jdk-24/test/jdk/com/sun/management/HotSpotDiagnosticMXBean/SetVMOption.java

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/*
 * @test
 * @bug     6314913
 * @summary Basic Test for HotSpotDiagnosticMXBean.setVMOption()
 *          and getDiagnosticOptions().
 * @author  Mandy Chung
 * @author  Jaroslav Bachorik
 *
 * @library /test/lib
 * @run main/othervm -XX:+HeapDumpOnOutOfMemoryError SetVMOption
 */

import java.lang.management.ManagementFactory;
import java.util.*;
import com.sun.management.HotSpotDiagnosticMXBean;
import com.sun.management.VMOption;
import com.sun.management.VMOption.Origin;
import jdk.test.lib.Platform;

public class SetVMOption {
    private static final String HEAP_DUMP_ON_OOM = "HeapDumpOnOutOfMemoryError";
    private static final String EXPECTED_VALUE = "true";
    private static final String BAD_VALUE = "yes";
    private static final String NEW_VALUE = "false";
    private static final String MANAGEMENT_SERVER = "ManagementServer";
    private static HotSpotDiagnosticMXBean mbean;

    public static void main(String[] args) throws Exception {
        mbean =
            ManagementFactory.getPlatformMXBean(HotSpotDiagnosticMXBean.class);

        VMOption option = findHeapDumpOnOomOption();
        if (!option.getValue().equalsIgnoreCase(EXPECTED_VALUE)) {
            throw new RuntimeException("Unexpected value: " +
                option.getValue() + " expected: " + EXPECTED_VALUE);
        }
        if (option.getOrigin() != Origin.VM_CREATION) {
            throw new RuntimeException("Unexpected origin: " +
                option.getOrigin() + " expected: VM_CREATION");
        }
        if (!option.isWriteable()) {
            throw new RuntimeException("Expected " + HEAP_DUMP_ON_OOM +
                " to be writeable");
        }

        // set VM option to a new value
        mbean.setVMOption(HEAP_DUMP_ON_OOM, NEW_VALUE);

        option = findHeapDumpOnOomOption();
        if (!option.getValue().equalsIgnoreCase(NEW_VALUE)) {
            throw new RuntimeException("Unexpected value: " +
                option.getValue() + " expected: " + NEW_VALUE);
        }
        if (option.getOrigin() != Origin.MANAGEMENT) {
            throw new RuntimeException("Unexpected origin: " +
                option.getOrigin() + " expected: MANAGEMENT");
        }
        VMOption o = mbean.getVMOption(HEAP_DUMP_ON_OOM);
        if (!option.getValue().equals(o.getValue())) {
            throw new RuntimeException("Unmatched value: " +
                option.getValue() + " expected: " + o.getValue());
        }
        if (!option.getValue().equals(o.getValue())) {
            throw new RuntimeException("Unmatched value: " +
                option.getValue() + " expected: " + o.getValue());
        }
        if (option.getOrigin() != o.getOrigin()) {
            throw new RuntimeException("Unmatched origin: " +
                option.getOrigin() + " expected: " + o.getOrigin());
        }
        if (option.isWriteable() != o.isWriteable()) {
            throw new RuntimeException("Unmatched writeable: " +
                option.isWriteable() + " expected: " + o.isWriteable());
        }


        // Today we don't have any manageable flags of the string type in the product build,
        // so we can only test DummyManageableStringFlag in the debug build.
        if (Platform.isDebugBuild()) {
            String optionName = "DummyManageableStringFlag";
            String toValue = "DummyManageableStringFlag_Is_Set_To_Hello";

            mbean.setVMOption(optionName, toValue);

            VMOption stringOption = findOption(optionName);
            Object newValue = stringOption.getValue();
            if (!toValue.equals(newValue)) {
                throw new RuntimeException("Unmatched value: " +
                                           newValue + " expected: " + toValue);
            }
        }

        // check if ManagementServer is not writeable
        List<VMOption> options = mbean.getDiagnosticOptions();
        VMOption mgmtServerOption = null;
        for (VMOption o1 : options) {
            if (o1.getName().equals(MANAGEMENT_SERVER)) {
                 mgmtServerOption = o1;
                 break;
            }
        }
        if (mgmtServerOption != null) {
            throw new RuntimeException(MANAGEMENT_SERVER +
                " is not expected to be writeable");
        }
        mgmtServerOption = mbean.getVMOption(MANAGEMENT_SERVER);
        if (mgmtServerOption == null) {
            throw new RuntimeException(MANAGEMENT_SERVER +
                " should exist.");
        }
        if (mgmtServerOption.getOrigin() != Origin.DEFAULT) {
            throw new RuntimeException(MANAGEMENT_SERVER +
                " should have the default value.");
        }
        if (mgmtServerOption.isWriteable()) {
            throw new RuntimeException(MANAGEMENT_SERVER +
                " is not expected to be writeable");
        }
    }

    public static VMOption findHeapDumpOnOomOption() {
        return findOption(HEAP_DUMP_ON_OOM);
    }

    private static VMOption findOption(String optionName) {
        List<VMOption> options = mbean.getDiagnosticOptions();
        VMOption found = null;
        for (VMOption o : options) {
            if (o.getName().equals(optionName)) {
                 found = o;
                 break;
            }
        }
        if (found == null) {
            throw new RuntimeException("VM option " + optionName +
                " not found");
        }
        return found;
    }
}