/*
* 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.datastructures;
import java.io.Externalizable;
import java.io.IOException;
import java.io.InvalidObjectException;
import java.io.ObjectInput;
import java.io.ObjectOutput;
import java.io.ObjectStreamException;
import java.util.concurrent.Callable;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicInteger;
import org.apache.ignite.IgniteCheckedException;
import org.apache.ignite.IgniteLogger;
import org.apache.ignite.internal.GridKernalContext;
import org.apache.ignite.internal.processors.cache.GridCacheContext;
import org.apache.ignite.internal.processors.cache.IgniteInternalCache;
import org.apache.ignite.internal.processors.cache.distributed.near.GridNearTxLocal;
import org.apache.ignite.internal.util.typedef.internal.A;
import org.apache.ignite.internal.util.typedef.internal.CU;
import org.apache.ignite.internal.util.typedef.internal.S;
import org.apache.ignite.internal.util.typedef.internal.U;
import org.apache.ignite.internal.processors.cluster.IgniteChangeGlobalStateSupport;
import org.apache.ignite.lang.IgniteBiTuple;
import static org.apache.ignite.internal.util.typedef.internal.CU.retryTopologySafe;
import static org.apache.ignite.transactions.TransactionConcurrency.PESSIMISTIC;
import static org.apache.ignite.transactions.TransactionIsolation.REPEATABLE_READ;
/**
* Cache count down latch implementation.
*/
public final class GridCacheCountDownLatchImpl implements GridCacheCountDownLatchEx, IgniteChangeGlobalStateSupport, Externalizable {
/** */
private static final long serialVersionUID = 0L;
/** Internal latch is in unitialized state. */
private static final int UNINITIALIZED_LATCH_STATE = 0;
/** Internal latch is being created. */
private static final int CREATING_LATCH_STATE = 1;
/** Internal latch is ready for the usage. */
private static final int READY_LATCH_STATE = 2;
/** Deserialization stash. */
private static final ThreadLocal<IgniteBiTuple<GridKernalContext, String>> stash =
new ThreadLocal<IgniteBiTuple<GridKernalContext, String>>() {
@Override protected IgniteBiTuple<GridKernalContext, String> initialValue() {
return new IgniteBiTuple<>();
}
};
/** Logger. */
private IgniteLogger log;
/** Latch name. */
private String name;
/** Removed flag.*/
private volatile boolean rmvd;
/** Latch key. */
private GridCacheInternalKey key;
/** Latch projection. */
private IgniteInternalCache<GridCacheInternalKey, GridCacheCountDownLatchValue> latchView;
/** Cache context. */
private GridCacheContext ctx;
/** Initial count. */
private int initCnt;
/** Auto delete flag. */
private boolean autoDel;
/** Internal latch (transient). */
private CountDownLatch internalLatch;
/** Initialization guard. */
private final AtomicInteger initGuard = new AtomicInteger();
/** Initialization latch. */
private final CountDownLatch initLatch = new CountDownLatch(1);
/** Latest latch value that is used at the stage while the internal latch is being initialized. */
private Integer lastLatchVal = null;
/**
* Empty constructor required by {@link Externalizable}.
*/
public GridCacheCountDownLatchImpl() {
// No-op.
}
/**
* Constructor.
*
* @param name Latch name.
* @param initCnt Initial count.
* @param autoDel Auto delete flag.
* @param key Latch key.
* @param latchView Latch projection.
* @param ctx Cache context.
*/
public GridCacheCountDownLatchImpl(String name,
int initCnt,
boolean autoDel,
GridCacheInternalKey key,
IgniteInternalCache<GridCacheInternalKey, GridCacheCountDownLatchValue> latchView,
GridCacheContext ctx)
{
assert name != null;
assert initCnt >= 0;
assert key != null;
assert latchView != null;
assert ctx != null;
this.name = name;
this.initCnt = initCnt;
this.autoDel = autoDel;
this.key = key;
this.latchView = latchView;
this.ctx = ctx;
log = ctx.logger(getClass());
}
/** {@inheritDoc} */
@Override public String name() {
return name;
}
/** {@inheritDoc} */
@Override public int count() {
try {
GridCacheCountDownLatchValue latchVal = latchView.get(key);
return latchVal == null ? 0 : latchVal.get();
}
catch (IgniteCheckedException e) {
throw U.convertException(e);
}
}
/** {@inheritDoc} */
@Override public int initialCount() {
return initCnt;
}
/** {@inheritDoc} */
@Override public boolean autoDelete() {
return autoDel;
}
/** {@inheritDoc} */
@Override public void await() {
try {
initializeLatch();
U.await(internalLatch);
}
catch (IgniteCheckedException e) {
throw U.convertException(e);
}
}
/** {@inheritDoc} */
@Override public boolean await(long timeout, TimeUnit unit) {
try {
initializeLatch();
return U.await(internalLatch, timeout, unit);
}
catch (IgniteCheckedException e) {
throw U.convertException(e);
}
}
/** {@inheritDoc} */
@Override public boolean await(long timeout) {
return await(timeout, TimeUnit.MILLISECONDS);
}
/** {@inheritDoc} */
@Override public int countDown() {
return countDown(1);
}
/** {@inheritDoc} */
@Override public int countDown(int val) {
A.ensure(val > 0, "val should be positive");
try {
return retryTopologySafe(new CountDownCallable(val));
}
catch (IgniteCheckedException e) {
throw U.convertException(e);
}
}
/** {@inheritDoc}*/
@Override public void countDownAll() {
try {
retryTopologySafe(new CountDownCallable(0));
}
catch (IgniteCheckedException e) {
throw U.convertException(e);
}
}
/** {@inheritDoc} */
@Override public boolean onRemoved() {
return rmvd = true;
}
/** {@inheritDoc} */
@Override public void needCheckNotRemoved() {
// No-op.
}
/** {@inheritDoc} */
@Override public GridCacheInternalKey key() {
return key;
}
/** {@inheritDoc} */
@Override public boolean removed() {
return rmvd;
}
/** {@inheritDoc} */
@Override public void onUpdate(int cnt) {
assert cnt >= 0;
CountDownLatch latch0;
synchronized (initGuard) {
int state = initGuard.get();
if (state != READY_LATCH_STATE) {
/* Internal latch is not fully initialized yet. Remember latest latch value. */
lastLatchVal = cnt;
return;
}
/* 'synchronized' statement guarantees visibility of internalLatch. No need to make it volatile. */
latch0 = internalLatch;
}
/* Internal latch is fully initialized and ready for the usage. */
assert latch0 != null;
while (latch0.getCount() > cnt)
latch0.countDown();
}
/**
* @throws IgniteCheckedException If operation failed.
*/
private void initializeLatch() throws IgniteCheckedException {
if (initGuard.compareAndSet(UNINITIALIZED_LATCH_STATE, CREATING_LATCH_STATE)) {
try {
internalLatch = retryTopologySafe(new Callable<CountDownLatch>() {
@Override public CountDownLatch call() throws Exception {
try (GridNearTxLocal tx = CU.txStartInternal(ctx, latchView, PESSIMISTIC, REPEATABLE_READ)) {
GridCacheCountDownLatchValue val = latchView.get(key);
if (val == null) {
if (log.isDebugEnabled())
log.debug("Failed to find count down latch with given name: " + name);
return new CountDownLatch(0);
}
tx.commit();
return new CountDownLatch(val.get());
}
}
});
synchronized (initGuard) {
if (lastLatchVal != null) {
while (internalLatch.getCount() > lastLatchVal)
internalLatch.countDown();
}
initGuard.set(READY_LATCH_STATE);
}
if (log.isDebugEnabled())
log.debug("Initialized internal latch: " + internalLatch);
}
finally {
initLatch.countDown();
}
}
else {
U.await(initLatch);
if (internalLatch == null)
throw new IgniteCheckedException("Internal latch has not been properly initialized.");
}
}
/** {@inheritDoc} */
@Override public void close() {
if (!rmvd) {
try {
ctx.kernalContext().dataStructures().removeCountDownLatch(name);
}
catch (IgniteCheckedException e) {
throw U.convertException(e);
}
}
}
/** {@inheritDoc} */
@Override public void onActivate(GridKernalContext kctx) throws IgniteCheckedException {
this.latchView = kctx.cache().atomicsCache();
this.ctx = latchView.context();
}
/** {@inheritDoc} */
@Override public void onDeActivate(GridKernalContext kctx) throws IgniteCheckedException {
// No-op.
}
/** {@inheritDoc} */
@Override public void writeExternal(ObjectOutput out) throws IOException {
out.writeObject(ctx.kernalContext());
out.writeUTF(name);
}
/** {@inheritDoc} */
@Override public void readExternal(ObjectInput in) throws IOException, ClassNotFoundException {
IgniteBiTuple<GridKernalContext, String> t = stash.get();
t.set1((GridKernalContext)in.readObject());
t.set2(in.readUTF());
}
/**
* Reconstructs object on unmarshalling.
*
* @return Reconstructed object.
* @throws ObjectStreamException Thrown in case of unmarshalling error.
*/
@SuppressWarnings({"ConstantConditions"})
private Object readResolve() throws ObjectStreamException {
try {
IgniteBiTuple<GridKernalContext, String> t = stash.get();
return t.get1().dataStructures().countDownLatch(t.get2(), 0, false, false);
}
catch (IgniteCheckedException e) {
throw U.withCause(new InvalidObjectException(e.getMessage()), e);
}
finally {
stash.remove();
}
}
/** {@inheritDoc} */
@Override public String toString() {
return S.toString(GridCacheCountDownLatchImpl.class, this);
}
/**
*
*/
private class CountDownCallable implements Callable<Integer> {
/** Value to count down on (if 0 then latch is counted down to 0). */
private final int val;
/**
* @param val Value to count down on (if 0 is passed latch is counted down to 0).
*/
private CountDownCallable(int val) {
assert val >= 0;
this.val = val;
}
/** {@inheritDoc} */
@Override public Integer call() throws Exception {
try (GridNearTxLocal tx = CU.txStartInternal(ctx, latchView, PESSIMISTIC, REPEATABLE_READ)) {
GridCacheCountDownLatchValue latchVal = latchView.get(key);
if (latchVal == null) {
if (log.isDebugEnabled())
log.debug("Failed to find count down latch with given name: " + name);
return 0;
}
int retVal;
if (val > 0) {
retVal = latchVal.get() - val;
if (retVal < 0)
retVal = 0;
}
else
retVal = 0;
latchVal.set(retVal);
latchView.put(key, latchVal);
tx.commit();
return retVal;
}
}
}
}