Track external allocated memory for weak persistent handles.

runtime/vm/dart_api_state.h

 // 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.
 
 #ifndef VM_DART_API_STATE_H_
 #define VM_DART_API_STATE_H_
 
 #include "include/dart_api.h"
 
 #include "platform/thread.h"
+#include "platform/utils.h"
 #include "vm/dart_api_impl.h"
 #include "vm/flags.h"
 #include "vm/growable_array.h"
 #include "vm/handles.h"
 #include "vm/object.h"
 #include "vm/os.h"
 #include "vm/raw_object.h"
 #include "vm/visitor.h"
 
 #include "vm/handles_impl.h"
@@ skipping 170 matching lines @@
   static intptr_t raw_offset() {
     return OFFSET_OF(FinalizablePersistentHandle, raw_);
   }
   void* peer() const { return peer_; }
   void set_peer(void* peer) { peer_ = peer; }
   Dart_WeakPersistentHandleFinalizer callback() const { return callback_; }
   void set_callback(Dart_WeakPersistentHandleFinalizer callback) {
     callback_ = callback;
   }
 
+  void SetExternalAllocationSize(intptr_t size, Heap* heap) {

[Ivan Posva, 2014/03/06 21:59:33]

SetExternalSize() to match the field.

[koda, 2014/03/06 22:55:07]

Done.

+    ASSERT(size >= 0);
+    external_size_ = Utils::RoundUp(size, kObjectAlignment);
+    // TODO(koda): On repeated/large external allocations for existing objects,
+    // without any intervening normal allocation, GC will not trigger.
+    heap->AllocateExternal(external_size_, raw());
+  }
+
+  // Called when the referent becomes unreachable.
+  void UpdateUnreachable(Heap* heap) {
+    heap->FreeExternal(external_size_, raw());
+    Finalize(this);
+  }
+
+  // Called when the referent has moved, potentially between generations.
+  void UpdateRelocated(RawObject* raw_before, Heap* heap) {
+    heap->FreeExternal(external_size_, raw_before);
+    heap->AllocateExternal(external_size_, raw());
+  }
+
   static void Finalize(FinalizablePersistentHandle* handle) {
     Dart_WeakPersistentHandleFinalizer callback = handle->callback();
     if (callback != NULL) {
       void* peer = handle->peer();
       handle->Clear();
       (*callback)(reinterpret_cast<Dart_WeakPersistentHandle>(handle), peer);
     } else {
       handle->Clear();
     }
   }
 
  private:
   friend class FinalizablePersistentHandles;
 
-  FinalizablePersistentHandle() : raw_(NULL), peer_(NULL), callback_(NULL) { }
+  FinalizablePersistentHandle()
+      : raw_(NULL),
+        peer_(NULL),
+        external_size_(0),
+        callback_(NULL) { }
   ~FinalizablePersistentHandle() { }
 
   // Overload the raw_ field as a next pointer when adding freed
   // handles to the free list.
   FinalizablePersistentHandle* Next() {
     return reinterpret_cast<FinalizablePersistentHandle*>(raw_);
   }
   void SetNext(FinalizablePersistentHandle* free_list) {
     raw_ = reinterpret_cast<RawObject*>(free_list);
     ASSERT(!raw_->IsHeapObject());
   }
   void FreeHandle(FinalizablePersistentHandle* free_list) {
     Clear();
     SetNext(free_list);
   }
 
   void Clear() {
     raw_ = Object::null();
     peer_ = NULL;
+    external_size_ = 0;
     callback_ = NULL;
   }
 
   RawObject* raw_;
   void* peer_;
+  intptr_t external_size_;

[siva, 2014/03/06 17:17:39]

Not for this CL but just a thought:
Now that we have an external field I am wondering if we should steal a bit from
here to indicate if the handle is a prolog weak persistent handle or a regular
weak persistent handle (current we tag the returned pointer).

[koda, 2014/03/06 22:55:07]

Sounds like a good idea. It would simplify the code (which became slightly more
complicated after merging with your tagging-change).

   Dart_WeakPersistentHandleFinalizer callback_;
   DISALLOW_ALLOCATION();  // Allocated through AllocateHandle methods.
   DISALLOW_COPY_AND_ASSIGN(FinalizablePersistentHandle);
 };
 
 
 // Local handles repository structure.
 static const int kLocalHandleSizeInWords = sizeof(LocalHandle) / kWordSize;
 static const int kLocalHandlesPerChunk = 64;
 static const int kOffsetOfRawPtrInLocalHandle = 0;
@@ skipping 181 matching lines @@
   // by calling FreeHandle.
   FinalizablePersistentHandle* AllocateHandle() {
     FinalizablePersistentHandle* handle;
     if (free_list_ != NULL) {
       handle = free_list_;
       free_list_ = handle->Next();
     } else {
       handle = reinterpret_cast<FinalizablePersistentHandle*>(
           AllocateScopedHandle());
     }
-    handle->set_callback(NULL);
+    handle->Clear();
     return handle;
   }
 
   void FreeHandle(FinalizablePersistentHandle* handle) {
     handle->FreeHandle(free_list());
     set_free_list(handle);
   }
 
   // Validate if passed in handle is a Persistent Handle.
   bool IsValidHandle(Dart_WeakPersistentHandle object) const {
@@ skipping 330 matching lines @@
           ApiNativeScope::Current()->zone()) {}
   ApiGrowableArray()
       : BaseGrowableArray<T, ValueObject>(
           ApiNativeScope::Current()->zone()) {}
 };
 
 
 }  // namespace dart
 
 #endif  // VM_DART_API_STATE_H_