SVR5 and SCO OpenServer 5

M_READ(D7str)

M_READ -- send read request downstream

Description

This message sends the number of bytes of a read request downstream when the following conditions are met:

A module/driver has requested it using the SO_MREADON option in the M_SETOPTS(D7str) message type.
No data is available at the Stream head.
The reader is about to sleep.

Priority.

ddi: 1, 2, 3, 4, 5, 5mp, 6, 6mp, 7, 7mp, 7.1, 7.1mp, 8, 8mp
oddi: 1, 2, 2mp, 3, 3mp, 4, 4mp, 5, 5mp