exo: Implement zcr_linux_explicit_synchronization_v1

components/exo/display_unittest.cc

 // Copyright 2015 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 "ash/common/shell_window_ids.h"
 #include "components/exo/buffer.h"
 #include "components/exo/display.h"
 #include "components/exo/shared_memory.h"
 #include "components/exo/shell_surface.h"
 #include "components/exo/sub_surface.h"
@@ skipping 68 matching lines @@
 
   std::vector<base::ScopedFD> invalid_fds;
   invalid_fds.push_back(base::ScopedFD());
   // Creating a prime buffer using an invalid fd should fail.
   std::unique_ptr<Buffer> buffer2 = display->CreateLinuxDMABufBuffer(
       buffer_size, gfx::BufferFormat::RGBA_8888, planes,
       std::move(invalid_fds));
   EXPECT_FALSE(buffer2);
 }
 
+TEST_F(DisplayTest, CreateLinuxFence) {
+  int sockets_unscoped[2];
+
+  ASSERT_EQ(0, socketpair(AF_UNIX, SOCK_STREAM, 0, fds));
+
+  // Emulate the behaviour of a fence FD (returns POLLIN when signaled) using
+  // a socket pair.
+  Base::ScopedFD socket_waitee(sockets_unscoped[0]);
+
+  std::unique_ptr<gfx::GpuFence> fence1 =
+      display->CreateLinuxFence(sockets_unscoped[1]);
+  EXPECT_TRUE(fence1);

[reveman, 2016/10/12 19:20:19]

nit: ASSERT_TRUE as code below will crash if this fails

+  close(sockets_unscoped[1]);
+
+  // The fence must be unsignaled when we start.
+  EXPECT_FALSE(fence1->Wait(TimeDelta::FromMilliseconds(50)));
+
+  // Unblock the fence, and make sure this signals success.
+  uint32_t dummy = 1;
+  ASSERT_EQ(sizeof(dummy), UnixDomainSocket::SendMsg(socket_waitee, &dummy,
+                                                     sizeof(dummy), nullptr));
+
+  EXPECT_TRUE(fence1->Wait(TimeDelta::FromMilliseconds(50)));
+
+  std::unique_ptr<gfx::GpuFence> fence2 =

[reveman, 2016/10/12 19:20:19]

nit: just a short comment here to explain that this checks that an invalid fence
is not causing bad behavior

+      display->CreateLinuxFence(-1);
+  EXPECT_FALSE(fence2);
+}
+
 // TODO(dcastagna): Add YV12 unittest once we can allocate the buffer
 // via Ozone. crbug.com/618516
 
 #endif
 
 TEST_F(DisplayTest, CreateShellSurface) {
   std::unique_ptr<Display> display(new Display);
 
   // Create two surfaces.
   std::unique_ptr<Surface> surface1 = display->CreateSurface();
@@ skipping 118 matching lines @@
   // Attempting to create a sub surface for parent with grandchild as its parent
   // should fail.
   EXPECT_FALSE(display->CreateSubSurface(parent.get(), grandchild.get()));
 
   // Create a sub surface for parent.
   EXPECT_TRUE(display->CreateSubSurface(parent.get(), toplevel.get()));
 }
 
 }  // namespace
 }  // namespace exo