blob: 27de8fc0e2fe7cc6e996b77ce86ff3927d4c49b6 [file] [log] [blame]
Vitaly Bukacbed2062015-08-17 12:54:05 -07001// Copyright (c) 2012 The Chromium Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5// This provides a wrapper around system calls which may be interrupted by a
6// signal and return EINTR. See man 7 signal.
7// To prevent long-lasting loops (which would likely be a bug, such as a signal
8// that should be masked) to go unnoticed, there is a limit after which the
9// caller will nonetheless see an EINTR in Debug builds.
10//
11// On Windows, this wrapper macro does nothing.
12//
13// Don't wrap close calls in HANDLE_EINTR. Use IGNORE_EINTR if the return
14// value of close is significant. See http://crbug.com/269623.
15
16#ifndef BASE_POSIX_EINTR_WRAPPER_H_
17#define BASE_POSIX_EINTR_WRAPPER_H_
18
Vitaly Buka8750b272015-08-18 18:39:08 -070019#include "base/build/build_config.h"
Vitaly Bukacbed2062015-08-17 12:54:05 -070020
21#if defined(OS_POSIX)
22
23#include <errno.h>
24
25#if defined(NDEBUG)
26
27#define HANDLE_EINTR(x) ({ \
28 decltype(x) eintr_wrapper_result; \
29 do { \
30 eintr_wrapper_result = (x); \
31 } while (eintr_wrapper_result == -1 && errno == EINTR); \
32 eintr_wrapper_result; \
33})
34
35#else
36
37#define HANDLE_EINTR(x) ({ \
38 int eintr_wrapper_counter = 0; \
39 decltype(x) eintr_wrapper_result; \
40 do { \
41 eintr_wrapper_result = (x); \
42 } while (eintr_wrapper_result == -1 && errno == EINTR && \
43 eintr_wrapper_counter++ < 100); \
44 eintr_wrapper_result; \
45})
46
47#endif // NDEBUG
48
49#define IGNORE_EINTR(x) ({ \
50 decltype(x) eintr_wrapper_result; \
51 do { \
52 eintr_wrapper_result = (x); \
53 if (eintr_wrapper_result == -1 && errno == EINTR) { \
54 eintr_wrapper_result = 0; \
55 } \
56 } while (0); \
57 eintr_wrapper_result; \
58})
59
60#else
61
62#define HANDLE_EINTR(x) (x)
63#define IGNORE_EINTR(x) (x)
64
65#endif // OS_POSIX
66
67#endif // BASE_POSIX_EINTR_WRAPPER_H_