001package org.eclipse.aether.named.providers; 002 003/* 004 * Licensed to the Apache Software Foundation (ASF) under one 005 * or more contributor license agreements. See the NOTICE file 006 * distributed with this work for additional information 007 * regarding copyright ownership. The ASF licenses this file 008 * to you under the Apache License, Version 2.0 (the 009 * "License"); you may not use this file except in compliance 010 * with the License. You may obtain a copy of the License at 011 * 012 * http://www.apache.org/licenses/LICENSE-2.0 013 * 014 * Unless required by applicable law or agreed to in writing, 015 * software distributed under the License is distributed on an 016 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 017 * KIND, either express or implied. See the License for the 018 * specific language governing permissions and limitations 019 * under the License. 020 */ 021 022import java.util.concurrent.Semaphore; 023import java.util.concurrent.TimeUnit; 024 025import javax.inject.Named; 026import javax.inject.Singleton; 027 028import org.eclipse.aether.named.support.AdaptedSemaphoreNamedLock; 029import org.eclipse.aether.named.support.NamedLockFactorySupport; 030 031/** 032 * A JVM-local named lock factory that uses named {@link Semaphore}s. 033 */ 034@Singleton 035@Named( LocalSemaphoreNamedLockFactory.NAME ) 036public class LocalSemaphoreNamedLockFactory 037 extends NamedLockFactorySupport 038{ 039 public static final String NAME = "semaphore-local"; 040 041 @Override 042 protected AdaptedSemaphoreNamedLock createLock( final String name ) 043 { 044 return new AdaptedSemaphoreNamedLock( name, this, new JVMSemaphore() ); 045 } 046 047 /** 048 * Adapted JVM {@link java.util.concurrent.Semaphore}. 049 */ 050 private static final class JVMSemaphore 051 implements AdaptedSemaphoreNamedLock.AdaptedSemaphore 052 { 053 private final Semaphore semaphore; 054 055 private JVMSemaphore() 056 { 057 this.semaphore = new Semaphore( Integer.MAX_VALUE ); 058 } 059 060 @Override 061 public boolean tryAcquire( final int perms, final long time, final TimeUnit unit ) throws InterruptedException 062 { 063 return semaphore.tryAcquire( perms, time, unit ); 064 } 065 066 @Override 067 public void release( final int perms ) 068 { 069 semaphore.release( perms ); 070 } 071 } 072}