org.eclipse.aether.named.support.NamedLockSupport Maven / Gradle / Ivy
/*
* 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.eclipse.aether.named.support;
import java.util.ArrayDeque;
import java.util.Collections;
import java.util.Deque;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.TimeUnit;
import org.eclipse.aether.named.NamedLock;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* Support class for {@link NamedLock} implementations providing reference counting.
*/
public abstract class NamedLockSupport implements NamedLock {
protected final Logger logger = LoggerFactory.getLogger(getClass());
private final String name;
private final NamedLockFactorySupport factory;
private final ConcurrentHashMap> diagnosticState; // non-null only if diag enabled
public NamedLockSupport(final String name, final NamedLockFactorySupport factory) {
this.name = name;
this.factory = factory;
this.diagnosticState = factory.isDiagnosticEnabled() ? new ConcurrentHashMap<>() : null;
}
@Override
public String name() {
return name;
}
@Override
public boolean lockShared(long time, TimeUnit unit) throws InterruptedException {
Deque steps = null;
if (diagnosticState != null) {
steps = diagnosticState.computeIfAbsent(Thread.currentThread(), k -> new ArrayDeque<>());
}
if (steps != null) {
steps.push("wait-shared");
}
boolean result = doLockShared(time, unit);
if (steps != null) {
steps.pop();
if (result) {
steps.push("shared");
}
}
return result;
}
protected abstract boolean doLockShared(long time, TimeUnit unit) throws InterruptedException;
@Override
public boolean lockExclusively(long time, TimeUnit unit) throws InterruptedException {
Deque steps = null;
if (diagnosticState != null) {
steps = diagnosticState.computeIfAbsent(Thread.currentThread(), k -> new ArrayDeque<>());
}
if (steps != null) {
steps.push("wait-exclusive");
}
boolean result = doLockExclusively(time, unit);
if (steps != null) {
steps.pop();
if (result) {
steps.push("exclusive");
}
}
return result;
}
protected abstract boolean doLockExclusively(long time, TimeUnit unit) throws InterruptedException;
@Override
public void unlock() {
doUnlock();
if (diagnosticState != null) {
diagnosticState
.computeIfAbsent(Thread.currentThread(), k -> new ArrayDeque<>())
.pop();
}
}
protected abstract void doUnlock();
@Override
public void close() {
doClose();
}
protected void doClose() {
factory.closeLock(name);
}
/**
* Returns the diagnostic state (if collected) or empty map, never {@code null}.
*
* @since 1.9.11
*/
public Map> diagnosticState() {
if (diagnosticState != null) {
return diagnosticState;
} else {
return Collections.emptyMap();
}
}
@Override
public String toString() {
return getClass().getSimpleName() + "{" + "name='" + name + '\'' + '}';
}
}