The resource manager library

Just to show you the utility of the library approach, here's the source for a single-threaded version of /dev/null:

/*
 *  resmgr1.c
 *
 *  /dev/null using the resource manager library
*/
#include <stdio.h>
#include <stdlib.h>
#include <stddef.h>
#include <string.h>
#include <sys/iofunc.h>
#include <sys/dispatch.h>

int main (int argc, char **argv)
{
    dispatch_t              *dpp;
    resmgr_attr_t           resmgr_attr;
    dispatch_context_t      *ctp;
    resmgr_connect_funcs_t  connect_func;
    resmgr_io_funcs_t       io_func;
    iofunc_attr_t           attr;

    // create the dispatch structure
    dpp = dispatch_create_channel ( -1, DISPATCH_FLAG_NOLOCK );
    if (dpp == NULL) {
        perror ("Unable to dispatch_create_channel");
        exit (EXIT_FAILURE);
    }

    // initialize the various data structures
    memset (&resmgr_attr, 0, sizeof (resmgr_attr));
    resmgr_attr.nparts_max = 1;
    resmgr_attr.msg_max_size = 2048;

    // bind default functions into the outcall tables
    iofunc_func_init (_RESMGR_CONNECT_NFUNCS, &connect_func,
                      _RESMGR_IO_NFUNCS, &io_func);
    iofunc_attr_init (&attr, S_IFNAM | 0666, 0, 0);

    // establish a name in the pathname space
    if (resmgr_attach (dpp, &resmgr_attr, "/dev/mynull",
                       _FTYPE_ANY, 0, &connect_func, &io_func,
                       &attr) == -1) {
        perror ("Unable to resmgr_attach");
        exit (EXIT_FAILURE);
    }

    ctp = dispatch_context_alloc (dpp);

    // wait here forever, handling messages
    while (1) {
        if ((ctp = dispatch_block (ctp)) == NULL) {
            perror ("Unable to dispatch_block");
            exit (EXIT_FAILURE);
        }
        dispatch_handler (ctp);
    }
}