test/gc/7072527/TestFullGCCount.java

rev 4494 : 7109087: gc/7072527/TestFullGCCount.java fails when GC is set in command-line
Reviewed-by: mgerdin

*** 1,7 ****
  /*
!  * Copyright (c) 2011, Oracle and/or its affiliates. All rights reserved.
   * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   *
   * This code is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 only, as
   * published by the Free Software Foundation.
--- 1,7 ----
  /*
!  * Copyright (c) 2011, 2013, Oracle and/or its affiliates. All rights reserved.
   * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   *
   * This code is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 only, as
   * published by the Free Software Foundation.
*** 23,95 ****
  
  /*
   * @test TestFullGCount.java
   * @bug 7072527
   * @summary CMS: JMM GC counters overcount in some cases
!  * @run main/othervm -XX:+UseConcMarkSweepGC TestFullGCCount
!  *
   */
  import java.util.*;
  import java.lang.management.*;
  
  public class TestFullGCCount {
  
!     public String collectorName = "ConcurrentMarkSweep";
  
!     public static void main(String [] args) {
  
!         TestFullGCCount t = null;
!         if (args.length==2) {
!             t = new TestFullGCCount(args[0], args[1]);
!         } else {
!             t = new TestFullGCCount();
          }
-         System.out.println("Monitoring collector: " + t.collectorName);
-         t.run();
-     }
  
!     public TestFullGCCount(String pool, String collector) {
!         collectorName = collector;
      }
  
!     public TestFullGCCount() {
!     }
  
!     public void run() {
!         int count = 0;
!         int iterations = 20;
!         long counts[] = new long[iterations];
!         boolean diffAlways2 = true; // assume we will fail
! 
!         for (int i=0; i<iterations; i++) {
!             System.gc();
!             counts[i] = getCollectionCount();
!             if (i>0) {
!                 if (counts[i] - counts[i-1] != 2) {
!                     diffAlways2 = false;
                  }
              }
          }
!         if (diffAlways2) {
!             throw new RuntimeException("FAILED: System.gc must be incrementing count twice.");
          }
          System.out.println("Passed.");
      }
  
!     private long getCollectionCount() {
!         long count = 0;
!         List<MemoryPoolMXBean> pools = ManagementFactory.getMemoryPoolMXBeans();
!         List<GarbageCollectorMXBean> collectors = ManagementFactory.getGarbageCollectorMXBeans();
!         for (int i=0; i<collectors.size(); i++) {
              GarbageCollectorMXBean collector = collectors.get(i);
!             String name = collector.getName();
!             if (name.contains(collectorName)) {
!                 System.out.println(name + ": collection count = "
!                                    + collector.getCollectionCount());
!                 count = collector.getCollectionCount();
              }
          }
-         return count;
-     }
- 
  }
- 
--- 23,91 ----
  
  /*
   * @test TestFullGCount.java
   * @bug 7072527
   * @summary CMS: JMM GC counters overcount in some cases
!  * @run main/othervm -XX:+PrintGC TestFullGCCount
   */
  import java.util.*;
  import java.lang.management.*;
  
+ /*
+  * Originally for a specific failure in CMS, this test now monitors all
+  * collectors for double-counting of collections.
+  */
  public class TestFullGCCount {
  
!     static List<GarbageCollectorMXBean> collectors = ManagementFactory.getGarbageCollectorMXBeans();
  
!     public static void main(String[] args) {
!         int iterations = 20;
!         boolean failed = false;
!         String errorMessage = "";
!         HashMap<String, List> counts = new HashMap<String, List>();
  
!         // Prime the collection of count lists for all collectors.
!         for (int i = 0; i < collectors.size(); i++) {
!             GarbageCollectorMXBean collector = collectors.get(i);
!             counts.put(collector.getName(), new ArrayList<Long>(iterations));
          }
  
!         // Perform some gc, record collector counts.
!         for (int i = 0; i < iterations; i++) {
!             System.gc();
!             addCollectionCount(counts, i);
          }
  
!         // Check the increments:
!         //   Old gen collectors should increase by one,
!         //   New collectors may or may not increase.
!         //   Any increase >=2 is unexpected.
!         for (String collector : counts.keySet()) {
!             System.out.println("Checking: " + collector);
  
!             for (int i = 0; i < iterations - 1; i++) {
!                 List<Long> theseCounts = counts.get(collector);
!                 long a = theseCounts.get(i);
!                 long b = theseCounts.get(i + 1);
!                 if (b - a >= 2) {
!                     failed = true;
!                     errorMessage += "Collector '" + collector + "' has increment " + (b - a) +
!                                     " at iteration " + i + "\n";
                  }
              }
          }
!         if (failed) {
!             System.err.println(errorMessage);
!             throw new RuntimeException("FAILED: System.gc collections miscounted.");
          }
          System.out.println("Passed.");
      }
  
!     private static void addCollectionCount(HashMap<String, List> counts, int iteration) {
!         for (int i = 0; i < collectors.size(); i++) {
              GarbageCollectorMXBean collector = collectors.get(i);
!             List thisList = counts.get(collector.getName());
!             thisList.add(collector.getCollectionCount());
          }
      }
  }