Comment 4 for bug 1318632

> AIUI the standard only guarantees that you can update and access two shared_ptr<>s to the same object safely in different threads.

You can also create two different shared_ptr<>s from the same source in different threads (assuming a const source, of course), which is what the scenario in the bug describes.

> You can't copy construct a shared_ptr<> in one thread while updating the source in another thread.

Agreed. That's the reason for the "there may still be some races around compositor_acquire() and resizing in give_buffer_to_client() that need further investigation" comment.