Showing the changes to java/pkg/sun/misc/ConditionLock.java (1 of 18352 files). Show all
Unified · Split
| @@ -0,0 +1,82 @@ | ||
| 1 | +/* | |
| 2 | + * Copyright (c) 1994, 2005, Oracle and/or its affiliates. All rights reserved. | |
| 3 | + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. | |
| 4 | + * | |
| 5 | + * This code is free software; you can redistribute it and/or modify it | |
| 6 | + * under the terms of the GNU General Public License version 2 only, as | |
| 7 | + * published by the Free Software Foundation. Oracle designates this | |
| 8 | + * particular file as subject to the "Classpath" exception as provided | |
| 9 | + * by Oracle in the LICENSE file that accompanied this code. | |
| 10 | + * | |
| 11 | + * This code is distributed in the hope that it will be useful, but WITHOUT | |
| 12 | + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
| 13 | + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
| 14 | + * version 2 for more details (a copy is included in the LICENSE file that | |
| 15 | + * accompanied this code). | |
| 16 | + * | |
| 17 | + * You should have received a copy of the GNU General Public License version | |
| 18 | + * 2 along with this work; if not, write to the Free Software Foundation, | |
| 19 | + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. | |
| 20 | + * | |
| 21 | + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA | |
| 22 | + * or visit www.oracle.com if you need additional information or have any | |
| 23 | + * questions. | |
| 24 | + */ | |
| 25 | + | |
| 26 | +package sun.misc; | |
| 27 | + | |
| 28 | +/** | |
| 29 | + * ConditionLock is a Lock with a built in state variable. This class | |
| 30 | + * provides the ability to wait for the state variable to be set to a | |
| 31 | + * desired value and then acquire the lock.<p> | |
| 32 | + * | |
| 33 | + * The lockWhen() and unlockWith() methods can be safely intermixed | |
| 34 | + * with the lock() and unlock() methods. However if there is a thread | |
| 35 | + * waiting for the state variable to become a particular value and you | |
| 36 | + * simply call Unlock(), that thread will not be able to acquire the | |
| 37 | + * lock until the state variable equals its desired value. <p> | |
| 38 | + * | |
| 39 | + * @author Peter King | |
| 40 | + */ | |
| 41 | +public final | |
| 42 | +class ConditionLock extends Lock { | |
| 43 | + private int state = 0; | |
| 44 | + | |
| 45 | + /** | |
| 46 | + * Creates a ConditionLock. | |
| 47 | + */ | |
| 48 | + public ConditionLock () { | |
| 49 | + } | |
| 50 | + | |
| 51 | + /** | |
| 52 | + * Creates a ConditionLock in an initialState. | |
| 53 | + */ | |
| 54 | + public ConditionLock (int initialState) { | |
| 55 | + state = initialState; | |
| 56 | + } | |
| 57 | + | |
| 58 | + /** | |
| 59 | + * Acquires the lock when the state variable equals the desired state. | |
| 60 | + * | |
| 61 | + * @param desiredState the desired state | |
| 62 | + * @exception java.lang.InterruptedException if any thread has | |
| 63 | + * interrupted this thread. | |
| 64 | + */ | |
| 65 | + public synchronized void lockWhen(int desiredState) | |
| 66 | + throws InterruptedException | |
| 67 | + { | |
| 68 | + while (state != desiredState) { | |
| 69 | + wait(); | |
| 70 | + } | |
| 71 | + lock(); | |
| 72 | + } | |
| 73 | + | |
| 74 | + /** | |
| 75 | + * Releases the lock, and sets the state to a new value. | |
| 76 | + * @param newState the new state | |
| 77 | + */ | |
| 78 | + public synchronized void unlockWith(int newState) { | |
| 79 | + state = newState; | |
| 80 | + unlock(); | |
| 81 | + } | |
| 82 | +} | |