You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.

76 lines
2.7 KiB

/*
* 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* __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