LargeHeapThresholdTest.java

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/*
 * @test
 * @bug 6653214
 * @requires os.simpleArch=="x64"
 * @run main/othervm -Xmx3000M LargeHeapThresholdTest
 * @summary MemoryPoolMXBean.setUsageThreshold() does not support large heap sizes
 *
 * Large is >= 2 gigabytes
 * This test tries to find memory pools with maximum allowable size of at
 * least 2 gigabytes and set their usage thresholds to this value. If tested
 * Java implementation is defective
 * "java.lang.IllegalArgumentException: Invalid threshold value > max value of size_t"
 * will be thrown.
 * If no pool with maximum allowable size of at least 2 gigabytes exists
 * the test passes. There is a good chance that such pool will exist if JVM
 * is started with '-Xmx3000M' command line switch.
 */


import java.lang.management.ManagementFactory;
import java.lang.management.MemoryPoolMXBean;
import java.util.List;


public class LargeHeapThresholdTest {

    final static long TWO_G = ((long) Integer.MAX_VALUE + 1); // 2 gigabytes

    public static void main(String[] args) {
        List<MemoryPoolMXBean> pools = ManagementFactory.getMemoryPoolMXBeans();
        boolean verified = false;
        for (MemoryPoolMXBean i : pools) {
            if ((i.getUsage().getMax() >= TWO_G)
                    && i.isUsageThresholdSupported()) {
                i.setUsageThreshold(TWO_G);
                if(i.getUsageThreshold() != TWO_G)
                    throw new RuntimeException("Usage threshold for"
                            + " pool '" + i.getName() + "' is " + i.getUsageThreshold()
                            + " and not equal to 2GB");
                verified = true;
            }
        }
        System.out.println("Ability to use big heap thresholds has "
                + (verified ? "" : "NOT ") + "been verified");
    }
}