Dave,
I have seen the MSG_DELIM flag used in a chain of M_DATA blocks to
deliminate packets. Although this might be a rather common use
of the MSG_DELIM flag, the user does set it. Perhaps SHARE is more
appropriate than PRIVATE, but, after all, it is just a designation
and not enforced by the code.
--brian
On Thu, 16 Jan 2003, Dave Grothe wrote:
>
> The mblk_t structure was never designed for users to keep their own
> information in. Queue_t structures have a "q_ptr" that is designed
> for the user (driver) to use to point to some sort of control block
> structure that belongs to the driver.
> For keeping information in messages you have just a few alternatives.
> * Set the db_type field to a value of your own. Just be sure not to
> send such messages to other drivers; they likely won't understand
> your message types.
> * Put a header in front of the data. You can make it visible or
> invisible as you prefer. You can put it just in front of visible
> data, just after, at the front of the buffer, at the end, wherever
> you like. When the buffer is sent to another module the extra
> information is presumed lost.
>
> -- Dave
> At 02:20 PM 1/16/2003 Thursday, Vinay Channagiri wrote:
>
> Hello Dave,
> Here's the msgb structure. The b_flag is quoted as "PRIVATE". Does
> that mean "The flags defined in b_flag is meant for only STREAMS
> framework"??? If that is the case, where should STREAMS
> modules/drivers need to introduce a new flag if required ???
> Please respond to me at the earliest. Thanks
> /*********************** Excerpts MSG.H ***********************/
> typedef
> struct msgb {
> SHARE
> struct msgb *b_next; /* next msg on queue */
> struct msgb *b_prev; /* prev msg on queue */
> struct msgb *b_cont; /* next blk of msg */
> unsigned char *b_rptr; /* 1st unread byte */
> unsigned char *b_wptr; /* 1st unwriten byte */
> EXPORT
> struct datab *b_datap; /* pointer to data */
> unsigned char b_band; /* message priority */
> unsigned char b_pad1;
> PRIVATE
> unsigned short b_flag; /* see below */
> long b_pad2;
> } msgb_t;
> /*********************** Excerpts MSG.H ***********************/
> Regards,
> VINAY
> ---------------------------
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> References
>
> 1. http://login.mail.lycos.com/brandPage.shtml?pageId=plus&ref=lmtplus
--
Brian F. G. Bidulock � The reasonable man adapts himself to the �
[EMAIL PROTECTED] � world; the unreasonable one persists in �
http://www.openss7.org/ � trying to adapt the world to himself. �
� Therefore all progress depends on the �
� unreasonable man. -- George Bernard Shaw �
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