--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/gc/g1/g1StringDedupThread.cpp	Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,151 @@
+/*
+ * Copyright (c) 2014, 2016, 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.
+ *
+ */
+
+#include "precompiled.hpp"
+#include "classfile/stringTable.hpp"
+#include "gc/g1/g1StringDedup.hpp"
+#include "gc/g1/g1StringDedupQueue.hpp"
+#include "gc/g1/g1StringDedupTable.hpp"
+#include "gc/g1/g1StringDedupThread.hpp"
+#include "gc/g1/suspendibleThreadSet.hpp"
+#include "logging/log.hpp"
+#include "oops/oop.inline.hpp"
+#include "runtime/atomic.hpp"
+
+G1StringDedupThread* G1StringDedupThread::_thread = NULL;
+
+G1StringDedupThread::G1StringDedupThread() :
+  ConcurrentGCThread() {
+  set_name("G1 StrDedup");
+  create_and_start();
+}
+
+G1StringDedupThread::~G1StringDedupThread() {
+  ShouldNotReachHere();
+}
+
+void G1StringDedupThread::create() {
+  assert(G1StringDedup::is_enabled(), "String deduplication not enabled");
+  assert(_thread == NULL, "One string deduplication thread allowed");
+  _thread = new G1StringDedupThread();
+}
+
+G1StringDedupThread* G1StringDedupThread::thread() {
+  assert(G1StringDedup::is_enabled(), "String deduplication not enabled");
+  assert(_thread != NULL, "String deduplication thread not created");
+  return _thread;
+}
+
+class G1StringDedupSharedClosure: public OopClosure {
+ private:
+  G1StringDedupStat& _stat;
+
+ public:
+  G1StringDedupSharedClosure(G1StringDedupStat& stat) : _stat(stat) {}
+
+  virtual void do_oop(oop* p) { ShouldNotReachHere(); }
+  virtual void do_oop(narrowOop* p) {
+    oop java_string = oopDesc::load_decode_heap_oop(p);
+    G1StringDedupTable::deduplicate(java_string, _stat);
+  }
+};
+
+// The CDS archive does not include the string dedupication table. Only the string
+// table is saved in the archive. The shared strings from CDS archive need to be
+// added to the string dedupication table before deduplication occurs. That is
+// done in the begining of the G1StringDedupThread (see G1StringDedupThread::run()
+// below).
+void G1StringDedupThread::deduplicate_shared_strings(G1StringDedupStat& stat) {
+  G1StringDedupSharedClosure sharedStringDedup(stat);
+  StringTable::shared_oops_do(&sharedStringDedup);
+}
+
+void G1StringDedupThread::run_service() {
+  G1StringDedupStat total_stat;
+
+  deduplicate_shared_strings(total_stat);
+
+  // Main loop
+  for (;;) {
+    G1StringDedupStat stat;
+
+    stat.mark_idle();
+
+    // Wait for the queue to become non-empty
+    G1StringDedupQueue::wait();
+    if (should_terminate()) {
+      break;
+    }
+
+    {
+      // Include thread in safepoints
+      SuspendibleThreadSetJoiner sts_join;
+
+      stat.mark_exec();
+      print_start(stat);
+
+      // Process the queue
+      for (;;) {
+        oop java_string = G1StringDedupQueue::pop();
+        if (java_string == NULL) {
+          break;
+        }
+
+        G1StringDedupTable::deduplicate(java_string, stat);
+
+        // Safepoint this thread if needed
+        if (sts_join.should_yield()) {
+          stat.mark_block();
+          sts_join.yield();
+          stat.mark_unblock();
+        }
+      }
+
+      stat.mark_done();
+
+      total_stat.add(stat);
+      print_end(stat, total_stat);
+    }
+
+    G1StringDedupTable::clean_entry_cache();
+  }
+}
+
+void G1StringDedupThread::stop_service() {
+  G1StringDedupQueue::cancel_wait();
+}
+
+void G1StringDedupThread::print_start(const G1StringDedupStat& last_stat) {
+  G1StringDedupStat::print_start(last_stat);
+}
+
+void G1StringDedupThread::print_end(const G1StringDedupStat& last_stat, const G1StringDedupStat& total_stat) {
+  G1StringDedupStat::print_end(last_stat, total_stat);
+  if (log_is_enabled(Debug, gc, stringdedup)) {
+    G1StringDedupStat::print_statistics(last_stat, false);
+    G1StringDedupStat::print_statistics(total_stat, true);
+    G1StringDedupTable::print_statistics();
+    G1StringDedupQueue::print_statistics();
+  }
+}