75 lines
2.0 KiB
Java
75 lines
2.0 KiB
Java
/*
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* Copyright (c) 2003, Oracle and/or its affiliates. All rights reserved.
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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*
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* This code is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 2 only, as
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* published by the Free Software Foundation.
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*
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* This code is distributed in the hope that it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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* version 2 for more details (a copy is included in the LICENSE file that
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* accompanied this code).
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*
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* You should have received a copy of the GNU General Public License version
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* 2 along with this work; if not, write to the Free Software Foundation,
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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*
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* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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* or visit www.oracle.com if you need additional information or have any
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* questions.
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*/
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/*
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* @bug 4530538
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* @summary A semaphore utility class.
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* @author Mandy Chung
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*/
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public class Semaphore {
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private Object go = new Object();
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private int semaCount;
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private int waiters = 0;
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public Semaphore() {
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semaCount = 0;
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}
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public Semaphore(int initialCount) {
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semaCount = initialCount;
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}
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public void semaP() {
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synchronized (go) {
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waiters++;
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while (semaCount == 0) {
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try {
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go.wait();
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} catch (InterruptedException e) {
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e.printStackTrace();
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throw new InternalError();
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}
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}
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semaCount--;
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waiters--;
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}
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}
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public void semaV() {
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synchronized (go) {
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semaCount++;
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go.notify();
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}
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}
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public int getWaiterCount() {
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synchronized (go) {
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return waiters;
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}
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}
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public Object getLock() {
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return go;
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}
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}
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