[wrapper-tracing] WebGL and friends: Add write barriers

third_party/WebKit/Source/modules/webgl/WebGLRenderingContextBase.cpp

 /*
  * Copyright (C) 2009 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
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  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #include "modules/webgl/WebGLRenderingContextBase.h"
 
 #include "bindings/core/v8/ExceptionMessages.h"
 #include "bindings/core/v8/ExceptionState.h"
+#include "bindings/core/v8/ScriptWrappableVisitor.h"
 #include "bindings/core/v8/V8BindingMacros.h"
 #include "bindings/modules/v8/HTMLCanvasElementOrOffscreenCanvas.h"
 #include "bindings/modules/v8/WebGLAny.h"
 #include "core/dom/DOMArrayBuffer.h"
 #include "core/dom/DOMTypedArray.h"
 #include "core/dom/FlexibleArrayBufferView.h"
 #include "core/fetch/ImageResource.h"
 #include "core/frame/ImageBitmap.h"
 #include "core/frame/LocalFrame.h"
 #include "core/frame/Settings.h"
@@ skipping 930 matching lines @@
                              passedOffscreenCanvas,
                              requestedAttributes),
       m_isHidden(false),
       m_contextLostMode(NotLostContext),
       m_autoRecoveryMethod(Manual),
       m_dispatchContextLostEventTimer(
           this,
           &WebGLRenderingContextBase::dispatchContextLostEvent),
       m_restoreAllowed(false),
       m_restoreTimer(this, &WebGLRenderingContextBase::maybeRestoreContext),
+      m_boundArrayBuffer(this, nullptr),
+      m_boundVertexArrayObject(this, nullptr),
+      m_currentProgram(this, nullptr),
+      m_framebufferBinding(this, nullptr),
+      m_renderbufferBinding(this, nullptr),
       m_generatedImageCache(4),
       m_synthesizedErrorsToConsole(true),
       m_numGLErrorsToConsoleAllowed(maxGLErrorsAllowedToConsole),
       m_onePlusMaxNonDefaultTextureUnit(0),
       m_isWebGL2FormatsTypesAdded(false),
       m_isWebGL2TexImageSourceFormatsTypesAdded(false),
       m_isWebGL2InternalFormatsCopyTexImageAdded(false),
       m_isOESTextureFloatFormatsTypesAdded(false),
       m_isOESTextureHalfFloatFormatsTypesAdded(false),
       m_isWebGLDepthTextureFormatsTypesAdded(false),
@@ skipping 770 matching lines @@
   } else if (target == GL_TEXTURE_CUBE_MAP) {
     m_textureUnits[m_activeTextureUnit].m_textureCubeMapBinding = texture;
   } else if (isWebGL2OrHigher() && target == GL_TEXTURE_2D_ARRAY) {
     m_textureUnits[m_activeTextureUnit].m_texture2DArrayBinding = texture;
   } else if (isWebGL2OrHigher() && target == GL_TEXTURE_3D) {
     m_textureUnits[m_activeTextureUnit].m_texture3DBinding = texture;
   } else {
     synthesizeGLError(GL_INVALID_ENUM, "bindTexture", "invalid target");
     return;
   }
+  ScriptWrappableVisitor::writeBarrier(this, texture);

[Michael Lippautz, 2016/10/12 10:57:12]

TextureUnitState didn't use Member<> types before. I didn't add the
TraceWrapperMembers since I assume having raw pointers is needed for fast
construction/passing around somewhere?

[haraken, 2016/10/12 11:51:28]

How about changing Member<>s in TextureUnitState to TraceWrapperMember<>s? Won't
it work?

[Michael Lippautz, 2016/10/12 12:50:38]

Done.

This exposes one corner case where the compiler doesn't warn us: Pre-sized
containers.

The problem is that when we resize a HeapVector we initialize it with empty
elements. Unlike with ::append (where  the signature makes sure we have the
proper types), it is ok to assign a raw value to m_vector[i] because of the
operator= overload for raw values. Raw assignments (not going through
TraceWrapperMember(this, ...)) to empty TraceWrapperMembers lack the parent
pointer and a DCHECK will fire. 

2 options:
(a) Be fine with that this one case fails at runtime.
(b) Remove the overload for raw values, effectively forcing us to always go
through TraceWrapperMember(..) on aissgnment. 

I'd like to stay with (a).

 
   contextGL()->BindTexture(target, objectOrZero(texture));
   if (texture) {
     texture->setTarget(target);
     m_onePlusMaxNonDefaultTextureUnit =
         max(m_activeTextureUnit + 1, m_onePlusMaxNonDefaultTextureUnit);
   } else {
     // If the disabled index is the current maximum, trace backwards to find the
     // new max enabled texture index
     if (m_onePlusMaxNonDefaultTextureUnit == m_activeTextureUnit + 1) {
@@ skipping 5749 matching lines @@
 
 void WebGLRenderingContextBase::getHTMLOrOffscreenCanvas(
     HTMLCanvasElementOrOffscreenCanvas& result) const {
   if (canvas())
     result.setHTMLCanvasElement(canvas());
   else
     result.setOffscreenCanvas(getOffscreenCanvas());
 }
 
 }  // namespace blink