Change the GPU process to use a CFRunLoop

content/gpu/gpu_main.cc

 // Copyright (c) 2012 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 <stdlib.h>
 
 #if defined(OS_WIN)
 #include <dwmapi.h>
 #include <windows.h>
 #endif
@@ skipping 33 matching lines @@
 #endif
 
 #if defined(USE_X11)
 #include "ui/base/x/x11_util.h"
 #endif
 
 #if defined(OS_LINUX)
 #include "content/public/common/sandbox_init.h"
 #endif
 
+#if defined(OS_MACOSX)
+#include "base/message_loop/message_pump_mac.h"
+#endif
+
 const int kGpuTimeout = 10000;
 
 namespace content {
 
 namespace {
 
 bool WarmUpSandbox(const CommandLine& command_line);
 #if defined(OS_LINUX)
 bool StartSandboxLinux(const gpu::GPUInfo&, GpuWatchdogThread*, bool);
 #elif defined(OS_WIN)
@@ skipping 58 matching lines @@
   // will need to tear down this process. However, we can not do so
   // safely until the IPC channel is set up, because the detection of
   // early return of a child process is implemented using an IPC
   // channel error. If the IPC channel is not fully set up between the
   // browser and GPU process, and the GPU process crashes or exits
   // early, the browser process will never detect it.  For this reason
   // we defer tearing down the GPU process until receiving the
   // GpuMsg_Initialize message from the browser.
   bool dead_on_arrival = false;
 
+#if defined(OS_WIN)

[ccameron, 2014/05/12 20:06:50]

IMO the MessageLoop type enums are of limited utility, since many platforms
don't have a clear definition of what a UI loop is (see the breakdown in
https://code.google.com/p/chromium/issues/detail?id=312462#c51).

I didn't try to shoehorn another type into the enum, but rather, followed the
model in
https://code.google.com/p/chromium/codesearch#chromium/src/content/renderer/r...

[Robert Sesek, 2014/05/12 20:11:43]

They do have limited utility, but we're starting to encounter other main-thread
non-TYPE_UI MessageLoops, which is what this is. I agree this is the right
approach.

   base::MessageLoop::Type message_loop_type = base::MessageLoop::TYPE_IO;
-#if defined(OS_WIN)
   // Unless we're running on desktop GL, we don't need a UI message
   // loop, so avoid its use to work around apparent problems with some
   // third-party software.
   if (command_line.HasSwitch(switches::kUseGL) &&
       command_line.GetSwitchValueASCII(switches::kUseGL) ==
           gfx::kGLImplementationDesktopName) {
     message_loop_type = base::MessageLoop::TYPE_UI;
   }
+  base::MessageLoop main_message_loop(message_loop_type);
 #elif defined(OS_LINUX)
-  message_loop_type = base::MessageLoop::TYPE_DEFAULT;
+  base::MessageLoop main_message_loop(base::MessageLoop::TYPE_DEFAULT);
+#elif defined(OS_MACOSX)
+  // This is necessary for CoreAnimation layers hosted in the GPU process to be

[Robert Sesek, 2014/05/12 20:11:43]

Do you know what specifically requires this? I'm assuming something installs a
CFRunLoopSource that needs to get serviced, likely because the library doesn't
use its own thread for this.

[ccameron, 2014/05/12 20:30:44]

Not sure. I've verified in Chrome and in stand-alone applications. I tried
running an example application with breakpoints in CFRunLoopSourceCreate and
CFMachPortCreateRunLoopSource, and didn't hit anything.

[Robert Sesek, 2014/05/12 22:11:50]

Interesting. What about CFRunLoopAddSource?

+  // drawn. See:
+  // http://crbug.com/312462

[Robert Sesek, 2014/05/12 20:11:43]

nit: No need for this to be on its own line.

[ccameron, 2014/05/12 20:30:44]

Done.

+  scoped_ptr<base::MessagePump> pump(new base::MessagePumpCFRunLoop());
+  base::MessageLoop main_message_loop(pump.Pass());
+#else
+  base::MessageLoop main_message_loop(base::MessageLoop::TYPE_IO);
 #endif
 
-  base::MessageLoop main_message_loop(message_loop_type);
   base::PlatformThread::SetName("CrGpuMain");
 
   // In addition to disabling the watchdog if the command line switch is
   // present, disable the watchdog on valgrind because the code is expected
   // to run slowly in that case.
   bool enable_watchdog =
       !command_line.HasSwitch(switches::kDisableGpuWatchdog) &&
       !RunningOnValgrind();
 
   // Disable the watchdog in debug builds because they tend to only be run by
@@ skipping 293 matching lines @@
     return true;
   }
 
   return false;
 }
 #endif  // defined(OS_WIN)
 
 }  // namespace.
 
 }  // namespace content