--- old/src/hotspot/share/jvmci/jvmciEnv.hpp	2019-01-18 21:34:27.000000000 +0100
+++ new/src/hotspot/share/jvmci/jvmciEnv.hpp	2019-01-18 21:34:27.000000000 +0100
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1999, 2017, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1999, 2019, 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
@@ -102,10 +102,13 @@
   const char*      _failure_reason;
   bool             _retryable;
 
-  // Cache JVMTI state
-  bool  _jvmti_can_hotswap_or_post_breakpoint;
-  bool  _jvmti_can_access_local_variables;
-  bool  _jvmti_can_post_on_exceptions;
+  // Cache JVMTI state. Defined as bytes so that reading them from Java
+  // via Unsafe is well defined (the C++ type for bool is implementation
+  // defined and may not be the same as a Java boolean).
+  jbyte  _jvmti_can_hotswap_or_post_breakpoint;
+  jbyte  _jvmti_can_access_local_variables;
+  jbyte  _jvmti_can_post_on_exceptions;
+  jbyte  _jvmti_can_pop_frame;
 
   // Implementation methods for loading and constant pool access.
   static Klass* get_klass_by_name_impl(Klass* accessing_klass,
@@ -144,6 +147,12 @@
 public:
   CompileTask* task() { return _task; }
 
+  bool  jvmti_state_changed() const;
+  bool  jvmti_can_hotswap_or_post_breakpoint() const { return  _jvmti_can_hotswap_or_post_breakpoint != 0; }
+  bool  jvmti_can_access_local_variables() const     { return  _jvmti_can_access_local_variables != 0; }
+  bool  jvmti_can_post_on_exceptions() const         { return  _jvmti_can_post_on_exceptions != 0; }
+  bool  jvmti_can_pop_frame() const                  { return  _jvmti_can_pop_frame != 0; }
+
   const char* failure_reason() { return _failure_reason; }
   bool retryable() { return _retryable; }