Make function lookup in classes thread-safe:

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 1719 matching lines @@
   const Context& context = Context::Handle(zone,
                                            Context::New(0, Heap::kOld));
   object_store->set_empty_context(context);
 
 #endif  // defined(DART_NO_SNAPSHOT).
 
   return Error::null();
 }
 
 
+#if defined(DEBUG)
+bool Object:: InVMHeap() const {
+  if (FLAG_verify_handles && raw()->IsVMHeapObject()) {
+    Heap* vm_isolate_heap = Dart::vm_isolate()->heap();
+    ASSERT(vm_isolate_heap->Contains(RawObject::ToAddr(raw())));
+  }
+  return raw()->IsVMHeapObject();
+}
+#endif  // DEBUG
+
+
 void Object::Print() const {
   THR_Print("%s\n", ToCString());
 }
 
 
 RawString* Object::DictionaryName() const {
   return String::null();
 }
 
 
@@ skipping 353 matching lines @@
     return String::HashRawSymbol(Function::Cast(key).name());
   }
   static uword Hash(const FunctionName& name) {
     return name.Hash();
   }
 };
 typedef UnorderedHashSet<ClassFunctionsTraits> ClassFunctionsSet;
 
 
 void Class::SetFunctions(const Array& value) const {
+  ASSERT(Thread::Current()->IsMutatorThread());
   ASSERT(!value.IsNull());
   StorePointer(&raw_ptr()->functions_, value.raw());
   const intptr_t len = value.Length();
   if (len >= kFunctionLookupHashTreshold) {
     ClassFunctionsSet set(HashTables::New<ClassFunctionsSet>(len, Heap::kOld));
     Function& func = Function::Handle();
     for (intptr_t i = 0; i < len; ++i) {
       func ^= value.At(i);
       // Verify that all the functions in the array have this class as owner.
       ASSERT(func.Owner() == raw());
       set.Insert(func);
     }
     StorePointer(&raw_ptr()->functions_hash_table_, set.Release().raw());
   } else {
     StorePointer(&raw_ptr()->functions_hash_table_, Array::null());
   }
 }
 
 
 void Class::AddFunction(const Function& function) const {
+  ASSERT(Thread::Current()->IsMutatorThread());
   const Array& arr = Array::Handle(functions());
   const Array& new_arr =
       Array::Handle(Array::Grow(arr, arr.Length() + 1, Heap::kOld));
   new_arr.SetAt(arr.Length(), function);
   StorePointer(&raw_ptr()->functions_, new_arr.raw());
   // Add to hash table, if any.
   const intptr_t new_len = new_arr.Length();
   if (new_len == kFunctionLookupHashTreshold) {
     // Transition to using hash table.
     SetFunctions(new_arr);
   } else if (new_len > kFunctionLookupHashTreshold) {
     ClassFunctionsSet set(raw_ptr()->functions_hash_table_);
     set.Insert(function);
     StorePointer(&raw_ptr()->functions_hash_table_, set.Release().raw());
   }
 }
 
 
 void Class::RemoveFunction(const Function& function) const {
+  ASSERT(Thread::Current()->IsMutatorThread());
   const Array& arr = Array::Handle(functions());
   StorePointer(&raw_ptr()->functions_, Object::empty_array().raw());
   StorePointer(&raw_ptr()->functions_hash_table_, Array::null());
   Function& entry = Function::Handle();
   for (intptr_t i = 0; i < arr.Length(); i++) {
     entry ^= arr.At(i);
     if (function.raw() != entry.raw()) {
       AddFunction(entry);
     }
   }
@@ skipping 1766 matching lines @@
     return Function::null();
   }
   REUSABLE_ARRAY_HANDLESCOPE(thread);
   REUSABLE_FUNCTION_HANDLESCOPE(thread);
   Array& funcs = thread->ArrayHandle();
   funcs ^= functions();
   ASSERT(!funcs.IsNull());
   const intptr_t len = funcs.Length();
   Function& function = thread->FunctionHandle();
   if (len >= kFunctionLookupHashTreshold) {
-    ClassFunctionsSet set(raw_ptr()->functions_hash_table_);
-    REUSABLE_STRING_HANDLESCOPE(thread);
-    function ^= set.GetOrNull(FunctionName(name, &(thread->StringHandle())));
-    // No mutations.
-    ASSERT(set.Release().raw() == raw_ptr()->functions_hash_table_);
-    return function.IsNull() ? Function::null()
-                             : CheckFunctionType(function, kind);
+    // Cache functions hash table to allow multi threaded access.
+    const Array& hash_table = Array::Handle(thread->zone(),
+                                            raw_ptr()->functions_hash_table_);
+    if (!hash_table.IsNull()) {
+      ClassFunctionsSet set(hash_table.raw());
+      REUSABLE_STRING_HANDLESCOPE(thread);
+      function ^= set.GetOrNull(FunctionName(name, &(thread->StringHandle())));
+      // No mutations.
+      ASSERT(set.Release().raw() == hash_table.raw());
+      return function.IsNull() ? Function::null()
+                               : CheckFunctionType(function, kind);
+    }
   }
   if (name.IsSymbol()) {
     // Quick Symbol compare.
     NoSafepointScope no_safepoint;
     for (intptr_t i = 0; i < len; i++) {
       function ^= funcs.At(i);
       if (function.name() == name.raw()) {
         return CheckFunctionType(function, kind);
       }
     }
@@ skipping 17477 matching lines @@
   return UserTag::null();
 }
 
 
 const char* UserTag::ToCString() const {
   const String& tag_label = String::Handle(label());
   return tag_label.ToCString();
 }
 
 }  // namespace dart