//
//         OpenPBS (Portable Batch System) v2.3 Software License
// 
// Copyright (c) 1999-2000 Veridian Information Solutions, Inc.
// All rights reserved.
// 
// ---------------------------------------------------------------------------
// For a license to use or redistribute the OpenPBS software under conditions
// other than those described below, or to purchase support for this software,
// please contact Veridian Systems, PBS Products Department ("Licensor") at:
// 
//    www.OpenPBS.org  +1 650 967-4675                  sales@OpenPBS.org
//                        877 902-4PBS (US toll-free)
// ---------------------------------------------------------------------------
// 
// This license covers use of the OpenPBS v2.3 software (the "Software") at
// your site or location, and, for certain users, redistribution of the
// Software to other sites and locations.  Use and redistribution of
// OpenPBS v2.3 in source and binary forms, with or without modification,
// are permitted provided that all of the following conditions are met.
// After December 31, 2001, only conditions 3-6 must be met:
// 
// 1. Commercial and/or non-commercial use of the Software is permitted
//    provided a current software registration is on file at www.OpenPBS.org.
//    If use of this software contributes to a publication, product, or
//    service, proper attribution must be given; see www.OpenPBS.org/credit.html
// 
// 2. Redistribution in any form is only permitted for non-commercial,
//    non-profit purposes.  There can be no charge for the Software or any
//    software incorporating the Software.  Further, there can be no
//    expectation of revenue generated as a consequence of redistributing
//    the Software.
// 
// 3. Any Redistribution of source code must retain the above copyright notice
//    and the acknowledgment contained in paragraph 6, this list of conditions
//    and the disclaimer contained in paragraph 7.
// 
// 4. Any Redistribution in binary form must reproduce the above copyright
//    notice and the acknowledgment contained in paragraph 6, this list of
//    conditions and the disclaimer contained in paragraph 7 in the
//    documentation and/or other materials provided with the distribution.
// 
// 5. Redistributions in any form must be accompanied by information on how to
//    obtain complete source code for the OpenPBS software and any
//    modifications and/or additions to the OpenPBS software.  The source code
//    must either be included in the distribution or be available for no more
//    than the cost of distribution plus a nominal fee, and all modifications
//    and additions to the Software must be freely redistributable by any party
//    (including Licensor) without restriction.
// 
// 6. All advertising materials mentioning features or use of the Software must
//    display the following acknowledgment:
// 
//     "This product includes software developed by NASA Ames Research Center,
//     Lawrence Livermore National Laboratory, and Veridian Information
//     Solutions, Inc.
//     Visit www.OpenPBS.org for OpenPBS software support,
//     products, and information."
// 
// 7. DISCLAIMER OF WARRANTY
// 
// THIS SOFTWARE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. ANY EXPRESS
// OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
// OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, AND NON-INFRINGEMENT
// ARE EXPRESSLY DISCLAIMED.
// 
// IN NO EVENT SHALL VERIDIAN CORPORATION, ITS AFFILIATED COMPANIES, OR THE
// U.S. GOVERNMENT OR ANY OF ITS AGENCIES BE LIABLE FOR ANY DIRECT OR INDIRECT,
// INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
// OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
// LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
// NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
// EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
// 
// This license will be governed by the laws of the Commonwealth of Virginia,
// without reference to its choice of law rules.
// 
//
// Returns the # of jobs having a "running" state in the que
Int numJobsRunning(Que que)
{
	Set Job jobs;
	Job	j;
	Int	running;

	running = 0;
	jobs = QueJobsGet(que);
	foreach( j in jobs ) {
		if( JobStateGet(j) EQ RUNNING ) {
			running++; 
		}
	}
	return(running);
}

// Returns the # of jobs having a "queued" state in the que
Int numJobsQueued(Que que)
{
	Set Job jobs;
	Job	j;
	Int	queued;

	queued = 0;
	jobs = QueJobsGet(que);
	foreach( j in jobs ) {
		if( JobStateGet(j) EQ QUEUED ) {
			queued++;
		}
	}
	return(queued);
}

// returns the Que in the set of 'queues' named "qname"
Que findQueByName(Set Que queues, String qname)
{
	Que q;

	foreach( q in queues ) {
		if( QueNameGet(q) EQ qname ) {
			return(q);
		}
	}
	return(NOQUE);
}

// print a simple message to stdout.
Void printMsg(String mesg)
{
	DateTime now;

	now      = datetimeGet();
	print(now);
	print("\t");
	print(mesg);
	print("\n");
	
}

// run the first job in the queue.
// Returns: SUCCESS if a job was successfully run;
//	    FAIL otherwise.
Int runFirstJob(Que que)
{
	Set Job jobs;
	Job	j;
	Int	i;
	String  jname;
	String  msg;

	jobs = QueJobsGet(que);
	foreach( j in jobs ) {

		jname = JobIdGet(j);
		// run job synchronously
		if( JobAction(j, SYNCRUN, NULLSTR) EQ SUCCESS ) {
			msg = "run job " + jname;
			printMsg(msg);
			return(SUCCESS);
		} else {
			msg = "run job " + jname + "failed";
			printMsg(msg);
			return(FAIL);
		}
	}
	return(FAIL);
}

// Run eligible jobs that are in master's queue identified by 'qname'
// Returns: SUCCESS if a job was run successfully; FAIL otherwise.
Int run_queue(Server master, String qname)
{
	Set Que  masterqs;
	Que      q;
	Int	 running;
	Int	 queued;
	Que	 newq;
	Int	 stat;

	masterqs = ServerQueuesGet(master);
	q	 = findQueByName(masterqs, qname);

	// Is the queue enabled for scheduling and
        // is it an execution queue ?
	if( QueStateGet(q) EQ SCHED_DISABLED OR
            QueTypeGet(q)  NEQ QTYPE_E ) {
		return(FAIL);
	}

	// Is the queue below the run limit
	if( QueMaxRunJobsGet(q) LE numJobsRunning(q) ) {
		return(FAIL);
	}

	printMsg("go to schedule jobs...");

        //  If the queue is system, queue then don't do alot
        //  of jobs limit checking, just start the job

	newq = QueFilter(q, JobStateGet, OP_EQ, QUEUED);
	if( newq EQ NOQUE ) {
		printMsg("no jobs to run...");
		return(SUCCESS);
	}

	// Just run the first job
	stat = runFirstJob(newq);
	return(stat);
}

// the main scheduling code
sched_main()
{
	Server master;

	// get the local server information
	master = AllServersHeadGet();

	// run a job in the local server's system queue 
	run_queue(master, "system");
}