93 lines
2.5 KiB
C
93 lines
2.5 KiB
C
#pragma once
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/***
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This file is part of systemd.
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Copyright 2014 David Herrmann <dh.herrmann@gmail.com>
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systemd is free software; you can redistribute it and/or modify it
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under the terms of the GNU Lesser General Public License as published by
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the Free Software Foundation; either version 2.1 of the License, or
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(at your option) any later version.
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systemd is distributed in the hope that it will be useful, but
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WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public License
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along with systemd; If not, see <http://www.gnu.org/licenses/>.
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***/
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#include <stdbool.h>
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#include <stdint.h>
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#include <sys/types.h>
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#include "macro.h"
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/* See source file for an API description. */
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typedef struct Barrier Barrier;
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enum {
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BARRIER_SINGLE = 1LL,
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BARRIER_ABORTION = INT64_MAX,
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/* bias values to store state; keep @WE < @THEY < @I */
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BARRIER_BIAS = INT64_MIN,
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BARRIER_WE_ABORTED = BARRIER_BIAS + 1LL,
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BARRIER_THEY_ABORTED = BARRIER_BIAS + 2LL,
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BARRIER_I_ABORTED = BARRIER_BIAS + 3LL,
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};
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enum {
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BARRIER_PARENT,
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BARRIER_CHILD,
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};
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struct Barrier {
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int me;
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int them;
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int pipe[2];
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int64_t barriers;
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};
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#define BARRIER_NULL {-1, -1, {-1, -1}, 0}
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int barrier_create(Barrier *obj);
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void barrier_destroy(Barrier *b);
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DEFINE_TRIVIAL_CLEANUP_FUNC(Barrier*, barrier_destroy);
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void barrier_set_role(Barrier *b, unsigned int role);
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bool barrier_place(Barrier *b);
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bool barrier_abort(Barrier *b);
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bool barrier_wait_next(Barrier *b);
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bool barrier_wait_abortion(Barrier *b);
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bool barrier_sync_next(Barrier *b);
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bool barrier_sync(Barrier *b);
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static inline bool barrier_i_aborted(Barrier *b) {
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return IN_SET(b->barriers, BARRIER_I_ABORTED, BARRIER_WE_ABORTED);
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}
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static inline bool barrier_they_aborted(Barrier *b) {
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return IN_SET(b->barriers, BARRIER_THEY_ABORTED, BARRIER_WE_ABORTED);
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}
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static inline bool barrier_we_aborted(Barrier *b) {
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return b->barriers == BARRIER_WE_ABORTED;
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}
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static inline bool barrier_is_aborted(Barrier *b) {
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return IN_SET(b->barriers, BARRIER_I_ABORTED, BARRIER_THEY_ABORTED,
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BARRIER_WE_ABORTED);
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}
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static inline bool barrier_place_and_sync(Barrier *b) {
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(void) barrier_place(b);
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return barrier_sync(b);
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}
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