test/java/lang/management/MemoryMXBean/LowMemoryTest.java

rev 10476 : 8035939: java/lang/management/MemoryMXBean/MemoryManagement.java timed out on Linux-amd64

*** 48,71 ****
      private static MemoryPoolMXBean mpool = null;
      private static boolean trace = false;
      private static boolean testFailed = false;
      private static final int NUM_TRIGGERS = 5;
      private static final int NUM_CHUNKS = 2;
      private static long chunkSize;
  
      /**
       * Run the test multiple times with different GC versions.
       * First with default command line specified by the framework.
       * Then with GC versions specified by the test.
       */
      public static void main(String a[]) throws Throwable {
          final String main = "LowMemoryTest$TestMain";
!         RunUtil.runTestKeepGcOpts(main);
!         RunUtil.runTestClearGcOpts(main, "-XX:+UseSerialGC");
!         RunUtil.runTestClearGcOpts(main, "-XX:+UseParallelGC");
!         RunUtil.runTestClearGcOpts(main, "-XX:+UseG1GC");
!         RunUtil.runTestClearGcOpts(main, "-XX:+UseConcMarkSweepGC");
      }
  
      private static volatile boolean listenerInvoked = false;
      static class SensorListener implements NotificationListener {
          @Override
--- 48,75 ----
      private static MemoryPoolMXBean mpool = null;
      private static boolean trace = false;
      private static boolean testFailed = false;
      private static final int NUM_TRIGGERS = 5;
      private static final int NUM_CHUNKS = 2;
+     private static final int YOUNG_GEN_SIZE = 8 * 1024 * 1024;
      private static long chunkSize;
  
      /**
       * Run the test multiple times with different GC versions.
       * First with default command line specified by the framework.
       * Then with GC versions specified by the test.
       */
      public static void main(String a[]) throws Throwable {
          final String main = "LowMemoryTest$TestMain";
!         // Use a low young gen size to ensure that the
!         // allocated objects are put in the old gen.
!         final String nmFlag = "-Xmn" + YOUNG_GEN_SIZE;
!         RunUtil.runTestKeepGcOpts(main, nmFlag);
!         RunUtil.runTestClearGcOpts(main, nmFlag, "-XX:+UseSerialGC");
!         RunUtil.runTestClearGcOpts(main, nmFlag, "-XX:+UseParallelGC");
!         RunUtil.runTestClearGcOpts(main, nmFlag, "-XX:+UseG1GC");
!         RunUtil.runTestClearGcOpts(main, nmFlag, "-XX:+UseConcMarkSweepGC");
      }
  
      private static volatile boolean listenerInvoked = false;
      static class SensorListener implements NotificationListener {
          @Override
*** 154,163 ****
--- 158,177 ----
              // Now set threshold
              MemoryUsage mu = mpool.getUsage();
              chunkSize = (mu.getMax() - mu.getUsed()) / 20;
              newThreshold = mu.getUsed() + (chunkSize * NUM_CHUNKS);
  
+             // Sanity check. Make sure the chunkSize is large than the YOUNG_GEN_SIZE
+             // If the chunkSize are lower than the YOUNG_GEN_SIZE, we will get intermittent
+             // failures when objects end up in the young gen instead of the old gen.
+             // Tweak the test if this fails.
+             if (chunkSize < YOUNG_GEN_SIZE) {
+                 throw new RuntimeException("TEST FAILED: " +
+                         " chunkSize: " + chunkSize + " is less than YOUNG_GEN_SIZE: " + YOUNG_GEN_SIZE +
+                         " max: " + mu.getMax() + " used: " + mu.getUsed() + " newThreshold: " + newThreshold);
+             }
+ 
              System.out.println("Setting threshold for " + mpool.getName() +
                  " from " + mpool.getUsageThreshold() + " to " + newThreshold +
                  ".  Current used = " + mu.getUsed());
              mpool.setUsageThreshold(newThreshold);