75 lines
2.7 KiB
C
75 lines
2.7 KiB
C
/*
|
|
* Copyright (C) 2008 The Android Open Source Project
|
|
* All rights reserved.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
* * Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* * Redistributions in binary form must reproduce the above copyright
|
|
* notice, this list of conditions and the following disclaimer in
|
|
* the documentation and/or other materials provided with the
|
|
* distribution.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
|
|
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
|
|
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
|
|
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
|
|
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
|
|
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
|
|
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
|
|
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
|
|
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
|
|
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
|
|
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
* SUCH DAMAGE.
|
|
*/
|
|
|
|
#pragma once
|
|
|
|
/**
|
|
* @file sys/eventfd.h
|
|
* @brief Event notification file descriptors.
|
|
*/
|
|
|
|
#include <sys/cdefs.h>
|
|
#include <fcntl.h>
|
|
|
|
__BEGIN_DECLS
|
|
|
|
/** The eventfd() flag to provide semaphore-like semantics for reads. */
|
|
#define EFD_SEMAPHORE (1 << 0)
|
|
/** The eventfd() flag for a close-on-exec file descriptor. */
|
|
#define EFD_CLOEXEC O_CLOEXEC
|
|
/** The eventfd() flag for a non-blocking file descriptor. */
|
|
#define EFD_NONBLOCK O_NONBLOCK
|
|
|
|
/**
|
|
* [eventfd(2)](http://man7.org/linux/man-pages/man2/eventfd.2.html) creates a file descriptor
|
|
* for event notification.
|
|
*
|
|
* Returns a new file descriptor on success, and returns -1 and sets `errno` on failure.
|
|
*/
|
|
int eventfd(unsigned int __initial_value, int __flags);
|
|
|
|
/** The type used by eventfd_read() and eventfd_write(). */
|
|
typedef uint64_t eventfd_t;
|
|
|
|
/**
|
|
* [eventfd_read(3)](http://man7.org/linux/man-pages/man2/eventfd.2.html) is a convenience
|
|
* wrapper to read an `eventfd_t` from an eventfd file descriptor.
|
|
*
|
|
* Returns 0 on success, or returns -1 otherwise.
|
|
*/
|
|
int eventfd_read(int __fd, eventfd_t* _Nonnull __value);
|
|
|
|
/**
|
|
* [eventfd_write(3)](http://man7.org/linux/man-pages/man2/eventfd.2.html) is a convenience
|
|
* wrapper to write an `eventfd_t` to an eventfd file descriptor.
|
|
*
|
|
* Returns 0 on success, or returns -1 otherwise.
|
|
*/
|
|
int eventfd_write(int __fd, eventfd_t __value);
|
|
|
|
__END_DECLS
|