xref: /illumos-gate/usr/src/man/man9f/canputnext.9f (revision 0250c53ad267726f2438e3c6556199a0bbf588a2)
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12.\" Copyright 2014 Garrett D'Amore <garrett@damore.org>
13.\"
14.Dd "April 9, 2016"
15.Dt CANPUTNEXT 9F
16.Os
17.Sh NAME
18.Nm canputnext ,
19.Nm bcanputnext
20.Nd test for room in next message queue
21.Sh SYNOPSIS
22.In sys/stream.h
23.
24.Ft int
25.Fo canputnext
26.Fa "queue_t *q"
27.Fc
28.
29.Ft int
30.Fo bcanputnext
31.Fa "queue_t *q"
32.Fa "unsigned char pri"
33.Fc
34.
35.Sh DESCRIPTION
36The
37.Fn canputnext
38and
39.Fn bcanputnext
40functions atomically test for available space in the next
41linked queue or priority band.
42They are preferable to and safer than calling
43.Xr canput 9F
44and
45.Xr bcanput 9F
46directly on the queue linked to by
47.Fa q Ns No -> Ns Fa q_next .
48.Lp
49Drivers and modules should call these routines to ensure that room
50on the next queue exists before calling
51.Xr putnext 9F .
52.Sh INTERFACE LEVEL
53Architecture independent (DDI/DDK).
54.Sh PARAMETERS
55.Bl -tag -width Ds
56.It Fa q
57STREAMS queue.
58.It Fa pri
59Priority band to test.
60.El
61.Sh CONTEXT
62These functions may be called in user, kernel, or interrupt
63context.
64.Sh RETURN VALUES
65.Bl -tag -width Ds
66.It 1
67If the next message queue is not full.
68.It 0
69If the next message queue is full.
70.El
71.Sh SEE ALSO
72.Rs
73.%B "STREAMS Programming Guide"
74.Re
75.Rs
76.%B "Writing Device Drivers"
77.Re
78.Pp
79.Xr bcanput 9F ,
80.Xr canput 9F ,
81.Xr putnext 9F ,
82