--- /dev/null	2018-04-03 12:55:20.301839954 +0200
+++ new/src/hotspot/share/gc/z/zTracer.hpp	2018-06-08 19:46:45.396814015 +0200
@@ -0,0 +1,66 @@
+/*
+ * Copyright (c) 2016, 2017, 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_GC_Z_ZTRACER_HPP
+#define SHARE_GC_Z_ZTRACER_HPP
+
+#include "gc/shared/gcTrace.hpp"
+#include "gc/z/zAllocationFlags.hpp"
+
+class ZStatCounter;
+class ZStatPhase;
+class ZStatSampler;
+
+class ZTracer : public GCTracer {
+private:
+  static ZTracer* _tracer;
+
+  ZTracer();
+
+  void send_stat_counter(uint32_t counter_id, uint64_t increment, uint64_t value);
+  void send_stat_sampler(uint32_t sampler_id, uint64_t value);
+  void send_thread_phase(const char* name, const Ticks& start, const Ticks& end);
+  void send_page_alloc(size_t size, size_t used, size_t free, size_t cache, bool nonblocking, bool noreserve);
+
+public:
+  static ZTracer* tracer();
+  static void initialize();
+
+  void report_stat_counter(const ZStatCounter& counter, uint64_t increment, uint64_t value);
+  void report_stat_sampler(const ZStatSampler& sampler, uint64_t value);
+  void report_thread_phase(const ZStatPhase& phase, const Ticks& start, const Ticks& end);
+  void report_thread_phase(const char* name, const Ticks& start, const Ticks& end);
+  void report_page_alloc(size_t size, size_t used, size_t free, size_t cache, ZAllocationFlags flags);
+};
+
+class ZTraceThreadPhase : public StackObj {
+private:
+  const Ticks       _start;
+  const char* const _name;
+
+public:
+  ZTraceThreadPhase(const char* name);
+  ~ZTraceThreadPhase();
+};
+
+#endif // SHARE_GC_Z_ZTRACER_HPP