xref: /freebsd/sys/sys/sigio.h (revision 29363fb446372cb3f10bc98664e9767c53fbb457)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1990, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #ifndef _SYS_SIGIO_H_
33 #define _SYS_SIGIO_H_
34 
35 /*
36  * This structure holds the information needed to send a SIGIO or
37  * a SIGURG signal to a process or process group when new data arrives
38  * on a device or socket.  The structure is placed on an SLIST belonging
39  * to the proc or pgrp so that the entire list may be revoked when the
40  * process exits or the process group disappears.
41  *
42  * (c)	const
43  * (pg)	locked by either the process or process group lock
44  */
45 struct sigio {
46 	union {
47 		struct	proc *siu_proc; /* (c)	process to receive SIGIO/SIGURG */
48 		struct	pgrp *siu_pgrp; /* (c)	process group to receive ... */
49 	} sio_u;
50 	SLIST_ENTRY(sigio) sio_pgsigio;	/* (pg)	sigio's for process or group */
51 	struct	sigio **sio_myref;	/* (c)	location of the pointer that holds
52 					 * 	the reference to this structure */
53 	struct	ucred *sio_ucred;	/* (c)	current credentials */
54 	pid_t	sio_pgid;		/* (c)	pgid for signals */
55 };
56 #define	sio_proc	sio_u.siu_proc
57 #define	sio_pgrp	sio_u.siu_pgrp
58 
59 SLIST_HEAD(sigiolst, sigio);
60 
61 pid_t	fgetown(struct sigio **sigiop);
62 int	fsetown(pid_t pgid, struct sigio **sigiop);
63 void	funsetown(struct sigio **sigiop);
64 void	funsetownlst(struct sigiolst *sigiolst);
65 
66 #endif /* _SYS_SIGIO_H_ */
67