gpu: Change Produce/ConsumeTexture to allow texture sharing

This changes the semantics of ProduceTexture to not replacing the current texture by a dud, but instead keeping the existing one, that it also puts into the mailbox. It changes the semantics of ConsumeTexture to deleting the current texture, and replacing it by the mailbox contents (without taking it out of the mailbox). The texture becomes shared. The mailbox is now effectively a weak pointer onto the texture.

BUG=230137

Review URL: https://chromiumcodereview.appspot.com/14188053

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@202992 0039d316-1c4b-4281-b951-d872f2087c98

content/common/gpu/texture_image_transport_surface.h

@@ -12,7 +12,6 @@
 #include "content/common/gpu/gpu_command_buffer_stub.h"
 #include "content/common/gpu/image_transport_surface.h"
 #include "gpu/command_buffer/service/mailbox_manager.h"
-#include "gpu/command_buffer/service/texture_definition.h"
 #include "gpu/command_buffer/service/texture_manager.h"
 #include "ui/gl/gl_context.h"
 #include "ui/gl/gl_surface.h"
@@ -33,7 +32,6 @@ class TextureImageTransportSurface
   virtual bool Initialize() OVERRIDE;
   virtual void Destroy() OVERRIDE;
   virtual bool DeferDraws() OVERRIDE;
-  virtual bool Resize(const gfx::Size& size) OVERRIDE;
   virtual bool IsOffscreen() OVERRIDE;
   virtual bool SwapBuffers() OVERRIDE;
   virtual gfx::Size GetSize() OVERRIDE;
@@ -42,7 +40,6 @@ class TextureImageTransportSurface
   virtual std::string GetExtensions() OVERRIDE;
   virtual unsigned int GetBackingFrameBufferObject() OVERRIDE;
   virtual bool PostSubBuffer(int x, int y, int width, int height) OVERRIDE;
-  virtual bool OnMakeCurrent(gfx::GLContext* context) OVERRIDE;
   virtual bool SetBackbufferAllocation(bool allocated) OVERRIDE;
   virtual void SetFrontbufferAllocation(bool allocated) OVERRIDE;
   virtual void* GetShareHandle() OVERRIDE;
@@ -64,31 +61,32 @@ class TextureImageTransportSurface
  private:
 
   gfx::Size backbuffer_size() const {
-    return gfx::Size(backbuffer_->level_infos()[0][0].width,
-                     backbuffer_->level_infos()[0][0].height);
+    DCHECK(backbuffer_);
+    GLsizei width = 0;
+    GLsizei height = 0;
+    backbuffer_->texture()->GetLevelSize(GL_TEXTURE_2D, 0, &width, &height);
+    return gfx::Size(width, height);
   }
 
   virtual ~TextureImageTransportSurface();
   void CreateBackTexture();
   void AttachBackTextureToFBO();
   void ReleaseBackTexture();
+  void ReleaseFrontTexture();
   void BufferPresentedImpl(const std::string& mailbox_name);
-  void ProduceTexture();
-  void ConsumeTexture();
-
-  static gpu::gles2::TextureDefinition* CreateTextureDefinition(gfx::Size size,
-                                                                int service_id);
 
   // The framebuffer that represents this surface (service id). Allocated lazily
   // in OnMakeCurrent.
   uint32 fbo_id_;
 
   // The current backbuffer.
-  scoped_ptr<gpu::gles2::TextureDefinition> backbuffer_;
+  scoped_refptr<gpu::gles2::TextureRef> backbuffer_;
+  scoped_refptr<gpu::gles2::TextureRef> frontbuffer_;
 
   // The mailbox name for the current backbuffer texture. Needs to be unique per
   // GL texture and is invalid while service_id is zero.
-  gpu::gles2::MailboxName mailbox_name_;
+  gpu::gles2::MailboxName back_mailbox_name_;
+  gpu::gles2::MailboxName front_mailbox_name_;
 
   // The current size of the GLSurface. Used to disambiguate from the current
   // texture size which might be outdated (since we use two buffers).
@@ -108,9 +106,6 @@ class TextureImageTransportSurface
   // the actual rendering is always redirected to an FBO.
   scoped_refptr<gfx::GLSurface> surface_;
 
-  // Holds a reference to the underlying context for cleanup.
-  scoped_refptr<gfx::GLContext> context_;
-
   // Whether a SwapBuffers is pending.
   bool is_swap_buffers_pending_;
 

gpu/GLES2/extensions/CHROMIUM/CHROMIUM_texture_mailbox.txt

@@ -20,9 +20,9 @@ Overview
     objects in different contexts where the contexts would not normally share
     texture resources. Three new functions are exported. glGenMailboxCHROMIUM
     generates a name that can be used to identify texture image data outside
-    the scope of a context group. glProduceMailboxCHROMIUM moves texture image
-    data out of a texture object and into a mailbox. glConsumeMailboxCHROMIUM
-    moves texture image data out of a mailbox and into a texture object.
+    the scope of a context group. glProduceMailboxCHROMIUM associates a texture
+    object with a global mailbox name. glConsumeMailboxCHROMIUM associates the
+    texture object referenced by a mailbox name to a texture name.
 
 New Procedures and Functions
 
@@ -38,18 +38,19 @@ New Procedures and Functions
 
     void glProduceTextureCHROMIUM (GLenum target, const GLbyte *mailbox)
 
-    Moves the image data and parameters of the currently bound texture object
-    into the mailbox. The texture object is redefined as though all its levels
-    had been resized to zero by zero and the texture object is therefore
-    incomplete.  The texture object parameters are undefined. The texture
-    object is no longer immutable. If the mailbox previously contained image
-    data, the old image data is deleted.
+    Associates the currently bound texture object with the mailbox name. A
+    given texture object can be associated with several mailbox names. If a
+    mailbox name was previously associated with a texture object, that
+    previous association is broken. The currently bound texture object is not
+    modified by the operation.
 
-    If glProduceTextureCHROMIUM generates an error, the associated image data
-    and state is preserved in the texture object.
+    If glProduceTextureCHROMIUM generates an error, the mailbox name keeps its
+    current association, if any.
 
-    The mailbox is emptied and the texture image data deleted if the context
-    is destroyed before being consumed. See glConsumeTextureCHROMIUM.
+    The mailbox does not keep a reference to the texture object. When the
+    texture object is destroyed (deleted from all context groups, and unbound
+    from all texture units and framebuffer attachments), the mailbox is
+    disassociated from the texture object.
 
     <target> uses the same parameters as TexImage2D.
 
@@ -58,10 +59,6 @@ New Procedures and Functions
 
     INVALID_OPERATION is generated if <target> is not a valid target.
 
-    INVALID_OPERATION is generated if the texture is attached to a framebuffer.
-
-    INVALID_OPERATION is generated if the texture is immutable.
-
     INVALID_OPERATION is generated if <mailbox> is invalid.
 
 
@@ -71,30 +68,32 @@ New Procedures and Functions
 
     <mailbox> identifies a GL_MAILBOX_SIZE_CHROMIUM byte sized name returned by
     glGenMailboxCHROMIUM.
-
-    Redefines the image data and parameters of the currently bound texture
-    object with the image data and parameters in the mailbox and empties the
-    mailbox. All levels are redefined, and the immutable state is set according
-    to the contents of the mailbox.
-
-    If glConsumeTextureCHROMIUM generates an error, the associated image data
-    is preserved in the texture object.
+
+    Deletes the currently bound texture object, and redefines its texture name
+    to point to the texture object associated with the mailbox name. All the
+    contexts that have consumed the texture object, as well as produced it share
+    the texture object, as if the contexts were part of the share group. The
+    texture object is deleted once all contexts have deleted the texture name
+    associated with the texture object, and detached it from all framebuffer
+    objects as well as texture unit bindings. See Appendix C of the OpenGL ES
+    2.0 specification for details relative to visibility in one context of
+    changes to the shared texture object in another context.
+
+    If glConsumeTextureCHROMIUM generates an error, the currently bound texture
+    object is preserved.
 
     INVALID_OPERATION is generated if <target> is not a valid target.
 
-    INVALID_OPERATION is generated if <mailbox> is empty.
-
-    INVALID_OPERATION is generated if <mailbox> is not in the scope of the
-    context.
-
     INVALID_OPERATION is generated if <mailbox> is invalid.
 
-    INVALID_OPERATION is generated if the texture is attached to a framebuffer.
+    INVALID_OPERATION is generated if <mailbox> is not associated with a texture
+    object.
 
-    INVALID_OPERATION is generated if the texture is immutable.
+    INVALID_OPERATION is generated if the texture object associated with
+    <mailbox> has a different target than <target>.
 
-    INVALID_OPERATION is generated if the image data is invalid in the current
-    context.
+    INVALID_OPERATION is generated if the currently bound texture was previously
+    deleted (for example in another context), hence doesn't have a name.
 
 New Tokens
 
@@ -117,3 +116,5 @@ New State
 Revision History
 
     4/25/2011    Documented the extension
+    5/23/2013    Major revision in Produce/Consume semantics, introducing
+                 sharing.

gpu/command_buffer/service/context_group.cc

@@ -277,8 +277,6 @@ void ContextGroup::Destroy(GLES2Decoder* decoder, bool have_context) {
   }
 
   if (texture_manager_ != NULL) {
-    mailbox_manager_->DestroyOwnedTextures(texture_manager_.get(),
-                                           have_context);
     texture_manager_->Destroy(have_context);
     texture_manager_.reset();
   }

gpu/command_buffer/service/framebuffer_manager.cc

@@ -55,6 +55,10 @@ class RenderbufferAttachment
     return renderbuffer_->samples();
   }
 
+  virtual GLuint object_name() const OVERRIDE {
+    return renderbuffer_->client_id();
+  }
+
   virtual bool cleared() const OVERRIDE {
     return renderbuffer_->cleared();
   }
@@ -149,6 +153,10 @@ class TextureAttachment
     return 0;
   }
 
+  virtual GLuint object_name() const OVERRIDE {
+    return texture_ref_->client_id();
+  }
+
   virtual bool cleared() const OVERRIDE {
     return texture_ref_->texture()->IsLevelCleared(target_, level_);
   }

gpu/command_buffer/service/framebuffer_manager.h

@@ -31,6 +31,7 @@ class GPU_EXPORT Framebuffer : public base::RefCounted<Framebuffer> {
     virtual GLsizei height() const = 0;
     virtual GLenum internal_format() const = 0;
     virtual GLsizei samples() const = 0;
+    virtual GLuint object_name() const = 0;
     virtual bool cleared() const = 0;
     virtual void SetCleared(
         RenderbufferManager* renderbuffer_manager,

gpu/command_buffer/service/gl_context_virtual.cc

@@ -72,8 +72,8 @@ void GLContextVirtual::ReleaseCurrent(gfx::GLSurface* surface) {
 bool GLContextVirtual::IsCurrent(gfx::GLSurface* surface) {
   // If it's a real surface it needs to be current.
   if (surface &&
-      !surface->GetBackingFrameBufferObject() &&
-      !surface->IsOffscreen())
+      !surface->IsOffscreen() &&
+      !surface->GetBackingFrameBufferObject())
     return shared_context_->IsCurrent(surface);
 
   // Otherwise, only insure the context itself is current.