--- a/src/hotspot/share/c1/c1_Runtime1.cpp	Thu Apr 16 03:29:28 2020 -0400
+++ b/src/hotspot/share/c1/c1_Runtime1.cpp	Thu Apr 16 10:14:25 2020 +0200
@@ -699,30 +699,22 @@
 JRT_END
 
 
-JRT_ENTRY_NO_ASYNC(void, Runtime1::monitorenter(JavaThread* thread, oopDesc* obj, BasicObjectLock* lock))
+JRT_BLOCK_ENTRY(void, Runtime1::monitorenter(JavaThread* thread, oopDesc* obj, BasicObjectLock* lock))
   NOT_PRODUCT(_monitorenter_slowcase_cnt++;)
-  if (PrintBiasedLockingStatistics) {
-    Atomic::inc(BiasedLocking::slow_path_entry_count_addr());
-  }
-  Handle h_obj(thread, obj);
   if (!UseFastLocking) {
     lock->set_obj(obj);
   }
   assert(obj == lock->obj(), "must match");
-  ObjectSynchronizer::enter(h_obj, lock->lock(), THREAD);
+  SharedRuntime::monitor_enter_helper(obj, lock->lock(), thread);
 JRT_END
 
 
 JRT_LEAF(void, Runtime1::monitorexit(JavaThread* thread, BasicObjectLock* lock))
   NOT_PRODUCT(_monitorexit_slowcase_cnt++;)
-  assert(thread == JavaThread::current(), "threads must correspond");
   assert(thread->last_Java_sp(), "last_Java_sp must be set");
-  // monitorexit is non-blocking (leaf routine) => no exceptions can be thrown
-  EXCEPTION_MARK;
-
   oop obj = lock->obj();
   assert(oopDesc::is_oop(obj), "must be NULL or an object");
-  ObjectSynchronizer::exit(obj, lock->lock(), THREAD);
+  SharedRuntime::monitor_exit_helper(obj, lock->lock(), thread);
 JRT_END
 
 // Cf. OptoRuntime::deoptimize_caller_frame

--- a/src/hotspot/share/jvmci/jvmciRuntime.cpp	Thu Apr 16 03:29:28 2020 -0400
+++ b/src/hotspot/share/jvmci/jvmciRuntime.cpp	Thu Apr 16 10:14:25 2020 +0200
@@ -382,48 +382,14 @@
   return continuation;
 }
 
-JRT_ENTRY_NO_ASYNC(void, JVMCIRuntime::monitorenter(JavaThread* thread, oopDesc* obj, BasicLock* lock))
-  IF_TRACE_jvmci_3 {
-    char type[O_BUFLEN];
-    obj->klass()->name()->as_C_string(type, O_BUFLEN);
-    markWord mark = obj->mark();
-    TRACE_jvmci_3("%s: entered locking slow case with obj=" INTPTR_FORMAT ", type=%s, mark=" INTPTR_FORMAT ", lock=" INTPTR_FORMAT, thread->name(), p2i(obj), type, mark.value(), p2i(lock));
-    tty->flush();
-  }
-  if (PrintBiasedLockingStatistics) {
-    Atomic::inc(BiasedLocking::slow_path_entry_count_addr());
-  }
-  Handle h_obj(thread, obj);
-  assert(oopDesc::is_oop(h_obj()), "must be NULL or an object");
-  ObjectSynchronizer::enter(h_obj, lock, THREAD);
-  TRACE_jvmci_3("%s: exiting locking slow with obj=" INTPTR_FORMAT, thread->name(), p2i(obj));
+JRT_BLOCK_ENTRY(void, JVMCIRuntime::monitorenter(JavaThread* thread, oopDesc* obj, BasicLock* lock))
+  SharedRuntime::monitor_enter_helper(obj, lock, thread);
 JRT_END
 
 JRT_LEAF(void, JVMCIRuntime::monitorexit(JavaThread* thread, oopDesc* obj, BasicLock* lock))
-  assert(thread == JavaThread::current(), "threads must correspond");
   assert(thread->last_Java_sp(), "last_Java_sp must be set");
-  // monitorexit is non-blocking (leaf routine) => no exceptions can be thrown
-  EXCEPTION_MARK;
-
-#ifdef ASSERT
-  if (!oopDesc::is_oop(obj)) {
-    ResetNoHandleMark rhm;
-    nmethod* method = thread->last_frame().cb()->as_nmethod_or_null();
-    if (method != NULL) {
-      tty->print_cr("ERROR in monitorexit in method %s wrong obj " INTPTR_FORMAT, method->name(), p2i(obj));
-    }
-    thread->print_stack_on(tty);
-    assert(false, "invalid lock object pointer dected");
-  }
-#endif
-
-  ObjectSynchronizer::exit(obj, lock, THREAD);
-  IF_TRACE_jvmci_3 {
-    char type[O_BUFLEN];
-    obj->klass()->name()->as_C_string(type, O_BUFLEN);
-    TRACE_jvmci_3("%s: exited locking slow case with obj=" INTPTR_FORMAT ", type=%s, mark=" INTPTR_FORMAT ", lock=" INTPTR_FORMAT, thread->name(), p2i(obj), type, obj->mark().value(), p2i(lock));
-    tty->flush();
-  }
+  assert(oopDesc::is_oop(obj), "invalid lock object pointer dected");
+  SharedRuntime::monitor_exit_helper(obj, lock, thread);
 JRT_END
 
 // Object.notify() fast path, caller does slow path

--- a/src/hotspot/share/runtime/sharedRuntime.cpp	Thu Apr 16 03:29:28 2020 -0400
+++ b/src/hotspot/share/runtime/sharedRuntime.cpp	Thu Apr 16 10:14:25 2020 +0200
@@ -2072,20 +2072,17 @@
   (void) JavaThread::current()->reguard_stack();
 JRT_END
 
-
-// Handles the uncommon case in locking, i.e., contention or an inflated lock.
-JRT_BLOCK_ENTRY(void, SharedRuntime::complete_monitor_locking_C(oopDesc* _obj, BasicLock* lock, JavaThread* thread))
+void SharedRuntime::monitor_enter_helper(oopDesc* obj, BasicLock* lock, JavaThread* thread) {
   if (!SafepointSynchronize::is_synchronizing()) {
     // Only try quick_enter() if we're not trying to reach a safepoint
     // so that the calling thread reaches the safepoint more quickly.
-    if (ObjectSynchronizer::quick_enter(_obj, thread, lock)) return;
+    if (ObjectSynchronizer::quick_enter(obj, thread, lock)) return;
   }
   // NO_ASYNC required because an async exception on the state transition destructor
   // would leave you with the lock held and it would never be released.
   // The normal monitorenter NullPointerException is thrown without acquiring a lock
   // and the model is that an exception implies the method failed.
   JRT_BLOCK_NO_ASYNC
-  oop obj(_obj);
   if (PrintBiasedLockingStatistics) {
     Atomic::inc(BiasedLocking::slow_path_entry_count_addr());
   }
@@ -2093,42 +2090,23 @@
   ObjectSynchronizer::enter(h_obj, lock, CHECK);
   assert(!HAS_PENDING_EXCEPTION, "Should have no exception here");
   JRT_BLOCK_END
+}
+
+// Handles the uncommon case in locking, i.e., contention or an inflated lock.
+JRT_BLOCK_ENTRY(void, SharedRuntime::complete_monitor_locking_C(oopDesc* obj, BasicLock* lock, JavaThread* thread))
+  SharedRuntime::monitor_enter_helper(obj, lock, thread);
 JRT_END
 
+void SharedRuntime::monitor_exit_helper(oopDesc* obj, BasicLock* lock, JavaThread* thread) {
+  assert(JavaThread::current() == thread, "invariant");
+  // Exit must be non-blocking, and therefore no exceptions can be thrown.
+  EXCEPTION_MARK;
+  ObjectSynchronizer::exit(obj, lock, THREAD);
+}
+
 // Handles the uncommon cases of monitor unlocking in compiled code
-JRT_LEAF(void, SharedRuntime::complete_monitor_unlocking_C(oopDesc* _obj, BasicLock* lock, JavaThread * THREAD))
-   oop obj(_obj);
-  assert(JavaThread::current() == THREAD, "invariant");
-  // I'm not convinced we need the code contained by MIGHT_HAVE_PENDING anymore
-  // testing was unable to ever fire the assert that guarded it so I have removed it.
-  assert(!HAS_PENDING_EXCEPTION, "Do we need code below anymore?");
-#undef MIGHT_HAVE_PENDING
-#ifdef MIGHT_HAVE_PENDING
-  // Save and restore any pending_exception around the exception mark.
-  // While the slow_exit must not throw an exception, we could come into
-  // this routine with one set.
-  oop pending_excep = NULL;
-  const char* pending_file;
-  int pending_line;
-  if (HAS_PENDING_EXCEPTION) {
-    pending_excep = PENDING_EXCEPTION;
-    pending_file  = THREAD->exception_file();
-    pending_line  = THREAD->exception_line();
-    CLEAR_PENDING_EXCEPTION;
-  }
-#endif /* MIGHT_HAVE_PENDING */
-
-  {
-    // Exit must be non-blocking, and therefore no exceptions can be thrown.
-    EXCEPTION_MARK;
-    ObjectSynchronizer::exit(obj, lock, THREAD);
-  }
-
-#ifdef MIGHT_HAVE_PENDING
-  if (pending_excep != NULL) {
-    THREAD->set_pending_exception(pending_excep, pending_file, pending_line);
-  }
-#endif /* MIGHT_HAVE_PENDING */
+JRT_LEAF(void, SharedRuntime::complete_monitor_unlocking_C(oopDesc* obj, BasicLock* lock, JavaThread* thread))
+  SharedRuntime::monitor_exit_helper(obj, lock, thread);
 JRT_END
 
 #ifndef PRODUCT

--- a/src/hotspot/share/runtime/sharedRuntime.hpp	Thu Apr 16 03:29:28 2020 -0400
+++ b/src/hotspot/share/runtime/sharedRuntime.hpp	Thu Apr 16 10:14:25 2020 +0200
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1997, 2019, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2020, 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
@@ -341,6 +341,9 @@
   // Find the method that called us.
   static methodHandle find_callee_method(JavaThread* thread, TRAPS);
 
+  static void monitor_enter_helper(oopDesc* obj, BasicLock* lock, JavaThread* thread);
+
+  static void monitor_exit_helper(oopDesc* obj, BasicLock* lock, JavaThread* thread);
 
  private:
   static Handle find_callee_info(JavaThread* thread,