lib/dns/lib.c

	lib.c revision 0c27b3fe77ac1d5094ba3521e8142d9e7973133f
/*
 * Copyright (C) 1999-2001, 2004, 2005, 2007, 2009, 2013-2016  Internet Systems Consortium, Inc. ("ISC")
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 */

/* $Id: lib.c,v 1.19 2009/09/03 00:12:23 each Exp $ */

/*! \file */

#include <config.h>

#include <stddef.h>

#include <isc/hash.h>
#include <isc/mem.h>
#include <isc/msgcat.h>
#include <isc/mutex.h>
#include <isc/once.h>
#include <isc/util.h>

#include <dns/db.h>
#include <dns/ecdb.h>
#include <dns/lib.h>
#include <dns/result.h>

#include <dst/dst.h>


/***
 *** Globals
 ***/

LIBDNS_EXTERNAL_DATA unsigned int           dns_pps = 0U;
LIBDNS_EXTERNAL_DATA isc_msgcat_t *         dns_msgcat = NULL;


/***
 *** Private
 ***/

static isc_once_t       msgcat_once = ISC_ONCE_INIT;


/***
 *** Functions
 ***/

static void
open_msgcat(void) {
    isc_msgcat_open("libdns.cat", &dns_msgcat);
}

void
dns_lib_initmsgcat(void) {

    /*
     * Initialize the DNS library's message catalog, dns_msgcat, if it
     * has not already been initialized.
     */

    RUNTIME_CHECK(isc_once_do(&msgcat_once, open_msgcat) == ISC_R_SUCCESS);
}

static isc_once_t init_once = ISC_ONCE_INIT;
static isc_mem_t *dns_g_mctx = NULL;
static dns_dbimplementation_t *dbimp = NULL;
static isc_boolean_t initialize_done = ISC_FALSE;
static isc_mutex_t reflock;
static unsigned int references = 0;

static void
initialize(void) {
    isc_result_t result;

    REQUIRE(initialize_done == ISC_FALSE);

    result = isc_mem_create(0, 0, &dns_g_mctx);
    if (result != ISC_R_SUCCESS)
        return;
    dns_result_register();
    result = dns_ecdb_register(dns_g_mctx, &dbimp);
    if (result != ISC_R_SUCCESS)
        goto cleanup_mctx;
    result = isc_hash_create(dns_g_mctx, NULL, DNS_NAME_MAXWIRE);
    if (result != ISC_R_SUCCESS)
        goto cleanup_db;

    result = dst_lib_init(dns_g_mctx, NULL, 0);
    if (result != ISC_R_SUCCESS)
        goto cleanup_hash;

    result = isc_mutex_init(&reflock);
    if (result != ISC_R_SUCCESS)
        goto cleanup_dst;

    initialize_done = ISC_TRUE;
    return;

  cleanup_dst:
    dst_lib_destroy();
  cleanup_hash:
    isc_hash_destroy();
  cleanup_db:
    if (dbimp != NULL)
        dns_ecdb_unregister(&dbimp);
  cleanup_mctx:
    if (dns_g_mctx != NULL)
        isc_mem_detach(&dns_g_mctx);
}

isc_result_t
dns_lib_init(void) {
    isc_result_t result;

    /*
     * Since this routine is expected to be used by a normal application,
     * it should be better to return an error, instead of an emergency
     * abort, on any failure.
     */
    result = isc_once_do(&init_once, initialize);
    if (result != ISC_R_SUCCESS)
        return (result);

    if (!initialize_done)
        return (ISC_R_FAILURE);

    LOCK(&reflock);
    references++;
    UNLOCK(&reflock);

    return (ISC_R_SUCCESS);
}

void
dns_lib_shutdown(void) {
    isc_boolean_t cleanup_ok = ISC_FALSE;

    LOCK(&reflock);
    if (--references == 0)
        cleanup_ok = ISC_TRUE;
    UNLOCK(&reflock);

    if (!cleanup_ok)
        return;

    dst_lib_destroy();

    if (isc_hashctx != NULL)
        isc_hash_destroy();
    if (dbimp != NULL)
        dns_ecdb_unregister(&dbimp);
    if (dns_g_mctx != NULL)
        isc_mem_detach(&dns_g_mctx);
}