Async exception safety? #31
Description
As far as I can tell, the handlers for resource cleanup handle in a regular mask, rather than an uninterruptibleMask. This means the handler can get interrupted and aborted midway if cleanup performs a blocking operation and an async exception arrives during this time. Perhaps resource cleanup should run in uninterruptibleMask? Alternatively, this problem should be documented on the page, so users can take relevant precautions themselves.