--- a/hotspot/src/share/vm/oops/method.cpp	Mon Oct 17 16:40:49 2016 -0700
+++ b/hotspot/src/share/vm/oops/method.cpp	Tue Oct 18 09:43:12 2016 +0200
@@ -97,7 +97,7 @@
   // Fix and bury in Method*
   set_interpreter_entry(NULL); // sets i2i entry and from_int
   set_adapter_entry(NULL);
-  clear_code(); // from_c/from_i get set to c2i/i2i
+  clear_code(false /* don't need a lock */); // from_c/from_i get set to c2i/i2i
 
   if (access_flags.is_native()) {
     clear_native_function();
@@ -907,8 +907,8 @@
 }
 
 // Revert to using the interpreter and clear out the nmethod
-void Method::clear_code() {
-
+void Method::clear_code(bool acquire_lock /* = true */) {
+  MutexLockerEx pl(acquire_lock ? Patching_lock : NULL, Mutex::_no_safepoint_check_flag);
   // this may be NULL if c2i adapters have not been made yet
   // Only should happen at allocate time.
   if (adapter() == NULL) {
@@ -1077,6 +1077,7 @@
 
 // Install compiled code.  Instantly it can execute.
 void Method::set_code(methodHandle mh, CompiledMethod *code) {
+  MutexLockerEx pl(Patching_lock, Mutex::_no_safepoint_check_flag);
   assert( code, "use clear_code to remove code" );
   assert( mh->check_code(), "" );