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/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
#pragma once
/***
This file is part of systemd.
Copyright 2014 David Herrmann <dh.herrmann@gmail.com>
systemd is free software; you can redistribute it and/or modify it
under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version.
systemd 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/
#include <errno.h>
#include <inttypes.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include "macro.h"
#include "util.h"
/* See source file for an API description. */
typedef struct Barrier Barrier;
enum {
BARRIER_SINGLE = 1LL,
BARRIER_ABORTION = INT64_MAX,
/* bias values to store state; keep @WE < @THEY < @I */
BARRIER_BIAS = INT64_MIN,
BARRIER_WE_ABORTED = BARRIER_BIAS + 1LL,
BARRIER_THEY_ABORTED = BARRIER_BIAS + 2LL,
BARRIER_I_ABORTED = BARRIER_BIAS + 3LL,
};
enum {
BARRIER_PARENT,
BARRIER_CHILD,
};
struct Barrier {
int me;
int them;
int pipe[2];
int64_t barriers;
};
#define BARRIER_NULL {-1, -1, {-1, -1}, 0}
int barrier_create(Barrier *obj);
void barrier_destroy(Barrier *b);
DEFINE_TRIVIAL_CLEANUP_FUNC(Barrier*, barrier_destroy);
void barrier_set_role(Barrier *b, unsigned int role);
bool barrier_place(Barrier *b);
bool barrier_abort(Barrier *b);
bool barrier_wait_next(Barrier *b);
bool barrier_wait_abortion(Barrier *b);
bool barrier_sync_next(Barrier *b);
bool barrier_sync(Barrier *b);
static inline bool barrier_i_aborted(Barrier *b) {
return b->barriers == BARRIER_I_ABORTED || b->barriers == BARRIER_WE_ABORTED;
}
static inline bool barrier_they_aborted(Barrier *b) {
return b->barriers == BARRIER_THEY_ABORTED || b->barriers == BARRIER_WE_ABORTED;
}
static inline bool barrier_we_aborted(Barrier *b) {
return b->barriers == BARRIER_WE_ABORTED;
}
static inline bool barrier_is_aborted(Barrier *b) {
return b->barriers == BARRIER_I_ABORTED || b->barriers == BARRIER_THEY_ABORTED || b->barriers == BARRIER_WE_ABORTED;
}
static inline bool barrier_place_and_sync(Barrier *b) {
(void)barrier_place(b);
return barrier_sync(b);
}
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