Lazy initialize WGC3DInProcessCommandBufferImpl

webkit/gpu/webgraphicscontext3d_in_process_command_buffer_impl.cc

 // Copyright (c) 2012 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 "webkit/gpu/webgraphicscontext3d_in_process_command_buffer_impl.h"
 
 #include <GLES2/gl2.h>
 #ifndef GL_GLEXT_PROTOTYPES
 #define GL_GLEXT_PROTOTYPES 1
 #endif
@@ skipping 80 matching lines @@
 
   // Create a GLInProcessContext that renders to an offscreen frame buffer. If
   // parent is not NULL, that GLInProcessContext can access a copy of the
   // created GLInProcessContext's frame buffer that is updated every time
   // SwapBuffers is called. It is not as general as shared GLInProcessContexts
   // in other implementations of OpenGL. If parent is not NULL, it must be used
   // on the same thread as the parent. A child GLInProcessContext may not
   // outlive its parent.  attrib_list must be NULL or a NONE-terminated list of
   // attribute/value pairs.
   static GLInProcessContext* CreateOffscreenContext(
-      GLInProcessContext* parent,
       const gfx::Size& size,
       GLInProcessContext* context_group,
       const char* allowed_extensions,
       const int32* attrib_list,
       gfx::GpuPreference gpu_preference);
 
   // For an offscreen frame buffer GLInProcessContext, return the texture ID
   // with respect to the parent GLInProcessContext. Returns zero if
   // GLInProcessContext does not have a parent.
   uint32 GetParentTextureId();
@@ skipping 26 matching lines @@
   // Return the current error.
   Error GetError();
 
   // Return true if GPU process reported GLInProcessContext lost or there was a
   // problem communicating with the GPU process.
   bool IsCommandBufferContextLost();
 
   CommandBufferService* GetCommandBufferService();
 
  private:
-  explicit GLInProcessContext(GLInProcessContext* parent);
+  GLInProcessContext();
 
   bool Initialize(const gfx::Size& size,
                   GLInProcessContext* context_group,
                   const char* allowed_extensions,
                   const int32* attrib_list,
                   gfx::GpuPreference gpu_preference);
   void Destroy();
 
   void OnContextLost();
 
-  base::WeakPtr<GLInProcessContext> parent_;
   base::Closure context_lost_callback_;
-  uint32 parent_texture_id_;
   scoped_ptr<TransferBufferManagerInterface> transfer_buffer_manager_;
   scoped_ptr<CommandBufferService> command_buffer_;
   scoped_ptr< ::gpu::GpuScheduler> gpu_scheduler_;
   scoped_ptr< ::gpu::gles2::GLES2Decoder> decoder_;
   scoped_refptr<gfx::GLContext> context_;
   scoped_refptr<gfx::GLSurface> surface_;
   scoped_ptr<GLES2CmdHelper> gles2_helper_;
   scoped_ptr<TransferBuffer> transfer_buffer_;
   scoped_ptr<GLES2Implementation> gles2_implementation_;
   Error last_error_;
@@ skipping 37 matching lines @@
 static base::LazyInstance<GLES2Initializer> g_gles2_initializer =
     LAZY_INSTANCE_INITIALIZER;
 
 }  // namespace anonymous
 
 GLInProcessContext::~GLInProcessContext() {
   Destroy();
 }
 
 GLInProcessContext* GLInProcessContext::CreateOffscreenContext(
-    GLInProcessContext* parent,
     const gfx::Size& size,
     GLInProcessContext* context_group,
     const char* allowed_extensions,
     const int32* attrib_list,
     gfx::GpuPreference gpu_preference) {
-  scoped_ptr<GLInProcessContext> context(new GLInProcessContext(parent));
+  scoped_ptr<GLInProcessContext> context(new GLInProcessContext);
   if (!context->Initialize(
       size,
       context_group,
       allowed_extensions,
       attrib_list,
       gpu_preference))
     return NULL;
 
   return context.release();
 }
@@ skipping 16 matching lines @@
       context_lost_ = true;
     }
   }
 }
 
 bool GLInProcessContext::GetBufferChanged(int32 transfer_buffer_id) {
   return gpu_scheduler_->SetGetBuffer(transfer_buffer_id);
 }
 
 uint32 GLInProcessContext::GetParentTextureId() {
-  return parent_texture_id_;
+  return NULL;
 }
 
 uint32 GLInProcessContext::CreateParentTexture(const gfx::Size& size) {
   uint32 texture = 0;
   gles2_implementation_->GenTextures(1, &texture);
   gles2_implementation_->Flush();
   return texture;
 }
 
 void GLInProcessContext::DeleteParentTexture(uint32 texture) {
@@ skipping 61 matching lines @@
 
 // TODO(gman): Remove This
 void GLInProcessContext::DisableShaderTranslation() {
   NOTREACHED();
 }
 
 GLES2Implementation* GLInProcessContext::GetImplementation() {
   return gles2_implementation_.get();
 }
 
-GLInProcessContext::GLInProcessContext(GLInProcessContext* parent)
-    : parent_(parent ?
-          parent->AsWeakPtr() : base::WeakPtr<GLInProcessContext>()),
-      parent_texture_id_(0),
-      last_error_(SUCCESS),
+GLInProcessContext::GLInProcessContext()
+    : last_error_(SUCCESS),
       context_lost_(false) {
 }
 
 bool GLInProcessContext::Initialize(const gfx::Size& size,
                                     GLInProcessContext* context_group,
                                     const char* allowed_extensions,
                                     const int32* attrib_list,
                                     gfx::GpuPreference gpu_preference) {
   // Use one share group for all contexts.
   CR_DEFINE_STATIC_LOCAL(scoped_refptr<gfx::GLShareGroup>, share_group,
                          (new gfx::GLShareGroup));
 
   DCHECK(size.width() >= 0 && size.height() >= 0);
 
   // Ensure the gles2 library is initialized first in a thread safe way.
   g_gles2_initializer.Get();
 
-  // Allocate a frame buffer ID with respect to the parent.
-  if (parent_.get()) {
-    // Flush any remaining commands in the parent context to make sure the
-    // texture id accounting stays consistent.
-    int32 token = parent_->gles2_helper_->InsertToken();
-    parent_->gles2_helper_->WaitForToken(token);
-    parent_texture_id_ = parent_->gles2_implementation_->MakeTextureId();
-  }
-
   std::vector<int32> attribs;
   while (attrib_list) {
     int32 attrib = *attrib_list++;
     switch (attrib) {
       // Known attributes
       case ALPHA_SIZE:
       case BLUE_SIZE:
       case GREEN_SIZE:
       case RED_SIZE:
       case DEPTH_SIZE:
@@ skipping 73 matching lines @@
                             true,
                             size,
                             disallowed_features,
                             allowed_extensions,
                             attribs)) {
     LOG(ERROR) << "Could not initialize decoder.";
     Destroy();
     return false;
   }
 
-  if (!decoder_->SetParent(
-      parent_.get() ? parent_->decoder_.get() : NULL,
-      parent_texture_id_)) {
-    LOG(ERROR) << "Could not set parent.";
-    Destroy();
-    return false;
-  }
-
   command_buffer_->SetPutOffsetChangeCallback(
       base::Bind(&GLInProcessContext::PumpCommands, base::Unretained(this)));
   command_buffer_->SetGetBufferChangeCallback(
       base::Bind(
           &GLInProcessContext::GetBufferChanged, base::Unretained(this)));
   command_buffer_->SetParseErrorCallback(
       base::Bind(&GLInProcessContext::OnContextLost, base::Unretained(this)));
 
   // Create the GLES2 helper, which writes the command buffer protocol.
   gles2_helper_.reset(new GLES2CmdHelper(command_buffer_.get()));
@@ skipping 19 matching lines @@
       kMaxTransferBufferSize)) {
     return false;
   }
 
   return true;
 }
 
 void GLInProcessContext::Destroy() {
   bool context_lost = IsCommandBufferContextLost();
 
-  if (parent_.get() && parent_texture_id_ != 0) {
-    parent_->gles2_implementation_->FreeTextureId(parent_texture_id_);
-    parent_texture_id_ = 0;
-  }
-
   if (gles2_implementation_.get()) {
     // First flush the context to ensure that any pending frees of resources
     // are completed. Otherwise, if this context is part of a share group,
     // those resources might leak. Also, any remaining side effects of commands
     // issued on this context might not be visible to other contexts in the
     // share group.
     gles2_implementation_->Flush();
 
     gles2_implementation_.reset();
   }
 
   transfer_buffer_.reset();
   gles2_helper_.reset();
   command_buffer_.reset();
 
   if (decoder_.get()) {
     decoder_->Destroy(!context_lost);
   }
 }
 
 void GLInProcessContext::OnContextLost() {
   if (!context_lost_callback_.is_null())
     context_lost_callback_.Run();
 }
 
 WebGraphicsContext3DInProcessCommandBufferImpl::
-    WebGraphicsContext3DInProcessCommandBufferImpl()
-    : context_(NULL),
+    WebGraphicsContext3DInProcessCommandBufferImpl(
+        const WebKit::WebGraphicsContext3D::Attributes& attributes)
+    : initialized_(false),
+      initialize_failed_(false),
+      context_(NULL),
       gl_(NULL),
       context_lost_callback_(NULL),
       context_lost_reason_(GL_NO_ERROR),
+      attributes_(attributes),
       cached_width_(0),
       cached_height_(0),
       bound_fbo_(0) {
 }
 
 WebGraphicsContext3DInProcessCommandBufferImpl::
     ~WebGraphicsContext3DInProcessCommandBufferImpl() {
   base::AutoLock a(g_all_shared_contexts_lock.Get());
   g_all_shared_contexts.Pointer()->erase(this);
 }
 
-bool WebGraphicsContext3DInProcessCommandBufferImpl::Initialize(
-    WebGraphicsContext3D::Attributes attributes,
-    WebKit::WebGraphicsContext3D* view_context) {
+bool WebGraphicsContext3DInProcessCommandBufferImpl::MaybeInitializeGL() {
+  if (initialized_)
+    return true;
+
+  if (initialize_failed_)
+    return false;
+
   // Convert WebGL context creation attributes into GLInProcessContext / EGL
   // size requests.
-  const int alpha_size = attributes.alpha ? 8 : 0;
-  const int depth_size = attributes.depth ? 24 : 0;
-  const int stencil_size = attributes.stencil ? 8 : 0;
-  const int samples = attributes.antialias ? 4 : 0;
-  const int sample_buffers = attributes.antialias ? 1 : 0;
+  const int alpha_size = attributes_.alpha ? 8 : 0;
+  const int depth_size = attributes_.depth ? 24 : 0;
+  const int stencil_size = attributes_.stencil ? 8 : 0;
+  const int samples = attributes_.antialias ? 4 : 0;
+  const int sample_buffers = attributes_.antialias ? 1 : 0;
   const int32 attribs[] = {
     GLInProcessContext::ALPHA_SIZE, alpha_size,
     GLInProcessContext::DEPTH_SIZE, depth_size,
     GLInProcessContext::STENCIL_SIZE, stencil_size,
     GLInProcessContext::SAMPLES, samples,
     GLInProcessContext::SAMPLE_BUFFERS, sample_buffers,
     GLInProcessContext::NONE,
   };
 
   const char* preferred_extensions = "*";
 
   // TODO(kbr): More work will be needed in this implementation to
   // properly support GPU switching. Like in the out-of-process
   // command buffer implementation, all previously created contexts
   // will need to be lost either when the first context requesting the
   // discrete GPU is created, or the last one is destroyed.
   gfx::GpuPreference gpu_preference = gfx::PreferDiscreteGpu;
 
-  GLInProcessContext* parent_context = NULL;
-  if (view_context) {
-    WebGraphicsContext3DInProcessCommandBufferImpl* context_impl =
-        static_cast<WebGraphicsContext3DInProcessCommandBufferImpl*>(
-            view_context);
-    parent_context = context_impl->context_;
-  }
-
   WebGraphicsContext3DInProcessCommandBufferImpl* context_group = NULL;
   base::AutoLock lock(g_all_shared_contexts_lock.Get());
-  if (attributes.shareResources)
+  if (attributes_.shareResources)
     context_group = g_all_shared_contexts.Pointer()->empty() ?
         NULL : *g_all_shared_contexts.Pointer()->begin();
 
   context_ = GLInProcessContext::CreateOffscreenContext(
-      parent_context,
       gfx::Size(1, 1),
       context_group ? context_group->context_ : NULL,
       preferred_extensions,
       attribs,
       gpu_preference);
 
-  if (!context_)
+  if (!context_) {
+    initialize_failed_ = true;
     return false;
+  }
 
   gl_ = context_->GetImplementation();
 
-  if (gl_ && attributes.noExtensions)
+  if (gl_ && attributes_.noExtensions)
     gl_->EnableFeatureCHROMIUM("webgl_enable_glsl_webgl_validation");
 
   context_->SetContextLostCallback(
       base::Bind(
           &WebGraphicsContext3DInProcessCommandBufferImpl::OnContextLost,
           base::Unretained(this)));
 
   // Set attributes_ from created offscreen context.
   {
-    attributes_ = attributes;
     GLint alpha_bits = 0;
     getIntegerv(GL_ALPHA_BITS, &alpha_bits);
     attributes_.alpha = alpha_bits > 0;
     GLint depth_bits = 0;
     getIntegerv(GL_DEPTH_BITS, &depth_bits);
     attributes_.depth = depth_bits > 0;
     GLint stencil_bits = 0;
     getIntegerv(GL_STENCIL_BITS, &stencil_bits);
     attributes_.stencil = stencil_bits > 0;
     GLint sample_buffers = 0;
     getIntegerv(GL_SAMPLE_BUFFERS, &sample_buffers);
     attributes_.antialias = sample_buffers > 0;
   }
-  makeContextCurrent();
 
-  if (attributes.shareResources)
+  if (attributes_.shareResources)
     g_all_shared_contexts.Pointer()->insert(this);
 
+  initialized_ = false;

[jamesr, 2013/03/21 23:19:18]

did you mean "initialized_ = true;" ?

   return true;
 }
 
 bool WebGraphicsContext3DInProcessCommandBufferImpl::makeContextCurrent() {
+  if (!MaybeInitializeGL())
+    return false;
+
   return GLInProcessContext::MakeCurrent(context_);
 }
 
 void WebGraphicsContext3DInProcessCommandBufferImpl::ClearContext() {
   // NOTE: Comment in the line below to check for code that is not calling
   // eglMakeCurrent where appropriate. The issue is code using
   // WebGraphicsContext3D does not need to call makeContextCurrent. Code using
   // direct OpenGL bindings needs to call the appropriate form of
   // eglMakeCurrent. If it doesn't it will be issuing commands on the wrong
   // context. Uncommenting the line below clears the current context so that
@@ skipping 1024 matching lines @@
 DELEGATE_TO_GL_1(genMailboxCHROMIUM, GenMailboxCHROMIUM, WGC3Dbyte*)
 DELEGATE_TO_GL_2(produceTextureCHROMIUM, ProduceTextureCHROMIUM,
                  WGC3Denum, const WGC3Dbyte*)
 DELEGATE_TO_GL_2(consumeTextureCHROMIUM, ConsumeTextureCHROMIUM,
                  WGC3Denum, const WGC3Dbyte*)
 
 DELEGATE_TO_GL_2(drawBuffersEXT, DrawBuffersEXT,
                  WGC3Dsizei, const WGC3Denum*)
 }  // namespace gpu
 }  // namespace webkit