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 "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 {
+
+void UnmapPixels(void* pixels, void* context) {
+  size_t* length = static_cast<size_t*>(context);
+  munmap(pixels, *length);
+  delete length;
+}
+
+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> sksurface_;

[spang, 2016/01/22 23:42:32]

SkSurface would become sk_surface_. Most code seems to just say surface_ though.

[Michael Forney, 2016/01/23 01:08:05]

I called it sk_surface_ to make the distinction between the wl_surface* that is
used in PresentCanvas (which could be confusing).

+  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 (sksurface_)
+    return sksurface_;
+
+  char tmp[] = "/tmp/chromium-XXXXXX";
+  base::ScopedFD fd(mkostemp(tmp, O_CLOEXEC));

[spang, 2016/01/22 23:42:32]

I think you want to use base::SharedMemory which will prefer to allocate in
/dev/shm.

[Michael Forney, 2016/01/23 01:08:05]

I should've guessed something like this would already exist. Done.

+  unlink(tmp);
+  if (!fd.is_valid()) {
+    LOG(ERROR) << "Failed to create temporary file to back SHM buffer";
+    return nullptr;
+  }
+  size_t length = size_.width() * size_.height() * 4;
+  if (posix_fallocate(fd.get(), 0, length) != 0) {
+    LOG(ERROR) << "Failed to allocate memory for SHM buffer";
+    return nullptr;
+  }
+
+  wl::Object<wl_shm_pool> pool(
+      wl_shm_create_pool(display_->GetShm(), fd.get(), 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 =
+      mmap(nullptr, length, PROT_READ | PROT_WRITE, MAP_SHARED, fd.get(), 0);
+  if (pixels == MAP_FAILED) {
+    LOG(ERROR) << "Failed to mmap contents of SHM buffer";
+    return nullptr;
+  }
+
+  sksurface_ = skia::AdoptRef(SkSurface::NewRasterDirectReleaseProc(
+      SkImageInfo::MakeN32Premul(size_.width(), size_.height()), pixels,
+      size_.width() * 4, &UnmapPixels, new size_t(length), nullptr));
+  pool_ = std::move(pool);
+  buffer_ = std::move(buffer);
+  return sksurface_;
+}
+
+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 (sksurface_) {
+    sksurface_.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
+  // 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;

[Michael Forney, 2016/01/21 22:11:48]

Even with returning false here, I have to comment out
https://chromium.googlesource.com/chromium/src/+/bf0b91e43cd331c6ebdb80755a2a...
in order to get it to actually fall back to software rendering.

Am I missing some option or something to get it to fallback, or if not, what are
the implications of removing the fatal log message?

[spang, 2016/01/22 23:42:33]

Your link is cut off :(

[Michael Forney, 2016/01/23 01:08:05]

Sorry, I copied from a draft comment on a previous patch set, and didn't realize
that the link was truncated.

https://code.google.com/p/chromium/codesearch#chromium/src/content/browser/co...

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

Some CrOS-only code doesn't support software rendering. I'm not aware of the
specifics; it probably breaks in strange ways or crashes, so we have the
assertion.

Maybe you can compile MUS instead? Rob..?

+}
+
+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