[compositorworker] Register compositor proxies with proxy client

third_party/WebKit/Source/core/dom/CompositorProxy.cpp

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "core/dom/CompositorProxy.h"
 
 #include "bindings/core/v8/ExceptionMessages.h"
 #include "bindings/core/v8/ExceptionState.h"
 #include "core/dom/DOMNodeIds.h"
 #include "core/dom/ExceptionCode.h"
 #include "core/dom/ExecutionContext.h"
+#include "core/workers/WorkerClients.h"
+#include "core/workers/WorkerGlobalScope.h"
 #include "platform/ThreadSafeFunctional.h"
 #include "platform/graphics/CompositorMutableProperties.h"
 #include "public/platform/Platform.h"
 #include "public/platform/WebTraceLocation.h"
 #include <algorithm>
 
 namespace blink {
 
 static const struct {
     const char* name;
@@ skipping 83 matching lines @@
 {
     if (!context->isDocument()) {
         exceptionState.throwTypeError(ExceptionMessages::failedToConstruct("CompositorProxy", "Can only be created from the main context."));
         exceptionState.throwIfNeeded();
         return nullptr;
     }
 
     return new CompositorProxy(*element, attributeArray);
 }
 
-CompositorProxy* CompositorProxy::create(uint64_t elementId, uint32_t compositorMutableProperties)
+CompositorProxy* CompositorProxy::create(ExecutionContext* context, uint64_t elementId, uint32_t compositorMutableProperties)
 {
-    return new CompositorProxy(elementId, compositorMutableProperties);
+    WorkerClients* clients = toWorkerGlobalScope(context)->clients();

[jbroman, 2016/06/08 14:45:34]

Won't this crash if you postMessage a CompositorProxy back to the main thread?
Why is it safe to assume the execution context is a WorkerGlobalScope?

[majidvp, 2016/06/09 20:34:21]

Fixed. It is not safe and crashes!
Modified one of existing tests to cover this.

+    DCHECK(clients);
+    CompositorProxyClient* client = CompositorProxyClient::from(clients);
+    return new CompositorProxy(elementId, compositorMutableProperties, client);
 }
 
 CompositorProxy::CompositorProxy(Element& element, const Vector<String>& attributeArray)
     : m_elementId(DOMNodeIds::idForNode(&element))
     , m_compositorMutableProperties(compositorMutablePropertiesFromNames(attributeArray))
+    , m_client(nullptr)
 {
     DCHECK(isMainThread());
     DCHECK(m_compositorMutableProperties);
 #if DCHECK_IS_ON()
     DCHECK(sanityCheckMutableProperties(m_compositorMutableProperties));
 #endif
 
     incrementCompositorProxiedPropertiesForElement(m_elementId, m_compositorMutableProperties);
 }
 
-CompositorProxy::CompositorProxy(uint64_t elementId, uint32_t compositorMutableProperties)
+CompositorProxy::CompositorProxy(uint64_t elementId, uint32_t compositorMutableProperties, CompositorProxyClient* client)
     : m_elementId(elementId)
     , m_compositorMutableProperties(compositorMutableProperties)
+    , m_client(client)
 {
     DCHECK(isControlThread());
 #if DCHECK_IS_ON()
     DCHECK(sanityCheckMutableProperties(m_compositorMutableProperties));
 #endif
     Platform::current()->mainThread()->getWebTaskRunner()->postTask(BLINK_FROM_HERE, threadSafeBind(&incrementCompositorProxiedPropertiesForElement, m_elementId, m_compositorMutableProperties));
+    m_client->registerCompositorProxy(this);
+    ThreadState::current()->registerPreFinalizer(this);
 }
 
 CompositorProxy::~CompositorProxy()
 {
-    if (m_connected)
+    if (isMainThread())
         disconnect();

[haraken, 2016/06/08 00:10:36]

You don't need to call disconnect() because disconnect() has already been called
in the pre-finalizer.

[majidvp, 2016/06/09 20:34:21]

Done.

+    DCHECK(!m_connected);
+}
+
+void CompositorProxy::dispose()
+{
+    // On compositor worker thread, disconnecting requires unregistering from
+    // CompositorProxyClient which needs to be done in pre-finalizer.
+    disconnect();
 }
 
 bool CompositorProxy::supports(const String& attributeName) const
 {
     return m_compositorMutableProperties & compositorMutablePropertyForName(attributeName);
 }
 
 double CompositorProxy::opacity(ExceptionState& exceptionState) const
 {
     if (raiseExceptionIfMutationNotAllowed(exceptionState))
@@ skipping 74 matching lines @@
 {
     if (m_connected && (m_compositorMutableProperties & property))
         return false;
     exceptionState.throwDOMException(NoModificationAllowedError,
         m_connected ? "Attempted to mutate non-mutable attribute." : "Attempted to mutate attribute on a disconnected proxy.");
     return true;
 }
 
 void CompositorProxy::disconnect()
 {
+    if (!m_connected)
+        return;
     m_connected = false;
-    if (isMainThread())
+    if (isMainThread()) {
         decrementCompositorProxiedPropertiesForElement(m_elementId, m_compositorMutableProperties);
-    else
+    } else {
         Platform::current()->mainThread()->getWebTaskRunner()->postTask(BLINK_FROM_HERE, threadSafeBind(&decrementCompositorProxiedPropertiesForElement, m_elementId, m_compositorMutableProperties));
+        if (m_client)
+            m_client->unregisterCompositorProxy(this);
+    }
 }
 
 } // namespace blink