org.eclipse.jetty.util.ProcessorUtils Maven / Gradle / Ivy
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//
// ========================================================================
// Copyright (c) 1995-2019 Mort Bay Consulting Pty. Ltd.
// ------------------------------------------------------------------------
// All rights reserved. This program and the accompanying materials
// are made available under the terms of the Eclipse Public License v1.0
// and Apache License v2.0 which accompanies this distribution.
//
// The Eclipse Public License is available at
// http://www.eclipse.org/legal/epl-v10.html
//
// The Apache License v2.0 is available at
// http://www.opensource.org/licenses/apache2.0.php
//
// You may elect to redistribute this code under either of these licenses.
// ========================================================================
//
package org.eclipse.jetty.util;
/**
* ProcessorUtils provides access to runtime info about processors, that may be
* overridden by system properties or environment variables.
* This can be useful in virtualized environments where the runtime may miss
* report the available resources.
*/
public class ProcessorUtils
{
public static final String AVAILABLE_PROCESSORS = "JETTY_AVAILABLE_PROCESSORS";
private static int __availableProcessors = init();
static int init()
{
String processors = System.getProperty(AVAILABLE_PROCESSORS, System.getenv(AVAILABLE_PROCESSORS));
if (processors != null)
{
try
{
return Integer.parseInt( processors );
}
catch (NumberFormatException ignored)
{
}
}
return Runtime.getRuntime().availableProcessors();
}
/**
* Returns the number of available processors, from System Property "JETTY_AVAILABLE_PROCESSORS",
* or if not set then from environment variable "JETTY_AVAILABLE_PROCESSORS" or if not set then
* from {@link Runtime#availableProcessors()}.
*
* @return the number of processors
*/
public static int availableProcessors()
{
return __availableProcessors;
}
public static void setAvailableProcessors(int processors)
{
if (processors < 1)
throw new IllegalArgumentException("Invalid number of processors: " + processors);
__availableProcessors = processors;
}
}