[thirdparty/systemd.git] / src / basic / barrier.h

#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 <stdbool.h>
#include <stdint.h>
#include <sys/types.h>

#include "macro.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);
}
Commit	Line	Data
279da1e3 DH	1	#pragma once
	2
	3	/***
	4	This file is part of systemd.
	5
	6	Copyright 2014 David Herrmann <dh.herrmann@gmail.com>
	7
	8	systemd is free software; you can redistribute it and/or modify it
	9	under the terms of the GNU Lesser General Public License as published by
	10	the Free Software Foundation; either version 2.1 of the License, or
	11	(at your option) any later version.
	12
	13	systemd is distributed in the hope that it will be useful, but
	14	WITHOUT ANY WARRANTY; without even the implied warranty of
	15	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	16	Lesser General Public License for more details.
	17
	18	You should have received a copy of the GNU Lesser General Public License
	19	along with systemd; If not, see <http://www.gnu.org/licenses/>.
	20	***/
	21
11c3a366 TA	22	#include <stdbool.h>
11c3a366 TA	23	#include <stdint.h>
279da1e3 DH	24	#include <sys/types.h>
	25
	26	#include "macro.h"
279da1e3 DH	27
	28	/* See source file for an API description. */
	29
	30	typedef struct Barrier Barrier;
	31
	32	enum {
	33	BARRIER_SINGLE = 1LL,
	34	BARRIER_ABORTION = INT64_MAX,
	35
	36	/* bias values to store state; keep @WE < @THEY < @I */
	37	BARRIER_BIAS = INT64_MIN,
	38	BARRIER_WE_ABORTED = BARRIER_BIAS + 1LL,
	39	BARRIER_THEY_ABORTED = BARRIER_BIAS + 2LL,
	40	BARRIER_I_ABORTED = BARRIER_BIAS + 3LL,
	41	};
	42
	43	enum {
	44	BARRIER_PARENT,
	45	BARRIER_CHILD,
	46	};
	47
	48	struct Barrier {
	49	int me;
	50	int them;
	51	int pipe[2];
	52	int64_t barriers;
	53	};
	54
7566e267 ZJS	55	#define BARRIER_NULL {-1, -1, {-1, -1}, 0}
	56
	57	int barrier_create(Barrier *obj);
279da1e3 DH	58	void barrier_destroy(Barrier *b);
279da1e3 DH	59
fc808616 DH	60	DEFINE_TRIVIAL_CLEANUP_FUNC(Barrier*, barrier_destroy);
fc808616 DH	61
279da1e3 DH	62	void barrier_set_role(Barrier *b, unsigned int role);
	63
	64	bool barrier_place(Barrier *b);
	65	bool barrier_abort(Barrier *b);
	66
	67	bool barrier_wait_next(Barrier *b);
	68	bool barrier_wait_abortion(Barrier *b);
	69	bool barrier_sync_next(Barrier *b);
	70	bool barrier_sync(Barrier *b);
	71
	72	static inline bool barrier_i_aborted(Barrier *b) {
	73	return b->barriers == BARRIER_I_ABORTED \|\| b->barriers == BARRIER_WE_ABORTED;
	74	}
	75
	76	static inline bool barrier_they_aborted(Barrier *b) {
	77	return b->barriers == BARRIER_THEY_ABORTED \|\| b->barriers == BARRIER_WE_ABORTED;
	78	}
	79
	80	static inline bool barrier_we_aborted(Barrier *b) {
	81	return b->barriers == BARRIER_WE_ABORTED;
	82	}
	83
	84	static inline bool barrier_is_aborted(Barrier *b) {
	85	return b->barriers == BARRIER_I_ABORTED \|\| b->barriers == BARRIER_THEY_ABORTED \|\| b->barriers == BARRIER_WE_ABORTED;
	86	}
	87
	88	static inline bool barrier_place_and_sync(Barrier *b) {
dc751688	89	(void) barrier_place(b);
279da1e3 DH	90	return barrier_sync(b);
279da1e3 DH	91	}