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/*
Copyright (C) 1993, 1994 Free Software Foundation
This program 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 2, or (at
your option) any later version.
This program 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 this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
#include "ioserver.h"
/* Called by an I/O server when an io_get_conch message is received.
The user represented by USER and USER_SH wants conch C; give it
to her or return an error. */
error_t
ioserver_handle_io_get_conch (struct conch *c, void *user,
struct shared_io *user_sh)
{
error_t error = 0;
if (c->holder == user)
{
if (user_sh->conch_status != USER_HAS_NOT_CONCH)
error = fetch_shared_data (user);
else
user_sh->accessed = user_sh->written = 0;
if (!error)
error = put_shared_data (user);
if (!error)
user_sh->conch_status = USER_HAS_CONCH;
}
else
{
error = get_conch (c);
if (!error)
{
c->holder = user;
c->holder_shared_page = user_sh;
if (user_sh->conch_status == USER_HAS_NOT_CONCH)
user_sh->accessed = user_sh->written = 0;
user_sh->conch_status = USER_HAS_CONCH;
put_shared_data (user);
}
}
return error;
}
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