Author: fhanik
Date: Tue Feb 5 15:29:56 2008
New Revision: 618823
URL: http://svn.apache.org/viewvc?rev=618823&view=rev
Log:
Remove synchronization on the DeltaRequest object, and let the object that
manages the delta request (session/manager) to handle the locking properly,
using the session lock
There is a case with a non sticky load balancer where using synchronized and a
lock (essentially two locks) can end up in a dead lock
Modified:
tomcat/trunk/java/org/apache/catalina/ha/session/DeltaManager.java
tomcat/trunk/java/org/apache/catalina/ha/session/DeltaRequest.java
tomcat/trunk/java/org/apache/catalina/ha/session/DeltaSession.java
Modified: tomcat/trunk/java/org/apache/catalina/ha/session/DeltaManager.java
URL:
http://svn.apache.org/viewvc/tomcat/trunk/java/org/apache/catalina/ha/session/DeltaManager.java?rev=618823&r1=618822&r2=618823&view=diff
==============================================================================
--- tomcat/trunk/java/org/apache/catalina/ha/session/DeltaManager.java
(original)
+++ tomcat/trunk/java/org/apache/catalina/ha/session/DeltaManager.java Tue Feb
5 15:29:56 2008
@@ -615,10 +615,15 @@
* @throws IOException
*/
protected DeltaRequest deserializeDeltaRequest(DeltaSession session,
byte[] data) throws ClassNotFoundException, IOException {
- ReplicationStream ois = getReplicationStream(data);
- session.getDeltaRequest().readExternal(ois);
- ois.close();
- return session.getDeltaRequest();
+ try {
+ session.lock();
+ ReplicationStream ois = getReplicationStream(data);
+ session.getDeltaRequest().readExternal(ois);
+ ois.close();
+ return session.getDeltaRequest();
+ }finally {
+ session.unlock();
+ }
}
/**
@@ -629,8 +634,13 @@
* @return serialized delta request
* @throws IOException
*/
- protected byte[] serializeDeltaRequest(DeltaRequest deltaRequest) throws
IOException {
- return deltaRequest.serialize();
+ protected byte[] serializeDeltaRequest(DeltaSession session, DeltaRequest
deltaRequest) throws IOException {
+ try {
+ session.lock();
+ return deltaRequest.serialize();
+ }finally {
+ session.unlock();
+ }
}
/**
@@ -1096,16 +1106,18 @@
* @return a SessionMessage to be sent,
*/
public ClusterMessage requestCompleted(String sessionId) {
+ DeltaSession session = null;
try {
- DeltaSession session = (DeltaSession) findSession(sessionId);
+ session = (DeltaSession) findSession(sessionId);
DeltaRequest deltaRequest = session.getDeltaRequest();
+ session.lock();
SessionMessage msg = null;
boolean isDeltaRequest = false ;
synchronized(deltaRequest) {
isDeltaRequest = deltaRequest.getSize() > 0 ;
if (isDeltaRequest) {
counterSend_EVT_SESSION_DELTA++;
- byte[] data = serializeDeltaRequest(deltaRequest);
+ byte[] data = serializeDeltaRequest(session,deltaRequest);
msg = new SessionMessageImpl(getName(),
SessionMessage.EVT_SESSION_DELTA,
data,
@@ -1155,6 +1167,8 @@
} catch (IOException x) {
log.error(sm.getString("deltaManager.createMessage.unableCreateDeltaRequest",sessionId),
x);
return null;
+ }finally {
+ if (session!=null) session.unlock();
}
}
@@ -1360,9 +1374,14 @@
DeltaSession session = (DeltaSession) findSession(msg.getSessionID());
if (session != null) {
if (log.isDebugEnabled())
log.debug(sm.getString("deltaManager.receiveMessage.delta",getName(),
msg.getSessionID()));
- DeltaRequest dreq = deserializeDeltaRequest(session, delta);
- dreq.execute(session, notifyListenersOnReplication);
- session.setPrimarySession(false);
+ try {
+ session.lock();
+ DeltaRequest dreq = deserializeDeltaRequest(session, delta);
+ dreq.execute(session, notifyListenersOnReplication);
+ session.setPrimarySession(false);
+ }finally {
+ session.unlock();
+ }
}
}
Modified: tomcat/trunk/java/org/apache/catalina/ha/session/DeltaRequest.java
URL:
http://svn.apache.org/viewvc/tomcat/trunk/java/org/apache/catalina/ha/session/DeltaRequest.java?rev=618823&r1=618822&r2=618823&view=diff
==============================================================================
--- tomcat/trunk/java/org/apache/catalina/ha/session/DeltaRequest.java
(original)
+++ tomcat/trunk/java/org/apache/catalina/ha/session/DeltaRequest.java Tue Feb
5 15:29:56 2008
@@ -118,7 +118,7 @@
addAction(TYPE_ISNEW,action,NAME_ISNEW,new Boolean(n));
}
- protected synchronized void addAction(int type,
+ protected void addAction(int type,
int action,
String name,
Object value) {
@@ -151,7 +151,7 @@
execute(session,true);
}
- public synchronized void execute(DeltaSession session, boolean
notifyListeners) {
+ public void execute(DeltaSession session, boolean notifyListeners) {
if ( !this.sessionId.equals( session.getId() ) )
throw new java.lang.IllegalArgumentException("Session id mismatch,
not executing the delta request");
session.access();
@@ -195,7 +195,7 @@
reset();
}
- public synchronized void reset() {
+ public void reset() {
while ( actions.size() > 0 ) {
try {
AttributeInfo info = (AttributeInfo) actions.removeFirst();
@@ -221,12 +221,12 @@
return actions.size();
}
- public synchronized void clear() {
+ public void clear() {
actions.clear();
actionPool.clear();
}
- public synchronized void readExternal(java.io.ObjectInput in) throws
IOException,ClassNotFoundException {
+ public void readExternal(java.io.ObjectInput in) throws
IOException,ClassNotFoundException {
//sessionId - String
//recordAll - boolean
//size - int
@@ -259,7 +259,7 @@
- public synchronized void writeExternal(java.io.ObjectOutput out ) throws
java.io.IOException {
+ public void writeExternal(java.io.ObjectOutput out ) throws
java.io.IOException {
//sessionId - String
//recordAll - boolean
//size - int
@@ -348,7 +348,7 @@
return other.getName().equals(this.getName());
}
- public synchronized void readExternal(java.io.ObjectInput in ) throws
IOException,ClassNotFoundException {
+ public void readExternal(java.io.ObjectInput in ) throws
IOException,ClassNotFoundException {
//type - int
//action - int
//name - String
@@ -361,7 +361,7 @@
if ( hasValue ) value = in.readObject();
}
- public synchronized void writeExternal(java.io.ObjectOutput out)
throws IOException {
+ public void writeExternal(java.io.ObjectOutput out) throws IOException
{
//type - int
//action - int
//name - String
Modified: tomcat/trunk/java/org/apache/catalina/ha/session/DeltaSession.java
URL:
http://svn.apache.org/viewvc/tomcat/trunk/java/org/apache/catalina/ha/session/DeltaSession.java?rev=618823&r1=618822&r2=618823&view=diff
==============================================================================
--- tomcat/trunk/java/org/apache/catalina/ha/session/DeltaSession.java
(original)
+++ tomcat/trunk/java/org/apache/catalina/ha/session/DeltaSession.java Tue Feb
5 15:29:56 2008
@@ -134,7 +134,12 @@
* @throws IOException
*/
public byte[] getDiff() throws IOException {
- return getDeltaRequest().serialize();
+ try{
+ lock();
+ return getDeltaRequest().serialize();
+ }finally{
+ unlock();
+ }
}
public ClassLoader[] getClassLoaders() {
@@ -158,15 +163,21 @@
* @throws IOException
*/
public void applyDiff(byte[] diff, int offset, int length) throws
IOException, ClassNotFoundException {
- ReplicationStream stream =
((ClusterManager)getManager()).getReplicationStream(diff,offset,length);
- getDeltaRequest().readExternal(stream);
- ClassLoader contextLoader =
Thread.currentThread().getContextClassLoader();
try {
- ClassLoader[] loaders = getClassLoaders();
- if ( loaders != null && loaders.length >0 )
Thread.currentThread().setContextClassLoader(loaders[0]);
- getDeltaRequest().execute(this);
+ lock();
+ ReplicationStream stream = ( (ClusterManager)
getManager()).getReplicationStream(diff, offset, length);
+ getDeltaRequest().readExternal(stream);
+ ClassLoader contextLoader =
Thread.currentThread().getContextClassLoader();
+ try {
+ ClassLoader[] loaders = getClassLoaders();
+ if (loaders != null && loaders.length > 0)
+
Thread.currentThread().setContextClassLoader(loaders[0]);
+ getDeltaRequest().execute(this);
+ } finally {
+
Thread.currentThread().setContextClassLoader(contextLoader);
+ }
}finally {
- Thread.currentThread().setContextClassLoader(contextLoader);
+ unlock();
}
}
@@ -264,8 +275,15 @@
if (isValid && interval == 0) {
expire();
} else {
- if (addDeltaRequest && (deltaRequest != null))
- deltaRequest.setMaxInactiveInterval(interval);
+ if (addDeltaRequest && (deltaRequest != null)) {
+ try {
+ lock();
+ deltaRequest.setMaxInactiveInterval(interval);
+ }finally{
+ unlock();
+ }
+ }
+
}
}
@@ -281,8 +299,14 @@
public void setNew(boolean isNew, boolean addDeltaRequest) {
super.setNew(isNew);
- if (addDeltaRequest && (deltaRequest != null))
- deltaRequest.setNew(isNew);
+ if (addDeltaRequest && (deltaRequest != null)){
+ try {
+ lock();
+ deltaRequest.setNew(isNew);
+ }finally{
+ unlock();
+ }
+ }
}
/**
@@ -376,8 +400,13 @@
* preparation for reuse of this object.
*/
public void recycle() {
- super.recycle();
- deltaRequest.clear();
+ try {
+ lock();
+ super.recycle();
+ deltaRequest.clear();
+ }finally{
+ unlock();
+ }
}
@@ -394,8 +423,13 @@
// ------------------------------------------------ Session Package Methods
- public synchronized void readExternal(ObjectInput in) throws
IOException,ClassNotFoundException {
- readObjectData(in);
+ public void readExternal(ObjectInput in) throws
IOException,ClassNotFoundException {
+ try {
+ lock();
+ readObjectData(in);
+ }finally{
+ unlock();
+ }
}
@@ -432,11 +466,16 @@
}
public void resetDeltaRequest() {
- if (deltaRequest == null) {
- deltaRequest = new DeltaRequest(getIdInternal(), false);
- } else {
- deltaRequest.reset();
- deltaRequest.setSessionId(getIdInternal());
+ try {
+ lock();
+ if (deltaRequest == null) {
+ deltaRequest = new DeltaRequest(getIdInternal(), false);
+ } else {
+ deltaRequest.reset();
+ deltaRequest.setSessionId(getIdInternal());
+ }
+ }finally{
+ unlock();
}
}
@@ -584,8 +623,13 @@
activate();
}
- public synchronized void writeExternal(ObjectOutput out ) throws
java.io.IOException {
- writeObject(out);
+ public void writeExternal(ObjectOutput out ) throws java.io.IOException {
+ try {
+ lock();
+ writeObject(out);
+ }finally {
+ unlock();
+ }
}
---------------------------------------------------------------------
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]
