/*
* Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
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* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
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* 2 along with this work; if not, write to the Free Software Foundation,
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package com.sun.btrace.instr;
import com.sun.btrace.BTraceRuntime;
import com.sun.btrace.instr.random.SharedRandomIntProvider;
import com.sun.btrace.instr.random.ThreadLocalRandomIntProvider;
/**
*
* @author Jaroslav Bachorik
*/
@SuppressWarnings("LiteralClassName")
abstract public class RandomIntProvider {
// for the testability purposes; BTraceRuntime initializes Unsafe instance
// and fails under JUnit
private static boolean useBtraceEnter = true;
private static final RandomIntProvider rndIntProvider;
static {
boolean entered = false;
try {
if (useBtraceEnter) {
entered = BTraceRuntime.enter();
}
Class clz = null;
try {
clz = Class.forName("java.util.concurrent.ThreadLocalRandom");
} catch (Throwable e) {
// ThreadLocalRandom not accessible -> pre JDK8
}
if (clz != null) {
rndIntProvider = new ThreadLocalRandomIntProvider();
} else {
rndIntProvider = new SharedRandomIntProvider();
}
} finally {
if (entered) BTraceRuntime.leave();
}
}
abstract public int nextInt(int bound);
protected RandomIntProvider() {}
public static RandomIntProvider getInstance() {
return rndIntProvider;
}
}