org.apache.hudi.org.openjdk.jol.vm.VMOptions Maven / Gradle / Ivy
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* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
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* 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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package org.openjdk.jol.vm;
import javax.management.*;
import javax.management.openmbean.CompositeDataSupport;
import java.lang.management.ManagementFactory;
/**
* Polls VM options.
*/
class VMOptions {
private static String getString(String key) throws Exception {
MBeanServer server = ManagementFactory.getPlatformMBeanServer();
ObjectName mbean = new ObjectName("com.sun.management:type=HotSpotDiagnostic");
CompositeDataSupport val = (CompositeDataSupport) server.invoke(mbean, "getVMOption", new Object[]{key}, new String[]{"java.lang.String"});
return val.get("value").toString();
}
public static Boolean pollCompressedOops() {
try {
return Boolean.valueOf(getString("UseCompressedOops"));
} catch (Exception exp) {
// TODO: log
return null;
}
}
public static Boolean pollCompressedClassPointers() {
try {
return Boolean.valueOf(getString("UseCompressedClassPointers"));
} catch (Exception exp) {
// TODO: log
return null;
}
}
public static Integer pollObjectAlignment() {
if (Boolean.TRUE.equals(pollCompressedOops())) {
try {
return Integer.valueOf(getString("ObjectAlignmentInBytes"));
} catch (Exception exp) {
// TODO: log
return null;
}
}
// TODO: log
return null;
}
}