Mercurial > hg > blitz_condensed
diff src/org/dancres/blitz/txn/TxnPinger.java @ 0:3dc0c5604566
Initial checkin of blitz 2.0 fcs - no installer yet.
author | Dan Creswell <dan.creswell@gmail.com> |
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date | Sat, 21 Mar 2009 11:00:06 +0000 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/org/dancres/blitz/txn/TxnPinger.java Sat Mar 21 11:00:06 2009 +0000 @@ -0,0 +1,116 @@ +package org.dancres.blitz.txn; + +import java.rmi.RemoteException; +import java.rmi.NoSuchObjectException; + +import java.util.List; +import java.util.Iterator; + +import java.util.logging.Level; + +import net.jini.core.transaction.UnknownTransactionException; + +import net.jini.config.ConfigurationException; + +import org.dancres.blitz.ActiveObject; +import org.dancres.blitz.ActiveObjectRegistry; + +import org.dancres.blitz.config.ConfigurationFactory; + +/** + <p>An instance of this class is created by <code>TransactionManager</code> + once recovery has been completed. It's purpose is to regularly check known + remote transactions status and abort any that can be declared "dead" as + a result of specific results from invoking the remote + <code>TransactionManager</code>'s <code>getState</code> method.</p> + */ +class TxnPinger implements ActiveObject, Runnable { + private static final String PING_PAUSE = "txnPingInterval"; + + static final long NO_PAUSE = -1; + + private long thePause = NO_PAUSE; + private Thread theThread; + private TxnManagerState theState; + + TxnPinger(TxnManagerState aState) { + try { + thePause = + ((Long) + ConfigurationFactory.getEntry(PING_PAUSE, + long.class, + new Long(NO_PAUSE))).longValue(); + } catch (ConfigurationException anE) { + TxnManager.theLogger.log(Level.SEVERE, + "Failed to load txn ping interval", + anE); + } + + if (thePause != NO_PAUSE) { + TxnManager.theLogger.log(Level.INFO, "Txn Pinger active with: " + + thePause + " ms"); + ActiveObjectRegistry.add(this); + } + } + + public void begin() { + theThread = new Thread(this, "TxnPinger"); + theThread.setDaemon(true); + theThread.start(); + } + + public void halt() { + theThread.interrupt(); + } + + public void run() { + while (true) { + try { + Thread.sleep(thePause); + } catch (InterruptedException anIE) { + return; + } + + + Iterator myTxnIds = theState.getActiveTxnIds().iterator(); + + while (myTxnIds.hasNext()) { + TxnId myId = (TxnId) myTxnIds.next(); + + // Skip local transactions + // + if (myId.isNull()) + continue; + + /* + NoSuchObjectException or UnknownTransactionException means + we can kill this transaction. + */ + try { + TxnGateway myGateway = TxnManager.get().getGateway(); + + myGateway.getState(myId); + } catch (RemoteException anRE) { + if (anRE instanceof NoSuchObjectException) { + attemptAbort(myId); + } + } catch (UnknownTransactionException aUTE) { + attemptAbort(myId); + } + } + } + } + + private void attemptAbort(TxnId anId) { + TxnManager myManager = TxnManager.get(); + + try { + myManager.abort(myManager.getTxnFor(anId)); + } catch (Exception anE) { + // Nothing more to do, try again next time + TxnManager.theLogger.log(Level.SEVERE, + "Attempted to abort dead transaction: " + + anId, anE); + } + } +} \ No newline at end of file