src/share/vm/gc_implementation/concurrentMarkSweep/vmCMSOperations.cpp

*** 190,207 ****
           (GC_locker::is_active() /* gc may have been skipped */
            && (_gc_count_before == gch->total_collections())),
           "total_collections() should be monotonically increasing");
  
    MutexLockerEx x(FullGCCount_lock, Mutex::_no_safepoint_check_flag);
    if (gch->total_full_collections() == _full_gc_count_before) {
!     // Disable iCMS until the full collection is done.
      CMSCollector::disable_icms();
      // In case CMS thread was in icms_wait(), wake it up.
      CMSCollector::start_icms();
      // Nudge the CMS thread to start a concurrent collection.
      CMSCollector::request_full_gc(_full_gc_count_before);
    } else {
      FullGCCount_lock->notify_all();  // Inform the Java thread its work is done
    }
  }
  
  bool VM_GenCollectFullConcurrent::evaluate_at_safepoint() const {
--- 190,211 ----
           (GC_locker::is_active() /* gc may have been skipped */
            && (_gc_count_before == gch->total_collections())),
           "total_collections() should be monotonically increasing");
  
    MutexLockerEx x(FullGCCount_lock, Mutex::_no_safepoint_check_flag);
+   assert(_full_gc_count_before <= gch->total_full_collections(), "Error");
    if (gch->total_full_collections() == _full_gc_count_before) {
!     // Disable iCMS until the full collection is done, and
!     // remember that we did so.
      CMSCollector::disable_icms();
+     _disabled_icms = true;
      // In case CMS thread was in icms_wait(), wake it up.
      CMSCollector::start_icms();
      // Nudge the CMS thread to start a concurrent collection.
      CMSCollector::request_full_gc(_full_gc_count_before);
    } else {
+     assert(_full_gc_count_before < gch->total_full_collections(), "Error");
      FullGCCount_lock->notify_all();  // Inform the Java thread its work is done
    }
  }
  
  bool VM_GenCollectFullConcurrent::evaluate_at_safepoint() const {
*** 257,264 ****
      // witness to our request.
      while (gch->total_full_collections_completed() <= _full_gc_count_before) {
        FullGCCount_lock->wait(Mutex::_no_safepoint_check_flag);
      }
    }
!   // Enable iCMS back.
    CMSCollector::enable_icms();
  }
--- 261,270 ----
      // witness to our request.
      while (gch->total_full_collections_completed() <= _full_gc_count_before) {
        FullGCCount_lock->wait(Mutex::_no_safepoint_check_flag);
      }
    }
!   // Enable iCMS back if we disabled it earlier.
!   if (_disabled_icms) {
      CMSCollector::enable_icms();
+   }
  }