1.\" $NetBSD: psignal.9,v 1.1 1996/06/22 22:57:35 pk Exp $
2.\"
3.\" Copyright (c) 1996 The NetBSD Foundation, Inc.
4.\" All rights reserved.
5.\"
6.\" This code is derived from software contributed to The NetBSD Foundation
7.\" by Paul Kranenburg.
8.\"
9.\" Redistribution and use in source and binary forms, with or without
10.\" modification, are permitted provided that the following conditions
11.\" are met:
12.\" 1. Redistributions of source code must retain the above copyright
13.\" notice, this list of conditions and the following disclaimer.
14.\" 2. Redistributions in binary form must reproduce the above copyright
15.\" notice, this list of conditions and the following disclaimer in the
16.\" documentation and/or other materials provided with the distribution.
17.\" 3. All advertising materials mentioning features or use of this software
18.\" must display the following acknowledgement:
19.\" This product includes software developed by the NetBSD
20.\" Foundation, Inc. and its contributors.
21.\" 4. Neither the name of The NetBSD Foundation nor the names of its
22.\" contributors may be used to endorse or promote products derived
23.\" from this software without specific prior written permission.
24.\"
25.\" THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
26.\" ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
27.\" TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
28.\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE
29.\" LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
30.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
31.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
32.\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
33.\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
34.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
35.\" POSSIBILITY OF SUCH DAMAGE.
36.\"
| 1.\" $NetBSD: psignal.9,v 1.1 1996/06/22 22:57:35 pk Exp $
2.\"
3.\" Copyright (c) 1996 The NetBSD Foundation, Inc.
4.\" All rights reserved.
5.\"
6.\" This code is derived from software contributed to The NetBSD Foundation
7.\" by Paul Kranenburg.
8.\"
9.\" Redistribution and use in source and binary forms, with or without
10.\" modification, are permitted provided that the following conditions
11.\" are met:
12.\" 1. Redistributions of source code must retain the above copyright
13.\" notice, this list of conditions and the following disclaimer.
14.\" 2. Redistributions in binary form must reproduce the above copyright
15.\" notice, this list of conditions and the following disclaimer in the
16.\" documentation and/or other materials provided with the distribution.
17.\" 3. All advertising materials mentioning features or use of this software
18.\" must display the following acknowledgement:
19.\" This product includes software developed by the NetBSD
20.\" Foundation, Inc. and its contributors.
21.\" 4. Neither the name of The NetBSD Foundation nor the names of its
22.\" contributors may be used to endorse or promote products derived
23.\" from this software without specific prior written permission.
24.\"
25.\" THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
26.\" ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
27.\" TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
28.\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE
29.\" LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
30.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
31.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
32.\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
33.\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
34.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
35.\" POSSIBILITY OF SUCH DAMAGE.
36.\"
|
37.Dd June 22, 1996
38.Dt PSIGNAL 9
39.Os
40.Sh NAME
41.Fd #include <sys/types.h>
42.Fd #include <sys/signalvar.h>
43.Nm psignal ,
44.Nm pgsignal ,
45.Nm gsignal
46.Nd post signal to a process or process group
47.Sh SYNOPSIS
48.Ft void
49.Fn psignal "struct proc *p" "int signum"
50.Ft void
51.Fn pgsignal "struct pgrp *pgrp" "int signum" "int checkctty"
52.Ft void
53.Fn gsignal "int pgid" "int signum"
54.Sh DESCRIPTION
55These functions post a signal to one or more processes. The argument
56.Fa signum
57common to all three functions should be in the range
58.Bq 1- Ns Dv NSIG .
59.Pp
60The
61.Fn psignal
62function posts signal number
63.Fa signum
64to the process represented by the process structure
65.Fa p .
66With a few exceptions noted below, the target process signal disposition is
67updated and is marked as runnable, so further handling of the signal is done
68in the context of the target process after a context switch. Note that
69.Fn psignal
70does not by itself cause a context switch to happen.
71.Pp
72The target process is not marked as runnable in the following cases:
73.Bl -bullet -offset indent
74.It
75The target process is sleeping uninterruptibly. The signal will be
76noticed when the process returns from the system call or trap.
77.It
78The target process is currently ignoring the signal.
79.It
80If a stop signal is sent to a sleeping process that takes the
81default action
82.Pq see Xr sigaction 2 ,
83the process is stopped without awakening it.
84.It
85.Dv SIGCONT
86restarts a stopped process
87.Pq or puts them back to sleep
88regardless of the signal action
89.Pq e.g., blocked or ignored .
90.El
91.Pp
92If the target process is being traced
93.Fn psignal
94behaves as if the target process were taking the default action for
95.Fa signum .
96This allows the tracing process to be notified of the signal.
97.Pp
98The
99.Fn pgsignal
100function posts signal number
101.Fa signum
102to each member of the process group described by
103.Fa pgrp .
104If
105.Fa checkctty
106is non-zero, the signal will be posted only to processes that have
107a controlling terminal.
108.Fn pgsignal
109is implemented by walking along the process list headed by the field
110.Li pg_members
111of the process group structure
112pointed at by
113.Fa pgrp
114and calling
115.Fn psignal
116as appropriate. If
117.Fa pgrp
118is
119.Dv NULL
120no action is taken.
121.Pp
122The
123.Fn gsignal
124function posts signal number
125.Fa signum
126to each member of the process group identified by the group id
127.Fa pgid .
128.Fn gsignal
129first finds the group structure associated with
130.Fa pgid ,
131then invokes
132.Fn pgsignal
133with the argument
134.Fa checkctty
135set to zero. If
136.Fa pgid
137is zero no action is taken.
138.Sh SEE ALSO
139.Xr sigaction 2 ,
140.Xr tsleep 9
| 39.Dd June 22, 1996
40.Dt PSIGNAL 9
41.Os
42.Sh NAME
43.Fd #include <sys/types.h>
44.Fd #include <sys/signalvar.h>
45.Nm psignal ,
46.Nm pgsignal ,
47.Nm gsignal
48.Nd post signal to a process or process group
49.Sh SYNOPSIS
50.Ft void
51.Fn psignal "struct proc *p" "int signum"
52.Ft void
53.Fn pgsignal "struct pgrp *pgrp" "int signum" "int checkctty"
54.Ft void
55.Fn gsignal "int pgid" "int signum"
56.Sh DESCRIPTION
57These functions post a signal to one or more processes. The argument
58.Fa signum
59common to all three functions should be in the range
60.Bq 1- Ns Dv NSIG .
61.Pp
62The
63.Fn psignal
64function posts signal number
65.Fa signum
66to the process represented by the process structure
67.Fa p .
68With a few exceptions noted below, the target process signal disposition is
69updated and is marked as runnable, so further handling of the signal is done
70in the context of the target process after a context switch. Note that
71.Fn psignal
72does not by itself cause a context switch to happen.
73.Pp
74The target process is not marked as runnable in the following cases:
75.Bl -bullet -offset indent
76.It
77The target process is sleeping uninterruptibly. The signal will be
78noticed when the process returns from the system call or trap.
79.It
80The target process is currently ignoring the signal.
81.It
82If a stop signal is sent to a sleeping process that takes the
83default action
84.Pq see Xr sigaction 2 ,
85the process is stopped without awakening it.
86.It
87.Dv SIGCONT
88restarts a stopped process
89.Pq or puts them back to sleep
90regardless of the signal action
91.Pq e.g., blocked or ignored .
92.El
93.Pp
94If the target process is being traced
95.Fn psignal
96behaves as if the target process were taking the default action for
97.Fa signum .
98This allows the tracing process to be notified of the signal.
99.Pp
100The
101.Fn pgsignal
102function posts signal number
103.Fa signum
104to each member of the process group described by
105.Fa pgrp .
106If
107.Fa checkctty
108is non-zero, the signal will be posted only to processes that have
109a controlling terminal.
110.Fn pgsignal
111is implemented by walking along the process list headed by the field
112.Li pg_members
113of the process group structure
114pointed at by
115.Fa pgrp
116and calling
117.Fn psignal
118as appropriate. If
119.Fa pgrp
120is
121.Dv NULL
122no action is taken.
123.Pp
124The
125.Fn gsignal
126function posts signal number
127.Fa signum
128to each member of the process group identified by the group id
129.Fa pgid .
130.Fn gsignal
131first finds the group structure associated with
132.Fa pgid ,
133then invokes
134.Fn pgsignal
135with the argument
136.Fa checkctty
137set to zero. If
138.Fa pgid
139is zero no action is taken.
140.Sh SEE ALSO
141.Xr sigaction 2 ,
142.Xr tsleep 9
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