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oldlinux-files/gnu/glibc/glibc-1.03/hurd/setdtablesize.c
2024-02-19 00:24:47 -05:00

87 lines
2.4 KiB
C

/* Copyright (C) 1991, 1992 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If
not, write to the Free Software Foundation, Inc., 675 Mass Ave,
Cambridge, MA 02139, USA. */
#include <hurd.h>
/* Change the size of the descriptor table.
You cannot shrink the table if any of the descriptors
which would be removed are being used. */
int
setdtablesize (size_t size)
{
int i;
struct _hurd_fd *table;
__mutex_lock (&_hurd_dtable_lock);
/* Check that no descriptors which are in use are going to disappear. */
for (i = size; i < _hurd_dtable.size; ++i)
{
struct _hurd_fd *const d = &_hurd_dtable.d[i];
__spin_lock (&d->port.lock);
if (d->port.port != MACH_PORT_NULL)
{
__spin_unlock (&d->port.lock);
__mutex_unlock (&_hurd_dtable_lock);
errno = EBUSY;
return -1;
}
}
/* Resize the table. */
if (_hurd_dtable_user_dealloc == NULL)
/* Noone is using the table. We can relocate it. */
table = realloc (_hurd_dtable.d, size * sizeof (*table));
else
/* Someone else is using the table.
We must make a new copy, and let them free the old one. */
table = malloc (size * sizeof (*table));
if (table == NULL)
{
__mutex_unlock (&_hurd_dtable_lock);
return -1;
}
if (_hurd_dtable_user_dealloc != NULL)
{
*_hurd_dtable_user_dealloc = 1;
_hurd_dtable_user_dealloc = NULL;
memcpy (table, _hurd_dtable.d, _hurd_dtable.size * sizeof (table[0]));
}
/* If the table grew, initialize the new slots. */
for (i = _hurd_dtable.size; i < size; ++i)
{
table[i].flags = 0;
_hurd_port_init (&table[i].port, MACH_PORT_NULL);
_hurd_port_init (&table[i].ctty, MACH_PORT_NULL);
}
_hurd_dtable.size = size;
_hurd_dtable.d = table;
__mutex_unlock (&_hurd_dtable_lock);
return 0;
}