diff -r 6e7e363c5a8f -r 595c0f60d50d src/share/vm/gc_implementation/g1/g1StringDedupStat.hpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/share/vm/gc_implementation/g1/g1StringDedupStat.hpp	Tue Mar 18 19:07:22 2014 +0100
@@ -0,0 +1,142 @@
+/*
+ * Copyright (c) 2014, 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.
+ *
+ * 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+#ifndef SHARE_VM_GC_IMPLEMENTATION_G1_G1STRINGDEDUPSTAT_HPP
+#define SHARE_VM_GC_IMPLEMENTATION_G1_G1STRINGDEDUPSTAT_HPP
+
+#include "memory/allocation.hpp"
+#include "runtime/os.hpp"
+
+// Macros for GC log output formating
+#define G1_STRDEDUP_OBJECTS_FORMAT         UINTX_FORMAT_W(12)
+#define G1_STRDEDUP_TIME_FORMAT            "%1.7lf secs"
+#define G1_STRDEDUP_PERCENT_FORMAT         "%5.1lf%%"
+#define G1_STRDEDUP_PERCENT_FORMAT_NS      "%.1lf%%"
+#define G1_STRDEDUP_BYTES_FORMAT           "%8.1lf%s"
+#define G1_STRDEDUP_BYTES_FORMAT_NS        "%.1lf%s"
+#define G1_STRDEDUP_BYTES_PARAM(bytes)     byte_size_in_proper_unit((double)(bytes)), proper_unit_for_byte_size((bytes))
+
+//
+// Statistics gathered by the deduplication thread.
+//
+class G1StringDedupStat : public StackObj {
+private:
+  // Counters
+  uintx  _inspected;
+  uintx  _skipped;
+  uintx  _hashed;
+  uintx  _known;
+  uintx  _new;
+  uintx  _new_bytes;
+  uintx  _deduped;
+  uintx  _deduped_bytes;
+  uintx  _deduped_young;
+  uintx  _deduped_young_bytes;
+  uintx  _deduped_old;
+  uintx  _deduped_old_bytes;
+  uintx  _idle;
+  uintx  _exec;
+  uintx  _block;
+
+  // Time spent by the deduplication thread in different phases
+  double _start;
+  double _idle_elapsed;
+  double _exec_elapsed;
+  double _block_elapsed;
+
+public:
+  G1StringDedupStat();
+
+  void inc_inspected() {
+    _inspected++;
+  }
+
+  void inc_skipped() {
+    _skipped++;
+  }
+
+  void inc_hashed() {
+    _hashed++;
+  }
+
+  void inc_known() {
+    _known++;
+  }
+
+  void inc_new(uintx bytes) {
+    _new++;
+    _new_bytes += bytes;
+  }
+
+  void inc_deduped_young(uintx bytes) {
+    _deduped++;
+    _deduped_bytes += bytes;
+    _deduped_young++;
+    _deduped_young_bytes += bytes;
+  }
+
+  void inc_deduped_old(uintx bytes) {
+    _deduped++;
+    _deduped_bytes += bytes;
+    _deduped_old++;
+    _deduped_old_bytes += bytes;
+  }
+
+  void mark_idle() {
+    _start = os::elapsedTime();
+    _idle++;
+  }
+
+  void mark_exec() {
+    double now = os::elapsedTime();
+    _idle_elapsed = now - _start;
+    _start = now;
+    _exec++;
+  }
+
+  void mark_block() {
+    double now = os::elapsedTime();
+    _exec_elapsed += now - _start;
+    _start = now;
+    _block++;
+  }
+
+  void mark_unblock() {
+    double now = os::elapsedTime();
+    _block_elapsed += now - _start;
+    _start = now;
+  }
+
+  void mark_done() {
+    double now = os::elapsedTime();
+    _exec_elapsed += now - _start;
+  }
+
+  void add(const G1StringDedupStat& stat);
+
+  static void print_summary(outputStream* st, const G1StringDedupStat& last_stat, const G1StringDedupStat& total_stat);
+  static void print_statistics(outputStream* st, const G1StringDedupStat& stat, bool total);
+};
+
+#endif // SHARE_VM_GC_IMPLEMENTATION_G1_G1STRINGDEDUPSTAT_HPP