[cw]
    /*
     * Listing 5:
     * delayed the allocation of new server processes
     * Ivan Griffin (ivan.griffin@ul.ie)
     */

    #include <unistd.h>
    #include <setjmp.h>
    #include <signal.h>

    static void _AlarmHandler(int);

    jmp_buf env = { 0 };

    const int NUMBER_SECONDS = 5; /* depends on particular application */ 

    struct sigaction alarmAction = 
    {
        _AlarmHandler, 0, SA_RESTART, NULL
    };


    int main(void)
    {
        /*
         * usual daemon/socket stuff goes here
         */

        sigaction(SIGALRM, &alarmAction, NULL);

        for (;;)
        {
            /*
             * block here on accept() call
             */

            (void) alarm(NUMBER_SECONDS);

            if (setjmp(env) != SIGALRM)  /* if SIGALRM is returned => parent */
            {
                /*
                 * request processing is performed here
                 * if slave, perhaps exit at end?
                 */
            }
        }

        /* never reached */
        return 0;
    }


    void _AlarmHandler(int signal)
    {
        int pid = fork();

        switch (pid)
        {
        case -1: perror("fork()");
                 exit(1);
                 break;

        case 0:  /* child */
                 break;

        default: /* parent */
                 longjmp(env, SIGALRM); /* indicate by returning SIGALRM */
                 break;

        }
    }

[ecw]

<B>Listing 5. Delayed process allocation.<B>