/* * VS is (c) 2008 by Paul C. Buetow * vs@dev.buetow.org */ package protocols.implementations; import java.util.ArrayList; import java.util.Vector; import protocols.VSAbstractProtocol; import core.VSMessage; /** * The Class OnePhaseCommitProtocol. */ public class OnePhaseCommitProtocol extends VSAbstractProtocol { private static final long serialVersionUID = 1L; /* Server variables, coordinator */ private ArrayList pids; /* Client variables */ private boolean ackSent; /** * Instantiates a one phase commit protocol. */ public OnePhaseCommitProtocol() { setClassname(getClass().toString()); /* Can be changed via GUI variables editor of each process */ Vector vec = new Vector(); vec.add(2); vec.add(3); initVector("pids", vec, "PIDs beteilitger Prozesse"); initLong("timeout", 5000, "Zeit bis erneuerter Anfrage", "ms"); } /* (non-Javadoc) * @see events.VSAbstractEvent#onInit() */ protected void onInit() { } /* (non-Javadoc) * @see protocols.VSAbstractProtocol#onClientReset() */ protected void onClientReset() { pids.clear(); pids.addAll(getVector("pids")); } /* (non-Javadoc) * @see protocols.VSAbstractProtocol#onClientStart() */ protected void onClientStart() { if (pids == null) { pids = new ArrayList(); pids.addAll(getVector("pids")); } if (pids.size() != 0) { long timeout = getLong("timeout") + process.getTime(); scheduleAt(timeout); /* Will run onClientSchedule() at the specified local time */ VSMessage message = new VSMessage(); message.setBoolean("wantAck", true); sendMessage(message); } } /* (non-Javadoc) * @see protocols.VSAbstractProtocol#onClientRecv(core.VSMessage) */ protected void onClientRecv(VSMessage recvMessage) { if (pids.size() == 0) return; if (recvMessage.getBoolean("isAck")) { Integer pid = recvMessage.getIntegerObj("pid"); if (pids.contains(pid)) pids.remove(pid); logg("ACK von Prozess " + pid + " erhalten!"); if (pids.size() == 0) logg("ACKs von allen beteiligten Prozessen erhalten! Festgeschrieben!"); } } /* (non-Javadoc) * @see protocols.VSAbstractProtocol#onClientSchedule() */ protected void onClientSchedule() { onClientStart(); } /* (non-Javadoc) * @see protocols.VSAbstractProtocol#onServerReset() */ protected void onServerReset() { ackSent = false; } /* (non-Javadoc) * @see protocols.VSAbstractProtocol#onServerRecv(core.VSMessage) */ protected void onServerRecv(VSMessage recvMessage) { if (ackSent) return; VSMessage message = new VSMessage(); message.setBoolean("isAck", true); message.setInteger("pid", process.getProcessID()); sendMessage(message); ackSent = true; logg("Festgeschrieben"); } /* (non-Javadoc) * @see protocols.VSAbstractProtocol#onServerSchedule() */ protected void onServerSchedule() { } /* (non-Javadoc) * @see protocols.VSAbstractProtocol#toString() */ public String toString() { return super.toString(); } }