1 /* 2 * Copyright (C) 2012 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package com.android.internal.os; 18 19 /** 20 * Helper class for passing more arguments though a message 21 * and avoiding allocation of a custom class for wrapping the 22 * arguments. This class maintains a pool of instances and 23 * it is responsibility of the client to recycle and instance 24 * once it is no longer used. 25 */ 26 public final class SomeArgs { 27 28 private static final int MAX_POOL_SIZE = 10; 29 30 private static SomeArgs sPool; 31 private static int sPoolSize; 32 private static Object sPoolLock = new Object(); 33 34 private SomeArgs mNext; 35 36 private boolean mInPool; 37 38 static final int WAIT_NONE = 0; 39 static final int WAIT_WAITING = 1; 40 static final int WAIT_FINISHED = 2; 41 int mWaitState = WAIT_NONE; 42 43 public Object arg1; 44 public Object arg2; 45 public Object arg3; 46 public Object arg4; 47 public Object arg5; 48 public Object arg6; 49 public Object arg7; 50 public Object arg8; 51 public int argi1; 52 public int argi2; 53 public int argi3; 54 public int argi4; 55 public int argi5; 56 public int argi6; 57 SomeArgs()58 private SomeArgs() { 59 /* do nothing - reduce visibility */ 60 } 61 obtain()62 public static SomeArgs obtain() { 63 synchronized (sPoolLock) { 64 if (sPoolSize > 0) { 65 SomeArgs args = sPool; 66 sPool = sPool.mNext; 67 args.mNext = null; 68 args.mInPool = false; 69 sPoolSize--; 70 return args; 71 } else { 72 return new SomeArgs(); 73 } 74 } 75 } 76 complete()77 public void complete() { 78 synchronized (this) { 79 if (mWaitState != WAIT_WAITING) { 80 throw new IllegalStateException("Not waiting"); 81 } 82 mWaitState = WAIT_FINISHED; 83 notifyAll(); 84 } 85 } 86 recycle()87 public void recycle() { 88 if (mInPool) { 89 throw new IllegalStateException("Already recycled."); 90 } 91 if (mWaitState != WAIT_NONE) { 92 return; 93 } 94 synchronized (sPoolLock) { 95 clear(); 96 if (sPoolSize < MAX_POOL_SIZE) { 97 mNext = sPool; 98 mInPool = true; 99 sPool = this; 100 sPoolSize++; 101 } 102 } 103 } 104 clear()105 private void clear() { 106 arg1 = null; 107 arg2 = null; 108 arg3 = null; 109 arg4 = null; 110 arg5 = null; 111 arg6 = null; 112 arg7 = null; 113 argi1 = 0; 114 argi2 = 0; 115 argi3 = 0; 116 argi4 = 0; 117 argi5 = 0; 118 argi6 = 0; 119 } 120 } 121