Move V8 to external/v8
Change-Id: If68025d67453785a651c5dfb34fad298c16676a4
diff --git a/src/global-handles.h b/src/global-handles.h
new file mode 100644
index 0000000..9e63ba7
--- /dev/null
+++ b/src/global-handles.h
@@ -0,0 +1,150 @@
+// Copyright 2007-2008 the V8 project authors. All rights reserved.
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+// * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+// * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following
+// disclaimer in the documentation and/or other materials provided
+// with the distribution.
+// * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived
+// from this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#ifndef V8_GLOBAL_HANDLES_H_
+#define V8_GLOBAL_HANDLES_H_
+
+#include "list-inl.h"
+
+namespace v8 {
+namespace internal {
+
+// Structure for tracking global handles.
+// A single list keeps all the allocated global handles.
+// Destroyed handles stay in the list but is added to the free list.
+// At GC the destroyed global handles are removed from the free list
+// and deallocated.
+
+// Callback function on handling weak global handles.
+// typedef bool (*WeakSlotCallback)(Object** pointer);
+
+// An object group is treated like a single JS object: if one of object in
+// the group is alive, all objects in the same group are considered alive.
+// An object group is used to simulate object relationship in a DOM tree.
+class ObjectGroup : public Malloced {
+ public:
+ ObjectGroup() : objects_(4) {}
+ explicit ObjectGroup(size_t capacity) : objects_(capacity) {}
+
+ List<Object**> objects_;
+};
+
+
+class GlobalHandles : public AllStatic {
+ public:
+ // Creates a new global handle that is alive until Destroy is called.
+ static Handle<Object> Create(Object* value);
+
+ // Destroy a global handle.
+ static void Destroy(Object** location);
+
+ // Make the global handle weak and set the callback parameter for the
+ // handle. When the garbage collector recognizes that only weak global
+ // handles point to an object the handles are cleared and the callback
+ // function is invoked (for each handle) with the handle and corresponding
+ // parameter as arguments. Note: cleared means set to Smi::FromInt(0). The
+ // reason is that Smi::FromInt(0) does not change during garage collection.
+ static void MakeWeak(Object** location,
+ void* parameter,
+ WeakReferenceCallback callback);
+
+ // Returns the current number of weak handles.
+ static int NumberOfWeakHandles() { return number_of_weak_handles_; }
+
+ // Returns the current number of weak handles to global objects.
+ // These handles are also included in NumberOfWeakHandles().
+ static int NumberOfGlobalObjectWeakHandles() {
+ return number_of_global_object_weak_handles_;
+ }
+
+ // Clear the weakness of a global handle.
+ static void ClearWeakness(Object** location);
+
+ // Tells whether global handle is near death.
+ static bool IsNearDeath(Object** location);
+
+ // Tells whether global handle is weak.
+ static bool IsWeak(Object** location);
+
+ // Process pending weak handles.
+ static void PostGarbageCollectionProcessing();
+
+ // Iterates over all handles.
+ static void IterateRoots(ObjectVisitor* v);
+
+ // Iterates over all weak roots in heap.
+ static void IterateWeakRoots(ObjectVisitor* v);
+
+ // Find all weak handles satisfying the callback predicate, mark
+ // them as pending.
+ static void IdentifyWeakHandles(WeakSlotCallback f);
+
+ // Add an object group.
+ // Should only used in GC callback function before a collection.
+ // All groups are destroyed after a mark-compact collection.
+ static void AddGroup(Object*** handles, size_t length);
+
+ // Returns the object groups.
+ static List<ObjectGroup*>* ObjectGroups();
+
+ // Remove bags, this should only happen after GC.
+ static void RemoveObjectGroups();
+
+ // Tear down the global handle structure.
+ static void TearDown();
+
+#ifdef DEBUG
+ static void PrintStats();
+ static void Print();
+#endif
+ private:
+ // Internal node structure, one for each global handle.
+ class Node;
+
+ // Field always containing the number of weak and near-death handles.
+ static int number_of_weak_handles_;
+
+ // Field always containing the number of weak and near-death handles
+ // to global objects. These objects are also included in
+ // number_of_weak_handles_.
+ static int number_of_global_object_weak_handles_;
+
+ // Global handles are kept in a single linked list pointed to by head_.
+ static Node* head_;
+ static Node* head() { return head_; }
+ static void set_head(Node* value) { head_ = value; }
+
+ // Free list for DESTROYED global handles not yet deallocated.
+ static Node* first_free_;
+ static Node* first_free() { return first_free_; }
+ static void set_first_free(Node* value) { first_free_ = value; }
+};
+
+
+} } // namespace v8::internal
+
+#endif // V8_GLOBAL_HANDLES_H_