lib/isc/random.c

	random.c revision 4a73cf8ee07ae396be20231ac252a24830f3c801
/*
 * Copyright (C) 1999  Internet Software Consortium.
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
 * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
 * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
 * SOFTWARE.
 */

#include <config.h>

#include <stdlib.h>
#include <string.h>

#include <isc/assertions.h>
#include <isc/mutex.h>
#include <isc/once.h>
#include <isc/random.h>

#include "util.h"

static isc_once_t once = ISC_ONCE_INIT;
static isc_mutex_t rand_lock;

static void
initialize_rand(void)
{
    RUNTIME_CHECK(isc_mutex_init(&rand_lock) == ISC_R_SUCCESS);
}

static void
initialize(void)
{
    RUNTIME_CHECK(isc_once_do(&once, initialize_rand) == ISC_R_SUCCESS);
}

isc_result_t
isc_random_init(isc_random_t *r)
{
    REQUIRE(r != NULL);

    r->magic = ISC_RANDOM_MAGIC;
#if 0
    return (isc_mutex_init(&r->lock));
#else
    return (ISC_R_SUCCESS);
#endif
}

isc_result_t
isc_random_invalidate(isc_random_t *r)
{
    isc_result_t result;

    REQUIRE(ISC_RANDOM_VALID(r));

#if 0
    result = isc_mutex_destroy(&r->lock);
#else
    result = ISC_R_SUCCESS;
#endif

    memset(r, 0, sizeof(isc_random_t));

    return (result);
}

void
isc_random_seed(isc_random_t *r, isc_uint32_t seed)
{
    REQUIRE(ISC_RANDOM_VALID(r));

    initialize();

#if 0
    LOCK(&r->lock);
#endif
    LOCK(&rand_lock);
    srand(seed);
    UNLOCK(&rand_lock);
#if 0
    UNLOCK(&r->lock);
#endif
}

void
isc_random_get(isc_random_t *r, isc_uint32_t *val)
{
    REQUIRE(ISC_RANDOM_VALID(r));
    REQUIRE(val != NULL);

    initialize();

#if 0
    LOCK(&r->lock);
#endif
    LOCK(&rand_lock);
    *val = rand();
    UNLOCK(&rand_lock);
#if 0
    UNLOCK(&r->lock);
#endif
}