0 on success, or -1 if the table is full.Register a completion handler for a given context pointer.
When an IOCP completion arrives with a completionKey matching context, the provided callback is invoked.
context | Opaque pointer used as the IOCP completion key. Typically the this pointer of the I/O object. |
callback | Function to invoke when a completion is dequeued. |
0 on success, or -1 if the table is full.