Lock the initialization of the GL bindings.

ui/gfx/gl/gl_implementation_linux.cc

 // Copyright (c) 2011 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 <vector>
 
 #include "base/base_paths.h"
 #include "base/command_line.h"
 #include "base/file_path.h"
 #include "base/logging.h"
 #include "base/native_library.h"
 #include "base/path_service.h"
+#include "base/synchronization/lock.h"
 #include "ui/gfx/gl/gl_bindings.h"
 #include "ui/gfx/gl/gl_implementation.h"
 
 namespace gfx {
 namespace {
 
 // TODO(piman): it should be Desktop GL marshalling from double to float. Today
 // on native GLES, we do float->double->float.
 void GL_BINDING_CALL MarshalClearDepthToClearDepthf(GLclampd depth) {
   glClearDepthf(static_cast<GLclampf>(depth));
@@ skipping 13 matching lines @@
     VLOG(1) << "Failed to load " << filename.MaybeAsASCII() << ": " << error;
     return NULL;
   }
   return library;
 }
 
 base::NativeLibrary LoadLibrary(const char* filename) {
   return LoadLibrary(FilePath(filename));
 }
 
+// TODO(backer): Find a more principled (less heavy handed) way to prevent a
+// race in the bindings initialization.
+#if defined(TOUCH_UI)
+base::Lock g_lock;

[Ken Russell (switch to Gerrit), 2011/08/25 04:19:54]

This isn't legal according to the Google C++ style guide -- see
http://google-styleguide.googlecode.com/svn/trunk/cppguide.xml#Static_and_Glo...
. Could you use an Atomic32 and base::subtle::NoBarrier_CompareAndSwap and a
spin loop instead? Or some other mechanism?

+#endif
+
 }  // namespace anonymous
 
 bool InitializeGLBindings(GLImplementation implementation) {
+#if defined(TOUCH_UI)
+  base::AutoLock locked(g_lock);
+#endif
   // Prevent reinitialization with a different implementation. Once the gpu
   // unit tests have initialized with kGLImplementationMock, we don't want to
   // later switch to another GL implementation.
   if (GetGLImplementation() != kGLImplementationNone)
     return true;
 
   switch (implementation) {
 #if !defined(USE_WAYLAND)
     case kGLImplementationOSMesaGL: {
       FilePath module_path;
@@ skipping 101 matching lines @@
 void InitializeDebugGLBindings() {
   InitializeDebugGLBindingsEGL();
   InitializeDebugGLBindingsGL();
 #if !defined(USE_WAYLAND)
   InitializeDebugGLBindingsGLX();
   InitializeDebugGLBindingsOSMESA();
 #endif
 }
 
 }  // namespace gfx