1/*
2 * Copyright (c) 2008 The Hewlett-Packard Development Company
3 * 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 are
7 * met: redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer;
9 * redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution;
12 * neither the name of the copyright holders nor the names of its
13 * contributors may be used to endorse or promote products derived from
14 * this software without specific prior written permission.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
17 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
18 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
19 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
20 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
21 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
22 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
26 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 *
28 * Authors: Nathan Binkert
29 */
30
31#ifndef __BASE_ATOMICIO_HH__
32#define __BASE_ATOMICIO_HH__
33
34#include <unistd.h>
35
36// These functions keep reading/writing, if possible, until all data
37// has been transferred.  Basically, try again when there's no error,
38// but there is data left also retry on EINTR.
39// This function blocks until it is done.
40
41ssize_t atomic_read(int fd, void *s, size_t n);
42ssize_t atomic_write(int fd, const void *s, size_t n);
43
44/**
45 * Statically allocate a string and write it to a file descriptor.
46 *
47 * @warning The return value will from atomic_write will be ignored
48 * which means that errors will be ignored. This is normally fine as
49 * this macro is intended to be used in fatal signal handlers where
50 * error handling might not be feasible.
51 */
52#define STATIC_MSG(fd, m)                                       \
53    do {                                                        \
54        static const char msg[] = m;                            \
55        atomic_write(fd, msg, sizeof(msg) - 1);                 \
56    } while (0)
57
58/**
59 * Statically allocate a string and write it to STDERR.
60 *
61 * @warning The return value will from atomic_write will be ignored
62 * which means that errors will be ignored. This is normally fine as
63 * this macro is intended to be used in fatal signal handlers where
64 * error handling might not be feasible.
65 */
66#define STATIC_ERR(m) STATIC_MSG(STDERR_FILENO, m)
67
68#endif // __BASE_ATOMICIO_HH__
69