Fix passing fd across modules

atom/node/osfhandle.h

@@ -0,0 +1,28 @@
+// Copyright (c) 2016 GitHub, Inc.
+// Use of this source code is governed by the MIT license that can be
+// found in the LICENSE file.
+
+#ifndef ATOM_NODE_OSFHANDLE_H_
+#define ATOM_NODE_OSFHANDLE_H_
+
+#include <windows.h>
+
+#include "node_extern.h"
+
+namespace node {
+
+// The _open_osfhandle and _close functions on Windows are provided by the
+// Visual C++ library, so the fd returned by them can only be used in the
+// same instance of VC++ library.
+// However Electron is linking with VC++ library statically, so electron.exe
+// shares a different instance of VC++ library with node.exe. This results
+// in fd created in electron.exe not usable in node.dll, so we have to ensure
+// we always create fd in one instance of VC++ library.
+// Followings wrappers are compiled in node.dll, and all code in electron.exe
+// should call these wrappers instead of calling _open_osfhandle directly.
+NODE_EXTERN int open_osfhandle(intptr_t osfhandle, int flags);
+NODE_EXTERN int close(int fd);
+
+}  // namespace node
+
+#endif  // ATOM_NODE_OSFHANDLE_H_