[Ozone] Adding a software rendering implementation of SurfaceFactoryOzone

ui/gfx/ozone/impl/software_surface_factory_ozone.cc

+// Copyright (c) 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/impl/software_surface_factory_ozone.h"
+
+#include <drm.h>
+#include <errno.h>
+#include <xf86drm.h>
+
+#include "base/message_loop/message_loop.h"
+#include "third_party/skia/include/core/SkBitmap.h"
+#include "third_party/skia/include/core/SkDevice.h"
+#include "ui/gfx/native_widget_types.h"
+#include "ui/gfx/ozone/impl/drm_skbitmap_ozone.h"
+#include "ui/gfx/ozone/impl/drm_wrapper_ozone.h"
+#include "ui/gfx/ozone/impl/hardware_display_controller_ozone.h"
+#include "ui/gfx/ozone/impl/software_surface_ozone.h"
+
+namespace gfx {
+
+namespace {
+
+const char kDefaultGraphicsCardPath[] = "/dev/dri/card0";
+
+const gfx::AcceleratedWidget kDefaultWidgetHandle = 1;
+
+// DRM callback on page flip events. This callback is triggered after the
+// page flip has happened and the backbuffer is now the new frontbuffer
+// The old frontbuffer is no longer used by the hardware and can be used for
+// future draw operations.
+//
+// |device| will contain a reference to the |SoftwareSurfaceOzone| object which
+// the event belongs to.
+//
+// TODO(dnicoara) When we have a FD handler for the DRM calls in the message
+// loop, we can move this function in the handler.
+void HandlePageFlipEvent(int fd,
+                         unsigned int frame,
+                         unsigned int seconds,
+                         unsigned int useconds,
+                         void* controller) {
+  static_cast<HardwareDisplayControllerOzone*>(controller)->get_surface()
+      ->SwapBuffers();
+}
+
+uint32_t GetCrtc(int fd, drmModeRes* resources, drmModeConnector* connector) {
+  // If the connector already has an encoder try to re-use.
+  if (connector->encoder_id) {
+    drmModeEncoder* encoder = drmModeGetEncoder(fd, connector->encoder_id);
+    if (encoder) {
+      if (encoder->crtc_id) {
+        uint32_t crtc = encoder->crtc_id;
+        drmModeFreeEncoder(encoder);
+        return crtc;
+      }
+      drmModeFreeEncoder(encoder);
+    }
+  }
+
+  // Try to find an encoder for the connector.
+  for (int i = 0; i < connector->count_encoders; ++i) {
+    drmModeEncoder* encoder = drmModeGetEncoder(fd, connector->encoders[i]);
+    if (!encoder)
+      continue;
+
+    for (int j = 0; j < resources->count_crtcs; ++j) {
+      // Check if the encoder is compatible with this CRTC
+      if (!(encoder->possible_crtcs & (1 << j)))
+        continue;
+
+      drmModeFreeEncoder(encoder);
+      return resources->crtcs[j];
+    }
+  }
+
+  return 0;
+}
+
+}  // namespace
+
+SoftwareSurfaceFactoryOzone::SoftwareSurfaceFactoryOzone()
+    : drm_(),
+      state_(UNINITIALIZED),
+      controller_() {
+}
+
+SoftwareSurfaceFactoryOzone::~SoftwareSurfaceFactoryOzone() {
+  if (state_ == INITIALIZED)
+    ShutdownHardware();
+}
+
+SurfaceFactoryOzone::HardwareState
+SoftwareSurfaceFactoryOzone::InitializeHardware() {
+  CHECK(state_ == UNINITIALIZED);
+
+  // TODO(dnicoara): Short-cut right now. What we want is to look at all the
+  // graphics devices available and select the primary one.
+  drm_.reset(CreateWrapper());
+  if (drm_->get_fd() < 0) {
+    LOG(ERROR) << "Cannot open graphics card '"
+               << kDefaultGraphicsCardPath << "': " << strerror(errno);
+    state_ = FAILED;
+    return state_;
+  }
+
+  state_ = INITIALIZED;
+  return state_;
+}
+
+void SoftwareSurfaceFactoryOzone::ShutdownHardware() {
+  CHECK(state_ == INITIALIZED);
+
+  controller_.reset();
+  drm_.reset();
+
+  state_ = UNINITIALIZED;
+}
+
+gfx::AcceleratedWidget SoftwareSurfaceFactoryOzone::GetAcceleratedWidget() {
+  CHECK(state_ != FAILED);
+
+  // TODO(dnicoara) When there's more information on which display we want,
+  // then we can return the widget associated with the display.
+  // For now just assume we have 1 display device and return it.
+  if (!controller_.get())
+    controller_.reset(new HardwareDisplayControllerOzone());
+
+  // TODO(dnicoara) We only have 1 display for now, so only 1 AcceleratedWidget.
+  // When we'll support multiple displays this needs to be changed to return a
+  // different handle for every display.
+  return kDefaultWidgetHandle;
+}
+
+gfx::AcceleratedWidget SoftwareSurfaceFactoryOzone::RealizeAcceleratedWidget(
+    gfx::AcceleratedWidget w) {
+  CHECK(state_ == INITIALIZED);
+  // TODO(dnicoara) Once we can handle multiple displays this needs to be
+  // changed.
+  CHECK(w == kDefaultWidgetHandle);
+
+  CHECK(controller_->get_state() ==
+        HardwareDisplayControllerOzone::UNASSOCIATED);
+
+  // Until now the controller is just a stub. Initializing it will link it to a
+  // hardware display.
+  if (!InitializeControllerForPrimaryDisplay(drm_.get(), controller_.get())) {
+    LOG(ERROR) << "Failed to initialize controller";
+    return gfx::kNullAcceleratedWidget;
+  }
+
+  // Create a surface suitable for the current controller.
+  SoftwareSurfaceOzone* surface = CreateSurface(controller_.get());
+
+  if (!surface->Initialize()) {
+    delete surface;
+    LOG(ERROR) << "Failed to initialize surface";
+    return gfx::kNullAcceleratedWidget;
+  }
+
+  // Bind the surface to the controller. This will register the backing buffers
+  // with the hardware CRTC such that we can show the buffers. On success the
+  // controller takes ownership of the surface.

[rjkroege, 2013/10/16 21:42:13]

In this kind of complicated ownership transferring, please use the appropriate
kind of scoped_ptr  (note the Pass operator)

[dnicoara, 2013/10/17 14:26:19]

Done. Thank you for the tip.

+  if (!controller_->BindSurfaceToController(surface)) {
+    delete surface;
+    LOG(ERROR) << "Failed to bind surface to controller";
+    return gfx::kNullAcceleratedWidget;
+  }
+
+  return reinterpret_cast<gfx::AcceleratedWidget>(
+      surface->GetDrawableForWidget());
+}
+
+bool SoftwareSurfaceFactoryOzone::LoadEGLGLES2Bindings() {
+  return false;
+}
+
+bool SoftwareSurfaceFactoryOzone::AttemptToResizeAcceleratedWidget(
+    gfx::AcceleratedWidget w,
+    const gfx::Rect& bounds) {
+  return false;
+}
+
+bool SoftwareSurfaceFactoryOzone::SchedulePageFlip(gfx::AcceleratedWidget w) {
+  CHECK(state_ == INITIALIZED);
+  // TODO(dnicoara) Change this CHECK once we're running with the threaded
+  // compositor.
+  CHECK(base::MessageLoop::current()->type() == base::MessageLoop::TYPE_UI);
+
+  // TODO(dnicoara) Once we can handle multiple displays this needs to be
+  // changed.
+  CHECK(w == kDefaultWidgetHandle);
+
+  if (!controller_->SchedulePageFlip())
+    return false;
+
+  // Only wait for the page flip event to finish if it was properly scheduled.
+  //
+  // TODO(dnicoara) This requires the threaded compositor.
+  // The following call will wait for the page flip event to complete. This
+  // means that it will block until the next VSync. Ideally the wait should
+  // happen in the message loop. The message loop would then schedule the next
+  // draw event. Alternatively, the VSyncProvider could be used to schedule the
+  // next draw. Unfortunately, at this point, SoftwareOutputDevice does not
+  // provide any means to use any of the above solutions.

[rjkroege, 2013/10/16 21:42:13]

You still say that WaitForPageFlipEvent needs threaded compositing. So this
function is safe to call on the UI thread but blocks? So this is currently a
performance problem only?

Maybe the comment needs to be even more clarified.

[dnicoara, 2013/10/17 14:26:19]

Oh, I see where the lack of clarity is. Added more comments to fix that.

+  WaitForPageFlipEvent(drm_->get_fd());
+
+  return true;
+}
+
+gfx::VSyncProvider* SoftwareSurfaceFactoryOzone::GetVSyncProvider(
+    gfx::AcceleratedWidget w) {
+  return NULL;
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// SoftwareSurfaceFactoryOzone private
+
+SoftwareSurfaceOzone* SoftwareSurfaceFactoryOzone::CreateSurface(
+    HardwareDisplayControllerOzone* controller) {
+  return new SoftwareSurfaceOzone(controller);
+}
+
+DrmWrapperOzone* SoftwareSurfaceFactoryOzone::CreateWrapper() {
+  return new DrmWrapperOzone(kDefaultGraphicsCardPath);
+}
+
+bool SoftwareSurfaceFactoryOzone::InitializeControllerForPrimaryDisplay(
+    DrmWrapperOzone* drm,
+    HardwareDisplayControllerOzone* controller) {
+  CHECK(state_ == SurfaceFactoryOzone::INITIALIZED);
+
+  drmModeRes* resources = drmModeGetResources(drm->get_fd());
+
+  // Search for an active connector.
+  for (int i = 0; i < resources->count_connectors; ++i) {
+    drmModeConnector* connector = drmModeGetConnector(
+        drm->get_fd(),
+        resources->connectors[i]);
+
+    if (!connector)
+      continue;
+
+    if (connector->connection != DRM_MODE_CONNECTED ||
+        connector->count_modes == 0) {
+      drmModeFreeConnector(connector);
+      continue;
+    }
+
+    uint32_t crtc = GetCrtc(drm->get_fd(), resources, connector);
+
+    if (!crtc)
+      continue;
+
+    // TODO(dnicoara) Select one mode for now. In the future we may need to
+    // save all the modes and allow the user to choose a specific mode. Or
+    // even some fullscreen applications may need to change the mode.
+    controller->SetControllerInfo(
+        drm,
+        connector->connector_id,
+        crtc,
+        connector->modes[0]);
+
+    drmModeFreeConnector(connector);
+
+    return true;
+  }
+
+  return false;
+}
+
+void SoftwareSurfaceFactoryOzone::WaitForPageFlipEvent(int fd) {
+  drmEventContext drm_event;
+  drm_event.version = DRM_EVENT_CONTEXT_VERSION;
+  drm_event.page_flip_handler = HandlePageFlipEvent;
+  drm_event.vblank_handler = NULL;
+
+  // Wait for the page-flip to complete.
+  drmHandleEvent(fd, &drm_event);
+}
+
+}  // namespace gfx