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/*
Authors:
Jan Cholasta <jcholast@redhat.com>
Copyright (C) 2012 Red Hat
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef __SSSD_ATOMIC_IO_H__
#define __SSSD_ATOMIC_IO_H__
#include <unistd.h>
#include <stdbool.h>
#include <poll.h>
#include <errno.h>
/* Performs a read or write operation in an manner that is seemingly atomic
* to the caller.
*
* Please note that the function does not perform any asynchronous operation
* so the operation might potentially block
*/
ssize_t sss_atomic_io_s(int fd, void *buf, size_t n, bool do_read);
#define sss_atomic_read_s(fd, buf, n) sss_atomic_io_s(fd, buf, n, true)
#define sss_atomic_write_s(fd, buf, n) sss_atomic_io_s(fd, buf, n, false)
/**
* Write length of the buffer then the buffer itself.
*
* (uint32_t)length + buffer
*/
ssize_t sss_atomic_write_safe_s(int fd, void *buf, size_t len);
/**
* First, read uint32_t as a message length, then read the rest of the message
* expecting given length. The exact length is returned in _len parameter.
*/
ssize_t sss_atomic_read_safe_s(int fd, void *buf, size_t max_len, size_t *_len);
#endif /* __SSSD_ATOMIC_IO_H__ */
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