public Result poll_usec (Event events, out Event revents, int64 timeout)
Wait up to the specified
timeout for the connection to become available for at least one of the operations specified in
When the function returns with OK,
contain a bitmask of available operations on this.
timeout can be 0, in which case this function might block forever.
This function can be cancelled with flush.
a bitmask of Event flags to check
location for result flags
a timeout in microseconds
OK on success.