exo: Implement zcr_linux_explicit_synchronization_v1

components/exo/wayland/server.cc

Index: components/exo/wayland/server.cc
diff --git a/components/exo/wayland/server.cc b/components/exo/wayland/server.cc
index 7b3d47ed80040647c1ddc52cbfadf1d94d6f513a..2e1401dff6acc5e14e867a616d8f41332ed678b1 100644
--- a/components/exo/wayland/server.cc
+++ b/components/exo/wayland/server.cc
@@ -14,6 +14,7 @@
 
 // Note: core wayland headers need to be included before protocol headers.
 #include <alpha-compositing-unstable-v1-server-protocol.h>  // NOLINT
+#include <linux-explicit-synchronization-unstable-v1-server-protocol.h>  // NOLINT
 #include <gaming-input-unstable-v1-server-protocol.h>       // NOLINT
 #include <remote-shell-unstable-v1-server-protocol.h>       // NOLINT
 #include <secure-output-unstable-v1-server-protocol.h>      // NOLINT
@@ -71,6 +72,7 @@
 #include "ui/events/keycodes/dom/keycode_converter.h"
 #include "ui/gfx/buffer_format_util.h"
 #include "ui/gfx/buffer_types.h"
+#include "ui/gfx/gpu_fence.h"
 #include "ui/views/widget/widget.h"
 #include "ui/views/widget/widget_observer.h"
 
@@ -154,6 +156,10 @@ DEFINE_SURFACE_PROPERTY_KEY(bool, kSurfaceHasSecurityKey, false);
 // associated with window.
 DEFINE_SURFACE_PROPERTY_KEY(bool, kSurfaceHasBlendingKey, false);
 
+// A property key containing a boolean set to true if a synchronization object
+// is associated with window.
+DEFINE_SURFACE_PROPERTY_KEY(bool, kSurfaceHasSynchronizationKey, false);
+
 wl_resource* GetSurfaceResource(Surface* surface) {
   return surface->GetProperty(kSurfaceResourceKey);
 }
@@ -761,8 +767,112 @@ void bind_linux_dmabuf(wl_client* client,
   for (const auto& supported_format : dmabuf_supported_formats)
     zwp_linux_dmabuf_v1_send_format(resource, supported_format.dmabuf_format);
 }
+#endif  // defined(USE_OZONE)
 
-#endif
+////////////////////////////////////////////////////////////////////////////////
+// synchronization interface:
+
+// Implements the synchronization interface to a Surface. A window property
+// will be set during the lifetime of this class to prevent multiple instances
+// from being created for the same Surface.
+class Synchronization : public SurfaceObserver {
+ public:
+  explicit Synchronization(Display* display, Surface* surface)
+      : surface_(surface), display_(display) {
+    surface_->AddSurfaceObserver(this);
+    surface_->SetProperty(kSurfaceHasSynchronizationKey, true);
+  }
+  ~Synchronization() override {
+    if (surface_) {
+      surface_->RemoveSurfaceObserver(this);
+      surface_->SetProperty(kSurfaceHasSynchronizationKey, false);
+    }
+  }
+
+  bool SetAcquireFence(base::ScopedFD fd) {
+    std::unique_ptr<gfx::GpuFence> fence =
+        display_->CreateLinuxFence(std::move(fd));
+    if (!fence)
+      return false;
+
+    surface_->SetAcquireFence(std::move(fence));
+    return true;
+  }
+
+  void OnSurfaceDestroying(Surface* surface) override {
+    surface->RemoveSurfaceObserver(this);
+    surface_ = nullptr;
+  }
+
+ private:
+  Surface* surface_;
+  Display* display_;
+
+  DISALLOW_COPY_AND_ASSIGN(Synchronization);
+};
+
+void synchronization_destroy(wl_client* client, wl_resource* resource) {
+  wl_resource_destroy(resource);
+}
+
+void synchronization_set_acquire_fence(wl_client* client,
+                                       wl_resource* resource,
+                                       int32_t fd) {
+  Synchronization* synchronization = GetUserDataAs<Synchronization>(resource);
+
+  if (!synchronization->SetAcquireFence(base::ScopedFD(fd))) {
+    wl_resource_post_error(resource, ZCR_SYNCHRONIZATION_V1_ERROR_INVALID_FENCE,
+                           "fence creation failed");
+  }
+}
+
+const struct zcr_synchronization_v1_interface synchronization_implementation = {
+    synchronization_destroy, synchronization_set_acquire_fence};
+
+////////////////////////////////////////////////////////////////////////////////
+// linux_explicit_synchronization interface:
+
+void linux_explicit_synchronization_destroy(wl_client* client,
+                                            wl_resource* resource) {
+  wl_resource_destroy(resource);
+}
+
+void linux_explicit_synchronization_get_surface(wl_client* client,
+                                                wl_resource* resource,
+                                                uint32_t id,
+                                                wl_resource* surface_resource) {
+  Display* display = GetUserDataAs<Display>(resource);
+  Surface* surface = GetUserDataAs<Surface>(surface_resource);
+
+  if (surface->GetProperty(kSurfaceHasSynchronizationKey)) {
+    wl_resource_post_error(
+        resource,
+        ZCR_LINUX_EXPLICIT_SYNCHRONIZATION_V1_ERROR_SYNCHRONIZATION_EXISTS,
+        "a synchronization object for that surface already exists");
+    return;
+  }
+
+  wl_resource* synchronization_resource =
+      wl_resource_create(client, &zcr_synchronization_v1_interface, 1, id);
+
+  SetImplementation(synchronization_resource, &synchronization_implementation,
+                    base::MakeUnique<Synchronization>(display, surface));
+}
+
+const struct zcr_linux_explicit_synchronization_v1_interface
+    linux_explicit_synchronization_implementation = {
+        linux_explicit_synchronization_destroy,
+        linux_explicit_synchronization_get_surface};
+
+void bind_linux_explicit_synchronization(wl_client* client,
+                                         void* data,
+                                         uint32_t version,
+                                         uint32_t id) {
+  wl_resource* resource = wl_resource_create(
+      client, &zcr_linux_explicit_synchronization_v1_interface, 1, id);
+  wl_resource_set_implementation(
+      resource, &linux_explicit_synchronization_implementation, data, nullptr);
+}
 
 ////////////////////////////////////////////////////////////////////////////////
 // wl_subsurface_interface:
@@ -2981,7 +3091,10 @@ Server::Server(Display* display)
                    bind_drm);
   wl_global_create(wl_display_.get(), &zwp_linux_dmabuf_v1_interface, 1,
                    display_, bind_linux_dmabuf);
-#endif
+#endif  // defined(USE_OZONE)
+  wl_global_create(wl_display_.get(),
+                   &zcr_linux_explicit_synchronization_v1_interface, 1,
+                   display_, bind_linux_explicit_synchronization);
   wl_global_create(wl_display_.get(), &wl_subcompositor_interface, 1, display_,
                    bind_subcompositor);
   wl_global_create(wl_display_.get(), &wl_shell_interface, 1, display_,