[debugger] Move clearing of optimized code map out of GC.

src/debug/debug.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/debug/debug.h"
 
 #include "src/api.h"
 #include "src/arguments.h"
 #include "src/bootstrapper.h"
 #include "src/code-stubs.h"
@@ skipping 1287 matching lines @@
 bool Debug::PrepareFunctionForBreakPoints(Handle<SharedFunctionInfo> shared) {
   DCHECK(shared->is_compiled());
 
   if (isolate_->concurrent_recompilation_enabled()) {
     isolate_->optimizing_compile_dispatcher()->Flush();
   }
 
   List<Handle<JSFunction> > functions;
   List<Handle<JSGeneratorObject> > suspended_generators;
 
-  if (!shared->optimized_code_map()->IsSmi()) {
-    shared->ClearOptimizedCodeMap();
+  // Flush all optimized code maps. Only flushing the optimized code map of the
+  // give shared function info {shared} is not enough, because other functions
+  // might have inlined the given function and don't contain breakpoints.

[Yang, 2015/11/05 18:46:49]

See below. We already deal with inlining.

+  {
+    SharedFunctionInfo::Iterator iterator(isolate_);
+    while (SharedFunctionInfo* shared = iterator.Next()) {
+      if (!shared->optimized_code_map()->IsSmi()) {
+        shared->ClearOptimizedCodeMap();
+      }
+    }
   }
 
   // Make sure we abort incremental marking.
   isolate_->heap()->CollectAllGarbage(Heap::kMakeHeapIterableMask,
                                       "prepare for break points");
 
   {
     HeapIterator iterator(isolate_->heap());
     HeapObject* obj;
     bool include_generators = shared->is_generator();
 
     while ((obj = iterator.next())) {
       if (obj->IsJSFunction()) {
         JSFunction* function = JSFunction::cast(obj);
         if (!function->Inlines(*shared)) continue;
         if (function->code()->kind() == Code::OPTIMIZED_FUNCTION) {
           Deoptimizer::DeoptimizeFunction(function);
         }
         if (function->shared() == *shared) functions.Add(handle(function));
       } else if (include_generators && obj->IsJSGeneratorObject()) {
         JSGeneratorObject* generator_obj = JSGeneratorObject::cast(obj);
         if (!generator_obj->is_suspended()) continue;
         JSFunction* function = generator_obj->function();
         if (!function->Inlines(*shared)) continue;

[Yang, 2015/11/05 18:46:49]

We check for functions that inlines this function, so we can actually narrow
down functions for which we have to flush the optimized code map.

[Michael Starzinger, 2015/11/05 18:54:35]

Yes, but if there is no closure (i.e. JSFunction) but still a SharedFunctionInfo
which has entires in the optimized code map, then the code will not be
deoptmized and the optimized code map will not be cleared.

         int pc_offset = generator_obj->continuation();
         int index =
             ComputeContinuationIndexFromPcOffset(function->code(), pc_offset);
         generator_obj->set_continuation(index);
         suspended_generators.Add(handle(generator_obj));
       }
     }
   }
 
   if (!shared->HasDebugCode()) {
@@ skipping 1237 matching lines @@
 }
 
 
 void LockingCommandMessageQueue::Clear() {
   base::LockGuard<base::Mutex> lock_guard(&mutex_);
   queue_.Clear();
 }
 
 }  // namespace internal
 }  // namespace v8