source: mainline/uspace/lib/c/generic/stdlib.c@ 275bdafb

/*
 * Copyright (c) 2006 Ondrej Palkovsky
 * Copyright (c) 2018 Jiri Svoboda
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/** @addtogroup libc
 * @{
 */
/** @file
 */

#include <adt/list.h>
#include <fibril_synch.h>
#include <stdlib.h>
#include "private/libc.h"
#include "private/stdlib.h"

static int glbl_seed = 1;

static LIST_INITIALIZE(exit_handlers);
static FIBRIL_MUTEX_INITIALIZE(exit_handlers_lock);

static LIST_INITIALIZE(quick_exit_handlers);
static FIBRIL_MUTEX_INITIALIZE(quick_exit_handlers_lock);


int rand(void)
{
        return glbl_seed = ((1366 * glbl_seed + 150889) % RAND_MAX);
}

void srand(unsigned int seed)
{
        glbl_seed = seed % RAND_MAX;
}

/** Register exit handler.
 *
 * @param func Function to be called during program terimnation
 * @return Zero on success, nonzero on failure
 */
int atexit(void (*func)(void))
{
        __exit_handler_t *entry;

        entry = malloc(sizeof(__exit_handler_t));
        if (entry == NULL)
                return -1;

        entry->func = func;

        fibril_mutex_lock(&exit_handlers_lock);
        list_prepend(&entry->llist, &exit_handlers);
        fibril_mutex_unlock(&exit_handlers_lock);
        return 0;
}

/** Terminate program with exit status.
 *
 * @param status Exit status
 */
void exit(int status)
{
        link_t *link;
        __exit_handler_t *eh;

        /* Call exit handlers */
        fibril_mutex_lock(&exit_handlers_lock);
        while (!list_empty(&exit_handlers)) {
                link = list_first(&exit_handlers);
                list_remove(link);
                fibril_mutex_unlock(&exit_handlers_lock);

                eh = list_get_instance(link, __exit_handler_t, llist);
                eh->func();
                free(eh);
                fibril_mutex_lock(&exit_handlers_lock);
        }

        fibril_mutex_unlock(&exit_handlers_lock);

        _Exit(status);
}

/** Register quick exit handler.
 *
 * @param func Function to be called during quick program terimnation
 * @return Zero on success, nonzero on failure
 */
int at_quick_exit(void (*func)(void))
{
        __exit_handler_t *entry;

        entry = malloc(sizeof(__exit_handler_t));
        if (entry == NULL)
                return -1;

        entry->func = func;

        fibril_mutex_lock(&exit_handlers_lock);
        list_prepend(&entry->llist, &exit_handlers);
        fibril_mutex_unlock(&exit_handlers_lock);
        return 0;
}

/** Quickly terminate program with exit status.
 *
 * @param status Exit status
 */
void quick_exit(int status)
{
        link_t *link;
        __exit_handler_t *eh;

        /* Call quick exit handlers */
        fibril_mutex_lock(&quick_exit_handlers_lock);
        while (!list_empty(&quick_exit_handlers)) {
                link = list_first(&quick_exit_handlers);
                list_remove(link);
                fibril_mutex_unlock(&quick_exit_handlers_lock);

                eh = list_get_instance(link, __exit_handler_t, llist);
                eh->func();
                free(eh);
                fibril_mutex_lock(&quick_exit_handlers_lock);
        }

        fibril_mutex_unlock(&quick_exit_handlers_lock);

        _Exit(status);
}

void _Exit(int status)
{
        __libc_exit(status);
}

/** Abnormal program termination */
void abort(void)
{
        __libc_abort();
}

/** Get environment list entry.
 *
 * Note that this function is not reentrant. The returned string is only
 * guaranteed to be valid until the next call to @c getenv.
 *
 * @param name Entry name
 * @return Pointer to string or @c NULL if not found
 */
char *getenv(const char *name)
{
        (void) name;
        return NULL;
}

/** Execute command.
 *
 * @param string Command to execute or @c NULL
 *
 * @return If @a string is @c NULL, return zero (no command processor
 *         available). If @a string is not @c NULL, return 1 (failure).
 */
int system(const char *string)
{
        if (string == NULL)
                return 0;

        return 1;
}

/** Compute the absolute value of an integer.
 *
 * If the result cannot be represented, the behavior is undefined.
 *
 * @param j Integer
 * @return The absolute value of @a j
 */
int abs(int j)
{
        int aj;

        if (j < 0) {
                aj = -j;
                assert(aj >= 0);
        } else {
                aj = j;
        }

        return aj;
}

/** Compute the absolute value of a long integer.
 *
 * If the result cannot be represented, the behavior is undefined.
 *
 * @param j Long integer
 * @return The absolute value of @a j
 */
long labs(long j)
{
        long aj;

        if (j < 0) {
                aj = -j;
                assert(aj >= 0);
        } else {
                aj = j;
        }

        return aj;
}

/** Compute the absolute value of a long long integer.
 *
 * If the result cannot be represented, the behavior is undefined.
 *
 * @param j Long long integer
 * @return The absolute value of @a j
 */
long long llabs(long long j)
{
        long long aj;

        if (j < 0) {
                aj = -j;
                assert(aj >= 0);
        } else {
                aj = j;
        }

        return aj;
}

/** Compute quotient and remainder of int division.
 *
 * @param numer Numerator
 * @param denom Denominator
 * @return Structure containing quotient and remainder
 */
div_t div(int numer, int denom)
{
        div_t d;

        d.quot = numer / denom;
        d.rem = numer % denom;

        return d;
}

/** Compute quotient and remainder of long division.
 *
 * @param numer Numerator
 * @param denom Denominator
 * @return Structure containing quotient and remainder
 */
ldiv_t ldiv(long numer, long denom)
{
        ldiv_t d;

        d.quot = numer / denom;
        d.rem = numer % denom;

        return d;
}

/** Compute quotient and remainder of long long division.
 *
 * @param numer Numerator
 * @param denom Denominator
 * @return Structure containing quotient and remainder
 */
lldiv_t lldiv(long long numer, long long denom)
{
        lldiv_t d;

        d.quot = numer / denom;
        d.rem = numer % denom;

        return d;
}

/** @}
 */