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/* client-create.c - Create a capability client.
Copyright (C) 2004 Free Software Foundation, Inc.
Written by Marcus Brinkmann <marcus@gnu.org>
This file is part of the GNU Hurd.
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this program; if not, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
#if HAVE_CONFIG_H
#include <config.h>
#endif
#include <errno.h>
#include <assert.h>
#include <pthread.h>
#include <stdlib.h>
#include "cap-server-intern.h"
/* Client management code. */
/* Allocate a new capability client structure for the slab cache. */
static error_t
_hurd_cap_client_constructor (void *hook, void *buffer)
{
_hurd_cap_client_t client = (_hurd_cap_client_t) buffer;
error_t err;
err = pthread_mutex_init (&client->lock, NULL);
if (err)
return err;
client->state = _HURD_CAP_STATE_GREEN;
client->pending_rpcs = NULL;
err = hurd_table_init (&client->caps, sizeof (struct _hurd_cap_obj_entry));
if (err)
goto err_cap_client_caps;
/* Capabilities are mapped to clients many to many, so we can not
use a location pointer. However, this is not critical as
removing an entry only blocks out RPCs for the same client, and
not others. */
hurd_ihash_init (&client->caps_reverse, HURD_IHASH_NO_LOCP);
return 0;
/* This is provided here in case you add more initialization to the
end of the above code. */
#if 0
hurd_table_destroy (&client->caps);
#endif
err_cap_client_caps:
pthread_mutex_destroy (&client->lock);
return err;
}
/* Allocate a new capability client structure for the slab cache. */
static void
_hurd_cap_client_destructor (void *hook, void *buffer)
{
_hurd_cap_client_t client = (_hurd_cap_client_t) buffer;
hurd_ihash_destroy (&client->caps_reverse);
hurd_table_destroy (&client->caps);
pthread_mutex_destroy (&client->lock);
}
/* The global slab for all capability clients. */
struct hurd_slab_space _hurd_cap_client_space
= HURD_SLAB_SPACE_INITIALIZER (struct _hurd_cap_client,
_hurd_cap_client_constructor,
_hurd_cap_client_destructor, NULL);
static error_t
_hurd_cap_client_alloc (hurd_task_id_t task_id,
_hurd_cap_client_t *r_client)
{
error_t err;
_hurd_cap_client_t client;
err = hurd_slab_alloc (&_hurd_cap_client_space, (void **) &client);
if (!client)
return errno;
/* CLIENT->id will be initialized by the caller when adding the
client to the client table of the class. */
client->task_id = task_id;
err = pthread_mutex_init (&client->lock, NULL);
if (err)
{
free (client);
return err;
}
client->state = _HURD_CAP_STATE_GREEN;
client->pending_rpcs = NULL;
err = hurd_table_init (&client->caps, sizeof (_hurd_cap_obj_entry_t));
if (err)
{
pthread_mutex_destroy (&client->lock);
free (client);
return err;
}
*r_client = client;
return 0;
}
/* Look up the client with the task ID TASK in the class CLASS, and
return it in R_CLIENT, with one additional reference. If it is not
found, create it. */
error_t
__attribute__((visibility("hidden")))
_hurd_cap_client_create (hurd_cap_bucket_t bucket,
hurd_task_id_t task_id,
_hurd_cap_client_t *r_client)
{
error_t err = 0;
_hurd_cap_client_t client;
_hurd_cap_client_entry_t entry;
struct _hurd_cap_client_entry new_entry;
pthread_mutex_lock (&bucket->lock);
client = (_hurd_cap_client_t) hurd_ihash_find (&bucket->clients_reverse,
task_id);
if (client)
{
entry = (_hurd_cap_client_entry_t)
HURD_TABLE_LOOKUP (&bucket->clients, client->id);
if (entry->dead)
err = EINVAL; /* FIXME: A more appropriate code? */
else
{
entry->refs++;
*r_client = entry->client;
}
pthread_mutex_unlock (&bucket->lock);
return err;
}
pthread_mutex_unlock (&bucket->lock);
/* The client is not yet registered. Block out processing task
death notifications, create a new client structure, and then
enter it into the table before resuming task death
notifications. */
hurd_task_death_notify_suspend ();
err = _hurd_cap_client_alloc (task_id, r_client);
if (err)
{
hurd_task_death_notify_resume ();
return err;
}
pthread_mutex_lock (&bucket->lock);
/* Somebody else might have been faster. */
client = (_hurd_cap_client_t) hurd_ihash_find (&bucket->clients_reverse,
task_id);
if (client)
{
entry = (_hurd_cap_client_entry_t)
HURD_TABLE_LOOKUP (&bucket->clients, client->id);
if (entry->dead)
err = EINVAL; /* FIXME: A more appropriate code? */
else
{
/* Somebody else was indeed faster. Use the existing entry. */
entry->refs++;
*r_client = entry->client;
}
pthread_mutex_unlock (&bucket->lock);
_hurd_cap_client_dealloc (bucket, *r_client);
return err;
}
client = *r_client;
/* Enter the new client. */
new_entry.client = client;
/* One reference for the fact that the client task lives, one for
the caller. */
new_entry.refs = 2;
err = hurd_table_enter (&bucket->clients, &new_entry, &client->id);
if (!err)
{
err = hurd_ihash_add (&bucket->clients_reverse, task_id, client);
if (err)
hurd_table_remove (&bucket->clients, client->id);
}
if (err)
{
pthread_mutex_unlock (&bucket->lock);
hurd_task_death_notify_resume ();
_hurd_cap_client_dealloc (bucket, client);
return err;
}
pthread_mutex_unlock (&bucket->lock);
hurd_task_death_notify_resume ();
*r_client = client;
return 0;
}
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