8320310: CompiledMethod::has_monitors flag can be incorrect

Reviewed-by: vlivanov, thartmann

src/hotspot/share/c1/c1_Compilation.cpp

@@ -390,10 +390,6 @@ int Compilation::compile_java_method() {
     BAILOUT_("mdo allocation failed", no_frame_size);
   }
 
-  if (method()->is_synchronized()) {
-    set_has_monitors(true);
-  }
-
   {
     PhaseTraceTime timeit(_t_buildIR);
     build_hir();
@@ -581,7 +577,7 @@ Compilation::Compilation(AbstractCompiler* compiler, ciEnv* env, ciMethod* metho
 , _would_profile(false)
 , _has_method_handle_invokes(false)
 , _has_reserved_stack_access(method->has_reserved_stack_access())
-, _has_monitors(false)
+, _has_monitors(method->is_synchronized() || method->has_monitor_bytecodes())
 , _install_code(install_code)
 , _bailout_msg(nullptr)
 , _first_failure_details(nullptr)

src/hotspot/share/c1/c1_GraphBuilder.cpp

@@ -2316,7 +2316,6 @@ void GraphBuilder::instance_of(int klass_index) {
 void GraphBuilder::monitorenter(Value x, int bci) {
   // save state before locking in case of deoptimization after a NullPointerException
   ValueStack* state_before = copy_state_for_exception_with_bci(bci);
-  compilation()->set_has_monitors(true);
   append_with_bci(new MonitorEnter(x, state()->lock(x), state_before), bci);
   kill_all();
 }
@@ -3510,6 +3509,15 @@ int GraphBuilder::recursive_inline_level(ciMethod* cur_callee) const {
   return recur_level;
 }
 
+static void set_flags_for_inlined_callee(Compilation* compilation, ciMethod* callee) {
+  if (callee->has_reserved_stack_access()) {
+    compilation->set_has_reserved_stack_access(true);
+  }
+  if (callee->is_synchronized() || callee->has_monitor_bytecodes()) {
+    compilation->set_has_monitors(true);
+  }
+}
+
 bool GraphBuilder::try_inline(ciMethod* callee, bool holder_known, bool ignore_return, Bytecodes::Code bc, Value receiver) {
   const char* msg = nullptr;
 
@@ -3526,9 +3534,7 @@ bool GraphBuilder::try_inline(ciMethod* callee, bool holder_known, bool ignore_r
   // method handle invokes
   if (callee->is_method_handle_intrinsic()) {
     if (try_method_handle_inline(callee, ignore_return)) {
-      if (callee->has_reserved_stack_access()) {
-        compilation()->set_has_reserved_stack_access(true);
-      }
+      set_flags_for_inlined_callee(compilation(), callee);
       return true;
     }
     return false;
@@ -3539,9 +3545,7 @@ bool GraphBuilder::try_inline(ciMethod* callee, bool holder_known, bool ignore_r
       callee->check_intrinsic_candidate()) {
     if (try_inline_intrinsics(callee, ignore_return)) {
       print_inlining(callee, "intrinsic");
-      if (callee->has_reserved_stack_access()) {
-        compilation()->set_has_reserved_stack_access(true);
-      }
+      set_flags_for_inlined_callee(compilation(), callee);
       return true;
     }
     // try normal inlining
@@ -3559,9 +3563,7 @@ bool GraphBuilder::try_inline(ciMethod* callee, bool holder_known, bool ignore_r
     bc = code();
   }
   if (try_inline_full(callee, holder_known, ignore_return, bc, receiver)) {
-    if (callee->has_reserved_stack_access()) {
-      compilation()->set_has_reserved_stack_access(true);
-    }
+    set_flags_for_inlined_callee(compilation(), callee);
     return true;
   }
 

src/hotspot/share/opto/locknode.cpp

@@ -179,8 +179,6 @@ void FastLockNode::create_rtm_lock_counter(JVMState* state) {
 void Parse::do_monitor_enter() {
   kill_dead_locals();
 
-  C->set_has_monitors(true);
-
   // Null check; get casted pointer.
   Node* obj = null_check(peek());
   // Check for locking null object
@@ -198,10 +196,6 @@ void Parse::do_monitor_enter() {
 void Parse::do_monitor_exit() {
   kill_dead_locals();
 
-  // need to set it for monitor exit as well.
-  // OSR compiled methods can start with lock taken
-  C->set_has_monitors(true);
-
   pop();                        // Pop oop to unlock
   // Because monitors are guaranteed paired (else we bail out), we know
   // the matching Lock for this Unlock.  Hence we know there is no need

src/hotspot/share/opto/parse1.cpp

@@ -423,7 +423,7 @@ Parse::Parse(JVMState* caller, ciMethod* parse_method, float expected_uses)
     C->set_has_reserved_stack_access(true);
   }
 
-  if (parse_method->is_synchronized()) {
+  if (parse_method->is_synchronized() || parse_method->has_monitor_bytecodes()) {
     C->set_has_monitors(true);
   }
 

src/hotspot/share/runtime/continuationFreezeThaw.cpp

@@ -1498,21 +1498,21 @@ static void jvmti_yield_cleanup(JavaThread* thread, ContinuationWrapper& cont) {
 #endif // INCLUDE_JVMTI
 
 #ifdef ASSERT
-// static bool monitors_on_stack(JavaThread* thread) {
-//   ContinuationEntry* ce = thread->last_continuation();
-//   RegisterMap map(thread,
-//                   RegisterMap::UpdateMap::include,
-//                   RegisterMap::ProcessFrames::include,
-//                   RegisterMap::WalkContinuation::skip);
-//   map.set_include_argument_oops(false);
-//   for (frame f = thread->last_frame(); Continuation::is_frame_in_continuation(ce, f); f = f.sender(&map)) {
-//     if ((f.is_interpreted_frame() && ContinuationHelper::InterpretedFrame::is_owning_locks(f)) ||
-//         (f.is_compiled_frame() && ContinuationHelper::CompiledFrame::is_owning_locks(map.thread(), &map, f))) {
-//       return true;
-//     }
-//   }
-//   return false;
-// }
+static bool monitors_on_stack(JavaThread* thread) {
+  ContinuationEntry* ce = thread->last_continuation();
+  RegisterMap map(thread,
+                  RegisterMap::UpdateMap::include,
+                  RegisterMap::ProcessFrames::include,
+                  RegisterMap::WalkContinuation::skip);
+  map.set_include_argument_oops(false);
+  for (frame f = thread->last_frame(); Continuation::is_frame_in_continuation(ce, f); f = f.sender(&map)) {
+    if ((f.is_interpreted_frame() && ContinuationHelper::InterpretedFrame::is_owning_locks(f)) ||
+        (f.is_compiled_frame() && ContinuationHelper::CompiledFrame::is_owning_locks(map.thread(), &map, f))) {
+      return true;
+    }
+  }
+  return false;
+}
 
 bool FreezeBase::interpreted_native_or_deoptimized_on_stack() {
   ContinuationEntry* ce = _thread->last_continuation();
@@ -1575,8 +1575,8 @@ static inline int freeze_internal(JavaThread* current, intptr_t* const sp) {
 
   assert(entry->is_virtual_thread() == (entry->scope(current) == java_lang_VirtualThread::vthread_scope()), "");
 
-  // assert(monitors_on_stack(current) == ((current->held_monitor_count() - current->jni_monitor_count()) > 0),
-  //        "Held monitor count and locks on stack invariant: " INT64_FORMAT " JNI: " INT64_FORMAT, (int64_t)current->held_monitor_count(), (int64_t)current->jni_monitor_count());
+  assert(monitors_on_stack(current) == ((current->held_monitor_count() - current->jni_monitor_count()) > 0),
+         "Held monitor count and locks on stack invariant: " INT64_FORMAT " JNI: " INT64_FORMAT, (int64_t)current->held_monitor_count(), (int64_t)current->jni_monitor_count());
 
   if (entry->is_pinned() || current->held_monitor_count() > 0) {
     log_develop_debug(continuations)("PINNED due to critical section/hold monitor");