link bboss.org.jgroups.protocols.UNICAST} is that it doesn't send acks for every
* message. Instead, it sends 'acks' after receiving max_bytes and/ or periodically (stable_interval).
* @author Bela Ban
* @version $Id: UNICAST2.java,v 1.9 2010/06/14 08:11:27 belaban Exp $
*/
@Experimental @Unsupported
@MBean(description="Reliable unicast layer")
public class UNICAST2 extends Protocol implements Retransmitter.RetransmitCommand, AgeOutCache.Handler {
public static final long DEFAULT_FIRST_SEQNO=Global.DEFAULT_FIRST_UNICAST_SEQNO;
/* ------------------------------------------ Properties ------------------------------------------ */
private long[] timeout= { 400, 800, 1600, 3200 }; // for NakSenderWindow: max time to wait for missing acks
@Property(description="Max number of messages to be removed from a NakReceiverWindow. This property might " +
"get removed anytime, so don't use it !")
private int max_msg_batch_size=50000;
@Property(description="Max number of bytes before a stability message is sent to the sender")
protected long max_bytes=10000000;
@Property(description="Max number of milliseconds before a stability message is sent to the sender(s)")
protected long stable_interval=10000L;
@Property(description="Max number of STABLE messages sent for the same highest_received seqno. A value < 1 is invalid")
protected int max_stable_msgs=5;
/* --------------------------------------------- JMX ---------------------------------------------- */
private long num_msgs_sent=0, num_msgs_received=0, num_bytes_sent=0, num_bytes_received=0, num_xmits=0;
/* --------------------------------------------- Fields ------------------------------------------------ */
private final ConcurrentMap send_table=new ConcurrentHashMap();
private final ConcurrentMap recv_table=new ConcurrentHashMap();
private final Vector members=new Vector(11);
private Address local_addr=null;
private TimeScheduler timer=null; // used for retransmissions (passed to AckSenderWindow)
private boolean started=false;
private short last_conn_id=0;
protected long max_retransmit_time=60 * 1000L;
private AgeOutCache cache=null;
private Future stable_task_future=null; // bcasts periodic STABLE message (added to timer below)
public long[] getTimeout() {return timeout;}
@Property(name="timeout",converter=PropertyConverters.LongArray.class)
public void setTimeout(long[] val) {
if(val != null)
timeout=val;
}
public void setMaxMessageBatchSize(int size) {
if(size >= 1)
max_msg_batch_size=size;
}
@ManagedAttribute
public String getLocalAddress() {return local_addr != null? local_addr.toString() : "null";}
@ManagedAttribute
public String getMembers() {return members != null? members.toString() : "[]";}
@ManagedOperation
public String printConnections() {
StringBuilder sb=new StringBuilder();
if(!send_table.isEmpty()) {
sb.append("send connections:\n");
for(Map.Entry entry: send_table.entrySet()) {
sb.append(entry.getKey()).append(": ").append(entry.getValue()).append("\n");
}
}
if(!recv_table.isEmpty()) {
sb.append("\nreceive connections:\n");
for(Map.Entry entry: recv_table.entrySet()) {
sb.append(entry.getKey()).append(": ").append(entry.getValue()).append("\n");
}
}
return sb.toString();
}
@ManagedAttribute
public long getNumMessagesSent() {
return num_msgs_sent;
}
@ManagedAttribute
public long getNumMessagesReceived() {
return num_msgs_received;
}
@ManagedAttribute
public long getNumBytesSent() {
return num_bytes_sent;
}
@ManagedAttribute
public long getNumBytesReceived() {
return num_bytes_received;
}
@ManagedAttribute
public long getNumberOfRetransmissions() {
return num_xmits;
}
public long getMaxRetransmitTime() {
return max_retransmit_time;
}
@Property(description="Max number of milliseconds we try to retransmit a message to any given member. After that, " +
"the connection is removed. Any new connection to that member will start with seqno #1 again. 0 disables this")
public void setMaxRetransmitTime(long max_retransmit_time) {
this.max_retransmit_time=max_retransmit_time;
if(cache != null && max_retransmit_time > 0)
cache.setTimeout(max_retransmit_time);
}
@ManagedAttribute
public int getAgeOutCacheSize() {
return cache != null? cache.size() : 0;
}
@ManagedOperation
public String printAgeOutCache() {
return cache != null? cache.toString() : "n/a";
}
public AgeOutCache getAgeOutCache() {
return cache;
}
@ManagedAttribute
public int getNumberOfMessagesInReceiveWindows() {
int num=0;
for(ReceiverEntry entry: recv_table.values()) {
if(entry.received_msgs != null)
num+=entry.received_msgs.size();
}
return num;
}
public void resetStats() {
num_msgs_sent=num_msgs_received=num_bytes_sent=num_bytes_received=num_xmits=0;
}
public Map dumpStats() {
Map m=super.dumpStats();
m.put("num_msgs_sent", num_msgs_sent);
m.put("num_msgs_received", num_msgs_received);
m.put("num_bytes_sent", num_bytes_sent);
m.put("num_bytes_received", num_bytes_received);
m.put("num_xmits", num_xmits);
m.put("num_msgs_in_recv_windows", getNumberOfMessagesInReceiveWindows());
return m;
}
public TimeScheduler getTimer() {
return timer;
}
/**
* Only used for unit tests, don't use !
* @param timer
*/
public void setTimer(TimeScheduler timer) {
this.timer=timer;
}
public void init() throws Exception {
super.init();
if(max_stable_msgs < 1)
throw new IllegalArgumentException("max_stable_msgs ( " + max_stable_msgs + ") must be > 0");
}
public void start() throws Exception {
timer=getTransport().getTimer();
if(timer == null)
throw new Exception("timer is null");
if(max_retransmit_time > 0)
cache=new AgeOutCache(timer, max_retransmit_time, this);
started=true;
if(stable_interval > 0) {
startStableTask();
}
}
public void stop() {
started=false;
stopStableTask();
removeAllConnections();
}
public Object up(Event evt) {
Message msg;
Address dst, src;
Unicast2Header hdr;
switch(evt.getType()) {
case Event.MSG:
msg=(Message)evt.getArg();
dst=msg.getDest();
if(dst == null || dst.isMulticastAddress()) // only handle unicast messages
break; // pass up
// changed from removeHeader(): we cannot remove the header because if we do loopback=true at the
// transport level, we will not have the header on retransmit ! (bela Aug 22 2006)
hdr=(Unicast2Header)msg.getHeader(this.id);
if(hdr == null)
break;
src=msg.getSrc();
switch(hdr.type) {
case Unicast2Header.DATA: // received regular message
handleDataReceived(src, hdr.seqno, hdr.conn_id, hdr.first, msg, evt);
return null; // we pass the deliverable message up in handleDataReceived()
case Unicast2Header.XMIT_REQ: // received ACK for previously sent message
handleXmitRequest(src, hdr.seqno, hdr.high_seqno);
break;
case Unicast2Header.SEND_FIRST_SEQNO:
handleResendingOfFirstMessage(src);
break;
case Unicast2Header.STABLE:
stable(msg.getSrc(), hdr.seqno, hdr.high_seqno);
break;
default:
log.error("UnicastHeader type " + hdr.type + " not known !");
break;
}
return null;
}
return up_prot.up(evt); // Pass up to the layer above us
}
public Object down(Event evt) {
switch (evt.getType()) {
case Event.MSG: // Add UnicastHeader, add to AckSenderWindow and pass down
Message msg=(Message)evt.getArg();
Address dst=msg.getDest();
/* only handle unicast messages */
if (dst == null || dst.isMulticastAddress()) {
break;
}
if(!started) {
if(log.isTraceEnabled())
log.trace("discarded message as start() has not yet been called, message: " + msg);
return null;
}
SenderEntry entry=send_table.get(dst);
if(entry == null) {
entry=new SenderEntry(getNewConnectionId());
SenderEntry existing=send_table.putIfAbsent(dst, entry);
if(existing != null)
entry=existing;
else {
if(log.isTraceEnabled())
log.trace(local_addr + ": created connection to " + dst);
if(cache != null && !members.contains(dst))
cache.add(dst);
}
}
long seqno=-2;
short send_conn_id=-1;
Unicast2Header hdr;
entry.lock(); // threads will only sync if they access the same entry
try {
seqno=entry.sent_msgs_seqno;
send_conn_id=entry.send_conn_id;
hdr=Unicast2Header.createDataHeader(seqno, send_conn_id, seqno == DEFAULT_FIRST_SEQNO);
msg.putHeader(this.id, hdr);
entry.sent_msgs.addToMessages(seqno, msg); // add *including* UnicastHeader, adds to retransmitter
entry.sent_msgs_seqno++;
}
finally {
entry.unlock();
}
if(log.isTraceEnabled()) {
StringBuilder sb=new StringBuilder();
sb.append(local_addr).append(" --> DATA(").append(dst).append(": #").append(seqno).
append(", conn_id=").append(send_conn_id);
if(hdr.first) sb.append(", first");
sb.append(')');
log.trace(sb);
}
try {
down_prot.down(evt);
num_msgs_sent++;
num_bytes_sent+=msg.getLength();
}
catch(Throwable t) {
log.warn("failed sending the message", t);
}
return null; // we already passed the msg down
case Event.VIEW_CHANGE: // remove connections to peers that are not members anymore !
View view=(View)evt.getArg();
Vector new_members=view.getMembers();
Set non_members=new HashSet(send_table.keySet());
non_members.addAll(recv_table.keySet());
synchronized(members) {
members.clear();
if(new_members != null)
members.addAll(new_members);
non_members.removeAll(members);
if(cache != null) {
cache.removeAll(members);
}
}
if(!non_members.isEmpty()) {
if(log.isTraceEnabled())
log.trace("removing non members " + non_members);
for(Address non_mbr: non_members)
removeConnection(non_mbr);
}
break;
case Event.SET_LOCAL_ADDRESS:
local_addr=(Address)evt.getArg();
break;
}
return down_prot.down(evt); // Pass on to the layer below us
}
/**
* Purge all messages in window for local_addr, which are <= low. Check if the window's highest received message is
* > high: if true, retransmit all messages from high - win.high to sender
* @param sender
* @param highest_delivered
* @param highest_seen
*/
protected void stable(Address sender, long highest_delivered, long highest_seen) {
SenderEntry entry=send_table.get(sender);
AckSenderWindow win=entry != null? entry.sent_msgs : null;
if(win == null)
return;
if(log.isTraceEnabled())
log.trace(new StringBuilder().append(local_addr).append(" <-- STABLE(").append(sender).
append(": ").append(highest_delivered).append("-").append(highest_seen).append(')'));
win.ack(highest_delivered);
long win_high=win.getHighest();
if(win_high > highest_seen) {
for(long seqno=highest_seen; seqno <= win_high; seqno++) {
Message msg=win.get(seqno); // destination is still the same (the member which sent the STABLE message)
if(msg != null)
down_prot.down(new Event(Event.MSG, msg));
}
}
}
@ManagedOperation(description="Sends a STABLE message to all senders. This causes message purging and potential" +
" retransmissions from senders")
public void sendStableMessages() {
for(Map.Entry entry: recv_table.entrySet()) {
Address dest=entry.getKey();
ReceiverEntry val=entry.getValue();
NakReceiverWindow win=val != null? val.received_msgs : null;
if(win != null) {
long low=win.getHighestDelivered();
long high=win.getHighestReceived();
if(val.last_highest == high) {
if(val.num_stable_msgs >= val.max_stable_msgs) {
continue;
}
else
val.num_stable_msgs++;
}
else {
val.last_highest=high;
val.num_stable_msgs=1;
}
sendStableMessage(dest, low, high);
}
}
}
protected void sendStableMessage(Address dest, long low, long high) {
Message stable_msg=new Message(dest, null, null);
Unicast2Header hdr=Unicast2Header.createStableHeader(low, high);
stable_msg.putHeader(this.id, hdr);
if(log.isTraceEnabled()) {
StringBuilder sb=new StringBuilder();
sb.append(local_addr).append(" --> STABLE(").append(dest).append(": ").append(low).append("-").append(high).append(")");
log.trace(sb.toString());
}
down_prot.down(new Event(Event.MSG, stable_msg));
}
private void startStableTask() {
if(stable_task_future == null || stable_task_future.isDone()) {
final Runnable stable_task=new Runnable() {
public void run() {
try {
sendStableMessages();
}
catch(Throwable t) {
log.error("sending of STABLE messages failed", t);
}
}
};
stable_task_future=timer.scheduleAtFixedRate(stable_task, stable_interval, stable_interval, TimeUnit.MILLISECONDS);
if(log.isTraceEnabled())
log.trace("stable task started");
}
}
private void stopStableTask() {
if(stable_task_future != null) {
stable_task_future.cancel(false);
stable_task_future=null;
}
}
/**
* Removes and resets from connection table (which is already locked). Returns true if member was found, otherwise
* false. This method is public only so it can be invoked by unit testing, but should not otherwise be used !
*/
public void removeConnection(Address mbr) {
SenderEntry entry=send_table.remove(mbr);
if(entry != null)
entry.reset();
ReceiverEntry entry2=recv_table.remove(mbr);
if(entry2 != null) {
NakReceiverWindow win=entry2.received_msgs;
if(win != null)
sendStableMessage(mbr, win.getHighestDelivered(), win.getHighestReceived());
entry2.reset();
}
}
/**
* This method is public only so it can be invoked by unit testing, but should not otherwise be used !
*/
@ManagedOperation(description="Trashes all connections to other nodes. This is only used for testing")
public void removeAllConnections() {
for(SenderEntry entry: send_table.values())
entry.reset();
send_table.clear();
sendStableMessages();
for(ReceiverEntry entry2: recv_table.values())
entry2.reset();
recv_table.clear();
}
public void retransmit(long first_seqno, long last_seqno, Address sender) {
Unicast2Header hdr=Unicast2Header.createXmitReqHeader(first_seqno, last_seqno);
Message xmit_req=new Message(sender, null, null);
xmit_req.putHeader(this.id, hdr);
down_prot.down(new Event(Event.MSG, xmit_req));
}
/**
* Called by AgeOutCache, to removed expired connections
* @param key
*/
public void expired(Address key) {
if(key != null) {
if(log.isDebugEnabled())
log.debug("removing connection to " + key + " because it expired");
removeConnection(key);
}
}
/**
* Check whether the hashtable contains an entry e for sender (create if not). If
* e.received_msgs is null and first is true: create a new AckReceiverWindow(seqno) and
* add message. Set e.received_msgs to the new window. Else just add the message.
*/
private void handleDataReceived(Address sender, long seqno, long conn_id, boolean first, Message msg, Event evt) {
if(log.isTraceEnabled()) {
StringBuilder sb=new StringBuilder();
sb.append(local_addr).append(" <-- DATA(").append(sender).append(": #").append(seqno);
if(conn_id != 0) sb.append(", conn_id=").append(conn_id);
if(first) sb.append(", first");
sb.append(')');
log.trace(sb);
}
ReceiverEntry entry=recv_table.get(sender);
NakReceiverWindow win=entry != null? entry.received_msgs : null;
if(first) {
if(entry == null) {
entry=getOrCreateReceiverEntry(sender, seqno, conn_id);
win=entry.received_msgs;
}
else { // entry != null && win != null
if(conn_id != entry.recv_conn_id) {
if(log.isTraceEnabled())
log.trace(local_addr + ": conn_id=" + conn_id + " != " + entry.recv_conn_id + "; resetting receiver window");
ReceiverEntry entry2=recv_table.remove(sender);
if(entry2 != null)
entry2.received_msgs.destroy();
entry=getOrCreateReceiverEntry(sender, seqno, conn_id);
win=entry.received_msgs;
}
else {
;
}
}
}
else { // entry == null && win == null OR entry != null && win == null OR entry != null && win != null
if(win == null || entry.recv_conn_id != conn_id) {
sendRequestForFirstSeqno(sender); // drops the message and returns (see below)
return;
}
}
boolean added=win.add(seqno, msg); // win is guaranteed to be non-null if we get here
num_msgs_received++;
num_bytes_received+=msg.getLength();
if(added && max_bytes > 0) {
int bytes=entry.received_bytes.addAndGet(msg.getLength());
if(bytes >= max_bytes) {
entry.received_bytes_lock.lock();
try {
entry.received_bytes.set(0);
}
finally {
entry.received_bytes_lock.unlock();
}
sendStableMessage(sender, win.getHighestDelivered(), win.getHighestReceived());
}
}
// An OOB message is passed up immediately. Later, when remove() is called, we discard it. This affects ordering !
// http://jira.jboss.com/jira/browse/JGRP-377
if(msg.isFlagSet(Message.OOB) && added) {
try {
up_prot.up(evt);
}
catch(Throwable t) {
log.error("couldn't deliver OOB message " + msg, t);
}
}
final AtomicBoolean processing=win.getProcessing();
if(!processing.compareAndSet(false, true)) {
return;
}
// try to remove (from the AckReceiverWindow) as many messages as possible and pass them up
// Prevents concurrent passing up of messages by different threads (http://jira.jboss.com/jira/browse/JGRP-198);
// this is all the more important once we have a concurrent stack (http://jira.jboss.com/jira/browse/JGRP-181),
// where lots of threads can come up to this point concurrently, but only 1 is allowed to pass at a time
// We *can* deliver messages from *different* senders concurrently, e.g. reception of P1, Q1, P2, Q2 can result in
// delivery of P1, Q1, Q2, P2: FIFO (implemented by UNICAST) says messages need to be delivered only in the
// order in which they were sent by their senders
try {
while(true) {
List msgs=win.removeMany(processing, true, max_msg_batch_size); // remove my own messages
if(msgs == null || msgs.isEmpty())
return;
for(Message m: msgs) {
// discard OOB msg: it has already been delivered (http://jira.jboss.com/jira/browse/JGRP-377)
if(m.isFlagSet(Message.OOB))
continue;
try {
up_prot.up(new Event(Event.MSG, m));
}
catch(Throwable t) {
log.error("couldn't deliver message " + m, t);
}
}
}
}
finally {
processing.set(false);
}
}
private ReceiverEntry getOrCreateReceiverEntry(Address sender, long seqno, long conn_id) {
NakReceiverWindow win=new NakReceiverWindow(local_addr, sender, this, seqno-1, seqno-1, timer);
win.setDiscardDeliveredMessages(true);
ReceiverEntry entry=new ReceiverEntry(win, conn_id, max_stable_msgs);
ReceiverEntry entry2=recv_table.putIfAbsent(sender, entry);
if(entry2 != null)
return entry2;
if(log.isTraceEnabled())
log.trace(local_addr + ": created receiver window for " + sender + " at seqno=#" + seqno + " for conn-id=" + conn_id);
return entry;
}
private void handleXmitRequest(Address sender, long low, long high) {
if(log.isTraceEnabled())
log.trace(new StringBuilder().append(local_addr).append(" <-- XMIT(").append(sender).
append(": #").append(low).append( "-").append(high).append(')'));
SenderEntry entry=send_table.get(sender);
AckSenderWindow win=entry != null? entry.sent_msgs : null;
if(win != null) {
for(long i=low; i <= high; i++) {
Message msg=win.get(i);
if(msg == null) {
if(log.isWarnEnabled() && !local_addr.equals(sender)) {
StringBuilder sb=new StringBuilder();
sb.append("(requester=").append(sender).append(", local_addr=").append(this.local_addr);
sb.append(") message ").append(sender).append("::").append(i);
sb.append(" not found in retransmission table of ").append(sender).append(":\n").append(win);
log.warn(sb.toString());
}
continue;
}
down_prot.down(new Event(Event.MSG, msg));
num_xmits++;
}
}
}
/**
* We need to resend our first message with our conn_id
* @param sender
*/
private void handleResendingOfFirstMessage(Address sender) {
if(log.isTraceEnabled())
log.trace(local_addr + " <-- SEND_FIRST_SEQNO(" + sender + ")");
SenderEntry entry=send_table.get(sender);
AckSenderWindow win=entry != null? entry.sent_msgs : null;
if(win == null) {
if(log.isErrorEnabled())
log.error(local_addr + ": sender window for " + sender + " not found");
return;
}
Message rsp=win.getLowestMessage();
if(rsp == null)
return;
// We need to copy the UnicastHeader and put it back into the message because Message.copy() doesn't copy
// the headers and therefore we'd modify the original message in the sender retransmission window
// (https://jira.jboss.org/jira/browse/JGRP-965)
Message copy=rsp.copy();
Unicast2Header hdr=(Unicast2Header)copy.getHeader(this.id);
Unicast2Header newhdr=hdr.copy();
newhdr.first=true;
copy.putHeader(this.id, newhdr);
if(log.isTraceEnabled()) {
StringBuilder sb=new StringBuilder();
sb.append(local_addr).append(" --> DATA(").append(copy.getDest()).append(": #").append(newhdr.seqno).
append(", conn_id=").append(newhdr.conn_id);
if(newhdr.first) sb.append(", first");
sb.append(')');
log.trace(sb);
}
down_prot.down(new Event(Event.MSG, copy));
}
private short getNewConnectionId() {
synchronized(this) {
short retval=last_conn_id;
if(last_conn_id >= Short.MAX_VALUE || last_conn_id < 0)
last_conn_id=0;
else
last_conn_id++;
return retval;
}
}
private void sendRequestForFirstSeqno(Address dest) {
Message msg=new Message(dest);
msg.setFlag(Message.OOB);
Unicast2Header hdr=Unicast2Header.createSendFirstSeqnoHeader();
msg.putHeader(this.id, hdr);
if(log.isTraceEnabled())
log.trace(local_addr + " --> SEND_FIRST_SEQNO(" + dest + ")");
down_prot.down(new Event(Event.MSG, msg));
}
/**
* The following types and fields are serialized:
*
* | DATA | seqno | conn_id | first |
* | ACK | seqno |
* | SEND_FIRST_SEQNO |
*
*/
public static class Unicast2Header extends Header {
public static final byte DATA = 0;
public static final byte XMIT_REQ = 1;
public static final byte SEND_FIRST_SEQNO = 2;
public static final byte STABLE = 3;
byte type;
long seqno; // DATA, XMIT_REQ and STABLE
long high_seqno; // XMIT_REQ and STABLE
short conn_id; // DATA
boolean first; // DATA
public Unicast2Header() {} // used for externalization
public static Unicast2Header createDataHeader(long seqno, short conn_id, boolean first) {
return new Unicast2Header(DATA, seqno, 0L, conn_id, first);
}
public static Unicast2Header createXmitReqHeader(long low, long high) {
Unicast2Header retval=new Unicast2Header(XMIT_REQ, low);
retval.high_seqno=high;
return retval;
}
public static Unicast2Header createStableHeader(long low, long high) {
Unicast2Header retval=new Unicast2Header(STABLE, low);
retval.high_seqno=high;
return retval;
}
public static Unicast2Header createSendFirstSeqnoHeader() {
return new Unicast2Header(SEND_FIRST_SEQNO, 0L);
}
private Unicast2Header(byte type, long seqno) {
this.type=type;
this.seqno=seqno;
}
private Unicast2Header(byte type, long seqno, long high, short conn_id, boolean first) {
this.type=type;
this.seqno=seqno;
this.high_seqno=high;
this.conn_id=conn_id;
this.first=first;
}
public long getSeqno() {
return seqno;
}
public String toString() {
StringBuilder sb=new StringBuilder();
sb.append(type2Str(type)).append(", seqno=").append(seqno);
if(conn_id != 0) sb.append(", conn_id=").append(conn_id);
if(first) sb.append(", first");
return sb.toString();
}
public static String type2Str(byte t) {
switch(t) {
case DATA: return "DATA";
case XMIT_REQ: return "XMIT_REQ";
case SEND_FIRST_SEQNO: return "SEND_FIRST_SEQNO";
case STABLE: return "STABLE";
default: return "";
}
}
public final int size() {
switch(type) {
case DATA:
return Global.BYTE_SIZE *2 + Global.LONG_SIZE + Global.SHORT_SIZE;
case XMIT_REQ:
case STABLE:
return Global.BYTE_SIZE + Global.LONG_SIZE *2;
case SEND_FIRST_SEQNO:
return Global.BYTE_SIZE;
}
return 0;
}
public Unicast2Header copy() {
return new Unicast2Header(type, seqno, high_seqno, conn_id, first);
}
public void writeTo(DataOutputStream out) throws IOException {
out.writeByte(type);
switch(type) {
case DATA:
out.writeLong(seqno);
out.writeShort(conn_id);
out.writeBoolean(first);
break;
case XMIT_REQ:
case STABLE:
out.writeLong(seqno);
out.writeLong(high_seqno);
break;
case SEND_FIRST_SEQNO:
break;
}
}
public void readFrom(DataInputStream in) throws IOException, IllegalAccessException, InstantiationException {
type=in.readByte();
switch(type) {
case DATA:
seqno=in.readLong();
conn_id=in.readShort();
first=in.readBoolean();
break;
case XMIT_REQ:
case STABLE:
seqno=in.readLong();
high_seqno=in.readLong();
break;
case SEND_FIRST_SEQNO:
break;
}
}
}
private static final class SenderEntry {
// stores (and retransmits) msgs sent by us to a certain peer
final AckSenderWindow sent_msgs;
long sent_msgs_seqno=DEFAULT_FIRST_SEQNO; // seqno for msgs sent by us
final short send_conn_id;
final Lock lock=new ReentrantLock();
public SenderEntry(short send_conn_id) {
this.send_conn_id=send_conn_id;
sent_msgs=new AckSenderWindow();
}
public void lock() {
lock.lock();
}
public void unlock() {
lock.unlock();
}
void reset() {
if(sent_msgs != null)
sent_msgs.reset();
sent_msgs_seqno=DEFAULT_FIRST_SEQNO;
}
public String toString() {
StringBuilder sb=new StringBuilder();
if(sent_msgs != null)
sb.append(sent_msgs).append(", ");
sb.append("send_conn_id=" + send_conn_id);
return sb.toString();
}
}
private static final class ReceiverEntry {
private final NakReceiverWindow received_msgs; // stores all msgs rcvd by a certain peer in seqno-order
private final long recv_conn_id;
final AtomicInteger received_bytes=new AtomicInteger(0);
final Lock received_bytes_lock=new ReentrantLock();
private long last_highest=-1;
private int num_stable_msgs=0;
public final int max_stable_msgs;
public ReceiverEntry(NakReceiverWindow received_msgs, long recv_conn_id, final int max_stable_msgs) {
this.received_msgs=received_msgs;
this.recv_conn_id=recv_conn_id;
this.max_stable_msgs=max_stable_msgs;
}
void reset() {
if(received_msgs != null)
received_msgs.destroy();
received_bytes.set(0);
last_highest=-1;
num_stable_msgs=0;
}
public String toString() {
StringBuilder sb=new StringBuilder();
if(received_msgs != null)
sb.append(received_msgs).append(", ");
sb.append("recv_conn_id=" + recv_conn_id);
return sb.toString();
}
}
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