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package org.jgroups.protocols;
import org.jgroups.*;
import org.jgroups.annotations.MBean;
import org.jgroups.annotations.ManagedAttribute;
import org.jgroups.annotations.ManagedOperation;
import org.jgroups.annotations.Property;
import org.jgroups.stack.Protocol;
import org.jgroups.util.*;
import java.io.DataInput;
import java.io.DataOutput;
import java.util.*;
import java.util.concurrent.ConcurrentMap;
import java.util.concurrent.Executor;
import java.util.concurrent.Future;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.concurrent.atomic.AtomicLong;
import java.util.concurrent.locks.ReentrantLock;
/**
* Reliable unicast protocol using a combination of positive and negative acks. See docs/design/UNICAST3.txt for details.
* @author Bela Ban
* @since 3.3
*/
@MBean(description="Reliable unicast layer")
public class UNICAST3 extends Protocol implements AgeOutCache.Handler {
protected static final long DEFAULT_FIRST_SEQNO=Global.DEFAULT_FIRST_UNICAST_SEQNO;
/* ------------------------------------------ Properties ------------------------------------------ */
@Property(description="Max number of messages to be removed from a retransmit window. This property might " +
"get removed anytime, so don't use it !")
protected int max_msg_batch_size=500;
@Property(description="Time (in milliseconds) after which an idle incoming or outgoing connection is closed. The " +
"connection will get re-established when used again. 0 disables connection reaping")
protected long conn_expiry_timeout=60000 * 2;
@Property(description="Time (in ms) until a connection marked to be closed will get removed. 0 disables this")
protected long conn_close_timeout=10000;
@Property(description="Number of rows of the matrix in the retransmission table (only for experts)",writable=false)
protected int xmit_table_num_rows=100;
@Property(description="Number of elements of a row of the matrix in the retransmission table; " +
"gets rounded to the next power of 2 (only for experts). The capacity of the matrix is xmit_table_num_rows * xmit_table_msgs_per_row",writable=false)
protected int xmit_table_msgs_per_row=1024;
@Property(description="Resize factor of the matrix in the retransmission table (only for experts)",writable=false)
protected double xmit_table_resize_factor=1.2;
@Property(description="Number of milliseconds after which the matrix in the retransmission table " +
"is compacted (only for experts)",writable=false)
protected long xmit_table_max_compaction_time=10 * 60 * 1000;
// @Property(description="Max time (in ms) after which a connection to a non-member is closed")
protected long max_retransmit_time=60 * 1000L;
@Property(description="Interval (in milliseconds) at which messages in the send windows are resent")
protected long xmit_interval=500;
@Property(description="If true, trashes warnings about retransmission messages not found in the xmit_table (used for testing)")
protected boolean log_not_found_msgs=true;
@Property(description="Send an ack for a batch immediately instead of using a delayed ack",
deprecatedMessage="replaced by ack_threshold")
@Deprecated
protected boolean ack_batches_immediately=true;
@Property(description="Send an ack immediately when a batch of ack_threshold (or more) messages is received. " +
"Otherwise send delayed acks. If 1, ack single messages (similar to UNICAST)")
protected int ack_threshold=5;
@Property(description="Min time (in ms) to elapse for successive SEND_FIRST_SEQNO messages to be sent to the same sender")
protected long sync_min_interval=2000;
@Property(description="Max number of messages to ask for in a retransmit request. 0 disables this and uses " +
"the max bundle size in the transport")
protected int max_xmit_req_size;
/* --------------------------------------------- JMX ---------------------------------------------- */
protected long num_msgs_sent=0, num_msgs_received=0;
protected long num_acks_sent=0, num_acks_received=0, num_xmits=0;
@ManagedAttribute(description="Number of retransmit requests received")
protected final AtomicLong xmit_reqs_received=new AtomicLong(0);
@ManagedAttribute(description="Number of retransmit requests sent")
protected final AtomicLong xmit_reqs_sent=new AtomicLong(0);
@ManagedAttribute(description="Number of retransmit responses sent")
protected final AtomicLong xmit_rsps_sent=new AtomicLong(0);
/* --------------------------------------------- Fields ------------------------------------------------ */
protected final ConcurrentMap send_table=Util.createConcurrentMap();
protected final ConcurrentMap recv_table=Util.createConcurrentMap();
protected final ReentrantLock recv_table_lock=new ReentrantLock();
/** Used by the retransmit task to keep the last retransmitted seqno per sender (https://issues.jboss.org/browse/JGRP-1539) */
protected final Map xmit_task_map=new HashMap<>();
/** RetransmitTask running every xmit_interval ms */
protected Future xmit_task;
protected volatile List members=new ArrayList<>(11);
protected Address local_addr;
protected TimeScheduler timer; // used for retransmissions
protected volatile boolean running=false;
protected short last_conn_id;
protected AgeOutCache cache;
protected TimeService time_service; // for aging out of receiver and send entries
protected final AtomicLong timestamper=new AtomicLong(0); // timestamping of ACKs / SEND_FIRST-SEQNOs
/** Keep track of when a SEND_FIRST_SEQNO message was sent to a given sender */
protected ExpiryCache last_sync_sent=null;
protected static final Message DUMMY_OOB_MSG=new Message().setFlag(Message.Flag.OOB);
protected final Filter drop_oob_and_dont_loopback_msgs_filter=new Filter() {
public boolean accept(Message msg) {
return msg != null && msg != DUMMY_OOB_MSG
&& (!msg.isFlagSet(Message.Flag.OOB) || msg.setTransientFlagIfAbsent(Message.TransientFlag.OOB_DELIVERED))
&& !(msg.isTransientFlagSet(Message.TransientFlag.DONT_LOOPBACK) && local_addr != null && local_addr.equals(msg.src()));
}
};
protected static final Filter dont_loopback_filter=new Filter() {
public boolean accept(Message msg) {
return msg != null && msg.isTransientFlagSet(Message.TransientFlag.DONT_LOOPBACK);
}
};
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 Util.printListWithDelimiter(members, ",");}
@ManagedAttribute(description="Returns the number of outgoing (send) connections")
public int getNumSendConnections() {
return send_table.size();
}
@ManagedAttribute(description="Returns the number of incoming (receive) connections")
public int getNumReceiveConnections() {
return recv_table.size();
}
@ManagedAttribute(description="Returns the total number of outgoing (send) and incoming (receive) connections")
public int getNumConnections() {
return getNumReceiveConnections() + getNumSendConnections();
}
@ManagedAttribute(description="Next seqno issued by the timestamper")
public long getTimestamper() {return timestamper.get();}
@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 getNumAcksSent() {return num_acks_sent;}
@ManagedAttribute
public long getNumAcksReceived() {return num_acks_received;}
@ManagedAttribute
public long getNumXmits() {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(description="Is the retransmit task running")
public boolean isXmitTaskRunning() {return xmit_task != null && !xmit_task.isDone();}
@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;
}
/** Used for testing only */
public boolean hasSendConnectionTo(Address dest) {
Entry entry=send_table.get(dest);
return entry != null && entry.state() == State.OPEN;
}
/** The number of messages in all Entry.sent_msgs tables (haven't received an ACK yet) */
@ManagedAttribute
public int getNumUnackedMessages() {
int num=0;
for(Entry entry: send_table.values()) {
if(entry.msgs != null)
num+=entry.msgs.size();
}
return num;
}
@ManagedAttribute(description="Total number of undelivered messages in all receive windows")
public long getXmitTableUndeliveredMessages() {
long retval=0;
for(Entry entry: recv_table.values()) {
if(entry.msgs != null)
retval+=entry.msgs.size();
}
return retval;
}
@ManagedAttribute(description="Total number of missing messages in all receive windows")
public long getXmitTableMissingMessages() {
long retval=0;
for(Entry entry: recv_table.values()) {
if(entry.msgs != null)
retval+=entry.msgs.getNumMissing();
}
return retval;
}
@ManagedAttribute(description="Number of compactions in all (receive and send) windows")
public int getXmitTableNumCompactions() {
int retval=0;
for(Entry entry: recv_table.values()) {
if(entry.msgs != null)
retval+=entry.msgs.getNumCompactions();
}
for(Entry entry: send_table.values()) {
if(entry.msgs != null)
retval+=entry.msgs.getNumCompactions();
}
return retval;
}
@ManagedAttribute(description="Number of moves in all (receive and send) windows")
public int getXmitTableNumMoves() {
int retval=0;
for(Entry entry: recv_table.values()) {
if(entry.msgs != null)
retval+=entry.msgs.getNumMoves();
}
for(Entry entry: send_table.values()) {
if(entry.msgs != null)
retval+=entry.msgs.getNumMoves();
}
return retval;
}
@ManagedAttribute(description="Number of resizes in all (receive and send) windows")
public int getXmitTableNumResizes() {
int retval=0;
for(Entry entry: recv_table.values()) {
if(entry.msgs != null)
retval+=entry.msgs.getNumResizes();
}
for(Entry entry: send_table.values()) {
if(entry.msgs != null)
retval+=entry.msgs.getNumResizes();
}
return retval;
}
@ManagedAttribute(description="Number of purges in all (receive and send) windows")
public int getXmitTableNumPurges() {
int retval=0;
for(Entry entry: recv_table.values()) {
if(entry.msgs != null)
retval+=entry.msgs.getNumPurges();
}
for(Entry entry: send_table.values()) {
if(entry.msgs != null)
retval+=entry.msgs.getNumPurges();
}
return retval;
}
@ManagedOperation(description="Prints the contents of the receive windows for all members")
public String printReceiveWindowMessages() {
StringBuilder ret=new StringBuilder(local_addr + ":\n");
for(Map.Entry entry: recv_table.entrySet()) {
Address addr=entry.getKey();
Table buf=entry.getValue().msgs;
ret.append(addr).append(": ").append(buf.toString()).append('\n');
}
return ret.toString();
}
@ManagedOperation(description="Prints the contents of the send windows for all members")
public String printSendWindowMessages() {
StringBuilder ret=new StringBuilder(local_addr + ":\n");
for(Map.Entry entry: send_table.entrySet()) {
Address addr=entry.getKey();
Table buf=entry.getValue().msgs;
ret.append(addr).append(": ").append(buf.toString()).append('\n');
}
return ret.toString();
}
public void resetStats() {
num_msgs_sent=num_msgs_received=num_acks_sent=num_acks_received=num_xmits=0;
}
public Map dumpStats() {
Map m=super.dumpStats();
m.put("num_unacked_msgs", getNumUnackedMessages());
m.put("num_msgs_in_recv_windows", getXmitTableUndeliveredMessages());
return m;
}
public void init() throws Exception {
super.init();
time_service=getTransport().getTimeService();
if(time_service == null)
throw new IllegalStateException("time service from transport is null");
last_sync_sent=new ExpiryCache<>(sync_min_interval);
// max bundle size (minus overhead) divided by times bits per long
int estimated_max_msgs_in_xmit_req=(getTransport().getMaxBundleSize() -50) * Global.LONG_SIZE;
int old_max_xmit_size=max_xmit_req_size;
if(max_xmit_req_size <= 0)
max_xmit_req_size=estimated_max_msgs_in_xmit_req;
else
max_xmit_req_size=Math.min(max_xmit_req_size, estimated_max_msgs_in_xmit_req);
if(old_max_xmit_size != max_xmit_req_size)
log.trace("%s: set max_xmit_req_size from %d to %d", local_addr, old_max_xmit_size, max_xmit_req_size);
}
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);
running=true;
startRetransmitTask();
}
public void stop() {
sendPendingAcks();
running=false;
stopRetransmitTask();
xmit_task_map.clear();
removeAllConnections();
}
public Object up(Event evt) {
switch(evt.getType()) {
case Event.MSG:
Message msg=(Message)evt.getArg();
if(msg.getDest() == null || msg.isFlagSet(Message.Flag.NO_RELIABILITY)) // only handle unicast messages
break; // pass up
Header hdr=(Header)msg.getHeader(this.id);
if(hdr == null)
break;
Address sender=msg.getSrc();
switch(hdr.type) {
case Header.DATA: // received regular message
if(log.isTraceEnabled())
log.trace("%s <-- DATA(%s: #%d, conn_id=%d%s)", local_addr, sender, hdr.seqno, hdr.conn_id, hdr.first? ", first" : "");
if(local_addr != null && local_addr.equals(sender))
handleDataReceivedFromSelf(sender, hdr.seqno, msg);
else
handleDataReceived(sender, hdr.seqno, hdr.conn_id, hdr.first, msg, evt);
break; // we pass the deliverable message up in handleDataReceived()
default:
handleUpEvent(sender, msg, hdr);
break;
}
return null;
}
return up_prot.up(evt); // Pass up to the layer above us
}
protected void handleUpEvent(Address sender, Message msg, Header hdr) {
try {
switch(hdr.type) {
case Header.DATA: // received regular message
throw new IllegalStateException("header of type DATA is not supposed to be handled by this method");
case Header.ACK: // received ACK for previously sent message
handleAckReceived(sender, hdr.seqno, hdr.conn_id, hdr.timestamp());
break;
case Header.SEND_FIRST_SEQNO:
handleResendingOfFirstMessage(sender, hdr.timestamp());
break;
case Header.XMIT_REQ: // received ACK for previously sent message
handleXmitRequest(sender, (SeqnoList)msg.getObject());
break;
case Header.CLOSE:
log.trace(local_addr + "%s <-- CLOSE(%s: conn-id=%s)", local_addr, sender, hdr.conn_id);
ReceiverEntry entry=recv_table.get(sender);
if(entry != null && entry.connId() == hdr.conn_id) {
recv_table.remove(sender, entry);
log.trace("%s: removed receive connection for %s", local_addr, sender);
}
break;
default:
log.error(Util.getMessage("TypeNotKnown"), local_addr, hdr.type);
break;
}
}
catch(Throwable t) { // we cannot let an exception terminate the processing of this batch
log.error(Util.getMessage("FailedHandlingEvent"), local_addr, t);
}
}
public void up(MessageBatch batch) {
if(batch.dest() == null) { // not a unicast batch
up_prot.up(batch);
return;
}
if(local_addr == null || local_addr.equals(batch.sender())) {
Entry entry=local_addr != null? send_table.get(local_addr) : null;
if(entry != null)
handleBatchFromSelf(batch, entry);
return;
}
int size=batch.size();
Map>> msgs=new LinkedHashMap<>();
ReceiverEntry entry=recv_table.get(batch.sender());
for(Message msg: batch) {
Header hdr;
if(msg == null || msg.isFlagSet(Message.Flag.NO_RELIABILITY) || (hdr=(Header)msg.getHeader(id)) == null)
continue;
batch.remove(msg); // remove the message from the batch, so it won't be passed up the stack
if(hdr.type != Header.DATA) {
handleUpEvent(msg.getSrc(), msg, hdr);
continue;
}
List> list=msgs.get(hdr.conn_id);
if(list == null)
msgs.put(hdr.conn_id, list=new ArrayList<>(size));
list.add(new Tuple<>(hdr.seqno(), msg));
if(hdr.first)
entry=getReceiverEntry(batch.sender(), hdr.seqno(), hdr.first, hdr.connId());
}
if(!msgs.isEmpty()) {
if(entry == null)
sendRequestForFirstSeqno(batch.sender());
else {
if(msgs.keySet().retainAll(Collections.singletonList(entry.connId()))) // remove all conn-ids that don't match
sendRequestForFirstSeqno(batch.sender());
List> list=msgs.get(entry.connId());
if(list != null && !list.isEmpty())
handleBatchReceived(entry, batch.sender(), list, batch.mode() == MessageBatch.Mode.OOB);
}
}
if(!batch.isEmpty())
up_prot.up(batch);
}
protected void handleBatchFromSelf(MessageBatch batch, Entry entry) {
List> list=new ArrayList<>(batch.size());
for(Message msg: batch) {
Header hdr;
if(msg == null || msg.isFlagSet(Message.Flag.NO_RELIABILITY) || (hdr=(Header)msg.getHeader(id)) == null)
continue;
batch.remove(msg); // remove the message from the batch, so it won't be passed up the stack
if(hdr.type != Header.DATA) {
handleUpEvent(msg.getSrc(), msg, hdr);
continue;
}
if(entry.conn_id != hdr.conn_id) {
batch.remove(msg);
continue;
}
list.add(new Tuple<>(hdr.seqno(), msg));
}
if(!list.isEmpty()) {
if(log.isTraceEnabled())
log.trace("%s <-- DATA(%s: %s)", local_addr, batch.sender(), printMessageList(list));
int len=list.size();
Table win=entry.msgs;
update(entry, len);
// OOB msg is passed up. When removed, we discard it. Affects ordering: http://jira.jboss.com/jira/browse/JGRP-379
if(batch.mode() == MessageBatch.Mode.OOB) {
MessageBatch oob_batch=new MessageBatch(local_addr, batch.sender(), batch.clusterName(), batch.multicast(), MessageBatch.Mode.OOB, len);
for(Tuple tuple: list) {
long seq=tuple.getVal1();
Message msg=win.get(seq); // we *have* to get the message, because loopback means we didn't add it to win !
if(msg != null && msg.isFlagSet(Message.Flag.OOB) && msg.setTransientFlagIfAbsent(Message.TransientFlag.OOB_DELIVERED))
oob_batch.add(msg);
}
deliverBatch(oob_batch);
}
final AtomicBoolean processing=win.getProcessing();
if(processing.compareAndSet(false, true))
removeAndDeliver(processing, win, batch.sender());
}
if(!batch.isEmpty())
up_prot.up(batch);
}
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 || msg.isFlagSet(Message.Flag.NO_RELIABILITY))
break;
if(!running) {
log.trace("%s: discarded message as start() has not yet been called, message: %s", local_addr, msg);
return null;
}
if(msg.src() == null)
msg.src(local_addr); // this needs to be done so we can check whether the message sender is the local_addr
SenderEntry entry=getSenderEntry(dst);
boolean dont_loopback_set=msg.isTransientFlagSet(Message.TransientFlag.DONT_LOOPBACK)
&& dst.equals(local_addr);
short send_conn_id=entry.connId();
long seqno=entry.sent_msgs_seqno.getAndIncrement();
long sleep=10;
do {
try {
msg.putHeader(this.id,Header.createDataHeader(seqno,send_conn_id,seqno == DEFAULT_FIRST_SEQNO));
entry.msgs.add(seqno, msg, dont_loopback_set? dont_loopback_filter : null); // add *including* UnicastHeader, adds to retransmitter
if(conn_expiry_timeout > 0)
entry.update();
if(dont_loopback_set)
entry.msgs.purge(entry.msgs.getHighestDeliverable());
break;
}
catch(Throwable t) {
if(running) {
Util.sleep(sleep);
sleep=Math.min(5000, sleep*2);
}
}
}
while(running);
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(seqno == DEFAULT_FIRST_SEQNO) sb.append(", first");
sb.append(')');
log.trace(sb);
}
num_msgs_sent++;
return down_prot.down(evt);
case Event.VIEW_CHANGE: // remove connections to peers that are not members anymore !
View view=(View)evt.getArg();
List new_members=view.getMembers();
Set non_members=new HashSet<>(send_table.keySet());
non_members.addAll(recv_table.keySet());
members=new_members;
non_members.removeAll(new_members);
if(cache != null)
cache.removeAll(new_members);
if(!non_members.isEmpty()) {
log.trace("%s: closing connections of non members %s", local_addr, non_members);
for(Address non_mbr: non_members)
closeConnection(non_mbr);
}
if(!new_members.isEmpty()) {
for(Address mbr: new_members) {
Entry e=send_table.get(mbr);
if(e != null && e.state() == State.CLOSING)
e.state(State.OPEN);
e=recv_table.get(mbr);
if(e != null && e.state() == State.CLOSING)
e.state(State.OPEN);
}
}
xmit_task_map.keySet().retainAll(new_members);
last_sync_sent.removeExpiredElements();
break;
case Event.SET_LOCAL_ADDRESS:
local_addr=(Address)evt.getArg();
break;
}
return down_prot.down(evt); // Pass on to the layer below us
}
/**
* 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 be used !
*/
public void closeConnection(Address mbr) {
closeSendConnection(mbr);
closeReceiveConnection(mbr);
}
public void closeSendConnection(Address mbr) {
SenderEntry entry=send_table.get(mbr);
if(entry != null)
entry.state(State.CLOSING);
}
public void closeReceiveConnection(Address mbr) {
ReceiverEntry entry=recv_table.get(mbr);
if(entry != null)
entry.state(State.CLOSING);
}
protected void removeSendConnection(Address mbr) {
SenderEntry entry=send_table.remove(mbr);
if(entry != null) {
entry.state(State.CLOSED);
if(members.contains(mbr))
sendClose(mbr, entry.connId());
}
}
protected void removeReceiveConnection(Address mbr) {
sendPendingAcks();
ReceiverEntry entry=recv_table.remove(mbr);
if(entry != null)
entry.state(State.CLOSED);
}
/**
* 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() {
send_table.clear();
recv_table.clear();
}
/** Sends a retransmit request to the given sender */
protected void retransmit(SeqnoList missing, Address sender) {
Message xmit_msg=new Message(sender, missing).setFlag(Message.Flag.OOB, Message.Flag.INTERNAL)
.putHeader(id, Header.createXmitReqHeader());
if(log.isTraceEnabled())
log.trace("%s: sending XMIT_REQ (%s) to %s", local_addr, missing, sender);
down_prot.down(new Event(Event.MSG, xmit_msg));
xmit_reqs_sent.addAndGet(missing.size());
}
/** Called by the sender to resend messages for which no ACK has been received yet */
protected void retransmit(Message msg) {
if(log.isTraceEnabled()) {
Header hdr=(Header)msg.getHeader(id);
long seqno=hdr != null? hdr.seqno : -1;
log.trace("%s --> XMIT(%s: #%d)", local_addr, 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) {
log.debug("%s: removing connection to %s because it expired", local_addr, key);
closeConnection(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.
*/
protected void handleDataReceived(final Address sender, long seqno, short conn_id, boolean first, final Message msg, Event evt) {
ReceiverEntry entry=getReceiverEntry(sender, seqno, first, conn_id);
if(entry == null)
return;
update(entry, 1);
boolean oob=msg.isFlagSet(Message.Flag.OOB);
final Table win=entry.msgs;
boolean added=win.add(seqno, oob? DUMMY_OOB_MSG : msg); // adding the same dummy OOB msg saves space (we won't remove it)
if(ack_threshold <= 1)
sendAck(sender, win.getHighestDeliverable(), entry.connId());
else
entry.sendAck(true); // will be sent delayed (on the next xmit_interval)
// 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(oob) {
if(added)
deliverMessage(evt, sender, seqno);
// we don't steal work if the message is internal (https://issues.jboss.org/browse/JGRP-1733)
if(msg.isFlagSet(Message.Flag.INTERNAL)) {
processInternalMessage(win, sender);
return;
}
}
final AtomicBoolean processing=win.getProcessing();
if(processing.compareAndSet(false, true))
removeAndDeliver(processing, win, sender);
}
/** Called when the sender of a message is the local member. In this case, we don't need to add the message
* to the table as the sender already did that */
protected void handleDataReceivedFromSelf(final Address sender, long seqno, Message msg) {
Entry entry=send_table.get(sender);
if(entry == null || entry.state() == State.CLOSED) {
log.warn("%s: entry not found for %s; dropping message", local_addr, sender);
return;
}
update(entry, 1);
final Table win=entry.msgs;
// 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.Flag.OOB)) {
msg=win.get(seqno); // we *have* to get a message, because loopback means we didn't add it to win !
if(msg != null && msg.isFlagSet(Message.Flag.OOB) && msg.setTransientFlagIfAbsent(Message.TransientFlag.OOB_DELIVERED))
deliverMessage(new Event(Event.MSG, msg), sender, seqno);
// we don't steal work if the message is internal (https://issues.jboss.org/browse/JGRP-1733)
if(msg != null && msg.isFlagSet(Message.Flag.INTERNAL)) {
processInternalMessage(win, sender);
return;
}
}
final AtomicBoolean processing=win.getProcessing();
if(processing.compareAndSet(false, true))
removeAndDeliver(processing, win, sender);
}
protected void processInternalMessage(final Table win, final Address sender) {
// If there are other msgs, tell the regular thread pool to handle them (https://issues.jboss.org/browse/JGRP-1732)
final AtomicBoolean processing=win.getProcessing();
if(!win.isEmpty() && !processing.get() /* && seqno < win.getHighestReceived() */) { // commented to handle hd == hr !
Executor pool=getTransport().getDefaultThreadPool();
pool.execute(new Runnable() {
public void run() {
if(processing.compareAndSet(false, true))
removeAndDeliver(processing, win, sender);
}
});
}
}
protected void handleBatchReceived(final ReceiverEntry entry, Address sender, List> msgs, boolean oob) {
if(log.isTraceEnabled())
log.trace("%s <-- DATA(%s: %s)", local_addr, sender, printMessageList(msgs));
int batch_size=msgs.size();
Table win=entry.msgs;
// adds all messages to the table, removing messages from 'msgs' which could not be added (already present)
boolean added=win.add(msgs, oob, oob? DUMMY_OOB_MSG : null);
update(entry, batch_size);
if(batch_size >= ack_threshold)
sendAck(sender, win.getHighestDeliverable(), entry.connId());
else
entry.sendAck(true);
// OOB msg is passed up. When removed, we discard it. Affects ordering: http://jira.jboss.com/jira/browse/JGRP-379
if(added && oob) {
MessageBatch oob_batch=new MessageBatch(local_addr, sender, null, false, MessageBatch.Mode.OOB, msgs.size());
for(Tuple tuple: msgs)
oob_batch.add(tuple.getVal2());
deliverBatch(oob_batch);
}
final AtomicBoolean processing=win.getProcessing();
if(processing.compareAndSet(false, true))
removeAndDeliver(processing, win, sender);
}
/**
* Try to remove as many messages as possible from the table as pass them up.
* Prevents concurrent passing up of messages by different threads (http://jira.jboss.com/jira/browse/JGRP-198);
* 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 in the
* order in which they were sent
*/
protected void removeAndDeliver(final AtomicBoolean processing, Table win, Address sender) {
boolean released_processing=false;
try {
while(true) {
List list=win.removeMany(processing, true, max_msg_batch_size, drop_oob_and_dont_loopback_msgs_filter);
if(list != null) // list is guaranteed to NOT contain any OOB messages as the drop_oob_msgs_filter removed them
deliverBatch(new MessageBatch(local_addr, sender, null, false, list));
else {
released_processing=true;
return;
}
}
}
finally {
// processing is always set in win.remove(processing) above and never here ! This code is just a
// 2nd line of defense should there be an exception before win.removeMany(processing) sets processing
if(!released_processing)
processing.set(false);
}
}
protected String printMessageList(List> list) {
StringBuilder sb=new StringBuilder();
int size=list.size();
Message first=size > 0? list.get(0).getVal2() : null, second=size > 1? list.get(size-1).getVal2() : first;
Header hdr;
if(first != null) {
hdr=(Header)first.getHeader(id);
if(hdr != null)
sb.append("#" + hdr.seqno);
}
if(second != null) {
hdr=(Header)second.getHeader(id);
if(hdr != null)
sb.append(" - #" + hdr.seqno);
}
return sb.toString();
}
protected ReceiverEntry getReceiverEntry(Address sender, long seqno, boolean first, short conn_id) {
ReceiverEntry entry=recv_table.get(sender);
if(entry != null && entry.connId() == conn_id)
return entry;
recv_table_lock.lock();
try {
entry=recv_table.get(sender);
if(first) {
if(entry == null) {
entry=createReceiverEntry(sender,seqno,conn_id);
}
else { // entry != null && win != null
if(conn_id != entry.connId()) {
log.trace("%s: conn_id=%d != %d; resetting receiver window", local_addr, conn_id, entry.connId());
recv_table.remove(sender);
entry=createReceiverEntry(sender,seqno,conn_id);
}
}
}
else { // entry == null && win == null OR entry != null && win == null OR entry != null && win != null
if(entry == null || entry.connId() != conn_id) {
recv_table_lock.unlock();
sendRequestForFirstSeqno(sender); // drops the message and returns (see below)
return null;
}
}
return entry;
}
finally {
if(recv_table_lock.isHeldByCurrentThread())
recv_table_lock.unlock();
}
}
protected SenderEntry getSenderEntry(Address dst) {
SenderEntry entry=send_table.get(dst);
if(entry == null || entry.state() == State.CLOSED) {
if(entry != null)
send_table.remove(dst, entry);
entry=new SenderEntry(getNewConnectionId());
SenderEntry existing=send_table.putIfAbsent(dst, entry);
if(existing != null)
entry=existing;
else {
log.trace("%s: created sender window for %s (conn-id=%s)", local_addr, dst, entry.connId());
if(cache != null && !members.contains(dst))
cache.add(dst);
}
}
if(entry.state() == State.CLOSING)
entry.state(State.OPEN);
return entry;
}
protected ReceiverEntry createReceiverEntry(Address sender, long seqno, short conn_id) {
Table table=new Table<>(xmit_table_num_rows, xmit_table_msgs_per_row, seqno-1,
xmit_table_resize_factor, xmit_table_max_compaction_time);
ReceiverEntry entry=new ReceiverEntry(table, conn_id);
ReceiverEntry entry2=recv_table.putIfAbsent(sender, entry);
if(entry2 != null)
return entry2;
log.trace("%s: created receiver window for %s at seqno=#%d for conn-id=%d", local_addr, sender, seqno, conn_id);
return entry;
}
/** Add the ACK to hashtable.sender.sent_msgs */
protected void handleAckReceived(Address sender, long seqno, short conn_id, long timestamp) {
if(log.isTraceEnabled())
log.trace("%s <-- ACK(%s: #%d, conn-id=%d, ts=%d)", local_addr, sender, seqno, conn_id, timestamp);
SenderEntry entry=send_table.get(sender);
if(entry != null && entry.connId() != conn_id) {
log.trace("%s: my conn_id (%d) != received conn_id (%d); discarding ACK", local_addr, entry.connId(), conn_id);
return;
}
Table win=entry != null? entry.msgs : null;
if(win != null && entry.updateLastTimestamp(timestamp)) {
win.purge(seqno, true); // removes all messages <= seqno (forced purge)
num_acks_received++;
}
}
/**
* We need to resend the first message with our conn_id
* @param sender
*/
protected void handleResendingOfFirstMessage(Address sender, long timestamp) {
log.trace("%s <-- SEND_FIRST_SEQNO(%s)", local_addr, sender);
SenderEntry entry=send_table.get(sender);
Table win=entry != null? entry.msgs : null;
if(win == null) {
log.warn(Util.getMessage("SenderNotFound"), local_addr, sender);
return;
}
if(!entry.updateLastTimestamp(timestamp))
return;
Message rsp=win.get(win.getLow() +1);
if(rsp != null) {
// 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();
Header hdr=(Header)copy.getHeader(this.id);
Header newhdr=hdr.copy();
newhdr.first=true;
copy.putHeader(this.id, newhdr);
down_prot.down(new Event(Event.MSG, copy));
}
}
protected void handleXmitRequest(Address sender, SeqnoList missing) {
if(log.isTraceEnabled())
log.trace("%s <-- XMIT(%s: #%s)", local_addr, sender, missing);
SenderEntry entry=send_table.get(sender);
xmit_reqs_received.addAndGet(missing.size());
Table win=entry != null? entry.msgs : null;
if(win != null) {
for(long seqno: missing) {
Message msg=win.get(seqno);
if(msg == null) {
if(log.isWarnEnabled() && log_not_found_msgs && !local_addr.equals(sender) && seqno > win.getLow())
log.warn(Util.getMessage("MessageNotFound"), local_addr, sender, seqno);
continue;
}
down_prot.down(new Event(Event.MSG, msg));
xmit_rsps_sent.incrementAndGet();
}
}
}
protected void deliverMessage(final Event evt, final Address sender, final long seqno) {
if(log.isTraceEnabled())
log.trace("%s: delivering %s#%s", local_addr, sender, seqno);
try {
up_prot.up(evt);
}
catch(Throwable t) {
Message msg=(Message)evt.getArg();
log.error(Util.getMessage("FailedToDeliverMsg"), local_addr, msg.isFlagSet(Message.Flag.OOB) ?
"OOB message" : "message", msg, t);
}
}
protected void deliverBatch(MessageBatch batch) {
try {
if(batch.isEmpty())
return;
if(log.isTraceEnabled()) {
Message first=batch.first(), last=batch.last();
StringBuilder sb=new StringBuilder(local_addr + ": delivering");
if(first != null && last != null) {
Header hdr1=(Header)first.getHeader(id), hdr2=(Header)last.getHeader(id);
sb.append(" #").append(hdr1.seqno).append(" - #").append(hdr2.seqno);
}
sb.append(" (" + batch.size()).append(" messages)");
log.trace(sb);
}
up_prot.up(batch);
}
catch(Throwable t) {
log.error(Util.getMessage("FailedToDeliverMsg"), local_addr, "batch", batch, t);
}
}
protected long getTimestamp() {
return time_service.timestamp();
}
protected void startRetransmitTask() {
if(xmit_task == null || xmit_task.isDone())
xmit_task=timer.scheduleWithFixedDelay(new RetransmitTask(), 0, xmit_interval, TimeUnit.MILLISECONDS);
}
protected void stopRetransmitTask() {
if(xmit_task != null) {
xmit_task.cancel(true);
xmit_task=null;
}
}
protected void sendAck(Address dst, long seqno, short conn_id) {
if(!running) // if we are disconnected, then don't send any acks which throw exceptions on shutdown
return;
Message ack=new Message(dst).setFlag(Message.Flag.INTERNAL).
putHeader(this.id, Header.createAckHeader(seqno, conn_id, timestamper.incrementAndGet()));
if(log.isTraceEnabled())
log.trace("%s --> ACK(%s: #%d)", local_addr, dst, seqno);
try {
down_prot.down(new Event(Event.MSG, ack));
num_acks_sent++;
}
catch(Throwable t) {
log.error(Util.getMessage("FailedSendingAck"), local_addr, seqno, dst, t);
}
}
protected synchronized short getNewConnectionId() {
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;
}
protected void sendRequestForFirstSeqno(Address dest) {
if(last_sync_sent.addIfAbsentOrExpired(dest)) {
Message msg=new Message(dest).setFlag(Message.Flag.OOB)
.putHeader(this.id, Header.createSendFirstSeqnoHeader(timestamper.incrementAndGet()));
log.trace("%s --> SEND_FIRST_SEQNO(%s)", local_addr, dest);
down_prot.down(new Event(Event.MSG, msg));
}
}
public void sendClose(Address dest, short conn_id) {
Message msg=new Message(dest).setFlag(Message.Flag.INTERNAL).putHeader(id, Header.createCloseHeader(conn_id));
log.trace("%s --> CLOSE(%s, conn-id=%d)", local_addr, dest, conn_id);
down_prot.down(new Event(Event.MSG, msg));
}
@ManagedOperation(description="Closes connections that have been idle for more than conn_expiry_timeout ms")
public void closeIdleConnections() {
// close expired connections in send_table
for(Map.Entry entry: send_table.entrySet()) {
SenderEntry val=entry.getValue();
if(val.state() != State.OPEN) // only look at open connections
continue;
long age=val.age();
if(age >= conn_expiry_timeout) {
log.debug("%s: closing expired connection for %s (%d ms old) in send_table",
local_addr, entry.getKey(), age);
closeSendConnection(entry.getKey());
}
}
// close expired connections in recv_table
for(Map.Entry entry: recv_table.entrySet()) {
ReceiverEntry val=entry.getValue();
if(val.state() != State.OPEN) // only look at open connections
continue;
long age=val.age();
if(age >= conn_expiry_timeout) {
log.debug("%s: closing expired connection for %s (%d ms old) in recv_table",
local_addr, entry.getKey(), age);
closeReceiveConnection(entry.getKey());
}
}
}
@ManagedOperation(description="Removes connections that have been closed for more than conn_close_timeout ms")
public int removeExpiredConnections() {
int num_removed=0;
// remove expired connections from send_table
for(Map.Entry entry: send_table.entrySet()) {
SenderEntry val=entry.getValue();
if(val.state() == State.OPEN) // only look at closing or closed connections
continue;
long age=val.age();
if(age >= conn_close_timeout) {
log.debug("%s: removing expired connection for %s (%d ms old) from send_table",
local_addr, entry.getKey(), age);
removeSendConnection(entry.getKey());
num_removed++;
}
}
// remove expired connections from recv_table
for(Map.Entry entry: recv_table.entrySet()) {
ReceiverEntry val=entry.getValue();
if(val.state() == State.OPEN) // only look at closing or closed connections
continue;
long age=val.age();
if(age >= conn_close_timeout) {
log.debug("%s: removing expired connection for %s (%d ms old) from recv_table",
local_addr, entry.getKey(), age);
removeReceiveConnection(entry.getKey());
num_removed++;
}
}
return num_removed;
}
protected void update(Entry entry, int num_received) {
if(conn_expiry_timeout > 0)
entry.update();
if(entry.state() == State.CLOSING)
entry.state(State.OPEN);
num_msgs_received+=num_received;
}
/** Compares 2 timestamps, handles numeric overflow */
protected static int compare(long ts1, long ts2) {
long diff=ts1 - ts2;
return diff < 0? -1 : diff > 0? 1 : 0;
}
protected enum State {OPEN, CLOSING, CLOSED}
/**
* The following types and fields are serialized:
*
*/
public static class Header extends org.jgroups.Header {
public static final byte DATA = 0;
public static final byte ACK = 1;
public static final byte SEND_FIRST_SEQNO = 2;
public static final byte XMIT_REQ = 3; // SeqnoList of missing message is in the message's payload
public static final byte CLOSE = 4;
byte type;
long seqno; // DATA and ACK
short conn_id; // DATA and CLOSE
boolean first; // DATA
long timestamp; // SEND_FIRST_SEQNO and ACK
public Header() {} // used for externalization
protected Header(byte type) {
this.type=type;
}
protected Header(byte type, long seqno) {
this.type=type;
this.seqno=seqno;
}
protected Header(byte type, long seqno, short conn_id, boolean first) {
this.type=type;
this.seqno=seqno;
this.conn_id=conn_id;
this.first=first;
}
public static Header createDataHeader(long seqno, short conn_id, boolean first) {
return new Header(DATA, seqno, conn_id, first);
}
public static Header createAckHeader(long seqno, short conn_id, long timestamp) {
return new Header(ACK, seqno, conn_id, false).timestamp(timestamp);
}
public static Header createSendFirstSeqnoHeader(long timestamp) {
return new Header(SEND_FIRST_SEQNO).timestamp(timestamp);
}
public static Header createXmitReqHeader() {
return new Header(XMIT_REQ);
}
public static Header createCloseHeader(short conn_id) {
return new Header(CLOSE, 0, conn_id, false);
}
public byte type() {return type;}
public long seqno() {return seqno;}
public short connId() {return conn_id;}
public boolean first() {return first;}
public long timestamp() {return timestamp;}
public Header timestamp(long ts) {timestamp=ts; return this;}
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");
if(timestamp != 0)
sb.append(", ts=").append(timestamp);
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";
case XMIT_REQ: return "XMIT_REQ";
case CLOSE: return "CLOSE";
default: return "";
}
}
public final int size() {
int retval=Global.BYTE_SIZE; // type
switch(type) {
case DATA:
retval+=Bits.size(seqno) // seqno
+ Global.SHORT_SIZE // conn_id
+ Global.BYTE_SIZE; // first
break;
case ACK:
retval+=Bits.size(seqno)
+ Global.SHORT_SIZE // conn_id
+ Bits.size(timestamp);
break;
case SEND_FIRST_SEQNO:
retval+=Bits.size(timestamp);
break;
case XMIT_REQ:
break;
case CLOSE:
retval+=Global.SHORT_SIZE; // conn-id
break;
}
return retval;
}
public Header copy() {
return new Header(type, seqno, conn_id, first);
}
public void writeTo(DataOutput out) throws Exception {
out.writeByte(type);
switch(type) {
case DATA:
Bits.writeLong(seqno, out);
out.writeShort(conn_id);
out.writeBoolean(first);
break;
case ACK:
Bits.writeLong(seqno, out);
out.writeShort(conn_id);
Bits.writeLong(timestamp, out);
break;
case SEND_FIRST_SEQNO:
Bits.writeLong(timestamp, out);
break;
case XMIT_REQ:
break;
case CLOSE:
out.writeShort(conn_id);
break;
}
}
public void readFrom(DataInput in) throws Exception {
type=in.readByte();
switch(type) {
case DATA:
seqno=Bits.readLong(in);
conn_id=in.readShort();
first=in.readBoolean();
break;
case ACK:
seqno=Bits.readLong(in);
conn_id=in.readShort();
timestamp=Bits.readLong(in);
break;
case SEND_FIRST_SEQNO:
timestamp=Bits.readLong(in);
break;
case XMIT_REQ:
break;
case CLOSE:
conn_id=in.readShort();
break;
}
}
}
protected abstract class Entry {
protected final Table msgs; // stores sent or received messages
protected final short conn_id;
protected final AtomicLong timestamp=new AtomicLong(0); // ns
protected volatile State state=State.OPEN;
protected Entry(short conn_id, Table msgs) {
this.conn_id=conn_id;
this.msgs=msgs;
update();
}
short connId() {return conn_id;}
void update() {timestamp.set(getTimestamp());}
State state() {return state;}
Entry state(State state) {if(this.state != state) {this.state=state; update();} return this;}
/** Returns the age of the entry in ms */
long age() {return TimeUnit.MILLISECONDS.convert(getTimestamp() - timestamp.longValue(), TimeUnit.NANOSECONDS);}
}
protected final class SenderEntry extends Entry {
final AtomicLong sent_msgs_seqno=new AtomicLong(DEFAULT_FIRST_SEQNO); // seqno for msgs sent by us
protected final long[] watermark={0,0}; // the highest acked and highest sent seqno
protected long last_timestamp; // to prevent out-of-order ACKs from a receiver
public SenderEntry(short send_conn_id) {
super(send_conn_id, new Table(xmit_table_num_rows, xmit_table_msgs_per_row, 0,
xmit_table_resize_factor, xmit_table_max_compaction_time));
}
long[] watermark() {return watermark;}
SenderEntry watermark(long ha, long hs) {watermark[0]=ha; watermark[1]=hs; return this;}
/** Updates last_timestamp. Returns true of the update was in order (ts > last_timestamp) */
protected synchronized boolean updateLastTimestamp(long ts) {
if(last_timestamp == 0) {
last_timestamp=ts;
return true;
}
boolean success=compare(ts, last_timestamp) > 0; // ts has to be > last_timestamp
if(success)
last_timestamp=ts;
return success;
}
public String toString() {
StringBuilder sb=new StringBuilder();
if(msgs != null)
sb.append(msgs).append(", ");
sb.append("send_conn_id=" + conn_id).append(" (" + age()/1000 + " secs old) - " + state);
if(last_timestamp != 0)
sb.append(", last-ts: ").append(last_timestamp);
return sb.toString();
}
}
protected final class ReceiverEntry extends Entry {
protected volatile boolean send_ack;
public ReceiverEntry(Table received_msgs, short recv_conn_id) {
super(recv_conn_id, received_msgs);
}
ReceiverEntry sendAck(boolean flag) {send_ack=flag; return this;}
boolean sendAck() {boolean retval=send_ack; send_ack=false; return retval;}
public String toString() {
StringBuilder sb=new StringBuilder();
if(msgs != null)
sb.append(msgs).append(", ");
sb.append("recv_conn_id=" + conn_id);
sb.append(" (" + age()/1000 + " secs old) - " + state);
if(send_ack)
sb.append(" [ack pending]");
return sb.toString();
}
}
/**
* Retransmitter task which periodically (every xmit_interval ms):
*
*
If any of the receiver windows have the ack flag set, clears the flag and sends an ack for the
* highest delivered seqno to the sender
*
Checks all receiver windows for missing messages and asks senders for retransmission
*
For all sender windows, checks if highest acked (HA) < highest sent (HS). If not, and HA/HS is the same
* as on the last retransmission run, send the highest sent message again
*
*/
protected class RetransmitTask implements Runnable {
public void run() {
triggerXmit();
}
public String toString() {
return UNICAST3.class.getSimpleName() + ": RetransmitTask (interval=" + xmit_interval + " ms)";
}
}
@ManagedOperation(description="Triggers the retransmission task")
public void triggerXmit() {
SeqnoList missing;
for(Map.Entry entry: recv_table.entrySet()) {
Address target=entry.getKey(); // target to send retransmit requests to
ReceiverEntry val=entry.getValue();
Table win=val != null? val.msgs : null;
// receiver: send ack for received messages if needed
if(win != null && val.sendAck()) // sendAck() resets send_ack to false
sendAck(target, win.getHighestDeliverable(), val.connId());
// receiver: retransmit missing messages
if(win != null && win.getNumMissing() > 0 && (missing=win.getMissing(max_xmit_req_size)) != null) { // getNumMissing() is fast
long highest=missing.getLast();
Long prev_seqno=xmit_task_map.get(target);
if(prev_seqno == null)
xmit_task_map.put(target, highest); // no retransmission
else {
missing.removeHigherThan(prev_seqno); // we only retransmit the 'previous batch'
if(highest > prev_seqno)
xmit_task_map.put(target, highest);
if(!missing.isEmpty())
retransmit(missing, target);
}
}
else if(!xmit_task_map.isEmpty())
xmit_task_map.remove(target); // no current gaps for target
}
// sender: only send the *highest sent* message if HA < HS and HA/HS didn't change from the prev run
for(SenderEntry val: send_table.values()) {
Table win=val != null? val.msgs : null;
if(win != null /** && !win.isEmpty() */) {
long highest_acked=win.getHighestDelivered(); // highest delivered == highest ack (sender win)
long highest_sent=win.getHighestReceived(); // we use table as a *sender* win, so it's highest *sent*...
if(highest_acked < highest_sent && val.watermark[0] == highest_acked && val.watermark[1] == highest_sent) {
// highest acked and sent hasn't moved up - let's resend the HS
Message highest_sent_msg=win.get(highest_sent);
if(highest_sent_msg != null)
retransmit(highest_sent_msg);
}
else
val.watermark(highest_acked, highest_sent);
}
}
// close idle connections
if(conn_expiry_timeout > 0)
closeIdleConnections();
if(conn_close_timeout > 0)
removeExpiredConnections();
}
@ManagedOperation(description="Sends ACKs immediately for entries which are marked as pending (ACK hasn't been sent yet)")
public void sendPendingAcks() {
for(Map.Entry entry: recv_table.entrySet()) {
Address target=entry.getKey(); // target to send retransmit requests to
ReceiverEntry val=entry.getValue();
Table win=val != null? val.msgs : null;
// receiver: send ack for received messages if needed
if(win != null && val.sendAck())// sendAck() resets send_ack to false
sendAck(target, win.getHighestDeliverable(), val.connId());
}
}
}
