Message Direction
Various system calls let the user create messages and send them downstream and prioritize the messages.
Table 4-3 Send and Recieve Mesages|
Creates a message from the caller supplied control and data buffers and sends the message downstream |
|
|
Does the same as putmsg(2) and lets the caller specify a priority band for the message |
|
|
Retrieves M_DATA, M_PROTO, or M_PCPROTO or high priority messages from the Stream head, and places the contents into two user buffers |
|
|
Does the same as getmsg(2) and lets the caller specify a priority band for the message |
The Stream head guarantees that the control part of a message generated by putmsg(2) is at least 64 bytes long. This promotes reusability of the buffer. When the buffer is a reasonable size, modules and drivers may reuse the buffer for other headers.
stropts.h contains the specification of strbuf, which describes the control and data buffers.
- © 2010, Oracle Corporation and/or its affiliates