1datab(9S)                 Data Structures for Drivers                datab(9S)
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NAME

6       datab, dblk - STREAMS message data structure
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SYNOPSIS

9       #include <sys/stream.h>
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INTERFACE LEVEL

13       Architecture independent level 1 (DDI/DKI).
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DESCRIPTION

16       The datab structure describes the data of a STREAMS message. The actual
17       data contained in a STREAMS message is stored in a data buffer  pointed
18       to  by  this  structure.  A   msgb (message block) structure includes a
19       field that points to a datab structure.
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22       Because a data block can have more than one message block  pointing  to
23       it  at one time, the db_ref member keeps track of a data block's refer‐
24       ences, preventing it from being deallocated until  all  message  blocks
25       are finished with it.
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STRUCTURE MEMBERS

28         unsigned char     *db_base;     /* first byte of buffer */
29         unsigned char     *db_lim;      /* last byte (+1) of buffer */
30         unsigned char      db_ref;      /* # of message pointers to this data */
31         unsigned char      db_type;     /* message type */
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35       A datab structure is defined as type dblk_t.
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SEE ALSO

38       free_rtn(9S), msgb(9S)
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41       Writing Device Drivers
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44       STREAMS Programming Guide
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48SunOS 5.11                        24 Oct 2003                        datab(9S)
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