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

runtime/vm/object.cc

 // Copyright (c) 2012, 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/object.h"
 
 #include "include/dart_api.h"
 #include "platform/assert.h"
 #include "vm/assembler.h"
 #include "vm/cpu.h"
@@ skipping 2735 matching lines @@
   virtual void ReportSwitchingCode(const Code& code) {
     if (FLAG_trace_deoptimization || FLAG_trace_deoptimization_verbose) {
       Function& function = Function::Handle(code.function());
       THR_Print("Switching %s to unoptimized code because CHA invalid"
                 " (%s)\n",
                 function.ToFullyQualifiedCString(),
                 cls_.ToCString());
     }
   }
 
-  virtual void IncrementInvalidationGen() {}
-
  private:
   const Class& cls_;
   DISALLOW_COPY_AND_ASSIGN(CHACodeArray);
 };
 
 
 #if defined(DEBUG)
 static bool IsMutatorOrAtSafepoint() {
   Thread* thread = Thread::Current();
   return thread->IsMutatorThread() || thread->IsAtSafepoint();
@@ skipping 4909 matching lines @@
   virtual void ReportSwitchingCode(const Code& code) {
     if (FLAG_trace_deoptimization || FLAG_trace_deoptimization_verbose) {
       Function& function = Function::Handle(code.function());
       THR_Print("Switching '%s' to unoptimized code because guard"
                 " on field '%s' was violated.\n",
                 function.ToFullyQualifiedCString(),
                 field_.ToCString());
     }
   }
 
-  virtual void IncrementInvalidationGen() {
-    Isolate::Current()->IncrFieldInvalidationGen();
-  }
-
  private:
   const Field& field_;
   DISALLOW_COPY_AND_ASSIGN(FieldDependentArray);
 };
 
 
 void Field::RegisterDependentCode(const Code& code) const {
   ASSERT(IsOriginal());
   DEBUG_ASSERT(IsMutatorOrAtSafepoint());
   ASSERT(code.is_optimized());
   FieldDependentArray a(*this);
   a.Register(code);
 }
 
 
 void Field::DeoptimizeDependentCode() const {
   ASSERT(Thread::Current()->IsMutatorThread());
   ASSERT(IsOriginal());
-  if (FLAG_background_compilation) {
-    Isolate::Current()->AddDisablingField(*this);
-  }
   FieldDependentArray a(*this);
   a.DisableCode();
 }
 
 
+bool Field::IsConsistentWith(const Field& other) const {
+  return (raw_ptr()->guarded_cid_ == other.raw_ptr()->guarded_cid_) &&
+         (raw_ptr()->is_nullable_ == other.raw_ptr()->is_nullable_) &&
+         (raw_ptr()->guarded_list_length_ ==
+             other.raw_ptr()->guarded_list_length_);
+}
+
+
 bool Field::IsUninitialized() const {
   const Instance& value = Instance::Handle(raw_ptr()->value_.static_value_);
   ASSERT(value.raw() != Object::transition_sentinel().raw());
   return value.raw() == Object::sentinel().raw();
 }
 
 
 void Field::SetPrecompiledInitializer(const Function& initializer) const {
   ASSERT(IsOriginal());
   StorePointer(&raw_ptr()->initializer_.precompiled_, initializer.raw());
@@ skipping 3240 matching lines @@
   virtual void ReportSwitchingCode(const Code& code) {
     if (FLAG_trace_deoptimization || FLAG_trace_deoptimization_verbose) {
       THR_Print("Prefix '%s': disabling %s code for %s function '%s'\n",
           String::Handle(prefix_.name()).ToCString(),
           code.is_optimized() ? "optimized" : "unoptimized",
           code.IsDisabled() ? "'patched'" : "'unpatched'",
           Function::Handle(code.function()).ToCString());
     }
   }
 
-  virtual void IncrementInvalidationGen() {}
-
  private:
   const LibraryPrefix& prefix_;
   DISALLOW_COPY_AND_ASSIGN(PrefixDependentArray);
 };
 
 
 void LibraryPrefix::RegisterDependentCode(const Code& code) const {
   ASSERT(is_deferred_load());
   // In background compilation, a library can be loaded while we are compiling.
   // The generated code will be rejected in that case,
@@ skipping 11621 matching lines @@
   return UserTag::null();
 }
 
 
 const char* UserTag::ToCString() const {
   const String& tag_label = String::Handle(label());
   return tag_label.ToCString();
 }
 
 }  // namespace dart