[C++] Implement filter lock.
[C++] Implement filter lock.

sgkim126/snippets,sgkim126/snippets,sgkim126/snippets,sgkim126/snippets,sgkim126/snippets,sgkim126/snippets,sgkim126/snippets,sgkim126/snippets,sgkim126/snippets,sgkim126/snippets,sgkim126/snippets,sgkim126/snippets