int io_tryreadtimeout(int64 fd,char* buf,int64 len);
DESCRIPTIONio_tryreadtimeout is identical to io_tryread, with the following exception: if
- io_tryread returns -1 (the descriptor is not ready for reading), and
- the descriptor has a timeout, and
- the read attempt was after the descriptor's timeout,
then io_tryreadtimeout instead returns -2, with errno set to ETIMEDOUT.