RaftAgent.java 文件源码

/**
 * Initialize the local Raft server.
 * <p/>
 * Sets up the service implementation classes, creates database
 * tables and starts any thread pools necessary. Following this
 * call all service classes are <strong>fully initialized</strong>.
 * Even though various threads are started they <strong>will not</strong>
 * use or interact with the service implementation classes. Callers
 * still have exclusive access to the system.
 * <p/>
 * This method should <strong>only</strong> be called once before {@link RaftAgent#start()}.
 *
 * @throws StorageException if the persistence components cannot be initialized
 * @throws IllegalStateException if this method is called multiple times
 */
public synchronized void initialize() throws StorageException {
    checkState(!running);
    checkState(!initialized);
    checkState(setupConversion);

    // start up the snapshots subsystem
    snapshotStore.initialize();
    // check that the snapshot metadata and the filesystem agree
    // FIXME (AG): this _may_ be expensive, especially if the user never bothers to clean out snapshots!
    // FIXME (AG): warning, warning - this is upfront work - probably a very, very bad idea
    snapshotStore.reconcileSnapshots();

    // initialize the log and store
    jdbcLog.initialize();
    jdbcStore.initialize();

    // initialize the various thread pools
    nonIoExecutorService = MoreExecutors.listeningDecorator(Executors.newCachedThreadPool());
    ioExecutorService = Executors.newCachedThreadPool();
    serverBossPool = new NioServerBossPool(ioExecutorService, 1);
    clientBossPool = new NioClientBossPool(ioExecutorService, 1);
    workerPool = new NioWorkerPool(ioExecutorService, 3);

    // TODO (AG): avoid creating threads in the initialize() method
    // initialize the networking subsystem
    sharedWorkerPool = new ShareableWorkerPool<NioWorker>(workerPool);
    ServerSocketChannelFactory serverChannelFactory = new NioServerSocketChannelFactory(serverBossPool, sharedWorkerPool);
    ClientSocketChannelFactory clientChannelFactory = new NioClientSocketChannelFactory(clientBossPool, sharedWorkerPool);
    raftNetworkClient.initialize(nonIoExecutorService, serverChannelFactory, clientChannelFactory, raftAlgorithm);

    raftAlgorithm.initialize();

    initialized = true;
}