.IX \f4datamsg\fP(D3DK)
.IX STREAMS messages

NAME

datamsg − test whether a message is a data message

SYNOPSIS

#include <sys/types.h>
#include <sys/stream.h>
#include <sys/ddi.h>
int datamsg(uchar_t type);

ARGUMENTS

typeThe type of message to be tested.  The db_type field of the datab structure contains the message type.  This field may be accessed through the message block using mp->b_datap->db_type. 

DESCRIPTION

The datamsg function tests the type of message to determine if it is a data message type (M_DATA, M_DELAY, M_PROTO, or M_PCPROTO).  .IX STREAMS messages

RETURN VALUE

datamsg returns 1 if the message is a data message and 0 if the message is any other type. 

LEVEL

Base or Interrupt. 

NOTES

Does not sleep. 

Driver-defined basic locks, read/write locks, and sleep locks may be held across calls to this function. 

SEE ALSO

allocb(D3DK), datab(D4DK), msgb(D4DK), messages(D5DK)

EXAMPLE

.IX \f4datamsg\fP(D3DK), example
.IX \f4putq\fP(D3DK), example

The put(D2DK) routine enqueues all data messages for handling by the srv(D2DK) (service) routine.  All non-data messages are handled in the put routine. 

 1  xxxput(q, mp)
 2queue_t ∗q;
 3mblk_t ∗mp;
 4  {
 5if (datamsg(mp->b_datap->db_type)) {
 6putq(q, mp);
 7return;
 8}
 9switch (mp->b_datap->db_type) {
10case M_FLUSH:
...
11}
12  }

.IX STREAMS messages

DDI/DKI  —  STREAMS