com.hazelcast.internal.util.RuntimeAvailableProcessors Maven / Gradle / Ivy
/*
* Copyright (c) 2008-2024, Hazelcast, Inc. All Rights Reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.hazelcast.internal.util;
/**
* Utility class to access {@link Runtime#availableProcessors()} and optionally override its return value.
*
* This class makes the number of available processors configurable for the sake of testing.
* {@link #override(int)} and {@link #resetOverride()} should only be used for testing purposes.
*/
public final class RuntimeAvailableProcessors {
// number of available processors currently configured
private static volatile int currentAvailableProcessors = Runtime.getRuntime().availableProcessors();
// number of processors to be used when reset
private static volatile int defaultAvailableProcessors = Runtime.getRuntime().availableProcessors();
private RuntimeAvailableProcessors() {
}
/**
* Returns the number of available processors.
*
* Returned value is either equal to {@link Runtime#availableProcessors()}
* or an overridden value by call of the method {@link #override(int)}.
*
* @return number of available processors
*/
public static int get() {
return currentAvailableProcessors;
}
/**
* Overrides the number of available processors returned by the method {@link #get()}.
*
* This is to be used only for testing.
*
* @param availableProcessors number of available processors
*/
public static void override(int availableProcessors) {
RuntimeAvailableProcessors.currentAvailableProcessors = availableProcessors;
}
/**
* Overrides the number of available processors that are set by the method {@link #override(int)}
*
* This is to be used only for testing.
*
* @param availableProcessors
*/
public static void overrideDefault(int availableProcessors) {
defaultAvailableProcessors = availableProcessors;
}
/**
* Resets the overridden number of available processors to {@link Runtime#availableProcessors()}.
*
* This is to be used only for testing.
*/
public static void resetOverride() {
RuntimeAvailableProcessors.currentAvailableProcessors = defaultAvailableProcessors;
}
}