Sweden-Number/server/mutex.c

268 lines
8.1 KiB
C

/*
* Server-side mutex management
*
* Copyright (C) 1998 Alexandre Julliard
*
* This library 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 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
*/
#include "config.h"
#include <assert.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <sys/types.h>
#include "ntstatus.h"
#define WIN32_NO_STATUS
#include "windef.h"
#include "winternl.h"
#include "handle.h"
#include "thread.h"
#include "request.h"
#include "security.h"
static const WCHAR mutex_name[] = {'M','u','t','a','n','t'};
struct type_descr mutex_type =
{
{ mutex_name, sizeof(mutex_name) }, /* name */
MUTANT_ALL_ACCESS, /* valid_access */
{ /* mapping */
STANDARD_RIGHTS_READ | MUTANT_QUERY_STATE,
STANDARD_RIGHTS_WRITE,
STANDARD_RIGHTS_EXECUTE | SYNCHRONIZE,
MUTANT_ALL_ACCESS
},
};
struct mutex
{
struct object obj; /* object header */
struct thread *owner; /* mutex owner */
unsigned int count; /* recursion count */
int abandoned; /* has it been abandoned? */
struct list entry; /* entry in owner thread mutex list */
};
static void mutex_dump( struct object *obj, int verbose );
static int mutex_signaled( struct object *obj, struct wait_queue_entry *entry );
static void mutex_satisfied( struct object *obj, struct wait_queue_entry *entry );
static void mutex_destroy( struct object *obj );
static int mutex_signal( struct object *obj, unsigned int access );
static const struct object_ops mutex_ops =
{
sizeof(struct mutex), /* size */
&mutex_type, /* type */
mutex_dump, /* dump */
add_queue, /* add_queue */
remove_queue, /* remove_queue */
mutex_signaled, /* signaled */
mutex_satisfied, /* satisfied */
mutex_signal, /* signal */
no_get_fd, /* get_fd */
default_map_access, /* map_access */
default_get_sd, /* get_sd */
default_set_sd, /* set_sd */
default_get_full_name, /* get_full_name */
no_lookup_name, /* lookup_name */
directory_link_name, /* link_name */
default_unlink_name, /* unlink_name */
no_open_file, /* open_file */
no_kernel_obj_list, /* get_kernel_obj_list */
no_close_handle, /* close_handle */
mutex_destroy /* destroy */
};
/* grab a mutex for a given thread */
static void do_grab( struct mutex *mutex, struct thread *thread )
{
assert( !mutex->count || (mutex->owner == thread) );
if (!mutex->count++) /* FIXME: avoid wrap-around */
{
assert( !mutex->owner );
mutex->owner = thread;
list_add_head( &thread->mutex_list, &mutex->entry );
}
}
/* release a mutex once the recursion count is 0 */
static void do_release( struct mutex *mutex )
{
assert( !mutex->count );
/* remove the mutex from the thread list of owned mutexes */
list_remove( &mutex->entry );
mutex->owner = NULL;
wake_up( &mutex->obj, 0 );
}
static struct mutex *create_mutex( struct object *root, const struct unicode_str *name,
unsigned int attr, int owned, const struct security_descriptor *sd )
{
struct mutex *mutex;
if ((mutex = create_named_object( root, &mutex_ops, name, attr, sd )))
{
if (get_error() != STATUS_OBJECT_NAME_EXISTS)
{
/* initialize it if it didn't already exist */
mutex->count = 0;
mutex->owner = NULL;
mutex->abandoned = 0;
if (owned) do_grab( mutex, current );
}
}
return mutex;
}
void abandon_mutexes( struct thread *thread )
{
struct list *ptr;
while ((ptr = list_head( &thread->mutex_list )) != NULL)
{
struct mutex *mutex = LIST_ENTRY( ptr, struct mutex, entry );
assert( mutex->owner == thread );
mutex->count = 0;
mutex->abandoned = 1;
do_release( mutex );
}
}
static void mutex_dump( struct object *obj, int verbose )
{
struct mutex *mutex = (struct mutex *)obj;
assert( obj->ops == &mutex_ops );
fprintf( stderr, "Mutex count=%u owner=%p\n", mutex->count, mutex->owner );
}
static int mutex_signaled( struct object *obj, struct wait_queue_entry *entry )
{
struct mutex *mutex = (struct mutex *)obj;
assert( obj->ops == &mutex_ops );
return (!mutex->count || (mutex->owner == get_wait_queue_thread( entry )));
}
static void mutex_satisfied( struct object *obj, struct wait_queue_entry *entry )
{
struct mutex *mutex = (struct mutex *)obj;
assert( obj->ops == &mutex_ops );
do_grab( mutex, get_wait_queue_thread( entry ));
if (mutex->abandoned) make_wait_abandoned( entry );
mutex->abandoned = 0;
}
static int mutex_signal( struct object *obj, unsigned int access )
{
struct mutex *mutex = (struct mutex *)obj;
assert( obj->ops == &mutex_ops );
if (!(access & SYNCHRONIZE))
{
set_error( STATUS_ACCESS_DENIED );
return 0;
}
if (!mutex->count || (mutex->owner != current))
{
set_error( STATUS_MUTANT_NOT_OWNED );
return 0;
}
if (!--mutex->count) do_release( mutex );
return 1;
}
static void mutex_destroy( struct object *obj )
{
struct mutex *mutex = (struct mutex *)obj;
assert( obj->ops == &mutex_ops );
if (!mutex->count) return;
mutex->count = 0;
do_release( mutex );
}
/* create a mutex */
DECL_HANDLER(create_mutex)
{
struct mutex *mutex;
struct unicode_str name;
struct object *root;
const struct security_descriptor *sd;
const struct object_attributes *objattr = get_req_object_attributes( &sd, &name, &root );
if (!objattr) return;
if ((mutex = create_mutex( root, &name, objattr->attributes, req->owned, sd )))
{
if (get_error() == STATUS_OBJECT_NAME_EXISTS)
reply->handle = alloc_handle( current->process, mutex, req->access, objattr->attributes );
else
reply->handle = alloc_handle_no_access_check( current->process, mutex,
req->access, objattr->attributes );
release_object( mutex );
}
if (root) release_object( root );
}
/* open a handle to a mutex */
DECL_HANDLER(open_mutex)
{
struct unicode_str name = get_req_unicode_str();
reply->handle = open_object( current->process, req->rootdir, req->access,
&mutex_ops, &name, req->attributes );
}
/* release a mutex */
DECL_HANDLER(release_mutex)
{
struct mutex *mutex;
if ((mutex = (struct mutex *)get_handle_obj( current->process, req->handle,
0, &mutex_ops )))
{
if (!mutex->count || (mutex->owner != current)) set_error( STATUS_MUTANT_NOT_OWNED );
else
{
reply->prev_count = mutex->count;
if (!--mutex->count) do_release( mutex );
}
release_object( mutex );
}
}
/* return details about the mutex */
DECL_HANDLER(query_mutex)
{
struct mutex *mutex;
if ((mutex = (struct mutex *)get_handle_obj( current->process, req->handle,
MUTANT_QUERY_STATE, &mutex_ops )))
{
reply->count = mutex->count;
reply->owned = (mutex->owner == current);
reply->abandoned = mutex->abandoned;
release_object( mutex );
}
}