在JINI中实现TransactionManager

Question

我正在使用JINI实现两阶段锁。我已经通过遵循算法定义做到了这一点。在我的实现中，我使用一些ArrayLists和HashMap来跟踪哪些参与者已经提交或中止了事务。

每次我执行join/commit/abort操作时，我的ArrayLists和HashMap都是空的(没有以前的参与者)，并且我的TransactionManager的HashCode总是不同的。我花了两天时间寻找一个问题，但仍然不能理解为什么会发生这种情况。

// here is the implementation of join method of my TransactionManager
private HashMap<Long, ArrayList<TransactionParticipant>> _transactions = new HashMap<Long, ArrayList<TransactionParticipant>>();
private ArrayList<TransactionParticipant> _participantTest = new ArrayList<TransactionParticipant>();

    @Override
    public synchronized void join(long trxId, TransactionParticipant tp, long crashCount) throws UnknownTransactionException, CannotJoinException, CrashCountException, RemoteException {
        // add new participant to list of participants that belong to current trxId
        List<TransactionParticipant> participants = _transactions.get(trxId);

        _participantTest.add(tp);
        participants.add(tp);

        System.out.println("Test hash code " + this.hashCode());

        System.out.println("Number of participants is " + participants.size() + "for Trxid " + trxId);
        System.out.println("Number of participants in other is " + _participantTest.size() + "for Trxid " + trxId);
    }

下面的代码用于“发布”我的TransactionManager

String[] groups = { "group" };
        ServiceInfo serviceInfo = new ServiceInfo(
                "twoPhaseTrxManager",
                "a",
                "b",
                "1.0",
                "Join Manager",
                "c");

        Entry[] entries = new Entry[] { serviceInfo };

        LookupDiscoveryManager lookupDiscoveryManager = new LookupDiscoveryManager(groups, null, null);
      // "this" (first argument) refers to Current instance of transaction manager (object being published)
        new JoinManager(this, entries, (ServiceIDListener)null, lookupDiscoveryManager, new LeaseRenewalManager() ); 

任何帮助都是非常感谢的。

Answer 1

我能够通过改变这个来解决这个问题：

new JoinManager(this, entries, (ServiceIDListener)null, lookupDiscoveryManager, new LeaseRenewalManager() ); 

要这样做：

new JoinManager(RemoteObject.toStub(this), entries, (ServiceIDListener)null, lookupDiscoveryManager, new LeaseRenewalManager() );