/*-*- 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); }