Let ANGLE use multithreaded devices if necessary.

This is needed to prevent lock-ups in application that use ANGLE from
multiple threads, as e.g. QtWebEngine based applications do.

The environment variable QT_D3DCREATE_MULTITHREADED is used to
communicate this from the QtWebEngine module.

Change-Id: Ibd5a5c75eb68af567d420d9a35efb3490c93b27c
Reviewed-by: Zeno Albisser <zeno.albisser@digia.com>

1 files changed, 13 insertions, 0 deletions

diff --git a/src/3rdparty/angle/src/libGLESv2/renderer/d3d/d3d11/Renderer11.cpp b/src/3rdparty/angle/src/libGLESv2/renderer/d3d/d3d11/Renderer11.cpp
index 17a13f97d6..651b065ca2 100644
--- a/src/3rdparty/angle/src/libGLESv2/renderer/d3d/d3d11/Renderer11.cpp
+++ b/src/3rdparty/angle/src/libGLESv2/renderer/d3d/d3d11/Renderer11.cpp
@@ -305,6 +305,19 @@ EGLint Renderer11::initialize()
         mMaxSupportedSamples = std::max(mMaxSupportedSamples, support.maxSupportedSamples);
     }
 
+#if !defined(ANGLE_PLATFORM_WINRT)
+    static wchar_t *qt_d3dcreate_multihreaded_var = _wgetenv(L"QT_D3DCREATE_MULTITHREADED");
+    if (qt_d3dcreate_multihreaded_var && wcsstr(qt_d3dcreate_multihreaded_var, L"1"))
+    {
+        ID3D10Multithread *multithread;
+        result = mDevice->QueryInterface(IID_PPV_ARGS(&multithread));
+        ASSERT(SUCCEEDED(result));
+        result = multithread->SetMultithreadProtected(true);
+        ASSERT(SUCCEEDED(result));
+        multithread->Release();
+    }
+#endif
+
     initializeDevice();
 
     return EGL_SUCCESS;