1 /* 2 * Copyright (C) 2007 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 android.database.sqlite; 18 19 /** 20 * An object create from a SQLiteDatabase that can be closed. 21 */ 22 public abstract class SQLiteClosable { 23 private int mReferenceCount = 1; 24 private Object mLock = new Object(); onAllReferencesReleased()25 protected abstract void onAllReferencesReleased(); onAllReferencesReleasedFromContainer()26 protected void onAllReferencesReleasedFromContainer(){} 27 acquireReference()28 public void acquireReference() { 29 synchronized(mLock) { 30 if (mReferenceCount <= 0) { 31 throw new IllegalStateException( 32 "attempt to acquire a reference on a close SQLiteClosable"); 33 } 34 mReferenceCount++; 35 } 36 } 37 releaseReference()38 public void releaseReference() { 39 synchronized(mLock) { 40 mReferenceCount--; 41 if (mReferenceCount == 0) { 42 onAllReferencesReleased(); 43 } 44 } 45 } 46 releaseReferenceFromContainer()47 public void releaseReferenceFromContainer() { 48 synchronized(mLock) { 49 mReferenceCount--; 50 if (mReferenceCount == 0) { 51 onAllReferencesReleasedFromContainer(); 52 } 53 } 54 } 55 } 56