xref: /freebsd/sys/sys/sigio.h (revision 3416500aef140042c64bc149cb1ec6620483bc44)
1 /*-
2  * Copyright (c) 1990, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. Neither the name of the University nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  *	@(#)filedesc.h	8.1 (Berkeley) 6/2/93
30  * $FreeBSD$
31  */
32 
33 #ifndef _SYS_SIGIO_H_
34 #define _SYS_SIGIO_H_
35 
36 /*
37  * This structure holds the information needed to send a SIGIO or
38  * a SIGURG signal to a process or process group when new data arrives
39  * on a device or socket.  The structure is placed on an SLIST belonging
40  * to the proc or pgrp so that the entire list may be revoked when the
41  * process exits or the process group disappears.
42  *
43  * (c)	const
44  * (pg)	locked by either the process or process group lock
45  */
46 struct sigio {
47 	union {
48 		struct	proc *siu_proc; /* (c)	process to receive SIGIO/SIGURG */
49 		struct	pgrp *siu_pgrp; /* (c)	process group to receive ... */
50 	} sio_u;
51 	SLIST_ENTRY(sigio) sio_pgsigio;	/* (pg)	sigio's for process or group */
52 	struct	sigio **sio_myref;	/* (c)	location of the pointer that holds
53 					 * 	the reference to this structure */
54 	struct	ucred *sio_ucred;	/* (c)	current credentials */
55 	pid_t	sio_pgid;		/* (c)	pgid for signals */
56 };
57 #define	sio_proc	sio_u.siu_proc
58 #define	sio_pgrp	sio_u.siu_pgrp
59 
60 SLIST_HEAD(sigiolst, sigio);
61 
62 pid_t	fgetown(struct sigio **sigiop);
63 int	fsetown(pid_t pgid, struct sigio **sigiop);
64 void	funsetown(struct sigio **sigiop);
65 void	funsetownlst(struct sigiolst *sigiolst);
66 
67 #endif /* _SYS_SIGIO_H_ */
68