diff -r 416a76fe8067 -r 516acf6956a2 test/hotspot/gtest/threadHelper.inline.hpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/hotspot/gtest/threadHelper.inline.hpp	Fri Jul 20 14:52:11 2018 -0400
@@ -0,0 +1,155 @@
+/*
+ * Copyright (c) 2018, 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 GTEST_THREADHELPER_INLINE_HPP
+#define GTEST_THREADHELPER_INLINE_HPP
+
+#include "runtime/mutex.hpp"
+#include "runtime/semaphore.hpp"
+#include "runtime/thread.hpp"
+#include "runtime/vmThread.hpp"
+#include "runtime/vm_operations.hpp"
+#include "unittest.hpp"
+
+class VM_StopSafepoint : public VM_Operation {
+public:
+  Semaphore* _test_complete;
+  VM_StopSafepoint(Semaphore* wait_for) : _test_complete(wait_for) {}
+  VMOp_Type type() const          { return VMOp_None; }
+  Mode evaluation_mode() const    { return _no_safepoint; }
+  bool is_cheap_allocated() const { return false; }
+  void doit()                     { _test_complete->wait(); }
+};
+
+// This class and thread keep the non-safepoint op running while we do our testing.
+class VMThreadBlocker : public JavaThread {
+public:
+  Semaphore* _unblock;
+  Semaphore* _done;
+  VMThreadBlocker(Semaphore* ub, Semaphore* done) : _unblock(ub), _done(done) {
+  }
+  virtual ~VMThreadBlocker() {}
+  void run() {
+    this->set_thread_state(_thread_in_vm);
+    {
+      MutexLocker ml(Threads_lock);
+      Threads::add(this);
+    }
+    VM_StopSafepoint ss(_unblock);
+    VMThread::execute(&ss);
+    _done->signal();
+    Threads::remove(this);
+    this->smr_delete();
+  }
+  void doit() {
+    if (os::create_thread(this, os::os_thread)) {
+      os::start_thread(this);
+    } else {
+      ASSERT_TRUE(false);
+    }
+  }
+};
+
+// For testing in a real JavaThread.
+class JavaTestThread : public JavaThread {
+public:
+  Semaphore* _post;
+  JavaTestThread(Semaphore* post)
+    : _post(post) {
+  }
+  virtual ~JavaTestThread() {}
+
+  void prerun() {
+    this->set_thread_state(_thread_in_vm);
+    {
+      MutexLocker ml(Threads_lock);
+      Threads::add(this);
+    }
+    {
+      MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
+    }
+  }
+
+  virtual void main_run() = 0;
+
+  void run() {
+    prerun();
+    main_run();
+    postrun();
+  }
+
+  void postrun() {
+    Threads::remove(this);
+    _post->signal();
+    this->smr_delete();
+  }
+
+  void doit() {
+    if (os::create_thread(this, os::os_thread)) {
+      os::start_thread(this);
+    } else {
+      ASSERT_TRUE(false);
+    }
+  }
+};
+
+template <typename FUNC>
+class SingleTestThread : public JavaTestThread {
+public:
+  FUNC& _f;
+  SingleTestThread(Semaphore* post, FUNC& f)
+    : JavaTestThread(post), _f(f) {
+  }
+
+  virtual ~SingleTestThread(){}
+
+  virtual void main_run() {
+    _f(this);
+  }
+};
+
+template <typename TESTFUNC>
+static void nomt_test_doer(TESTFUNC &f) {
+  Semaphore post, block_done, vmt_done;
+  VMThreadBlocker* blocker = new VMThreadBlocker(&block_done, &vmt_done);
+  blocker->doit();
+  SingleTestThread<TESTFUNC>* stt = new SingleTestThread<TESTFUNC>(&post, f);
+  stt->doit();
+  post.wait();
+  block_done.signal();
+  vmt_done.wait();
+}
+
+template <typename RUNNER>
+static void mt_test_doer() {
+  Semaphore post, block_done, vmt_done;
+  VMThreadBlocker* blocker = new VMThreadBlocker(&block_done, &vmt_done);
+  blocker->doit();
+  RUNNER* runner = new RUNNER(&post);
+  runner->doit();
+  post.wait();
+  block_done.signal();
+  vmt_done.wait();
+}
+
+#endif // include guard