/*
 * Copyright (c) 2012 The DragonFly Project.  All rights reserved.
 *
 * This code is derived from software contributed to The DragonFly Project
 * by Matthew Dillon <dillon@backplane.com> and Thomas Nikolajsen
 * <thomas.nikolajsen@mail.dk>
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 * 3. Neither the name of The DragonFly Project nor the names of its
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific, prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, 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.
 */

#include <sys/types.h>
#include <sys/usched.h>
#include <sys/cpumask.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>

static void usage(void);

int DebugOpt;

int
main(int ac, char **av)
{
        int ch;
        int res;
        char *sched = NULL;
        char *cpustr = NULL;
        char *sched_cpustr = NULL;
        char *p = NULL;
        cpumask_t cpumask;
        int cpuid;
        pid_t pid = getpid();  /* See usched_set(2) - BUGS */

        CPUMASK_ASSZERO(cpumask);

        while ((ch = getopt(ac, av, "d")) != -1) {
                switch (ch) {
                case 'd':
                        DebugOpt = 1;
                        break;
                default:
                        usage();
                        /* NOTREACHED */
                }
        }
        ac -= optind;
        av += optind;

        if (ac < 2) {
                usage();
                /* NOTREACHED */
        }
        sched_cpustr = strdup(av[0]);
        sched = strsep(&sched_cpustr, ":");
        if (strcmp(sched, "default") == 0)
                fprintf(stderr,
                        "Ignoring scheduler == \"default\": "
                        "not implemented\n");
        cpustr = strsep(&sched_cpustr, "");
        if (strlen(sched) == 0 && cpustr == NULL) {
                usage();
                /* NOTREACHED */
        }

        /*
         * XXX needs expanded support for > 64 cpus
         */
        if (cpustr != NULL) {
                uint64_t v;
                int baseid;
                char *ptr = cpustr;

                baseid = 0;
                for (;;) {
                        if (baseid >= CPU_SETSIZE) {
                                fprintf(stderr, "cpumask too large\n");
                                usage();
                        }
                        v = (uint64_t)strtoull(ptr, &ptr, 0);
                        for (cpuid = 0; cpuid < (int)sizeof(v) * 8; ++cpuid) {
                                if (v & (1LU << cpuid))
                                        CPUMASK_ORBIT(cpumask, baseid + cpuid);
                        }
                        if (*ptr == 0)
                                break;
                        if (*ptr != ',') {
                                fprintf(stderr, "cpumask format error\n");
                                usage();
                        }
                        ++ptr;
                        baseid += (int)sizeof(v) * 8;
                }
        }

        if (strlen(sched) != 0) {
                if (DebugOpt) {
                        fprintf(stderr,
                                "DEBUG: USCHED_SET_SCHEDULER: scheduler: %s\n",
                                sched);
                }
                res = usched_set(pid, USCHED_SET_SCHEDULER,
                                 sched, strlen(sched));
                if (res != 0) {
                        asprintf(&p,
                                "usched_set(%d, USCHED_SET_SCHEDULER, "
                                "\"%s\", %d)",
                                pid, sched, (int)strlen(sched));
                        perror(p);
                        exit(1);
                }
        }
        if (CPUMASK_TESTNZERO(cpumask)) {
                for (cpuid = 0; cpuid < CPU_SETSIZE; ++cpuid) {
                        if (CPUMASK_TESTBIT(cpumask, cpuid))
                                break;
                }
                if (DebugOpt) {
                        fprintf(stderr, "DEBUG: USCHED_SET_CPU: cpuid: %d\n",
                                cpuid);
                }
                res = usched_set(pid, USCHED_SET_CPU, &cpuid, sizeof(int));
                if (res != 0) {
                        asprintf(&p, "usched_set(%d, USCHED_SET_CPU, &%d, %d)",
                                pid, cpuid, (int)sizeof(int));
                        perror(p);
                        exit(1);
                }
                CPUMASK_NANDBIT(cpumask, cpuid);
                while (CPUMASK_TESTNZERO(cpumask)) {
                        ++cpuid;
                        if (CPUMASK_TESTBIT(cpumask, cpuid) == 0)
                                continue;
                        CPUMASK_NANDBIT(cpumask, cpuid);
                        if (DebugOpt) {
                                fprintf(stderr,
                                        "DEBUG: USCHED_ADD_CPU: cpuid: %d\n",
                                        cpuid);
                        }
                        res = usched_set(pid, USCHED_ADD_CPU,
                                         &cpuid, sizeof(int));
                        if (res != 0) {
                                asprintf(&p,
                                        "usched_set(%d, USCHED_ADD_CPU, "
                                        "&%d, %d)",
                                        pid, cpuid, (int)sizeof(int));
                                perror(p);
                                exit(1);
                        }
                }
        }
        execvp(av[1], av + 1);
        exit(1);
}

static
void
usage(void)
{
        fprintf(stderr,
                "usage: usched [-d] {scheduler[:cpumask] | :cpumask} "
                "program [argument ...]\n");
        fprintf(stderr,
                "cpumask format: val[,val[,val[,val]]] in 64-bit chunks, "
                "lsb chunk first\n");
        exit(1);
}