mes/lib/gnu/io-write.c

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/* -*-comment-start: "//";comment-end:""-*-
* GNU Mes --- Maxwell Equations of Software
* Copyright © 2019 Jan (janneke) Nieuwenhuizen <janneke@gnu.org>
*
* This file is part of GNU Mes.
*
* GNU Mes is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 3 of the License, or (at
* your option) any later version.
*
* GNU Mes 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with GNU Mes. If not, see <http://www.gnu.org/licenses/>.
*/
#include <gnu/syscall.h>
struct mach_msg_pointer_loff
{
mach_msg_header_t header;
mach_msg_type_long_t type_one; char *one;
mach_msg_type_t type_two; loff_t two;
};
kern_return_t
__io_write (io_t io, data_t data, mach_msg_type_number_t size, loff_t offset, vm_size_t *wrote)
{
struct mach_msg_pointer_loff message = {0};
message.header.msgh_size = sizeof (struct mach_msg_pointer_loff);
message.type_one = mach_msg_type_pointer;
message.one = data;
message.type_two = mach_msg_type_int64;
message.two = offset;
message.type_one.msgtl_number = size;
message.type_one.msgtl_header.msgt_inline = 0;
message.header.msgh_bits = MACH_MSGH_BITS_COMPLEX;
kern_return_t result = __syscall_put (io, SYS__io_write,
&message.header,
sizeof (struct mach_msg_2));
if (result == KERN_SUCCESS)
*wrote = message.two;
return result;
}