--- /dev/null	2018-03-12 09:19:30.040007636 +0100
+++ new/src/hotspot/share/runtime/safepointVerifiers.hpp	2018-03-22 17:04:18.200829953 +0100
@@ -0,0 +1,175 @@
+/*
+ * Copyright (c) 1997, 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 SHARE_VM_RUNTIME_SAFEPOINTVERIFIERS_HPP
+#define SHARE_VM_RUNTIME_SAFEPOINTVERIFIERS_HPP
+
+#include "memory/allocation.hpp"
+#include "runtime/thread.hpp"
+
+// A NoGCVerifier object can be placed in methods where one assumes that
+// no garbage collection will occur. The destructor will verify this property
+// unless the constructor is called with argument false (not verifygc).
+//
+// The check will only be done in debug mode and if verifygc true.
+
+class NoGCVerifier: public StackObj {
+ friend class PauseNoGCVerifier;
+
+ protected:
+  bool _verifygc;
+  unsigned int _old_invocations;
+
+ public:
+#ifdef ASSERT
+  NoGCVerifier(bool verifygc = true);
+  ~NoGCVerifier();
+#else
+  NoGCVerifier(bool verifygc = true) {}
+  ~NoGCVerifier() {}
+#endif
+};
+
+// A PauseNoGCVerifier is used to temporarily pause the behavior
+// of a NoGCVerifier object. If we are not in debug mode or if the
+// NoGCVerifier object has a _verifygc value of false, then there
+// is nothing to do.
+
+class PauseNoGCVerifier: public StackObj {
+ private:
+  NoGCVerifier * _ngcv;
+
+ public:
+#ifdef ASSERT
+  PauseNoGCVerifier(NoGCVerifier * ngcv);
+  ~PauseNoGCVerifier();
+#else
+  PauseNoGCVerifier(NoGCVerifier * ngcv) {}
+  ~PauseNoGCVerifier() {}
+#endif
+};
+
+
+// A NoSafepointVerifier object will throw an assertion failure if
+// the current thread passes a possible safepoint while this object is
+// instantiated. A safepoint, will either be: an oop allocation, blocking
+// on a Mutex or JavaLock, or executing a VM operation.
+//
+// If StrictSafepointChecks is turned off, it degrades into a NoGCVerifier
+//
+class NoSafepointVerifier : public NoGCVerifier {
+ friend class PauseNoSafepointVerifier;
+
+ private:
+  bool _activated;
+  Thread *_thread;
+ public:
+#ifdef ASSERT
+  NoSafepointVerifier(bool activated = true, bool verifygc = true ) :
+    NoGCVerifier(verifygc),
+    _activated(activated) {
+    _thread = Thread::current();
+    if (_activated) {
+      _thread->_allow_allocation_count++;
+      _thread->_allow_safepoint_count++;
+    }
+  }
+
+  ~NoSafepointVerifier() {
+    if (_activated) {
+      _thread->_allow_allocation_count--;
+      _thread->_allow_safepoint_count--;
+    }
+  }
+#else
+  NoSafepointVerifier(bool activated = true, bool verifygc = true) : NoGCVerifier(verifygc){}
+  ~NoSafepointVerifier() {}
+#endif
+};
+
+// A PauseNoSafepointVerifier is used to temporarily pause the
+// behavior of a NoSafepointVerifier object. If we are not in debug
+// mode then there is nothing to do. If the NoSafepointVerifier
+// object has an _activated value of false, then there is nothing to
+// do for safepoint and allocation checking, but there may still be
+// something to do for the underlying NoGCVerifier object.
+
+class PauseNoSafepointVerifier : public PauseNoGCVerifier {
+ private:
+  NoSafepointVerifier * _nsv;
+
+ public:
+#ifdef ASSERT
+  PauseNoSafepointVerifier(NoSafepointVerifier * nsv)
+    : PauseNoGCVerifier(nsv) {
+
+    _nsv = nsv;
+    if (_nsv->_activated) {
+      _nsv->_thread->_allow_allocation_count--;
+      _nsv->_thread->_allow_safepoint_count--;
+    }
+  }
+
+  ~PauseNoSafepointVerifier() {
+    if (_nsv->_activated) {
+      _nsv->_thread->_allow_allocation_count++;
+      _nsv->_thread->_allow_safepoint_count++;
+    }
+  }
+#else
+  PauseNoSafepointVerifier(NoSafepointVerifier * nsv)
+    : PauseNoGCVerifier(nsv) {}
+  ~PauseNoSafepointVerifier() {}
+#endif
+};
+
+// A NoAllocVerifier object can be placed in methods where one assumes that
+// no allocation will occur. The destructor will verify this property
+// unless the constructor is called with argument false (not activated).
+//
+// The check will only be done in debug mode and if activated.
+// Note: this only makes sense at safepoints (otherwise, other threads may
+// allocate concurrently.)
+
+class NoAllocVerifier : public StackObj {
+ private:
+  bool  _activated;
+
+ public:
+#ifdef ASSERT
+  NoAllocVerifier(bool activated = true) {
+    _activated = activated;
+    if (_activated) Thread::current()->_allow_allocation_count++;
+  }
+
+  ~NoAllocVerifier() {
+    if (_activated) Thread::current()->_allow_allocation_count--;
+  }
+#else
+  NoAllocVerifier(bool activated = true) {}
+  ~NoAllocVerifier() {}
+#endif
+};
+
+#endif // SHARE_VM_RUNTIME_SAFEPOINTVERIFIERS_HPP