Blink JavaScript shared memory prototype.

Source/core/dom/LockManager.h

Index: Source/core/dom/LockManager.h
diff --git a/Source/core/dom/MessageChannel.h b/Source/core/dom/LockManager.h
similarity index 57%
copy from Source/core/dom/MessageChannel.h
copy to Source/core/dom/LockManager.h
index 5b1dc49a04fac99bcb7d28eca14def9f13cbb13a..b4ec53fa55d5a6eebe6a29389db4fa56ae25c018 100644
--- a/Source/core/dom/MessageChannel.h
+++ b/Source/core/dom/LockManager.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2008 Apple Inc. All Rights Reserved.
+ * Copyright (C) 2014 Google Inc. All Rights Reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -24,34 +24,69 @@
  *
  */
 
-#ifndef MessageChannel_h
-#define MessageChannel_h
+#ifndef LockManager_h
+#define LockManager_h
 
 #include "bindings/v8/ScriptWrappable.h"
+#include "wtf/HashMap.h"
 #include "wtf/PassRefPtr.h"
 #include "wtf/RefCounted.h"
 #include "wtf/RefPtr.h"
+#include "wtf/ThreadSafeRefCounted.h"
+#include "wtf/ThreadingPrimitives.h"
 
 namespace WebCore {
 
-class MessagePort;
 class ExecutionContext;
 
-class MessageChannel : public RefCounted<MessageChannel>, public ScriptWrappable {
+class LockInfo;
+
+typedef WTF::HashMap<uint32_t, LockInfo*> LockHashMap;
+
+class LockShard {
 public:
-    static PassRefPtr<MessageChannel> create(ExecutionContext* context) { return adoptRef(new MessageChannel(context)); }
-    ~MessageChannel();
+    ~LockShard();
+
+    LockInfo* get(uint32_t uid);
+
+    Mutex mutex;
+private:
+    LockHashMap locks;
+};
+
+#define SHARD_BITS 5
+#define NUM_SHARDS (1 << SHARD_BITS)
+#define SHARD_MASK (NUM_SHARDS-1)
+
+class LockManagerImpl FINAL : public ThreadSafeRefCounted<LockManagerImpl> {
+public:
+    void lock(uint32_t uid);
+    void unlock(uint32_t uid);
+
+private:
+    LockShard shards[NUM_SHARDS];
+};
+
+class LockManager FINAL : public RefCounted<LockManager>
+    , public ScriptWrappable {
+public:
+    static PassRefPtr<LockManager> create(ExecutionContext* context)
+    {
+        return adoptRef(new LockManager(context));
+    }
+
+    void lock(unsigned long uid);
+    void unlock(unsigned long uid);
 
-    MessagePort* port1() const { return m_port1.get(); }
-    MessagePort* port2() const { return m_port2.get(); }
+    // HACK for performance testing.
+    void nop();
 
 private:
-    explicit MessageChannel(ExecutionContext*);
+    explicit LockManager(ExecutionContext*);
 
-    RefPtr<MessagePort> m_port1;
-    RefPtr<MessagePort> m_port2;
+    RefPtr<LockManagerImpl> impl;
 };
 
 } // namespace WebCore
 
-#endif // MessageChannel_h
+#endif // LockManager_h