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// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
// This provides a wrapper around system calls which may be interrupted by a
// signal and return EINTR. See man 7 signal.
// To prevent long-lasting loops (which would likely be a bug, such as a signal
// that should be masked) to go unnoticed, there is a limit after which the
// caller will nonetheless see an EINTR in Debug builds.
//
// On Windows and Fuchsia, this wrapper macro does nothing because there are no
// signals.
//
// Don't wrap close calls in HANDLE_EINTR. Use IGNORE_EINTR if the return
// value of close is significant. See http://crbug.com/269623.
#ifndef BASE_POSIX_EINTR_WRAPPER_H_
#define BASE_POSIX_EINTR_WRAPPER_H_
#include "build/build_config.h"
#if defined(OS_POSIX)
#include <errno.h>
#if defined(NDEBUG)
#define HANDLE_EINTR(x) ({ \
decltype(x) eintr_wrapper_result; \
do { \
eintr_wrapper_result = (x); \
} while (eintr_wrapper_result == -1 && errno == EINTR); \
eintr_wrapper_result; \
})
#else
#define HANDLE_EINTR(x) ({ \
int eintr_wrapper_counter = 0; \
decltype(x) eintr_wrapper_result; \
do { \
eintr_wrapper_result = (x); \
} while (eintr_wrapper_result == -1 && errno == EINTR && \
eintr_wrapper_counter++ < 100); \
eintr_wrapper_result; \
})
#endif // NDEBUG
#define IGNORE_EINTR(x) ({ \
decltype(x) eintr_wrapper_result; \
do { \
eintr_wrapper_result = (x); \
if (eintr_wrapper_result == -1 && errno == EINTR) { \
eintr_wrapper_result = 0; \
} \
} while (0); \
eintr_wrapper_result; \
})
#else // !OS_POSIX
#define HANDLE_EINTR(x) (x)
#define IGNORE_EINTR(x) (x)
#endif // !OS_POSIX
#endif // BASE_POSIX_EINTR_WRAPPER_H_