Lock around all EGL and GL calls with a global mutex.

BUILD.gn

@@ -76,6 +76,10 @@ config("internal_config") {
   } else {
     defines += [ "ANGLE_IS_32_BIT_CPU" ]
   }
+
+  if (angle_force_thread_safety) {
+    defines += [ "ANGLE_FORCE_THREAD_SAFETY=1" ]
+  }
 }
 
 config("extra_warnings") {

gni/angle.gni

@@ -64,6 +64,7 @@ declare_args() {
   angle_enable_null = true
   angle_enable_essl = true
   angle_enable_glsl = true
+  angle_force_thread_safety = false
 }
 
 declare_args() {

scripts/generate_entry_points.py

@@ -181,6 +181,7 @@ template_entry_point_decl = """ANGLE_EXPORT {return_type}GL_APIENTRY {name}{expl
 
 template_entry_point_def = """{return_type}GL_APIENTRY {name}{explicit_context_suffix}({explicit_context_param}{explicit_context_comma}{params})
 {{
+    ANGLE_SCOPED_GLOBAL_LOCK();
     {event_comment}EVENT("({format_params})"{comma_if_needed}{pass_params});
 
     Context *context = {context_getter};

scripts/run_code_generation_hashes.json

@@ -48,7 +48,7 @@
   "GL entry point:scripts/entry_point_packed_gl_enums.json":
     "df2c879ccb62109a31c24d4b1df45354",
   "GL entry point:scripts/generate_entry_points.py":
-    "bfe4041311e3ae882ed218e306d7b683",
+    "5a110a1e99777cf8c904f30e54af15a1",
   "GL entry point:scripts/gl.xml":
     "b470cb06b06cbbe7adb2c8129ec85708",
   "GL format map:src/libANGLE/es3_format_type_combinations.json":

src/libANGLE/features.h

@@ -62,4 +62,9 @@
 #endif  // defined(ANGLE_PLATFORM_WINDOWS)
 #endif  // !defined(ANGLE_STD_ASYNC_WORKERS)
 
-#endif // LIBANGLE_FEATURES_H_
+// Force thread safety in all of ANGLE by locking a global mutex in every ANGLE entry point.
+#if !defined(ANGLE_FORCE_THREAD_SAFETY)
+#define ANGLE_FORCE_THREAD_SAFETY ANGLE_DISABLED
+#endif  // !defined(ANGLE_FORCE_THREAD_SAFETY)
+
+#endif  // LIBANGLE_FEATURES_H_

src/libGLESv2/global_state.cpp

@@ -93,6 +93,21 @@ Debug *GetDebug()
 
 }  // namespace egl
 
+#if ANGLE_FORCE_THREAD_SAFETY == ANGLE_ENABLED
+namespace angle
+{
+namespace
+{
+std::mutex g_Mutex;
+}  // anonymous namespace
+
+std::mutex &GetGlobalMutex()
+{
+    return g_Mutex;
+}
+}  // namespace angle
+#endif
+
 #ifdef ANGLE_PLATFORM_WINDOWS
 namespace egl
 {

src/libGLESv2/global_state.h

@@ -9,6 +9,10 @@
 #ifndef LIBGLESV2_GLOBALSTATE_H_
 #define LIBGLESV2_GLOBALSTATE_H_
 
+#include "libANGLE/features.h"
+
+#include <mutex>
+
 namespace gl
 {
 class Context;
@@ -28,4 +32,16 @@ Debug *GetDebug();
 
 }  // namespace egl
 
+#if ANGLE_FORCE_THREAD_SAFETY == ANGLE_ENABLED
+namespace angle
+{
+std::mutex &GetGlobalMutex();
+}  // namespace angle
+
+#define ANGLE_SCOPED_GLOBAL_LOCK() \
+    std::lock_guard<std::mutex> globalMutexLock(angle::GetGlobalMutex())
+#else
+#define ANGLE_SCOPED_GLOBAL_LOCK()
+#endif
+
 #endif  // LIBGLESV2_GLOBALSTATE_H_