1f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project/* Licensed to the Apache Software Foundation (ASF) under one or more 2f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * contributor license agreements. See the NOTICE file distributed with 3f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * this work for additional information regarding copyright ownership. 4f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * The ASF licenses this file to You under the Apache License, Version 2.0 5f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * (the "License"); you may not use this file except in compliance with 6f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * the License. You may obtain a copy of the License at 7f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * 8f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * http://www.apache.org/licenses/LICENSE-2.0 9f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * 10f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * Unless required by applicable law or agreed to in writing, software 11f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * distributed under the License is distributed on an "AS IS" BASIS, 12f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * See the License for the specific language governing permissions and 14f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * limitations under the License. 15f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project */ 16f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project 17f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Projectpackage org.apache.harmony.nio.internal; 18f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project 19f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Projectimport java.io.IOException; 20f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Projectimport java.nio.channels.ClosedChannelException; 21f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Projectimport java.nio.channels.FileChannel; 22f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Projectimport java.nio.channels.FileLock; 23f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project 24d2510429e70ab91a04c67d5ca39b30f354eba221Jesse Wilson/** 25f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * The concrete implementation of an NIO file lock object. 26f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project */ 27f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Projectfinal class FileLockImpl extends FileLock { 28f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project 29f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project // Remembers if this lock has been released via the API. 30f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project private boolean isReleased = false; 31f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project 32d2510429e70ab91a04c67d5ca39b30f354eba221Jesse Wilson /** 33d2510429e70ab91a04c67d5ca39b30f354eba221Jesse Wilson * Answers a new file lock object with the given parameters. 34f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * 35d2510429e70ab91a04c67d5ca39b30f354eba221Jesse Wilson * @param channel 36d2510429e70ab91a04c67d5ca39b30f354eba221Jesse Wilson * the file channel hosting the lock. 37d2510429e70ab91a04c67d5ca39b30f354eba221Jesse Wilson * @param position 38d2510429e70ab91a04c67d5ca39b30f354eba221Jesse Wilson * the start position of the lock, in bytes 39d2510429e70ab91a04c67d5ca39b30f354eba221Jesse Wilson * @param size 40d2510429e70ab91a04c67d5ca39b30f354eba221Jesse Wilson * the length of the lock, in bytes 41d2510429e70ab91a04c67d5ca39b30f354eba221Jesse Wilson * @param shared 42d2510429e70ab91a04c67d5ca39b30f354eba221Jesse Wilson * whether this lock is shared (true) or exclusive (false) 43f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project */ 44f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project public FileLockImpl(FileChannel channel, long position, long size, 45f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project boolean shared) { 46f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project super(channel, position, size, shared); 47f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project } 48f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project 49d2510429e70ab91a04c67d5ca39b30f354eba221Jesse Wilson /** 50f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * Tests to see if the lock is valid. A lock can be invalidated if the 51f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * channel it is acquired on is closed or if it is released. (non-Javadoc) 52f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * 53f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * @see java.nio.channels.FileLock#isValid() 54f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project */ 55d2510429e70ab91a04c67d5ca39b30f354eba221Jesse Wilson @Override 56f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project public boolean isValid() { 57f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project return !isReleased && channel().isOpen(); 58f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project } 59f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project 60d2510429e70ab91a04c67d5ca39b30f354eba221Jesse Wilson /** 61f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * Releases the file lock on the channel that acquired it. Releasing an 62f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * invalid lock has no effect. 63f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * 64f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * @see java.nio.channels.FileLock#release() 65f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project */ 66d2510429e70ab91a04c67d5ca39b30f354eba221Jesse Wilson @Override 67f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project public void release() throws IOException { 68f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project if (!channel().isOpen()) { 69f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project throw new ClosedChannelException(); 70f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project } 71f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project 72f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project if (!isReleased) { 73f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project ((FileChannelImpl) channel()).release(this); 74f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project isReleased = true; 75f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project } 76f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project } 77f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project} 78