Function exipc_post_config

modules/examples/mod_example_ipc.c:119–189

 */

static int exipc_post_config(apr_pool_t *pconf, apr_pool_t *plog,
                             apr_pool_t *ptemp, server_rec *s)
{
    apr_status_t rs;
    exipc_data *base;
    const char *tempdir;


    /*
     * Do nothing if we are not creating the final configuration.
     * The parent process gets initialized a couple of times as the
     * server starts up, and we don't want to create any more mutexes
     * and shared memory segments than we're actually going to use.
     */
    if (ap_state_query(AP_SQ_MAIN_STATE) == AP_SQ_MS_CREATE_PRE_CONFIG)
        return OK;

    /*
     * The shared memory allocation routines take a file name.
     * Depending on system-specific implementation of these
     * routines, that file may or may not actually be created. We'd
     * like to store those files in the operating system's designated
     * temporary directory, which APR can point us to.
     */
    rs = apr_temp_dir_get(&tempdir, pconf);
    if (APR_SUCCESS != rs) {
        ap_log_error(APLOG_MARK, APLOG_ERR, rs, s, APLOGNO(02992)
                     "Failed to find temporary directory");
        return HTTP_INTERNAL_SERVER_ERROR;
    }

    /* Create the shared memory segment */

    /*
     * Create a unique filename using our pid. This information is
     * stashed in the global variable so the children inherit it.
     */
    shmfilename = apr_psprintf(pconf, "%s/httpd_shm.%ld", tempdir,
                               (long int)getpid());

    /* Now create that segment */
    rs = apr_shm_create(&exipc_shm, sizeof(exipc_data),
                        (const char *) shmfilename, pconf);
    if (APR_SUCCESS != rs) {
        ap_log_error(APLOG_MARK, APLOG_ERR, rs, s, APLOGNO(02993)
                     "Failed to create shared memory segment on file %s",
                     shmfilename);
        return HTTP_INTERNAL_SERVER_ERROR;
    }

    /* Created it, now let's zero it out */
    base = (exipc_data *)apr_shm_baseaddr_get(exipc_shm);
    base->counter = 0;

    /* Create global mutex */

    rs = ap_global_mutex_create(&exipc_mutex, NULL, exipc_mutex_type, NULL,
                                s, pconf, 0);