Improve session sweeping logic in AdHocCommandManager

Fixes SMACK-624.
This commit is contained in:
Florian Schmaus 2019-05-20 08:57:03 +02:00
parent e8d9aed4be
commit 02f7cfcf27
1 changed files with 46 additions and 54 deletions

View File

@ -20,10 +20,13 @@ package org.jivesoftware.smackx.commands;
import java.lang.reflect.InvocationTargetException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import java.util.WeakHashMap;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.TimeUnit;
import java.util.logging.Level;
import java.util.logging.Logger;
@ -126,15 +129,6 @@ public final class AdHocCommandManager extends Manager {
private final ServiceDiscoveryManager serviceDiscoveryManager;
/**
* Thread that reaps stale sessions.
*/
// FIXME The session sweeping is horrible implemented. The thread will never stop running. A different approach must
// be implemented. For example one that does stop reaping sessions and the thread if there are no more, and restarts
// the reaping process on demand. Or for every command a scheduled task should be created that removes the session
// if it's timed out. See SMACK-624.
private Thread sessionsSweeper;
private AdHocCommandManager(XMPPConnection connection) {
super(connection);
this.serviceDiscoveryManager = ServiceDiscoveryManager.getInstanceFor(connection);
@ -186,8 +180,6 @@ public final class AdHocCommandManager extends Manager {
}
}
});
sessionsSweeper = null;
}
/**
@ -380,49 +372,8 @@ public final class AdHocCommandManager extends Manager {
// available for the next call
response.setStatus(Status.executing);
executingCommands.put(sessionId, command);
// See if the session reaping thread is started. If not, start it.
if (sessionsSweeper == null) {
sessionsSweeper = new Thread(new Runnable() {
@Override
public void run() {
while (true) {
for (String sessionId : executingCommands.keySet()) {
LocalCommand command = executingCommands.get(sessionId);
// Since the command could be removed in the meanwhile
// of getting the key and getting the value - by a
// processed packet. We must check if it still in the
// map.
if (command != null) {
long creationStamp = command.getCreationDate();
// Check if the Session data has expired (default is
// 10 minutes)
// To remove it from the session list it waits for
// the double of the of time out time. This is to
// let
// the requester know why his execution request is
// not accepted. If the session is removed just
// after the time out, then whe the user request to
// continue the execution he will received an
// invalid session error and not a time out error.
if (System.currentTimeMillis() - creationStamp > SESSION_TIMEOUT * 1000 * 2) {
// Remove the expired session
executingCommands.remove(sessionId);
}
}
}
try {
Thread.sleep(1000);
}
catch (InterruptedException ie) {
// Ignore.
}
}
}
});
sessionsSweeper.setDaemon(true);
sessionsSweeper.start();
}
// See if the session sweeper thread is scheduled. If not, start it.
maybeWindUpSessionSweeper();
}
// Sends the response packet
@ -558,6 +509,47 @@ public final class AdHocCommandManager extends Manager {
}
}
private boolean sessionSweeperScheduled;
private final Runnable sessionSweeper = () -> {
final long currentTime = System.currentTimeMillis();
synchronized (this) {
for (Iterator<Entry<String, LocalCommand>> it = executingCommands.entrySet().iterator(); it.hasNext();) {
Entry<String, LocalCommand> entry = it.next();
LocalCommand command = entry.getValue();
long creationStamp = command.getCreationDate();
// Check if the Session data has expired (default is 10 minutes)
// To remove it from the session list it waits for the double of
// the of time out time. This is to let
// the requester know why his execution request is
// not accepted. If the session is removed just
// after the time out, then once the user requests to
// continue the execution he will received an
// invalid session error and not a time out error.
if (currentTime - creationStamp > SESSION_TIMEOUT * 1000 * 2) {
// Remove the expired session
it.remove();
}
}
sessionSweeperScheduled = false;
}
if (!executingCommands.isEmpty()) {
maybeWindUpSessionSweeper();
}
};
private synchronized void maybeWindUpSessionSweeper() {
if (sessionSweeperScheduled) {
return;
}
sessionSweeperScheduled = true;
schedule(sessionSweeper, 10, TimeUnit.SECONDS);
}
/**
* Responds an error with an specific condition.
*