The GPU process cannot be placed on a UI thread in --single-process mode...

The GPU process cannot be placed on a UI thread in --single-process mode because glib is not thread safe. This patch moves it onto a IO thread instead.

Connections to the X server are not thread safe. I've made changes so that each thread gets it's own connection.

Finally, GpuHostMsg_GetViewXID needed to be needed to be sent from the thread added to GpuChannel instead of ChildThread::current().

BUG=69674
TEST=try --single-process with --enable-accelerated-layers on http://webkit.org/blog/386/3d-transforms/

Review URL: http://codereview.chromium.org/6340004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@71655 0039d316-1c4b-4281-b951-d872f2087c98

app/gfx/gl/gl_context_egl.cc

@@ -4,11 +4,14 @@
 
 #include <EGL/egl.h>
 
-#include "build/build_config.h"
 #if defined(OS_LINUX)
-#include "app/x11_util.h"
+extern "C" {
+#include <X11/Xlib.h>
+}
 #define EGL_HAS_PBUFFERS 1
 #endif
+
+#include "build/build_config.h"
 #include "base/logging.h"
 #include "base/scoped_ptr.h"
 #include "app/gfx/gl/gl_bindings.h"
@@ -80,7 +83,7 @@ bool BaseEGLContext::InitializeOneOff() {
     return true;
 
 #ifdef OS_LINUX
-  EGLNativeDisplayType native_display = x11_util::GetXDisplay();
+  EGLNativeDisplayType native_display = XOpenDisplay(NULL);
 #else
   EGLNativeDisplayType native_display = EGL_DEFAULT_DISPLAY;
 #endif

app/gfx/gl/gl_context_linux.cc

@@ -28,16 +28,14 @@ Display* GetXDisplayHelper() {
   static Display* display = NULL;
 
   if (!display) {
-    if (x11_util::XDisplayExists()) {
-      display = x11_util::GetXDisplay();
-    } else {
-      display = XOpenDisplay(NULL);
-    }
+    display = XOpenDisplay(NULL);
+    CHECK(display);
   }
+
   return display;
 }
 
-}
+}  // namespace
 
 namespace gfx {
 

chrome/browser/gpu_process_host.cc

@@ -574,26 +574,23 @@ bool GpuProcessHost::CanLaunchGpuProcess() const {
 bool GpuProcessHost::LaunchGpuProcess() {
   const CommandLine& browser_command_line = *CommandLine::ForCurrentProcess();
 
-  // TODO(apatrick): This cannot be a UI message pump on Linux because glib is
-  // not thread safe. Changing this to an IO message pump does not completely
-  // resolve the problem, most likely because we're sharing a connection to the
-  // X server with the browser.
-#if !defined(OS_LINUX)
-
   // If the single-process switch is present, just launch the GPU service in a
   // new thread in the browser process.
   if (browser_command_line.HasSwitch(switches::kSingleProcess)) {
     GpuMainThread* thread = new GpuMainThread(channel_id());
 
     base::Thread::Options options;
+#if defined(OS_LINUX)
+    options.message_loop_type = MessageLoop::TYPE_IO;
+#else
     options.message_loop_type = MessageLoop::TYPE_UI;
+#endif
 
     if (!thread->StartWithOptions(options))
       return false;
 
     return true;
   }
-#endif
 
   CommandLine::StringType gpu_launcher =
       browser_command_line.GetSwitchValueNative(switches::kGpuLauncher);

chrome/gpu/gpu_channel.cc

@@ -141,13 +141,8 @@ void GpuChannel::OnCreateViewCommandBuffer(
   // "render target" the GpuCommandBufferStub targets.
   handle = gfx::NativeViewFromId(view_id);
 #elif defined(OS_LINUX)
-  ChildThread* gpu_thread = ChildThread::current();
   // Ask the browser for the view's XID.
-  // TODO(piman): This assumes that it doesn't change. It can change however
-  // when tearing off tabs. This needs a fix in the browser UI code. A possible
-  // alternative would be to add a socket/plug pair like with plugins but that
-  // has issues with events and focus.
-  gpu_thread->Send(new GpuHostMsg_GetViewXID(view_id, &handle));
+  gpu_thread_->Send(new GpuHostMsg_GetViewXID(view_id, &handle));
 #elif defined(OS_MACOSX)
   // On Mac OS X we currently pass a (fake) PluginWindowHandle for the
   // NativeViewId. We could allocate fake NativeViewIds on the browser