/*
 * Chained pipe test with 900,000 processes and 900,000 pipes
 *
 * Requires system w/ 128GB+ of ram, kern.maxproc=4000000 set in
 * /boot/loader.conf.  80 second stabilization time after last
 * process is forked.
 *
 * Also test tear-down by ^C'ing the test.
 */
#include <sys/types.h>
#include <sys/wait.h>
#include <sys/mman.h>
#include <sys/resource.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <signal.h>

#define COUNT   900000

int
main(int ac, char **av)
{
        int status;
        int i;
        int j;
        int idno;
        int fdsbeg[2];
        int fdsend[2];
        char *path;
        char *id;
        char c;

        if (ac == 1) {
                pipe(fdsbeg);
                for (i = 0; i < COUNT; i += 100) {
#if 0
                        asprintf(&path, "cp %s /tmp/x%06d", av[0], i);
                        system(path);
                        free(path);
                        asprintf(&path, "/tmp/x%06d", i);
#else
                        asprintf(&path, "%s", av[0]);
#endif
                        asprintf(&id, "%d", i);
                        pipe(fdsend);
                        if (vfork() == 0) {
                                close(fdsbeg[1]);
                                dup2(fdsbeg[0], 0);
                                dup2(fdsend[1], 1);
                                close(fdsbeg[0]);
                                close(fdsend[1]);
                                execl(path, path, id, NULL);
                                _exit(0);
                        }
                        close(fdsbeg[0]);
                        close(fdsend[1]);
                        fdsbeg[0] = fdsend[0];
                        if (i % 1000 == 0) {
                                printf("running %d\r", i);
                                fflush(stdout);
                        }
                        free(path);
                        free(id);
                }
        } else {
                idno = strtol(av[1], NULL, 0);
                setpriority(PRIO_PROCESS, 0, 5);
                for (j = 0; j < 100; ++j) {
                        if (j != 99)
                                pipe(fdsend);
                        else
                                fdsend[1] = 1;
                        if (j == 99 || fork() == 0) {
                                if (fdsend[1] != 1) {
                                        dup2(fdsend[1], 1);
                                        close(fdsend[1]);
                                }
                                if (j != 99)
                                        close(fdsend[0]);
                                setpriority(PRIO_PROCESS, 0, 15);

                                while (1) {
                                        if (read(0, &c, 1) < 0)
                                                break;
#if 0
                                        fprintf(stderr, "x%d\n", idno + j);
                                        fflush(stderr);
#endif
                                        write(1, &c, 1);
                                }
                                _exit(0);
                        }
                        dup2(fdsend[0], 0);
                        close(fdsend[1]);
                        close(fdsend[0]);
                }
                while (wait3(NULL, 0, NULL) >= 0 || errno == EINTR)
                        ;
                _exit(0);
        }
        printf("running %d\n", i);
        for (;;) {
                write(fdsbeg[1], &c, 1);
                if (read(fdsend[0], &c, 1) < 0)
                        break;
                write(2, "x", 1);
        }
        return 0;
}