/*      $OpenBSD: job.c,v 1.15 2020/04/17 02:12:56 millert Exp $        */

/* Copyright 1988,1990,1993,1994 by Paul Vixie
 * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
 * Copyright (c) 1997,2000 by Internet Software Consortium, Inc.
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
 * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <sys/types.h>

#include <bitstring.h>          /* for structs.h */
#include <stdio.h>
#include <stdlib.h>
#include <syslog.h>
#include <time.h>               /* for structs.h */

#include "macros.h"
#include "structs.h"
#include "funcs.h"

typedef struct _job {
        SIMPLEQ_ENTRY(_job) entries;
        entry           *e;
        user            *u;
        pid_t           pid;
} job;


static SIMPLEQ_HEAD(job_queue, _job) jobs = SIMPLEQ_HEAD_INITIALIZER(jobs);

void
job_add(entry *e, user *u)
{
        job *j;

        /* if already on queue, keep going */
        SIMPLEQ_FOREACH(j, &jobs, entries) {
                if (j->e == e && j->u == u) {
                        if ((j->e->flags & DONT_LOG) == 0) {
                                syslog(LOG_INFO, "(%s) SKIPPING (%s)",
                                    j->u->name, j->e->cmd);
                        }
                        return;
                }
        }

        /* build a job queue element */
        if ((j = malloc(sizeof(job))) == NULL)
                return;
        j->e = e;
        j->u = u;
        j->pid = -1;

        /* add it to the tail */
        SIMPLEQ_INSERT_TAIL(&jobs, j, entries);
}

void
job_remove(entry *e, user *u)
{
        job *j, *prev = NULL;

        SIMPLEQ_FOREACH(j, &jobs, entries) {
                if (j->e == e && j->u == u) {
                        if (prev == NULL)
                                SIMPLEQ_REMOVE_HEAD(&jobs, entries);
                        else
                                SIMPLEQ_REMOVE_AFTER(&jobs, prev, entries);
                        free(j);
                        break;
                }
                prev = j;
        }
}

void
job_exit(pid_t jobpid)
{
        job *j, *prev = NULL;

        /* If a singleton exited, remove and free it. */
        SIMPLEQ_FOREACH(j, &jobs, entries) {
                if (jobpid == j->pid) {
                        if (prev == NULL)
                                SIMPLEQ_REMOVE_HEAD(&jobs, entries);
                        else
                                SIMPLEQ_REMOVE_AFTER(&jobs, prev, entries);
                        free(j);
                        break;
                }
                prev = j;
        }
}

int
job_runqueue(void)
{
        struct job_queue singletons = SIMPLEQ_HEAD_INITIALIZER(singletons);
        job *j;
        int run = 0;

        while ((j = SIMPLEQ_FIRST(&jobs))) {
                SIMPLEQ_REMOVE_HEAD(&jobs, entries);

                /* Only start the job if it is not a running singleton. */
                if (j->pid == -1) {
                        j->pid = do_command(j->e, j->u);
                        run++;
                }

                /* Singleton jobs persist in the queue until they exit. */
                if (j->pid != -1)
                        SIMPLEQ_INSERT_TAIL(&singletons, j, entries);
                else
                        free(j);
        }
        SIMPLEQ_CONCAT(&jobs, &singletons);
        return (run);
}