/*
 * This software is part of the SBCL system. See the README file for
 * more information.
 *
 * This software is derived from the CMU CL system, which was
 * written at Carnegie Mellon University and released into the
 * public domain. The software is in the public domain and is
 * provided with absolutely no warranty. See the COPYING and CREDITS
 * files for more information.
 */

#include <stdio.h>
#include <errno.h>
#include <string.h>

#include "sbcl.h"
#include "os.h"
#include "interr.h"

/* Except for os_zero, these routines are only called by Lisp code.
 * These routines may also be replaced by os-dependent versions
 * instead. See hpux-os.c for some useful restrictions on actual
 * usage. */

void
os_zero(os_vm_address_t addr, os_vm_size_t length)
{
    os_vm_address_t block_start;
    os_vm_size_t block_size;

#ifdef DEBUG
    fprintf(stderr,";;; os_zero: addr: 0x%08x, len: 0x%08x\n",addr,length);
#endif

    block_start = os_round_up_to_page(addr);

    length -= block_start-addr;
    block_size = os_trunc_size_to_page(length);

    if (block_start > addr)
        bzero((char *)addr, block_start-addr);
    if (block_size < length)
        bzero((char *)block_start+block_size, length-block_size);

    if (block_size != 0) {
        /* Now deallocate and allocate the block so that it faults in
         * zero-filled. */

        os_invalidate(block_start, block_size);
        addr = os_validate(block_start, block_size);

        if (addr == NULL || addr != block_start)
            lose("os_zero: block moved! 0x%08x ==> 0x%08x\n",
                 block_start,
                 addr);
    }
}

os_vm_address_t
os_allocate(os_vm_size_t len)
{
    return os_validate((os_vm_address_t)NULL, len);
}

void
os_deallocate(os_vm_address_t addr, os_vm_size_t len)
{
    os_invalidate(addr,len);
}

int
os_get_errno(void)
{
    return errno;
}