/*****************************************************************************\
 *  backfill_wrapper.c - plugin for Slurm backfill scheduler.
 *  Operates like FIFO, but backfill scheduler daemon will explicitly modify
 *  the priority of jobs as needed to achieve backfill scheduling.
 *****************************************************************************
 *  Copyright (C) 2003 The Regents of the University of California.
 *  Produced at Lawrence Livermore National Laboratory (cf, DISCLAIMER).
 *  Written by Jay Windley <jwindley@lnxi.com>, Morris Jette <jette1@llnl.gov>
 *  CODE-OCEC-09-009. All rights reserved.
 *
 *  This file is part of Slurm, a resource management program.
 *  For details, see <https://slurm.schedmd.com/>.
 *  Please also read the included file: DISCLAIMER.
 *
 *  Slurm 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 2 of the License, or (at your option)
 *  any later version.
 *
 *  In addition, as a special exception, the copyright holders give permission
 *  to link the code of portions of this program with the OpenSSL library under
 *  certain conditions as described in each individual source file, and
 *  distribute linked combinations including the two. You must obey the GNU
 *  General Public License in all respects for all of the code used other than
 *  OpenSSL. If you modify file(s) with this exception, you may extend this
 *  exception to your version of the file(s), but you are not obligated to do
 *  so. If you do not wish to do so, delete this exception statement from your
 *  version.  If you delete this exception statement from all source files in
 *  the program, then also delete it here.
 *
 *  Slurm 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 Slurm; if not, write to the Free Software Foundation, Inc.,
 *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301  USA.
\*****************************************************************************/

#include <pthread.h>
#include <stdio.h>
#include <unistd.h>

#include "slurm/slurm_errno.h"

#include "src/common/plugin.h"
#include "src/common/log.h"
#include "src/common/macros.h"
#include "src/slurmctld/slurmctld.h"
#include "backfill.h"

const char plugin_name[] = "Slurm Backfill Scheduler plugin";
const char plugin_type[] = "sched/backfill";
const uint32_t plugin_version = SLURM_VERSION_NUMBER;

static pthread_t backfill_thread = 0;
static pthread_mutex_t thread_flag_mutex = PTHREAD_MUTEX_INITIALIZER;

extern int init(void)
{
	if (slurmctld_config.scheduling_disabled)
		return SLURM_SUCCESS;

	sched_verbose("Backfill scheduler plugin loaded");

	slurm_mutex_lock(&thread_flag_mutex);
	if (backfill_thread) {
		debug2("Backfill thread already running, not starting another");
		slurm_mutex_unlock(&thread_flag_mutex);
		return SLURM_ERROR;
	}

	/* since we do a join on this later we don't make it detached */
	slurm_thread_create(&backfill_thread, backfill_agent, NULL);

	slurm_mutex_unlock(&thread_flag_mutex);

	return SLURM_SUCCESS;
}

extern void fini(void)
{
	slurm_mutex_lock(&thread_flag_mutex);
	if (backfill_thread) {
		verbose("Backfill scheduler plugin shutting down");
		stop_backfill_agent();
		slurm_thread_join(backfill_thread);
	}
	slurm_mutex_unlock(&thread_flag_mutex);
}

extern int sched_p_reconfig(void)
{
	backfill_reconfig();
	return SLURM_SUCCESS;
}