VM: Fix race between background compiler and guarded cid update.

runtime/vm/isolate.cc

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/isolate.h"
 
 #include "include/dart_api.h"
 #include "include/dart_native_api.h"
 #include "platform/assert.h"
 #include "platform/text_buffer.h"
@@ skipping 804 matching lines @@
       sticky_error_(Error::null()),
       background_compiler_(NULL),
       background_compiler_disabled_depth_(0),
       pending_service_extension_calls_(GrowableObjectArray::null()),
       registered_service_extension_handlers_(GrowableObjectArray::null()),
       metrics_list_head_(NULL),
       compilation_allowed_(true),
       all_classes_finalized_(false),
       next_(NULL),
       pause_loop_monitor_(NULL),
-      field_invalidation_gen_(kInvalidGen),
       loading_invalidation_gen_(kInvalidGen),
       top_level_parsing_count_(0),
       field_list_mutex_(new Mutex()),
       boxed_field_list_(GrowableObjectArray::null()),
-      disabling_field_list_(GrowableObjectArray::null()),
       spawn_count_monitor_(new Monitor()),
       spawn_count_(0),
       has_attempted_reload_(false),
       no_reload_scope_depth_(0),
       reload_context_(NULL) {
   NOT_IN_PRODUCT(FlagsCopyFrom(api_flags));
   // TODO(asiva): A Thread is not available here, need to figure out
   // how the vm_tag (kEmbedderTagId) can be set, these tags need to
   // move to the OSThread structure.
   set_user_tag(UserTags::kDefaultUserTag);
@@ skipping 918 matching lines @@
   // Visit the registered service extension handlers.
   visitor->VisitPointer(
       reinterpret_cast<RawObject**>(&registered_service_extension_handlers_));
 
   // Visit the boxed_field_list_.
   // 'boxed_field_list_' access via mutator and background compilation threads
   // is guarded with a monitor. This means that we can visit it only
   // when at safepoint or the field_list_mutex_ lock has been taken.
   visitor->VisitPointer(reinterpret_cast<RawObject**>(&boxed_field_list_));
 
-  // Visit the disabling_field_list.
-  // 'disabling_field_list_' access via mutator and background compilation
-  // threads is guarded with a monitor. This means that we can visit it only
-  // when at safepoint or the field_list_mutex_ lock has been taken.
-  visitor->VisitPointer(reinterpret_cast<RawObject**>(&disabling_field_list_));
-
   // Visit objects in the debugger.
   if (FLAG_support_debugger) {
     debugger()->VisitObjectPointers(visitor);
   }
 
   NOT_IN_PRODUCT(
     // Visit objects that are being used for isolate reload.
     if (reload_context() != NULL) {
       reload_context()->VisitObjectPointers(visitor);
     }
@@ skipping 228 matching lines @@
   pending_service_extension_calls_ = value.raw();
 }
 
 
 void Isolate::set_registered_service_extension_handlers(
     const GrowableObjectArray& value) {
   registered_service_extension_handlers_ = value.raw();
 }
 
 
-// Used by mutator thread to notify background compiler which fields
-// triggered code invalidation.
-void Isolate::AddDisablingField(const Field& field) {
-  ASSERT(Thread::Current()->IsMutatorThread());
-  SafepointMutexLocker ml(field_list_mutex_);
-  if (disabling_field_list_ == GrowableObjectArray::null()) {
-    disabling_field_list_ = GrowableObjectArray::New(Heap::kOld);
-  }
-  const GrowableObjectArray& array =
-      GrowableObjectArray::Handle(disabling_field_list_);
-  array.Add(field, Heap::kOld);
-}
-
-
-RawField* Isolate::GetDisablingField() {
-  ASSERT(Compiler::IsBackgroundCompilation() &&
-         (!Isolate::Current()->HasMutatorThread() ||
-         Isolate::Current()->mutator_thread()->IsAtSafepoint()));
-  ASSERT(Thread::Current()->IsAtSafepoint());
-  if (disabling_field_list_ == GrowableObjectArray::null()) {
-    return Field::null();
-  }
-  const GrowableObjectArray& array =
-      GrowableObjectArray::Handle(disabling_field_list_);
-  if (array.Length() == 0) {
-    return Field::null();
-  }
-  return Field::RawCast(array.RemoveLast());
-}
-
-
-void Isolate::ClearDisablingFieldList() {
-  MutexLocker ml(field_list_mutex_);
-  if (disabling_field_list_ == GrowableObjectArray::null()) {
-    return;
-  }
-  const GrowableObjectArray& array =
-      GrowableObjectArray::Handle(disabling_field_list_);
-  if (array.Length() > 0) {
-    array.SetLength(0);
-  }
-}
-
-
 void Isolate::AddDeoptimizingBoxedField(const Field& field) {
   ASSERT(Compiler::IsBackgroundCompilation());
   ASSERT(field.IsOriginal());
   // The enclosed code allocates objects and can potentially trigger a GC,
   // ensure that we account for safepoints when grabbing the lock.
   SafepointMutexLocker ml(field_list_mutex_);
   if (boxed_field_list_ == GrowableObjectArray::null()) {
     boxed_field_list_ = GrowableObjectArray::New(Heap::kOld);
   }
   const GrowableObjectArray& array =
@@ skipping 765 matching lines @@
 void IsolateSpawnState::DecrementSpawnCount() {
   ASSERT(spawn_count_monitor_ != NULL);
   ASSERT(spawn_count_ != NULL);
   MonitorLocker ml(spawn_count_monitor_);
   ASSERT(*spawn_count_ > 0);
   *spawn_count_ = *spawn_count_ - 1;
   ml.Notify();
 }
 
 }  // namespace dart