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/** Notice of modification as required by the LGPL
* This file was modified by Gemstone Systems Inc. on
* $Date$
**/
// $Id: ParticipantGmsImpl.java,v 1.17 2005/12/23 14:57:06 belaban Exp $
package com.gemstone.org.jgroups.protocols.pbcast;
import com.gemstone.org.jgroups.*;
import com.gemstone.org.jgroups.util.ExternalStrings;
import com.gemstone.org.jgroups.util.Promise;
import java.util.Collections;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Set;
import java.util.Vector;
public class ParticipantGmsImpl extends GmsImpl {
private final Vector suspected_mbrs=new Vector(11);
private final Set departed_mbrs = new HashSet(); // GemStoneAddition
private final Promise leave_promise=new Promise();
public ParticipantGmsImpl(GMS g) {
super(g);
}
@Override // GemStoneAddition
public void init() throws Exception {
super.init();
synchronized(suspected_mbrs) { // GemStoneAddition
suspected_mbrs.removeAllElements();
}
leave_promise.reset();
}
@Override // GemStoneAddition
public boolean join(Address mbr) { // GemStoneAddition - return boolean
wrongMethod("join");
return false;
}
@Override
public void handleJoinsAndLeaves(List joins, List leaves, List suspects, List suspectReasons, boolean forceInclusion) {
for (Iterator it=suspects.iterator(); it.hasNext(); ) {
handleSuspect((Address)it.next());
}
if (leaves != null && !leaves.isEmpty()) {
handleLeave(leaves, false, null, false);
}
}
/**
* This is used when we are shutting down to inform others
* Loop: determine coord. If coord is me --> handleLeave().
* Else send handleLeave() to coord until success
*/
@Override // GemStoneAddition
public void leave(Address mbr) {
Address coord;
int max_tries=3;
Object result;
leave_promise.reset();
if(mbr.equals(gms.local_addr))
leaving=true;
while ((coord=gms.determineCoordinator()) != null && max_tries-- > 0) {
if(gms.local_addr.equals(coord)) { // I'm the coordinator
if (leaving) { // don't know who to tell that we're shutting down - bale out
break; // GemStoneAddition - bug #42969 hang during shutdown
}
gms.becomeCoordinator(this.suspected_mbrs);
// gms.getImpl().handleLeave(mbr, false); // regular leave
gms.getImpl().leave(mbr); // regular leave
return;
}
if(log.isDebugEnabled()) log.debug("sending LEAVE request to " + coord + " (local_addr=" + gms.local_addr + ")");
sendLeaveMessage(coord, mbr);
// GemStoneAddition - if I'm the coordinator
// don't wait for a response
// GemStoneAddition - scale up the leave_timeout if there are a lot of
// members
long leaveTimeout = gms.leave_timeout * gms.members.size() / 10;
synchronized(leave_promise) {
result=leave_promise.getResult(leaveTimeout);
if(result != null)
break;
}
// GemStoneAddition - we used to only break out of the loop
// if wouldIBeCoordinator returned true, but we've already
// sent a ShutdownMessage in GemFire so the other members know
// that this process shut down normally, so no need to wait
// for a new view if the coordinator is probably gone
synchronized(this.suspected_mbrs) {
if (this.suspected_mbrs.contains(coord)) {
break;
}
}
synchronized(this.departed_mbrs) {
if (this.departed_mbrs.contains(coord)) {
break;
}
}
// GemStoneAddition - also just quit if the coordinator hasn't
// changed after LEAVE has already been sent (and probably retransmitted)
// to it
if (gms.determineCoordinator() == coord) {
break;
}
}
gms.becomeClient();
}
public Vector getSuspects() { // GemStoneAddition
synchronized(this.suspected_mbrs) {
return new Vector(this.suspected_mbrs);
}
}
@Override // GemStoneAddition
public void handleJoinResponse(JoinRsp join_rsp) {
// wrongMethod("handleJoinResponse");
}
@Override // GemStoneAddition
public void handleLeaveResponse(String reason) {
if (reason != null && reason.length() > 0) {
gms.passUp(new Event(Event.EXIT,
gms.stack.gfBasicFunctions.getForcedDisconnectException(
"This member has been forced out of the distributed system. Reason='"
+ reason + "'")));
}
synchronized(leave_promise) {
leave_promise.setResult(Boolean.TRUE); // unblocks thread waiting in leave()
}
}
public void suspect(Address mbr) {
handleSuspect(mbr);
}
/** Removes previously suspected member from list of currently suspected members */
@Override // GemStoneAddition
public void unsuspect(Address mbr) {
synchronized(suspected_mbrs) { // GemStoneAddition
if(mbr != null)
suspected_mbrs.remove(mbr);
}
}
@Override // GemStoneAddition
public void handleJoin(Address mbr) {
}
// @Override // GemStoneAddition
// public void handleJoin(List mbrList) { // GemStoneAddition
// }
public void handleLeave(Address mbr, boolean suspected) {
if (suspected) { // GemStoneAddition
handleSuspect(mbr);
} else {
handleLeave(Collections.singletonList(mbr), false, null, false);
}
}
// GemStoneAddition - list of mbrs and 'reason'
@Override // GemStoneAddition
public void handleLeave(List members, boolean suspected, List reasons, boolean forceInclusion) {
if (suspected) { // GemStoneAddition
for (Iterator it=members.iterator(); it.hasNext() && (gms.getImpl() == this); ) {
handleSuspect((Address)it.next());
}
} else {
boolean becomeCoordinator = false;
Vector suspects = null;
Set departed = null;
synchronized(this.suspected_mbrs) {
suspects = new Vector(suspected_mbrs);
}
synchronized(this.departed_mbrs) {
this.departed_mbrs.addAll(members);
departed = new HashSet(this.departed_mbrs);
}
if (wouldIBeCoordinator(suspects, departed)) {
if(log.isDebugEnabled()) log.debug("suspected mbrs=" + suspected_mbrs + "; departed="+this.departed_mbrs
+ "; members are " +
gms.members + ", coord=" + gms.local_addr + ": I'm the new coord !");
becomeCoordinator = true;
}
if (becomeCoordinator) {
synchronized(this.suspected_mbrs) {
suspected_mbrs.removeAll(suspects);
}
synchronized(this.departed_mbrs) {
this.departed_mbrs.removeAll(departed);
}
gms.incrementLtime(10);
gms.becomeCoordinator(suspects);
}
}
}
/**
* If we are leaving, we have to wait for the view change (last msg in the current view) that
* excludes us before we can leave.
* @param new_view The view to be installed
* @param digest If view is a MergeView, digest contains the seqno digest of all members and has to
* be set by GMS
*/
@Override // GemStoneAddition
public void handleViewChange(View new_view, Digest digest) {
Vector mbrs=new_view.getMembers();
if(log.isDebugEnabled()) log.debug("view=" + new_view);
synchronized(suspected_mbrs) { // GemStoneAddition
suspected_mbrs.removeAllElements();
}
synchronized(this.departed_mbrs) {
this.departed_mbrs.clear();
}
if(!mbrs.contains(gms.local_addr)) {
if (leaving) {
// received a view in which I'm not member: ignore
return;
}
else {
// GemStoneChange - if not leaving and we get a LEAVE_RSP, it means
// this process has been ousted as a suspect
gms.passUp(new Event(Event.EXIT,
gms.stack.gfBasicFunctions.getForcedDisconnectException(
ExternalStrings.
PGMS_THIS_MEMBER_HAS_BEEN_FORCED_OUT_OF_THE_DISTRIBUTED_SYSTEM_PLEASE_CONSULT_GEMFIRE_LOGS_TO_FIND_THE_REASON_PGMS
.toLocalizedString(new_view.getCreator()))));
}
}
gms.installView(new_view, digest);
}
public void handleSuspect(Address mbr) {
boolean becomeCoordinator = false; // GemStoneAddition
Vector suspects = null;
if (mbr == null) return;
synchronized (suspected_mbrs) { // GemStoneAddition - bug 35063
// Both contains() and addElement() are synchronized, but
// there is a window between the two, so we must synchronize.
if(!suspected_mbrs.contains(mbr))
suspected_mbrs.addElement(mbr);
if(log.getLogWriter().fineEnabled()) log.getLogWriter().fine(
"PGMS: suspected mbr=" + mbr + ", suspected_mbrs=" + suspected_mbrs + ", members=" +
gms.members + ", local_addr=" + gms.local_addr);
if(wouldIBeCoordinator(this.suspected_mbrs, Collections.EMPTY_SET)) {
if(log.isDebugEnabled()) log.debug("suspected mbr=" + mbr + "), departed="+this.departed_mbrs
+ "; members are " +
gms.members + ", coord=" + gms.local_addr + ": I'm the new coord !");
becomeCoordinator = true;
suspects = new Vector(suspected_mbrs);
suspected_mbrs.removeAllElements();
}
} // synchronized
if (becomeCoordinator) {
synchronized(this.departed_mbrs) {
this.departed_mbrs.clear();
}
gms.incrementLtime(10);
gms.becomeCoordinator(suspects);
// gms.getImpl().suspect(mbr);
}
}
@Override // GemStoneAddition
public void handleMergeRequest(Address sender, ViewId merge_id) {
// only coords handle this method; reject it if we're not coord
sendMergeRejectedResponse(sender, merge_id);
}
/* ---------------------------------- Private Methods --------------------------------------- */
/**
* Determines whether this member is the new coordinator given a list of suspected members. This is
* computed as follows: the list of currently suspected members (suspected_mbrs) is removed from the current
* membership. If the first member of the resulting list is equals to the local_addr, then it is true,
* otherwise false. Example: own address is B, current membership is {A, B, C, D}, suspected members are {A,
* D}. The resulting list is {B, C}. The first member of {B, C} is B, which is equal to the
* local_addr. Therefore, true is returned.
* @param suspects members that have crashed
* @param departures members that have departed normally
*/
boolean wouldIBeCoordinator(Vector suspects, Set departures) {
Address new_coord;
Vector mbrs=gms.members.getMembers(); // getMembers() returns a *copy* of the membership vector
if (log.isDebugEnabled()) {
log.debug("wouldIBeCoordinator:\nmembers = " + mbrs + "\ndeparted = " + this.departed_mbrs
+ "\nsuspected = " + this.suspected_mbrs);
}
if (suspects != null) {
mbrs.removeAll(suspects);
}
if (departures != null) {
mbrs.removeAll(departures);
}
if(mbrs.size() < 1) return false;
// GemStoneAddition - revised for split-brain detection
new_coord = new Membership(mbrs).getCoordinator();
// log.getLogWriterI18n().info(JGroupsStrings.DEBUG, "pgms: of members " + mbrs + " the coordinator would be " + new_coord);
if (new_coord == null) { // oops - no eligable coordinators
return false;
}
return gms.local_addr.equals(new_coord);
}
void sendLeaveMessage(Address coord, Address mbr) {
Message msg=new Message(coord, null, null);
GMS.GmsHeader hdr=new GMS.GmsHeader(GMS.GmsHeader.LEAVE_REQ, mbr);
msg.putHeader(gms.getName(), hdr);
gms.passDown(new Event(Event.MSG, msg));
}
// @Override // GemStoneAddition
// public void suspect(Address mbr, String reason) {
// suspect(mbr);
// }
/* (non-Javadoc) GemStoneAddition
* @see com.gemstone.org.jgroups.protocols.pbcast.GmsImpl#handleAlreadyJoined(com.gemstone.org.jgroups.Address)
*/
@Override // GemStoneAddition
public void handleAlreadyJoined(Address mbr) {
}
/* ------------------------------ End of Private Methods ------------------------------------ */
}