modules/core/src/main/java/org/apache/ignite/internal/processors/cache/distributed/near/TxTopologyVersionFuture.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.ignite.internal.processors.cache.distributed.near;

import org.apache.ignite.IgniteCheckedException;
import org.apache.ignite.internal.IgniteInternalFuture;
import org.apache.ignite.internal.processors.affinity.AffinityTopologyVersion;
import org.apache.ignite.internal.processors.cache.CacheStoppedException;
import org.apache.ignite.internal.processors.cache.GridCacheContext;
import org.apache.ignite.internal.processors.cache.distributed.dht.GridDhtTopologyFuture;
import org.apache.ignite.internal.util.future.GridFutureAdapter;
import org.apache.ignite.internal.util.typedef.CI1;

/**
 * Future to obtain/lock topology version for SELECT FOR UPDATE.
 */
public class TxTopologyVersionFuture extends GridFutureAdapter<AffinityTopologyVersion> {
    /** Transaction. */
    private final GridNearTxLocal tx;

    /** Target cache context. */
    private final GridCacheContext<?, ?> cctx;

    /** Topology locked flag. */
    private boolean topLocked;

    /**
     * @param tx Transaction.
     * @param cctx Target cache context.
     */
    public TxTopologyVersionFuture(GridNearTxLocal tx, GridCacheContext cctx) {
        this.tx = tx;
        this.cctx = cctx;

        init();
    }

    /** */
    private void init() {
        // Obtain the topology version to use.
        long threadId = Thread.currentThread().getId();

        AffinityTopologyVersion topVer = cctx.mvcc().lastExplicitLockTopologyVersion(threadId);

        // If there is another system transaction in progress, use it's topology version to prevent deadlock.
        if (topVer == null && tx.system())
            topVer = cctx.tm().lockedTopologyVersion(threadId, tx);

        if (topVer != null)
            tx.topologyVersion(topVer);

        if (topVer == null)
            topVer = tx.topologyVersionSnapshot();

        if (topVer != null) {
            for (GridDhtTopologyFuture fut : cctx.shared().exchange().exchangeFutures()) {
                if (fut.exchangeDone() && fut.topologyVersion().equals(topVer)) {
                    Throwable err = fut.validateCache(cctx, false, false, null, null);

                    if (err != null) {
                        onDone(err);

                        return;
                    }

                    break;
                }
            }

            onDone(topVer);

            topLocked = true;

            return;
        }

        acquireTopologyVersion();
    }

    /**
     * Acquire topology future and wait for its completion.
     */
    private void acquireTopologyVersion() {
        cctx.topology().readLock();

        try {
            if (cctx.topology().stopping()) {
                onDone(new CacheStoppedException(cctx.name()));

                return;
            }

            GridDhtTopologyFuture fut = cctx.topologyVersionFuture();

            if (fut.isDone()) {
                Throwable err = fut.validateCache(cctx, false, false, null, null);

                if (err != null) {
                    onDone(err);

                    return;
                }

                AffinityTopologyVersion topVer = fut.topologyVersion();

                if (tx != null)
                    tx.topologyVersion(topVer);

                onDone(topVer);
            }
            else {
                fut.listen(new CI1<IgniteInternalFuture<AffinityTopologyVersion>>() {
                    @Override public void apply(IgniteInternalFuture<AffinityTopologyVersion> fut) {
                        try {
                            fut.get();

                            acquireTopologyVersion();
                        }
                        catch (IgniteCheckedException e) {
                            onDone(e);
                        }
                        finally {
                            cctx.shared().txContextReset();
                        }
                    }
                });
            }
        }
        finally {
            cctx.topology().readUnlock();
        }
    }

    /**
     * @return Client first flag.
     */
    public boolean clientFirst() {
        return cctx.localNode().isClient() && !topLocked && !tx.hasRemoteLocks();
    }
}