gpu: Add async pixel transfer interface, stub and tests.

ui/gl/async_pixel_transfer_delegate_android.cc

Index: ui/gl/async_pixel_transfer_delegate_android.cc
diff --git a/ui/gl/async_pixel_transfer_delegate_android.cc b/ui/gl/async_pixel_transfer_delegate_android.cc
new file mode 100644
index 0000000000000000000000000000000000000000..9d931b6af4efa7b99c71941f02acd3b65cdbdb97
--- /dev/null
+++ b/ui/gl/async_pixel_transfer_delegate_android.cc
@@ -0,0 +1,467 @@
+// 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 "ui/gl/async_pixel_transfer_delegate_android.h"
+
+#include "base/bind.h"
+#include "base/cancelable_callback.h"
+#include "base/debug/trace_event.h"
+#include "base/lazy_instance.h"
+#include "base/logging.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/threading/thread.h"
+#include "build/build_config.h"
+#include "third_party/angle/include/EGL/egl.h"
+#include "third_party/angle/include/EGL/eglext.h"
+#include "ui/gfx/point.h"
+#include "ui/gfx/size.h"
+#include "ui/gl/async_pixel_transfer_delegate.h"
+#include "ui/gl/egl_util.h"
+#include "ui/gl/gl_bindings.h"
+#include "ui/gl/gl_context.h"
+#include "ui/gl/gl_surface_egl.h"
+
+namespace gfx {
+
+namespace {
+bool CheckErrors(const char* file, int line) {
+  EGLint eglerror;
+  GLenum glerror;
+  bool success = true;
+  while ((eglerror = eglGetError()) != EGL_SUCCESS) {
+     LOG(ERROR) << "Async transfer eglerror at "
+                << file << ":" << line << " " << eglerror;
+     success = false;
+  }
+  while ((glerror = glGetError()) != GL_NO_ERROR) {
+     LOG(ERROR) << "Async transfer openglerror at "
+                << file << ":" << line << " " << glerror;
+     success = false;
+  }
+  return success;
+}
+#define CHK() CheckErrors(__FILE__, __LINE__)
+} // namespace
+
+// Class which holds async pixel transfers state (EGLImage).
+// The EGLImage is accessed by either thread, but the everything

[apatrick_chromium, 2012/12/04 20:59:22]

nit: fix comment

[epenner, 2012/12/08 03:15:04]

Is this regarding thread-safe ref counting? Let me know if you are still
concerned about that (explanation is in AsyncPixelTransferState)

+// else (and the lifetime of this object) is access only by the main
+// GPU thread.
+class AsyncTransferStateAndroid : public AsyncPixelTransferState {
+ public:
+  AsyncTransferStateAndroid(GLuint texture_id)
+      : texture_id_(texture_id),
+        needs_bind_(false),
+        transfer_in_progress_(false),
+        egl_image_(0) {}
+
+  virtual ~AsyncTransferStateAndroid() {
+     if (egl_image_) {

[apatrick_chromium, 2012/12/04 20:59:22]

nit: indentation out by 1 space

[epenner, 2012/12/08 03:15:04]

Done.

+       EGLDisplay display = eglGetCurrentDisplay();
+       eglDestroyImageKHR(display, egl_image_);
+     }
+  }
+
+  // implement AsyncPixelTransferState:
+  virtual bool TransferIsInProgress() {
+    return transfer_in_progress_;
+  }
+
+  virtual void BindTexture(GLenum target) {
+    glBindTexture(target, texture_id_);
+    if (needs_bind_)
+      glEGLImageTargetTexture2DOES(GL_TEXTURE_2D, egl_image_);
+    needs_bind_ = false;
+  }
+
+  // Completion callbacks.
+  void TexImage2DCompleted() {
+    needs_bind_ = true;
+    transfer_in_progress_ = false;
+  }
+  void TexSubImage2DCompleted() {
+    transfer_in_progress_ = false;
+  }
+
+  // The 'real' texture.
+  GLuint texture_id_;
+
+  // Indicates there is a new EGLImage and the 'real'
+  // texture needs to be bound to it.
+  bool needs_bind_;
+
+  // Indicates that an async transfer is in progress.
+  bool transfer_in_progress_;
+
+  // It would be nice if we could just create a new EGLImage for
+  // every upload, but I found that didn't work, so this stores
+  // one for the lifetime of the texture.
+  EGLImageKHR egl_image_;
+};
+
+// Class which handles async pixel transfers on Android (using
+// EGLImageKHR and another upload thread)
+class AsyncPixelTransferDelegateAndroid : public AsyncPixelTransferDelegate {
+ public:
+  AsyncPixelTransferDelegateAndroid();
+  virtual ~AsyncPixelTransferDelegateAndroid();
+
+  // implement AsyncPixelTransferDelegate:
+  virtual scoped_refptr<AsyncPixelTransferState>
+      CreatePixelTransferState(GLuint);
+
+  virtual void AsyncNotifyCompletion(
+      const base::Closure& task);
+
+  virtual void AsyncTexImage2D(
+      AsyncPixelTransferState*,
+      GLenum target,
+      GLint level,
+      GLenum internal_format,
+      GLsizei width,
+      GLsizei height,
+      GLint border,
+      GLenum format,
+      GLenum type,
+      const void* data);
+
+  virtual void AsyncTexSubImage2D(
+      AsyncPixelTransferState*,
+      GLenum target,
+      GLint level,
+      GLint xoffset,
+      GLint yoffset,
+      GLsizei width,
+      GLsizei height,
+      GLenum format,
+      GLenum type,
+      const void* data);
+
+ private:
+  void Initialize();
+  void Shutdown();
+  void PerformInitialize();
+  void PerformShutdown();
+
+  void PerformAsyncTexImage2D(
+      EGLImageKHR* egl_image,
+      std::pair<GLenum, GLenum> formats,
+      gfx::Size size,
+      GLint border,
+      GLenum type,
+      const void* data);
+
+  void PerformAsyncTexSubImage2D(
+      EGLImageKHR egl_image,
+      gfx::Point offset,
+      gfx::Size size,
+      GLenum format,
+      GLenum type,
+      const void* data);
+
+  scoped_ptr<base::Thread> thread_;
+  scoped_refptr<gfx::GLContext> thread_context_;
+  scoped_refptr<gfx::GLSurface> thread_surface_;
+
+  DISALLOW_COPY_AND_ASSIGN(AsyncPixelTransferDelegateAndroid);
+};
+
+// Lazy instance creation.
+base::LazyInstance<AsyncPixelTransferDelegateAndroid>
+    g_async_pixel_transfer_delegate_ = LAZY_INSTANCE_INITIALIZER;
+
+AsyncPixelTransferDelegate* AsyncPixelTransferDelegate::Get() {
+   return g_async_pixel_transfer_delegate_.Pointer();
+}
+
+scoped_refptr<AsyncPixelTransferState>
+    AsyncPixelTransferDelegateAndroid::
+        CreatePixelTransferState(GLuint texture_id) {
+  return make_scoped_refptr(static_cast<AsyncPixelTransferState*>(
+      new AsyncTransferStateAndroid(texture_id)));
+}
+
+AsyncPixelTransferDelegateAndroid::AsyncPixelTransferDelegateAndroid()
+    : thread_(new base::Thread("GPUAsyncTransferThread"))
+{
+   Initialize();
+}
+
+AsyncPixelTransferDelegateAndroid::~AsyncPixelTransferDelegateAndroid()
+{
+   Shutdown();
+}
+
+void AsyncPixelTransferDelegateAndroid::Initialize() {
+  // Start the thread and initialize on the thread.
+  thread_->Start();
+  thread_->message_loop()->PostTask(FROM_HERE, base::Bind(
+      &AsyncPixelTransferDelegateAndroid::PerformInitialize,
+      base::Unretained(this)));
+}
+
+void AsyncPixelTransferDelegateAndroid::Shutdown() {
+  // Shutdown and wait for the thread to finish.
+  thread_->message_loop()->PostTask(FROM_HERE, base::Bind(
+      &AsyncPixelTransferDelegateAndroid::PerformShutdown,
+      base::Unretained(this)));
+  thread_->Stop();
+}
+
+
+namespace {
+// Dummy function to measure completion on
+// the upload thread.
+void NoOp() {}
+} // namespace
+
+void AsyncPixelTransferDelegateAndroid::AsyncNotifyCompletion(
+      const base::Closure& task) {
+  // Post a no-op task to the upload thread followed
+  // by a reply to the callback. The reply will then occur after
+  // all async transfers are complete.
+  thread_->message_loop_proxy()->PostTaskAndReply(FROM_HERE,
+      base::Bind(&NoOp), task);
+}
+
+void AsyncPixelTransferDelegateAndroid::AsyncTexImage2D(
+    AsyncPixelTransferState* transfer_state,
+    GLenum target,
+    GLint level,
+    GLenum internal_format,
+    GLsizei width,
+    GLsizei height,
+    GLint border,
+    GLenum format,
+    GLenum type,
+    const void* data) {
+  AsyncTransferStateAndroid* state =
+      static_cast<AsyncTransferStateAndroid*>(transfer_state);
+  DCHECK(state);
+  DCHECK(state->texture_id_);
+  DCHECK(!state->transfer_in_progress_);
+
+  // TODO: Implement other targets/levels if needed.
+  DCHECK(target == GL_TEXTURE_2D);
+  DCHECK(level == 0);
+
+  state->transfer_in_progress_ = true;
+
+  // Any existing EGLImage is made an 'orphan' by a call to
+  // texImage2D. We can delete the existing one safely since
+  // the client texture is not effected.

[apatrick_chromium, 2012/12/04 20:59:22]

nit: effected -> affected

[epenner, 2012/12/08 03:15:04]

Done.

+  if (state->egl_image_) {
+    EGLDisplay display = eglGetCurrentDisplay();
+    eglDestroyImageKHR(display, state->egl_image_);
+    state->egl_image_ = 0;
+  }
+
+  // Post the upload task. The reply also keeps the texture
+  // state referenced until the reply executes on the main thread.
+  thread_->message_loop_proxy()->PostTaskAndReply(FROM_HERE,
+      base::Bind(
+          &AsyncPixelTransferDelegateAndroid::PerformAsyncTexImage2D,
+          base::Unretained(this),
+          &state->egl_image_,
+          std::pair<GLenum, GLenum>(internal_format, format),
+          gfx::Size(width, height),
+          border, type, data),
+      base::Bind(
+          &AsyncTransferStateAndroid::TexImage2DCompleted,
+          state));
+}
+
+void AsyncPixelTransferDelegateAndroid::AsyncTexSubImage2D(
+      AsyncPixelTransferState* transfer_state,
+      GLenum target,
+      GLint level,
+      GLint xoffset,
+      GLint yoffset,
+      GLsizei width,
+      GLsizei height,
+      GLenum format,
+      GLenum type,
+      const void* data) {
+  TRACE_EVENT2("gpu", "AsyncTexSubImage2D",
+               "width", width,
+               "height", height);
+  AsyncTransferStateAndroid* state =
+      static_cast<AsyncTransferStateAndroid*>(transfer_state);
+  DCHECK(state);
+  DCHECK(state->texture_id_);
+  DCHECK(!state->transfer_in_progress_);
+
+  // TODO: Implement other targets/levels if needed.
+  DCHECK(target == GL_TEXTURE_2D);
+  DCHECK(level == 0);
+
+  state->transfer_in_progress_ = true;
+
+  // Create the EGLImage if it hasn't already been created.
+  if (!state->egl_image_) {
+    EGLDisplay egl_display = eglGetCurrentDisplay();
+    EGLContext egl_context = eglGetCurrentContext();
+    EGLenum egl_target = EGL_GL_TEXTURE_2D_KHR;
+    EGLClientBuffer egl_buffer =
+        reinterpret_cast<EGLClientBuffer>(state->texture_id_);
+    EGLint egl_attrib_list[] = {
+        EGL_GL_TEXTURE_LEVEL_KHR, level,   // mip-map level to reference.
+        EGL_IMAGE_PRESERVED_KHR, EGL_TRUE, // preserve the data in the texture.
+        EGL_NONE
+    };
+    state->egl_image_ = eglCreateImageKHR(
+        egl_display,
+        egl_context,
+        egl_target,
+        egl_buffer,
+        egl_attrib_list);
+  }
+
+  // Post the upload task. The reply also keeps the texture
+  // state referenced until the reply executes on the main thread.
+  thread_->message_loop_proxy()->PostTaskAndReply(FROM_HERE,
+      base::Bind(
+          &AsyncPixelTransferDelegateAndroid::PerformAsyncTexSubImage2D,
+          base::Unretained(this),
+          state->egl_image_,
+          gfx::Point(xoffset, yoffset),
+          gfx::Size(width, height),
+          format, type, data),
+      base::Bind(
+          &AsyncTransferStateAndroid::TexSubImage2DCompleted,
+          state));
+}
+
+void AsyncPixelTransferDelegateAndroid::PerformInitialize() {
+  DCHECK(!thread_surface_);
+  DCHECK(!thread_context_);
+  GLShareGroup* share_group = NULL;
+  bool software = false;
+  thread_surface_ = new gfx::PbufferGLSurfaceEGL(software, gfx::Size(1,1));
+  thread_surface_->Initialize();

[apatrick_chromium, 2012/12/04 20:59:22]

What if this fails?

[epenner, 2012/12/08 03:15:04]

Hmm, is this normally treated as a recoverable error with a resonable fallback?
Or do you just mean I should change to CHECK below?   I could fall back on the
stub implementation possibly, but I don't think we want this to happen without
knowing about it.

+  thread_context_ = gfx::GLContext::CreateGLContext(share_group,

[apatrick_chromium, 2012/12/04 20:59:22]

And this.

[epenner, 2012/12/08 03:15:04]

See above.

+                                                    thread_surface_,
+                                                    gfx::PreferDiscreteGpu);
+  bool is_current = thread_context_->MakeCurrent(thread_surface_);

[apatrick_chromium, 2012/12/04 20:59:22]

Ditto.

[epenner, 2012/12/08 03:15:04]

See above.

+  DCHECK(thread_surface_);
+  DCHECK(thread_context_);
+  DCHECK(is_current);
+}
+
+void AsyncPixelTransferDelegateAndroid::PerformShutdown() {
+  DCHECK(thread_surface_);
+  DCHECK(thread_context_);
+  thread_surface_ = NULL;
+  thread_context_->ReleaseCurrent(thread_surface_);
+  thread_context_ = NULL;
+}
+
+namespace {
+void WaitForGlFence() {
+  // TODO: Fix bindings (link errors) to enable the code below.
+  // TODO: Should we only sync just before we report completion?
+
+  // Uploads usually finish on the CPU, but just in case add a fence
+  // and guarantee the upload has completed. Flush bit is set to
+  // insure we don't wait forever.
+  // EGLSyncKHR fence = eglCreateSyncKHR(display, EGL_SYNC_FENCE_KHR, NULL);
+  // EGLint flags = EGL_SYNC_FLUSH_COMMANDS_BIT_KHR;
+  // EGLTimeKHR time = EGL_FOREVER_KHR;
+  // eglClientWaitSyncKHR(display, fence, flags, time);
+  glFinish();
+}
+} // namespace
+
+void AsyncPixelTransferDelegateAndroid::PerformAsyncTexImage2D(
+      EGLImageKHR* egl_image,
+      std::pair<GLenum, GLenum> formats,
+      gfx::Size size,
+      GLint border,
+      GLenum type,
+      const void* data) {
+  // In texImage2D, we do everything on the upload thread.
+  // This is because texImage2D can incur the allocation cost, and
+  // it also 'orphans' any previous EGLImage bound to the texture.
+  DCHECK(egl_image);
+  DCHECK(!(*egl_image));
+  TRACE_EVENT2("gpu", "performAsyncTexImage2D",
+               "width", size.width(),
+               "height", size.height());
+
+  // Create a texture from the image and upload to it.
+  GLenum internal_format = formats.first;
+  GLenum format = formats.second;
+  GLuint temp_texture = 0;
+  glGenTextures(1, &temp_texture);
+  glActiveTexture(GL_TEXTURE0);
+  glBindTexture(GL_TEXTURE_2D, temp_texture);
+  {
+    TRACE_EVENT0("gpu", "performAsyncTexSubImage2D glTexImage2D");
+    glTexImage2D(GL_TEXTURE_2D, 0,
+        internal_format,
+        size.width(), size.height(),
+        border, format, type, data);
+  }
+
+  // Create the EGLImage, as texSubImage always 'orphan's a previous EGLImage.
+  GLuint level = 0;
+  EGLDisplay egl_display = eglGetCurrentDisplay();
+  EGLContext egl_context = eglGetCurrentContext();
+  EGLenum egl_target = EGL_GL_TEXTURE_2D_KHR;
+  EGLClientBuffer egl_buffer = (EGLClientBuffer) temp_texture;
+  EGLint egl_attrib_list[] = {
+      EGL_GL_TEXTURE_LEVEL_KHR, level,   // mip-map level to reference.
+      EGL_IMAGE_PRESERVED_KHR, EGL_TRUE, // preserve the data in the texture.
+      EGL_NONE
+  };
+  (*egl_image) = eglCreateImageKHR(
+      egl_display,
+      egl_context,
+      egl_target,
+      egl_buffer,
+      egl_attrib_list);
+
+  WaitForGlFence();
+
+  // We can delete this thread's texture as the real texture
+  // now contains the data.
+  glDeleteTextures(1, &temp_texture);
+}
+
+void AsyncPixelTransferDelegateAndroid::PerformAsyncTexSubImage2D(
+    EGLImageKHR egl_image,
+    gfx::Point offset,
+    gfx::Size size,
+    GLenum format,
+    GLenum type,
+    const void* data) {
+  // For a texSubImage, the texture must already have been
+  // created on the main thread, along with EGLImageKHR.
+  DCHECK(egl_image);
+  TRACE_EVENT2("gpu", "performAsyncTexSubImage2D",
+               "width", size.width(),
+               "height", size.height());
+
+  // Create a texture from the image and upload to it.
+  GLuint temp_texture = 0;
+  glGenTextures(1, &temp_texture);
+  glActiveTexture(GL_TEXTURE0);
+  glBindTexture(GL_TEXTURE_2D, temp_texture);
+  glEGLImageTargetTexture2DOES(GL_TEXTURE_2D, egl_image);
+  {
+    TRACE_EVENT0("gpu", "performAsyncTexSubImage2D glTexSubImage2D");
+    glTexSubImage2D(GL_TEXTURE_2D, 0,
+        offset.x(), offset.y(),
+        size.width(), size.height(),
+        format, type, data);
+  }
+
+  WaitForGlFence();
+
+  // We can delete this thread's texture as the real texture
+  // now contains the data.
+  glDeleteTextures(1, &temp_texture);
+}
+
+}  // namespace gfx