xref: /netbsd-src/lib/libc/sys/eventfd_write.c (revision e714af64e34d645bc9a36b629f42f374c83acc91)
1 /* $NetBSD: eventfd_write.c,v 1.1 2021/09/19 15:51:28 thorpej Exp $ */
2 
3 /*-
4  * Copyright (c) 2020 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Jason R. Thorpe.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29  * POSSIBILITY OF SUCH DAMAGE.
30  */
31 #include <sys/cdefs.h>
32 #if defined(LIBC_SCCS) && !defined(lint)
33 __RCSID("$NetBSD: eventfd_write.c,v 1.1 2021/09/19 15:51:28 thorpej Exp $");
34 #endif /* LIBC_SCCS and not lint */
35 
36 #include "namespace.h"
37 #include <sys/types.h>
38 #include <sys/eventfd.h>
39 #include <errno.h>
40 #include <unistd.h>
41 
42 int
eventfd_write(int efd,eventfd_t val)43 eventfd_write(int efd, eventfd_t val)
44 {
45 
46 	switch (write(efd, &val, sizeof(val))) {
47 	case -1:
48 		return -1;
49 
50 	case sizeof(val):
51 		return 0;
52 
53 	default:
54 		/* This should never happen, but... */
55 		errno = EIO;
56 		return -1;
57 	}
58 }
59