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 Semaphore semaphore = new Semaphore( Integer.MAX_VALUE ); 045 return new AdaptedSemaphoreNamedLock( name, this, new JVMSemaphore( semaphore ) ); 046 } 047 048 /** 049 * Adapted JVM {@link java.util.concurrent.Semaphore}. 050 */ 051 private static final class JVMSemaphore 052 implements AdaptedSemaphoreNamedLock.AdaptedSemaphore 053 { 054 private final Semaphore semaphore; 055 056 private JVMSemaphore( final Semaphore semaphore ) 057 { 058 this.semaphore = semaphore; 059 } 060 061 @Override 062 public boolean tryAcquire( final int perms, final long time, final TimeUnit unit ) throws InterruptedException 063 { 064 return semaphore.tryAcquire( perms, time, unit ); 065 } 066 067 @Override 068 public void release( final int perms ) 069 { 070 semaphore.release( perms ); 071 } 072 } 073}