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/*
* Copyright (c) 2008, 2018, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* 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).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
package vm.share;
import com.sun.management.HotSpotDiagnosticMXBean;
import com.sun.management.VMOption;
import java.lang.management.ManagementFactory;
import java.util.Objects;
public class VMRuntimeEnvUtils {
private static HotSpotDiagnosticMXBean DIAGNOSTIC_BEAN
= ManagementFactory.getPlatformMXBean(HotSpotDiagnosticMXBean.class);
private VMRuntimeEnvUtils() {
}
public static boolean isJITEnabled() {
boolean isJITEnabled = ManagementFactory.getCompilationMXBean() != null;
return isJITEnabled;
}
/**
* Returns value of VM option.
*
* @param name option's name
* @return value of option or {@code null}, if option doesn't exist
* @throws NullPointerException if name is null
* @see HotSpotDiagnosticMXBean#getVMOption(String)
*/
public static String getVMOption(String name) {
Objects.requireNonNull(name);
VMOption tmp;
try {
tmp = DIAGNOSTIC_BEAN.getVMOption(name);
} catch (IllegalArgumentException e) {
tmp = null;
}
return (tmp == null ? null : tmp.getValue());
}
/**
* Returns value of VM option or default value.
*
* @param name option's name
* @param defaultValue default value
* @return value of option or {@code defaultValue}, if option doesn't exist
* @throws NullPointerException if name is null
* @see #getVMOption(String)
*/
public static String getVMOption(String name, String defaultValue) {
String result = getVMOption(name);
return result == null ? defaultValue : result;
}
/**
* Returns if a boolean VM option is enabled or not.
*
* @param name option's name
* @return true iff enabled
* @throws IllegalArgumentException if naming non-boolean or non-existing option
*/
public static boolean isVMOptionEnabled(String name) {
String isSet = getVMOption(name, "error");
if (isSet.equals("true")) {
return true;
} else if (isSet.equals("false")) {
return false;
}
throw new IllegalArgumentException(name + " is not a boolean option.");
}
/**
* Sets a specified value for VM option of given name.
*
* @param name option's name
* @param value new value
* @throws NullPointerException if name is null
* @throws IllegalArgumentException if new value is invalid or if vm option
* is not writable.
* @see HotSpotDiagnosticMXBean#setVMOption(String, String)
*/
public static void setVMOption(String name, String value) {
Objects.requireNonNull(name);
DIAGNOSTIC_BEAN.setVMOption(name, value);
}
}
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