Add initial SHM-only Wayland Ozone implementation

ui/ozone/platform/wayland/wayland_surface_factory.cc

+// Copyright 2016 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/ozone/platform/wayland/wayland_surface_factory.h"
+
+#include <fcntl.h>
+#include <sys/mman.h>
+
+#include "base/memory/shared_memory.h"
+#include "third_party/skia/include/core/SkSurface.h"
+#include "ui/gfx/vsync_provider.h"
+#include "ui/ozone/platform/wayland/wayland_display.h"
+#include "ui/ozone/platform/wayland/wayland_object.h"
+#include "ui/ozone/platform/wayland/wayland_window.h"
+#include "ui/ozone/public/surface_ozone_canvas.h"
+#include "ui/ozone/public/surface_ozone_egl.h"
+
+namespace ui {
+
+static void DeleteSharedMemory(void* pixels, void* context) {
+  delete static_cast<base::SharedMemory*>(context);
+}
+
+class WaylandCanvasSurface : public SurfaceOzoneCanvas {
+ public:
+  WaylandCanvasSurface(WaylandDisplay* display, WaylandWindow* window_);
+  ~WaylandCanvasSurface() override;
+
+  // SurfaceOzoneCanvas
+  skia::RefPtr<SkSurface> GetSurface() override;
+  void ResizeCanvas(const gfx::Size& viewport_size) override;
+  void PresentCanvas(const gfx::Rect& damage) override;
+  scoped_ptr<gfx::VSyncProvider> CreateVSyncProvider() override;
+
+ private:
+  WaylandDisplay* display_;
+  WaylandWindow* window_;
+
+  gfx::Size size_;
+  skia::RefPtr<SkSurface> sk_surface_;
+  wl::Object<wl_shm_pool> pool_;
+  wl::Object<wl_buffer> buffer_;
+
+  DISALLOW_COPY_AND_ASSIGN(WaylandCanvasSurface);
+};
+
+WaylandCanvasSurface::WaylandCanvasSurface(WaylandDisplay* display,
+                                           WaylandWindow* window)
+    : display_(display), window_(window) {}
+
+WaylandCanvasSurface::~WaylandCanvasSurface() {}
+
+skia::RefPtr<SkSurface> WaylandCanvasSurface::GetSurface() {
+  if (sk_surface_)
+    return sk_surface_;
+
+  size_t length = size_.width() * size_.height() * 4;
+  auto shared_memory = make_scoped_ptr(new base::SharedMemory);
+  if (!shared_memory->CreateAndMapAnonymous(length))
+    return nullptr;
+
+  wl::Object<wl_shm_pool> pool(
+      wl_shm_create_pool(display_->shm(), shared_memory->handle().fd, length));
+  if (!pool) {
+    LOG(ERROR) << "Failed to create SHM pool";
+    return nullptr;
+  }
+  wl::Object<wl_buffer> buffer(
+      wl_shm_pool_create_buffer(pool.get(), 0, size_.width(), size_.height(),
+                                size_.width() * 4, WL_SHM_FORMAT_ARGB8888));
+  if (!buffer) {
+    LOG(ERROR) << "Failed to create SHM buffer";
+    return nullptr;
+  }
+
+  void* pixels = shared_memory->memory();
+  sk_surface_ = skia::AdoptRef(SkSurface::NewRasterDirectReleaseProc(
+      SkImageInfo::MakeN32Premul(size_.width(), size_.height()), pixels,
+      size_.width() * 4, &DeleteSharedMemory, shared_memory.release(),

[spang, 2016/01/25 18:57:57]

Is it possible for NewRasterDirectReleaseProc to fail? You'll leak the
base::SharedMemory in that case.

[Michael Forney, 2016/01/26 02:25:26]

It looks like it does do some width/height/stride validation, so I am now
checking that it was successfully constructed before releasing the shared_memory
pointer.

+      nullptr));
+  pool_ = std::move(pool);
+  buffer_ = std::move(buffer);
+  return sk_surface_;
+}
+
+void WaylandCanvasSurface::ResizeCanvas(const gfx::Size& viewport_size) {
+  if (size_ == viewport_size)
+    return;
+  // TODO(forney): We could implement more efficient resizes by allocating
+  // buffers rounded up to larger sizes, and then reusing them if the new size
+  // still fits (but still reallocate if the new size is much smaller than the
+  // old size).
+  if (sk_surface_) {
+    sk_surface_.clear();
+    buffer_.reset();
+    pool_.reset();
+  }
+  size_ = viewport_size;
+}
+
+void WaylandCanvasSurface::PresentCanvas(const gfx::Rect& damage) {
+  // TODO(forney): This is just a naive implementation that allows chromium to
+  // draw to the buffer at any time, even if it is being used by the Wayland

[kalyank, 2016/01/25 22:05:16]

Also, we should make sure that we don't release buffer while it's still being
used by Wayland compositor.

[Michael Forney, 2016/01/26 02:25:26]

Acknowledged.

+  // compositor. Instead, we should track buffer releases and frame callbacks
+  // from Wayland to ensure perfect frames (while minimizing copies).
+  wl_surface* surface = window_->GetSurface();
+  wl_surface_damage(surface, damage.x(), damage.y(), damage.width(),
+                    damage.height());
+  wl_surface_attach(surface, buffer_.get(), 0, 0);
+  wl_surface_commit(surface);
+  display_->Flush();
+}
+
+scoped_ptr<gfx::VSyncProvider> WaylandCanvasSurface::CreateVSyncProvider() {
+  // TODO(forney): This can be implemented with information from frame
+  // callbacks, and possibly output refresh rate.
+  NOTIMPLEMENTED();
+  return nullptr;
+}
+
+WaylandSurfaceFactory::WaylandSurfaceFactory(WaylandDisplay* display)
+    : display_(display) {}
+
+WaylandSurfaceFactory::~WaylandSurfaceFactory() {}
+
+intptr_t WaylandSurfaceFactory::GetNativeDisplay() {
+  NOTIMPLEMENTED();
+  return 0;
+}
+
+const int32_t* WaylandSurfaceFactory::GetEGLSurfaceProperties(
+    const int32_t* desired_list) {
+  NOTIMPLEMENTED();
+  return nullptr;
+}
+
+bool WaylandSurfaceFactory::LoadEGLGLES2Bindings(
+    AddGLLibraryCallback add_gl_library,
+    SetGLGetProcAddressProcCallback set_gl_get_proc_address) {
+  // This Ozone implementation does not support multi-process rendering so
+  // disable EGL unconditionally for now.
+  return false;
+}
+
+scoped_ptr<SurfaceOzoneCanvas> WaylandSurfaceFactory::CreateCanvasForWidget(
+    gfx::AcceleratedWidget widget) {
+  DCHECK(display_);
+  WaylandWindow* window = display_->GetWindow(widget);
+  DCHECK(window);
+  return make_scoped_ptr(new WaylandCanvasSurface(display_, window));
+}
+
+scoped_ptr<SurfaceOzoneEGL> WaylandSurfaceFactory::CreateEGLSurfaceForWidget(
+    gfx::AcceleratedWidget widget) {
+  NOTREACHED();
+  return nullptr;
+}
+
+scoped_refptr<NativePixmap> WaylandSurfaceFactory::CreateNativePixmap(
+    gfx::AcceleratedWidget widget,
+    gfx::Size size,
+    gfx::BufferFormat format,
+    gfx::BufferUsage usage) {
+  NOTIMPLEMENTED();
+  return nullptr;
+}
+
+scoped_refptr<NativePixmap> WaylandSurfaceFactory::CreateNativePixmapFromHandle(
+    const gfx::NativePixmapHandle& handle) {
+  NOTIMPLEMENTED();
+  return nullptr;
+}
+
+}  // namespace ui