Not for review.

ui/gfx/ozone/dri/gbm_surface.cc

+// Copyright 2013 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/gfx/ozone/dri/gbm_surface.h"
+
+#include "base/logging.h"
+#include "third_party/mesa/src/src/gbm/main/gbm.h"
+#include "ui/gfx/ozone/dri/hardware_display_controller.h"
+
+namespace gfx {
+
+namespace {
+
+// Pixel configuration for the current buffer format.
+// TODO(dnicoara) These will need to change once we'll query the hardware for
+// supported configurations.
+const uint8_t kColorDepth = 24;
+const uint8_t kPixelDepth = 32;
+
+class BufferData {
+ public:
+  // When we create the BufferData we need to register the buffer with the
+  // controller. Once successfully registered, the |framebuffer_| field will
+  // hold the ID of the buffer. The controller will use this ID when scanning
+  // out the buffer. On creation we will also associate the BufferData with the
+  // buffer.
+  static BufferData* CreateData(HardwareDisplayController* controller,
+                                gbm_bo* buffer);
+
+  // Callback used by GBM to destory the BufferData associated with a buffer.
+  static void Destroy(gbm_bo* buffer, void* data);
+
+  // Returns the BufferData associated with |buffer|. NULL if no data is
+  // associated.
+  static BufferData* GetData(gbm_bo* buffer);
+
+  uint32_t get_framebuffer() const { return framebuffer_; }
+
+ private:
+  BufferData(HardwareDisplayController* controller);
+
+  ~BufferData();
+
+  HardwareDisplayController* controller_;
+
+  // ID provided by the controller when the buffer is registered. This ID is
+  // used when scanning out the buffer.
+  uint32_t framebuffer_;
+
+  DISALLOW_COPY_AND_ASSIGN(BufferData);
+};
+
+BufferData::BufferData(HardwareDisplayController* controller)
+  : controller_(controller),
+    framebuffer_(0) {
+}
+
+BufferData::~BufferData() {
+  if (framebuffer_)
+    controller_->RemoveFramebuffer(framebuffer_);
+}
+
+// static
+BufferData* BufferData::CreateData(HardwareDisplayController* controller,
+                                   gbm_bo* buffer) {
+  uint32_t handle = gbm_bo_get_handle(buffer).u32;
+  uint32_t stride = gbm_bo_get_stride(buffer);
+
+  BufferData* data = new BufferData(controller);
+  // Register the buffer with the controller. This will allow us to scan out the
+  // buffer once we're done drawing into it. If we can't register the buffer
+  // then there's no point in having BufferData associated with it.
+  if (!controller->AddFramebuffer(kColorDepth,
+                                  kPixelDepth,
+                                  stride,
+                                  handle,
+                                  &data->framebuffer_)) {
+    delete data;
+    return NULL;
+  }
+
+  // GBM can destroy the buffers at any time as long as they aren't locked. This
+  // sets a callback such that we can clean up all our state when GBM destroys
+  // the buffer.
+  gbm_bo_set_user_data(buffer, data, BufferData::Destroy);
+
+  return data;
+}
+
+// static
+void BufferData::Destroy(gbm_bo* buffer, void* data) {
+  BufferData* bd = static_cast<BufferData*>(data);
+  delete bd;
+}
+
+// static
+BufferData* BufferData::GetData(gbm_bo* buffer) {
+  return static_cast<BufferData*>(gbm_bo_get_user_data(buffer));
+}
+
+}  // namespace
+
+GbmSurface::GbmSurface(HardwareDisplayController* controller,
+                                 gbm_device* device)
+    : controller_(controller),
+      gbm_device_(device),
+      native_surface_(NULL),
+      buffers_(),
+      front_buffer_(0) {
+  for (int i = 0; i < 2; ++i)
+    buffers_[i] = NULL;
+}
+
+GbmSurface::~GbmSurface() {
+  for (int i = 0; i < 2; ++i) {
+    if (buffers_[i]) {
+      gbm_surface_release_buffer(native_surface_, buffers_[i]);
+    }
+  }
+
+  if (native_surface_)
+    gbm_surface_destroy(native_surface_);
+}
+
+bool GbmSurface::Initialize() {
+  // TODO(dnicoara) Check underlying system support for pixel format.
+  native_surface_ = gbm_surface_create(
+      gbm_device_,
+      controller_->get_mode().hdisplay,
+      controller_->get_mode().vdisplay,
+      GBM_BO_FORMAT_XRGB8888,
+      GBM_BO_USE_SCANOUT | GBM_BO_USE_RENDERING);
+
+  if (!native_surface_)
+    return false;
+
+  return true;
+}
+
+uint32_t GbmSurface::GetFramebufferId() const {
+  BufferData* data = BufferData::GetData(buffers_[front_buffer_ ^ 1]);
+  return data->get_framebuffer();
+}
+
+void GbmSurface::SwapBuffers() {
+  // If there was a frontbuffer, is no longer active. Release it back to GBM.
+  if (buffers_[front_buffer_])
+    gbm_surface_release_buffer(native_surface_, buffers_[front_buffer_]);
+
+  // Update the index to the frontbuffer.
+  front_buffer_ ^= 1;
+  // We've just released it. Since GBM doesn't guarantee we'll get the same
+  // buffer back, we set it to NULL so we don't keep track of objects that may
+  // have been destroyed.
+  buffers_[front_buffer_ ^ 1] = NULL;
+}
+
+void GbmSurface::LockCurrentDrawable() {
+  // Lock the buffer we want to display.
+  buffers_[front_buffer_ ^ 1] = gbm_surface_lock_front_buffer(native_surface_);
+
+  BufferData* data = BufferData::GetData(buffers_[front_buffer_ ^ 1]);
+  // If it is a new buffer, it won't have any data associated with it. So we
+  // create it. On creation it will associate itself with the buffer and
+  // register the buffer with the |controller_|.
+  if (data == NULL) {
+    data = BufferData::CreateData(controller_, buffers_[front_buffer_ ^ 1]);
+    DCHECK(data) << "Failed to associate the buffer with the controller";
+  }
+}
+
+}  // namespace gfx