bboss.org.jgroups.protocols.UNICAST 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.atomic.AtomicBoolean;
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.DeprecatedProperty;
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.conf.PropertyConverters;
import bboss.org.jgroups.stack.AckReceiverWindow;
import bboss.org.jgroups.stack.AckSenderWindow;
import bboss.org.jgroups.stack.Protocol;
import bboss.org.jgroups.stack.StaticInterval;
import bboss.org.jgroups.util.AgeOutCache;
import bboss.org.jgroups.util.TimeScheduler;
import bboss.org.jgroups.util.Tuple;
import bboss.org.jgroups.util.Util;
/**
* Reliable unicast layer. Uses acknowledgement scheme similar to TCP to provide lossless transmission
* of unicast messages (for reliable multicast see NAKACK layer). When a message is sent to a peer for
* the first time, we add the pair to the hashtable (peer address is the key). All
* messages sent to that peer will be added to hashtable.peer_addr.sent_msgs. When we receive a
* message from a peer for the first time, another entry will be created and added to the hashtable
* (unless already existing). Msgs will then be added to hashtable.peer_addr.received_msgs. This
* layer is used to reliably transmit point-to-point messages, that is, either messages sent to a
* single receiver (vs. messages multicast to a group) or for example replies to a multicast message. The
* sender uses an AckSenderWindow which retransmits messages for which it hasn't received
* an ACK, the receiver uses AckReceiverWindow which keeps track of the lowest seqno
* received so far, and keeps messages in order.
* Messages in both AckSenderWindows and AckReceiverWindows will be removed. A message will be removed from
* AckSenderWindow when an ACK has been received for it and messages will be removed from AckReceiverWindow
* whenever a message is received: the new message is added and then we try to remove as many messages as
* possible (until we stop at a gap, or there are no more messages).
* @author Bela Ban
* @version $Id: UNICAST.java,v 1.166 2010/03/12 09:07:44 belaban Exp $
*/
@MBean(description="Reliable unicast layer")
@DeprecatedProperty(names={"immediate_ack", "use_gms", "enabled_mbrs_timeout", "eager_lock_release"})
public class UNICAST extends Protocol implements AckSenderWindow.RetransmitCommand, AgeOutCache.Handler
{
public static final long DEFAULT_FIRST_SEQNO=Global.DEFAULT_FIRST_UNICAST_SEQNO;
/* ------------------------------------------ Properties ------------------------------------------ */
@Property(description="Whether to loop back messages sent to self. Default is false",
deprecatedMessage="might get removed soon as it can destroy ordering. " +
"See https://jira.jboss.org/jira/browse/JGRP-1092 for details")
@Deprecated
private boolean loopback=false;
private long[] timeout= { 400, 800, 1600, 3200 }; // for AckSenderWindow: max time to wait for missing acks
@Property(description="Max number of messages to be removed from the AckReceiverWindow. This property might " +
"get removed anytime, so don't use it !")
private int max_msg_batch_size=50000;
/* --------------------------------------------- JMX ---------------------------------------------- */
private long num_msgs_sent=0, num_msgs_received=0, num_bytes_sent=0, num_bytes_received=0;
private long num_acks_sent=0, num_acks_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;
// didn't make this 'connected' in case we need to send early acks which may race to the socket
private volatile boolean disconnected=false;
private short last_conn_id=0;
protected long max_retransmit_time=60 * 1000L;
private AgeOutCache cache=null;
@Deprecated @ManagedAttribute
public static int getUndeliveredMessages() {
return 0;
}
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("\nsend 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 getNumAcksSent() {
return num_acks_sent;
}
@ManagedAttribute
public long getNumAcksReceived() {
return num_acks_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;
}
/** The number of messages in all Entry.sent_msgs tables (haven't received an ACK yet) */
@ManagedAttribute
public int getNumberOfUnackedMessages() {
int num=0;
for(SenderEntry entry: send_table.values()) {
if(entry.sent_msgs != null)
num+=entry.sent_msgs.size();
}
return num;
}
@ManagedOperation
public String printUnackedMessages() {
StringBuilder sb=new StringBuilder();
for(Map.Entry entry: send_table.entrySet()) {
sb.append(entry.getKey()).append(": ");
SenderEntry val=entry.getValue();
if(val.sent_msgs != null)
sb.append(val.sent_msgs).append("\n");
}
return sb.toString();
}
@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_acks_sent=num_acks_received=0;
num_xmits=0;
}
public Map dumpStats() {
Map m=super.dumpStats();
m.put("unacked_msgs", printUnackedMessages());
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_acks_sent", num_acks_sent);
m.put("num_acks_received", num_acks_received);
m.put("num_xmits", num_xmits);
m.put("num_unacked_msgs", getNumberOfUnackedMessages());
m.put("num_msgs_in_recv_windows", getNumberOfMessagesInReceiveWindows());
return m;
}
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;
}
public void stop() {
started=false;
removeAllConnections();
}
public Object up(Event evt) {
Message msg;
Address dst, src;
UnicastHeader 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=(UnicastHeader)msg.getHeader(this.id);
if(hdr == null)
break;
src=msg.getSrc();
switch(hdr.type) {
case UnicastHeader.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 UnicastHeader.ACK: // received ACK for previously sent message
handleAckReceived(src, hdr.seqno);
break;
case UnicastHeader.SEND_FIRST_SEQNO:
handleResendingOfFirstMessage(src);
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(), this, timeout, timer, local_addr);
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;
UnicastHeader 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=UnicastHeader.createDataHeader(seqno, send_conn_id, seqno == DEFAULT_FIRST_SEQNO);
msg.putHeader(this.id, hdr);
// AckSenderWindow.add() is costly as it calls Retransmitter.add() which calls TimeScheduler.schedule(),
// which adds the scheduled task to a DelayQueue, which does costly tree rebalancing.
// In 2.9 (or 3.0), we'll replace use of ScheduledThreadPoolExecutor in TimeScheduler with
// a ConcurrentSkipListMap, which is faster (log(n) access cost for most ops). CSLM requires JDK 1.6
// Note that moving the next statement out of the lock scope made for some really ugly code, that's
// why this was reverted !
// entry.sent_msgs.add(seqno, msg); // add *including* UnicastHeader, adds to retransmitter
entry.sent_msgs.addToMessages(seqno, msg); // add *including* UnicastHeader, adds to retransmitter
entry.sent_msgs_seqno++;
}
finally {
entry.unlock();
}
long sleep_time=100;
for(int i=1; i <= 10; i++) {
try {
entry.sent_msgs.addToRetransmitter(seqno, msg); // adds to retransmitter
break;
}
catch(Throwable t) {
log.error("failed adding message " + seqno + " to " + dst +
" to the retransmitter, retrying... (attempt #" + i + ")");
Util.sleep(sleep_time);
sleep_time*=2;
}
}
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);
}
// moved passing down of message out of the synchronized block: similar to NAKACK, we do *not* need
// to send unicast messages in order of sequence numbers because they will be sorted into the correct
// order at the receiver anyway. Of course, most of the time, the order will be correct (FIFO), so
// the cost of reordering is minimal. This is part of http://jira.jboss.com/jira/browse/JGRP-303
try { // we catch the exception in this case because the msg is in the XMIT table and will be retransmitted
send(msg, evt);
}
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;
case Event.CONNECT:
disconnected=false;
break;
case Event.DISCONNECT:
disconnected=true;
break;
}
return down_prot.down(evt); // Pass on to the layer below us
}
private void send(Message msg, Event evt) {
down_prot.down(evt);
num_msgs_sent++;
num_bytes_sent+=msg.getLength();
}
/**
* 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)
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();
for(ReceiverEntry entry2: recv_table.values())
entry2.reset();
recv_table.clear();
}
/** Called by AckSenderWindow to resend messages for which no ACK has been received yet */
public void retransmit(long seqno, Message msg) {
if(log.isTraceEnabled())
log.trace(local_addr + " --> XMIT(" + msg.getDest() + ": #" + seqno + ')');
down_prot.down(new Event(Event.MSG, msg));
num_xmits++;
}
/**
* 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);
AckReceiverWindow 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.reset();
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;
}
}
byte result=win.add2(seqno, msg); // win is guaranteed to be non-null if we get here
boolean added=result > 0;
num_msgs_received++;
num_bytes_received+=msg.getLength();
// Cannot be replaced with if(!added), see https://jira.jboss.org/jira/browse/JGRP-1043 comment 15/Sep/09 06:57 AM
// We *have* to do send the ACK, to cover the following scenario:
// - A sends #3 to B
// - B removes #3 and sends ACK(3) to A. B's next_to_remove is now 4
// - B's ACK(3) to A is dropped by the network
// - A keeps retransmitting #3 to B, until it gets an ACK(3)
// -B will never ACK #3 if the 2 lines below are commented ==> endless retransmission of A's #3 !
if(result == -1) { // only ack if seqno was < next_to_remove !
sendAck(sender, seqno);
}
// 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 as 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) {
Tuple,Long> tuple=win.removeMany(max_msg_batch_size);
if(tuple == null)
return;
List msgs=tuple.getVal1();
if(msgs.isEmpty())
return;
long highest_removed=tuple.getVal2();
if(highest_removed > 0)
sendAck(sender, highest_removed); // guaranteed not to throw an exception !
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) {
ReceiverEntry entry=new ReceiverEntry(new AckReceiverWindow(seqno), conn_id);
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;
}
/** Add the ACK to hashtable.sender.sent_msgs */
private void handleAckReceived(Address sender, long seqno) {
if(log.isTraceEnabled())
log.trace(new StringBuilder().append(local_addr).append(" <-- ACK(").append(sender).
append(": #").append(seqno).append(')'));
SenderEntry entry=send_table.get(sender);
AckSenderWindow win=entry != null? entry.sent_msgs : null;
if(win != null) {
win.ack(seqno); // removes message from retransmission
num_acks_received++;
}
}
/**
* 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();
UnicastHeader hdr=(UnicastHeader)copy.getHeader(this.id);
UnicastHeader 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 void sendAck(Address dst, long seqno) {
if(disconnected) // if we are disconnected, then don't send any acks which throw exceptions on shutdown
return;
Message ack=new Message(dst);
// commented Jan 23 2008 (bela): TP.enable_unicast_bundling should decide whether we bundle or not, and *not*
// the OOB flag ! Bundling UNICAST ACKs should be really fast
// https://jira.jboss.org/jira/browse/JGRP-1125; will be reverted in 2.10
// ack.setFlag(Message.OOB);
ack.putHeader(this.id, UnicastHeader.createAckHeader(seqno));
if(log.isTraceEnabled())
log.trace(new StringBuilder().append(local_addr).append(" --> ACK(").append(dst).
append(": #").append(seqno).append(')'));
try {
down_prot.down(new Event(Event.MSG, ack));
num_acks_sent++;
}
catch(Throwable t) {
log.error("failed sending ACK(" + seqno + ") to " + dst, t);
}
}
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);
UnicastHeader hdr=UnicastHeader.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 UnicastHeader extends Header {
public static final byte DATA = 0;
public static final byte ACK = 1;
public static final byte SEND_FIRST_SEQNO = 2;
byte type;
long seqno; // DATA and ACK
short conn_id; // DATA
boolean first; // DATA
public UnicastHeader() {} // used for externalization
public static UnicastHeader createDataHeader(long seqno, short conn_id, boolean first) {
return new UnicastHeader(DATA, seqno, conn_id, first);
}
public static UnicastHeader createAckHeader(long seqno) {
return new UnicastHeader(ACK, seqno);
}
public static UnicastHeader createSendFirstSeqnoHeader() {
return new UnicastHeader(SEND_FIRST_SEQNO, 0L);
}
private UnicastHeader(byte type, long seqno) {
this.type=type;
this.seqno=seqno;
}
private UnicastHeader(byte type, long seqno, short conn_id, boolean first) {
this.type=type;
this.seqno=seqno;
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 ACK: return "ACK";
case SEND_FIRST_SEQNO: return "SEND_FIRST_SEQNO";
default: return "";
}
}
public final int size() {
switch(type) {
case DATA:
return Global.BYTE_SIZE *2 + Global.LONG_SIZE + Global.SHORT_SIZE;
case ACK:
return Global.BYTE_SIZE + Global.LONG_SIZE;
case SEND_FIRST_SEQNO:
return Global.BYTE_SIZE;
}
return 0;
}
public UnicastHeader copy() {
return new UnicastHeader(type, 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 ACK:
out.writeLong(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 ACK:
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, AckSenderWindow.RetransmitCommand cmd, long[] timeout,
TimeScheduler timer, Address local_addr) {
this.send_conn_id=send_conn_id;
sent_msgs=new AckSenderWindow(cmd, new StaticInterval(timeout), timer, local_addr);
}
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 AckReceiverWindow received_msgs; // stores all msgs rcvd by a certain peer in seqno-order
private final long recv_conn_id;
public ReceiverEntry(AckReceiverWindow received_msgs, long recv_conn_id) {
this.received_msgs=received_msgs;
this.recv_conn_id=recv_conn_id;
}
void reset() {
if(received_msgs != null)
received_msgs.reset();
}
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();
}
}
}