58     private static final int NUM_GCS = 3;
  59     private static final int THRESHOLD = 10;
  60     private static volatile int numGCs = 0;
  61 
  62     // semaphore to signal the arrival of a low memory notification
  63     private static final Semaphore signals = new Semaphore(0);
  64     // barrier for the main thread to wait until the checker thread
  65     // finishes checking the low memory notification result
  66     private static final CyclicBarrier barrier = new CyclicBarrier(2);
  67 
  68     /**
  69      * Run the test multiple times with different GC versions.
  70      * First with default command line specified by the framework.
  71      * Then with GC versions specified by the test.
  72      */
  73     public static void main(String a[]) throws Throwable {
  74         final String main = "CollectionUsageThreshold$TestMain";
  75         RunUtil.runTestKeepGcOpts(main);
  76         RunUtil.runTestClearGcOpts(main, "-XX:+UseSerialGC");
  77         RunUtil.runTestClearGcOpts(main, "-XX:+UseParallelGC");
  78         RunUtil.runTestClearGcOpts(main, "-XX:+UseG1GC");

  79         if (!Compiler.isGraalEnabled()) { // Graal does not support CMS
  80             RunUtil.runTestClearGcOpts(main, "-XX:+UseConcMarkSweepGC");
  81         }
  82     }
  83 
  84     static class PoolRecord {
  85         private final MemoryPoolMXBean pool;
  86         private final AtomicInteger listenerInvoked = new AtomicInteger(0);
  87         private volatile long notifCount = 0;
  88         PoolRecord(MemoryPoolMXBean p) {
  89             this.pool = p;
  90         }
  91         int getListenerInvokedCount() {
  92             return listenerInvoked.get();
  93         }
  94         long getNotifCount() {
  95             return notifCount;
  96         }
  97         MemoryPoolMXBean getPool() {
  98             return pool;

  58     private static final int NUM_GCS = 3;
  59     private static final int THRESHOLD = 10;
  60     private static volatile int numGCs = 0;
  61 
  62     // semaphore to signal the arrival of a low memory notification
  63     private static final Semaphore signals = new Semaphore(0);
  64     // barrier for the main thread to wait until the checker thread
  65     // finishes checking the low memory notification result
  66     private static final CyclicBarrier barrier = new CyclicBarrier(2);
  67 
  68     /**
  69      * Run the test multiple times with different GC versions.
  70      * First with default command line specified by the framework.
  71      * Then with GC versions specified by the test.
  72      */
  73     public static void main(String a[]) throws Throwable {
  74         final String main = "CollectionUsageThreshold$TestMain";
  75         RunUtil.runTestKeepGcOpts(main);
  76         RunUtil.runTestClearGcOpts(main, "-XX:+UseSerialGC");
  77         RunUtil.runTestClearGcOpts(main, "-XX:+UseParallelGC");
  78         RunUtil.runTestClearGcOpts(main, "-XX:+UseG1GC", "-XX:-G1UseLegacyMonitoring");
  79         RunUtil.runTestClearGcOpts(main, "-XX:+UseG1GC", "-XX:+G1UseLegacyMonitoring");
  80         if (!Compiler.isGraalEnabled()) { // Graal does not support CMS
  81             RunUtil.runTestClearGcOpts(main, "-XX:+UseConcMarkSweepGC");
  82         }
  83     }
  84 
  85     static class PoolRecord {
  86         private final MemoryPoolMXBean pool;
  87         private final AtomicInteger listenerInvoked = new AtomicInteger(0);
  88         private volatile long notifCount = 0;
  89         PoolRecord(MemoryPoolMXBean p) {
  90             this.pool = p;
  91         }
  92         int getListenerInvokedCount() {
  93             return listenerInvoked.get();
  94         }
  95         long getNotifCount() {
  96             return notifCount;
  97         }
  98         MemoryPoolMXBean getPool() {
  99             return pool;