Implement WEBGL_shared_resources

Source/core/html/canvas/WebGLSharedObject.h

 /*
  * Copyright (C) 2011 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. 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.
  *
  * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``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 APPLE COMPUTER, INC. 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 WebGLSharedObject_h
 #define WebGLSharedObject_h
 
+#include "core/dom/ScriptExecutionContext.h"
 #include "core/html/canvas/WebGLObject.h"
+#include "wtf/Deque.h"
+#include "wtf/HashMap.h"
 
 namespace WebCore {
 
 class GraphicsContext3D;
+class WebGLAcquireSharedResourceCallback;
 class WebGLContextGroup;
 class WebGLRenderingContext;
+class WebGLSharedObject;
+class WebGLAcquireSharedResourceRequest;
 
 // WebGLSharedObject the base class for objects that can be shared by multiple
 // WebGLRenderingContexts.
 class WebGLSharedObject : public WebGLObject {
 public:
+    enum AcquireMode {
+        Unacquired = 0,
+        ReadOnly = 1,
+        Exclusive = 4,
+    };
+
     virtual ~WebGLSharedObject();
 
     WebGLContextGroup* contextGroup() const { return m_contextGroup; }
 
     virtual bool isBuffer() const { return false; }
-    virtual bool isFramebuffer() const { return false; }
     virtual bool isProgram() const { return false; }
     virtual bool isRenderbuffer() const { return false; }
     virtual bool isShader() const { return false; }
     virtual bool isTexture() const { return false; }
 
-    virtual bool validate(const WebGLContextGroup* contextGroup, const WebGLRenderingContext*) const
-    {
-        return contextGroup == m_contextGroup;
-    }
+    virtual const char* typeName() const = 0;
+
+    bool validate(const char*, WebGLRenderingContext*, WebGLSharedObject::AcquireMode, bool, bool*) const;
 
     void detachContextGroup();
 
+    bool isLost() const
+    {
+        return !m_contextGroup;
+    }
+    bool isAcquiredForContext(const WebGLRenderingContext*, WebGLSharedObject::AcquireMode, bool, bool*, const char**) const;
+    bool hasBeenBoundInContextSinceLastAcquire(const WebGLRenderingContext*);
+    void markAsBoundSinceLastAcquireForContext(const WebGLRenderingContext*);
+    bool addAcquireRequest(WebGLRenderingContext*, WebGLSharedObject::AcquireMode, PassRefPtr<WebGLAcquireSharedResourceCallback>, long&);
+    // cancels an acquire request. Returns true if id was found.
+    bool cancelAcquireRequest(const WebGLRenderingContext*, long);
+    bool release(WebGLRenderingContext*);
+
+    void cancelAllPendingRequestsForContext(const WebGLRenderingContext*);
+
 protected:
     WebGLSharedObject(WebGLRenderingContext*);
 
     virtual bool hasGroupOrContext() const
     {
         return m_contextGroup;
     }
 
     virtual GraphicsContext3D* getAGraphicsContext3D() const;
 
 private:
+    friend class WebGLAcquireSharedResourceRequest;
+    class DispatchCallbackTask : public ScriptExecutionContext::Task {
+    public:
+        DispatchCallbackTask(PassRefPtr<WebGLAcquireSharedResourceRequest> request)
+            : m_request(request)
+        {
+        }
+        ~DispatchCallbackTask();
+
+        virtual void performTask(ScriptExecutionContext*);
+
+    private:
+        RefPtr<WebGLAcquireSharedResourceRequest> m_request;
+    };
+
+    typedef HashMap<const WebGLRenderingContext*, bool> AcquireContextMap;
+    typedef Deque<RefPtr<WebGLAcquireSharedResourceRequest> > AcquireRequestQueue;
+    typedef Deque<RefPtr<WebGLAcquireSharedResourceRequest> > AcquireRequestList;
+
+    bool acquire(WebGLSharedObject::AcquireMode, const WebGLRenderingContext*);
+    bool isRequestPending(const WebGLRenderingContext*);
+    void processAcquireRequests();
+    void removePostedAcquireRequest(const WebGLRenderingContext*, long);
+    static int generateAcquireRequestId();
+
     WebGLContextGroup* m_contextGroup;
+
+    WebGLSharedObject::AcquireMode m_acquireMode;
+
+    // A map of contexts that currently have this resource acquired.
+    // and whether or not it's been bound since last acquired.
+    AcquireContextMap m_acquireContextMap;
+
+    AcquireRequestQueue m_acquireRequestQueue; // requests that are waiting for resources.
+    AcquireRequestList m_acquireRequestPostedList; // requests what have had script tasks posted but the script has not executed.
 };
 
+class WebGLAcquireSharedResourceRequest : public RefCounted<WebGLAcquireSharedResourceRequest> {
+public:
+    static PassRefPtr<WebGLAcquireSharedResourceRequest> create(PassRefPtr<WebGLSharedObject>, PassRefPtr<WebGLAcquireSharedResourceCallback>, WebGLSharedObject::AcquireMode, WebGLRenderingContext*, long);
+    ~WebGLAcquireSharedResourceRequest();
+
+    long id() const { return m_id; }
+    WebGLRenderingContext* context() const { return m_context; }
+    WebGLSharedObject::AcquireMode acquireMode() const { return m_acquireMode; }
+    void cancel();
+
+    // Run the callback.
+    void run();
+
+private:
+    WebGLAcquireSharedResourceRequest(PassRefPtr<WebGLSharedObject>, PassRefPtr<WebGLAcquireSharedResourceCallback>, WebGLSharedObject::AcquireMode, WebGLRenderingContext*, long);
+
+    RefPtr<WebGLSharedObject> m_sharedObject;
+    // This weak pointer is okay because on context destruction we remove all outstanding requests.
+    WebGLRenderingContext* m_context;
+    long m_id;
+    WebGLSharedObject::AcquireMode m_acquireMode;
+    RefPtr<WebGLAcquireSharedResourceCallback> m_callback;
+};
+
+
 } // namespace WebCore
 
 #endif // WebGLSharedObject_h