/*      $NetBSD: h_execthr.c,v 1.7 2016/11/24 00:37:29 dholland Exp $   */

/*
 * Copyright (c) 2011 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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/sysctl.h>

#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <pthread.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include <rump/rumpclient.h>
#include <rump/rump_syscalls.h>

//#define VERBOSE

#ifdef VERBOSE
#define SAY(...) printf(__VA_ARGS__)
#else
#define SAY(...)
#endif

static int canreturn = 0;

/*
 * Use a fairly large number of threads so that we have
 * a better chance catching races.  XXX: this is rumpuser's
 * MAXWORKER-1.
 */
#define NTHR 63

#define P1_0 3
#define P1_1 4
#define P2_0 5
#define P2_1 6

static void *
wrk(void *arg)
{
        int fd = (uintptr_t)arg;

        rump_sys_read(fd, &fd, sizeof(fd));
        if (!canreturn)
                errx(1, "should not have returned");
        if (fd != 37)
                errx(1, "got invalid magic");

        return NULL;
}

static int
getproc(pid_t mypid, struct kinfo_proc2 *p)
{
        int name[6];
        size_t len = sizeof(*p);

        name[0] = CTL_KERN;
        name[1] = KERN_PROC2;
        name[2] = KERN_PROC_PID;
        name[3] = mypid;
        name[4] = len;
        name[5] = 1;

        return rump_sys___sysctl(name, __arraycount(name), p, &len, NULL, 0);
} 

int
main(int argc, char *argv[], char *envp[])
{
        struct kinfo_proc2 p;
        char *execarg[3];
        int p1[2], p2[2];
        pid_t mypid;
        pthread_t pt;
        ssize_t n;
        int i, execd;
        char nexec[16];

        if (argc > 1)
                execd = atoi(argv[1]);
        else
                execd = 0;
        sprintf(nexec, "%d", execd+1);
        SAY("execd: %d\n", execd);

        if (rumpclient_init() == -1) {
                if (execd)
                        err(1, "init execd");
                else
                        err(1, "init");
        }
        mypid = rump_sys_getpid();
        SAY("rumpclient_init finished.\n");

        if (execd) {
                canreturn = 1;
                errno = pthread_create(&pt, NULL,
                    wrk, (void *)(uintptr_t)P2_0);
                if (errno != 0)
                        err(1, "exec pthread_create");
                SAY("startup pthread_create finished.\n");

                i = 37;
                rump_sys_write(P2_1, &i, sizeof(i));
                pthread_join(pt, NULL);
                SAY("startup pthread_join finished.\n");

                n = rump_sys_read(P1_0, &i, sizeof(i));
                if (n != -1 || errno != EBADF)
                        errx(1, "post-exec cloexec works");
                SAY("startup rump_sys_read finished.\n");

                getproc(mypid, &p);
                SAY("startup getproc finished.\n");
                if (p.p_nlwps != 2)
                        errx(1, "invalid nlwps: %lld", (long long)p.p_nlwps);

                /* we passed? */
                if (execd > 10) {
                        SAY("done.\n");
                        exit(0);
                }

                rump_sys_close(P2_0);
                rump_sys_close(P2_1);
        }

        SAY("making pipes...\n");

        if (rump_sys_pipe(p1) == -1)
                err(1, "pipe1");
        if (p1[0] != P1_0 || p1[1] != P1_1)
                errx(1, "p1 assumptions failed %d %d", p1[0], p1[1]);
        if (rump_sys_pipe(p2) == -1)
                err(1, "pipe1");
        if (p2[0] != P2_0 || p2[1] != P2_1)
                errx(1, "p2 assumptions failed");
        if (rump_sys_fcntl(p1[0], F_SETFD, FD_CLOEXEC) == -1)
                err(1, "cloexec");
        if (rump_sys_fcntl(p1[1], F_SETFD, FD_CLOEXEC) == -1)
                err(1, "cloexec");

        SAY("making threads...\n");

        for (i = 0; i < NTHR; i++) {
                errno = pthread_create(&pt, NULL,
                    wrk, (void *)(uintptr_t)p1[0]);
                if (errno != 0)
                        err(1, "pthread_create 1 %d", i);
        }

        for (i = 0; i < NTHR; i++) {
                errno = pthread_create(&pt, NULL,
                    wrk, (void *)(uintptr_t)p2[0]);
                if (errno != 0)
                        err(1, "pthread_create 2 %d", i);
        }

        SAY("waiting for threads to start...\n");

        /* wait for all the threads to be enjoying themselves */
        for (;;) {
                getproc(mypid, &p);
                SAY("getproc finished.\n");
                if (p.p_nlwps == 2*NTHR + 2)
                        break;
                usleep(10000);
        }

        SAY("making some more threads start...\n");

        /*
         * load up one more (big) set.  these won't start executing, though,
         * but we're interested in if they create blockage
         */
        for (i = 0; i < 3*NTHR; i++) {
                errno = pthread_create(&pt, NULL,
                    wrk, (void *)(uintptr_t)p1[0]);
                if (errno != 0)
                        err(1, "pthread_create 3 %d", i);
        }

        SAY("calling exec...\n");

        /* then, we exec! */
        execarg[0] = argv[0];
        execarg[1] = nexec;
        execarg[2] = NULL;
        if (rumpclient_exec(argv[0], execarg, envp) == -1)
                err(1, "exec");
}