--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/share/vm/gc_implementation/g1/concurrentZFThread.hpp	Thu Jun 05 15:57:56 2008 -0700
@@ -0,0 +1,85 @@
+/*
+ * Copyright 2001-2007 Sun Microsystems, Inc.  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.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ *
+ */
+
+// The Concurrent ZF Thread.  Performs concurrent zero-filling.
+
+class ConcurrentZFThread: public ConcurrentGCThread {
+  friend class VMStructs;
+  friend class ZeroFillRegionClosure;
+
+ private:
+
+  // Zero fill the heap region.
+  void processHeapRegion(HeapRegion* r);
+
+  // Stats
+  //   Allocation (protected by heap lock).
+  static int _region_allocs;  // Number of regions allocated
+  static int _sync_zfs;       //   Synchronous zero-fills +
+  static int _zf_waits;      //   Wait for conc zero-fill completion.
+
+  // Number of regions CFZ thread fills.
+  static int _regions_filled;
+
+  COTracker _co_tracker;
+
+  double _vtime_start;  // Initial virtual time.
+
+  // These are static because the "print_summary_info" method is, and
+  // it currently assumes there is only one ZF thread.  We'll change when
+  // we need to.
+  static double _vtime_accum;  // Initial virtual time.
+  static double vtime_accum() { return _vtime_accum; }
+
+  // Offer yield for GC.  Returns true if yield occurred.
+  bool offer_yield();
+
+ public:
+  // Constructor
+  ConcurrentZFThread();
+
+  // Main loop.
+  virtual void run();
+
+  // Printing
+  void print();
+
+  // Waits until "r" has been zero-filled.  Requires caller to hold the
+  // ZF_mon.
+  static void wait_for_ZF_completed(HeapRegion* r);
+
+  // Get or clear the current unclean region.  Should be done
+  // while holding the ZF_needed_mon lock.
+
+  // shutdown
+  static void stop();
+
+  // Stats
+  static void note_region_alloc() {_region_allocs++; }
+  static void note_sync_zfs() { _sync_zfs++; }
+  static void note_zf_wait() { _zf_waits++; }
+  static void note_region_filled() { _regions_filled++; }
+
+  static void print_summary_info();
+};