cgroups/fork_bomb_simple.c

This is cgroups/fork_bomb_simple.c, an example to accompany the book, The Linux Programming Interface.

This file is not printed in the book; it demonstrates Linux features that are not described in the book (typically features that have appeared since the book was published).

In the listing below, the names of Linux system calls and C library functions are hyperlinked to manual pages from the Linux man-pages project, and the names of functions implemented in the book are hyperlinked to the implementations of those functions.

Download cgroups/fork_bomb_simple.c

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main()

/* fork_bomb_simple.c

   A simple fork-bomb program that can be useful when experimenting with
   the cgroups 'pids' controller.

   The program creates as many children as possible. Each child sleeps for
   60 seconds, as does the parent when it can create no more children.
*/
#include <sys/wait.h>
#include "tlpi_hdr.h"

int
main(int argc, char *argv[])
{
    printf("Parent PID = %ld\n", (long) getpid());

    for (int j = 1; ; j++) {
        pid_t childPid = fork();

        if (childPid == 0)      /* Child falls out of loop */
            break;

        if (childPid == -1) {   /* Could not create another child? */
            errMsg("fork");
            break;              /* If so, parent falls out of loop */
        }

        printf("Child %d: PID = %ld\n", j, (long) childPid);
    }

    /* Parent and all children fall through to here */

    sleep(60);
    exit(EXIT_SUCCESS);
}

Download cgroups/fork_bomb_simple.c

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