2 * Server-side semaphore management
4 * Copyright (C) 1998 Alexandre Julliard
6 * This library is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
11 * This library is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with this library; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
22 #include "wine/port.h"
30 #define WIN32_NO_STATUS
41 struct object obj
; /* object header */
42 unsigned int count
; /* current count */
43 unsigned int max
; /* maximum possible count */
46 static void semaphore_dump( struct object
*obj
, int verbose
);
47 static struct object_type
*semaphore_get_type( struct object
*obj
);
48 static int semaphore_signaled( struct object
*obj
, struct wait_queue_entry
*entry
);
49 static void semaphore_satisfied( struct object
*obj
, struct wait_queue_entry
*entry
);
50 static unsigned int semaphore_map_access( struct object
*obj
, unsigned int access
);
51 static int semaphore_signal( struct object
*obj
, unsigned int access
);
53 static const struct object_ops semaphore_ops
=
55 sizeof(struct semaphore
), /* size */
56 semaphore_dump
, /* dump */
57 semaphore_get_type
, /* get_type */
58 add_queue
, /* add_queue */
59 remove_queue
, /* remove_queue */
60 semaphore_signaled
, /* signaled */
61 semaphore_satisfied
, /* satisfied */
62 semaphore_signal
, /* signal */
63 no_get_fd
, /* get_fd */
64 semaphore_map_access
, /* map_access */
65 default_get_sd
, /* get_sd */
66 default_set_sd
, /* set_sd */
67 no_lookup_name
, /* lookup_name */
68 no_open_file
, /* open_file */
69 no_close_handle
, /* close_handle */
70 no_destroy
/* destroy */
74 static struct semaphore
*create_semaphore( struct directory
*root
, const struct unicode_str
*name
,
75 unsigned int attr
, unsigned int initial
, unsigned int max
,
76 const struct security_descriptor
*sd
)
78 struct semaphore
*sem
;
80 if (!max
|| (initial
> max
))
82 set_error( STATUS_INVALID_PARAMETER
);
85 if ((sem
= create_named_object_dir( root
, name
, attr
, &semaphore_ops
)))
87 if (get_error() != STATUS_OBJECT_NAME_EXISTS
)
89 /* initialize it if it didn't already exist */
92 if (sd
) default_set_sd( &sem
->obj
, sd
, OWNER_SECURITY_INFORMATION
|
93 GROUP_SECURITY_INFORMATION
|
94 DACL_SECURITY_INFORMATION
|
95 SACL_SECURITY_INFORMATION
);
101 static int release_semaphore( struct semaphore
*sem
, unsigned int count
,
104 if (prev
) *prev
= sem
->count
;
105 if (sem
->count
+ count
< sem
->count
|| sem
->count
+ count
> sem
->max
)
107 set_error( STATUS_SEMAPHORE_LIMIT_EXCEEDED
);
112 /* there cannot be any thread to wake up if the count is != 0 */
118 wake_up( &sem
->obj
, count
);
123 static void semaphore_dump( struct object
*obj
, int verbose
)
125 struct semaphore
*sem
= (struct semaphore
*)obj
;
126 assert( obj
->ops
== &semaphore_ops
);
127 fprintf( stderr
, "Semaphore count=%d max=%d ", sem
->count
, sem
->max
);
128 dump_object_name( &sem
->obj
);
129 fputc( '\n', stderr
);
132 static struct object_type
*semaphore_get_type( struct object
*obj
)
134 static const WCHAR name
[] = {'S','e','m','a','p','h','o','r','e'};
135 static const struct unicode_str str
= { name
, sizeof(name
) };
136 return get_object_type( &str
);
139 static int semaphore_signaled( struct object
*obj
, struct wait_queue_entry
*entry
)
141 struct semaphore
*sem
= (struct semaphore
*)obj
;
142 assert( obj
->ops
== &semaphore_ops
);
143 return (sem
->count
> 0);
146 static void semaphore_satisfied( struct object
*obj
, struct wait_queue_entry
*entry
)
148 struct semaphore
*sem
= (struct semaphore
*)obj
;
149 assert( obj
->ops
== &semaphore_ops
);
150 assert( sem
->count
);
154 static unsigned int semaphore_map_access( struct object
*obj
, unsigned int access
)
156 if (access
& GENERIC_READ
) access
|= STANDARD_RIGHTS_READ
| SEMAPHORE_QUERY_STATE
;
157 if (access
& GENERIC_WRITE
) access
|= STANDARD_RIGHTS_WRITE
| SEMAPHORE_MODIFY_STATE
;
158 if (access
& GENERIC_EXECUTE
) access
|= STANDARD_RIGHTS_EXECUTE
| SYNCHRONIZE
;
159 if (access
& GENERIC_ALL
) access
|= STANDARD_RIGHTS_ALL
| SEMAPHORE_ALL_ACCESS
;
160 return access
& ~(GENERIC_READ
| GENERIC_WRITE
| GENERIC_EXECUTE
| GENERIC_ALL
);
163 static int semaphore_signal( struct object
*obj
, unsigned int access
)
165 struct semaphore
*sem
= (struct semaphore
*)obj
;
166 assert( obj
->ops
== &semaphore_ops
);
168 if (!(access
& SEMAPHORE_MODIFY_STATE
))
170 set_error( STATUS_ACCESS_DENIED
);
173 return release_semaphore( sem
, 1, NULL
);
176 /* create a semaphore */
177 DECL_HANDLER(create_semaphore
)
179 struct semaphore
*sem
;
180 struct unicode_str name
;
181 struct directory
*root
= NULL
;
182 const struct object_attributes
*objattr
= get_req_data();
183 const struct security_descriptor
*sd
;
187 if (!objattr_is_valid( objattr
, get_req_data_size() ))
190 sd
= objattr
->sd_len
? (const struct security_descriptor
*)(objattr
+ 1) : NULL
;
191 objattr_get_name( objattr
, &name
);
193 if (objattr
->rootdir
&& !(root
= get_directory_obj( current
->process
, objattr
->rootdir
, 0 )))
196 if ((sem
= create_semaphore( root
, &name
, req
->attributes
, req
->initial
, req
->max
, sd
)))
198 if (get_error() == STATUS_OBJECT_NAME_EXISTS
)
199 reply
->handle
= alloc_handle( current
->process
, sem
, req
->access
, req
->attributes
);
201 reply
->handle
= alloc_handle_no_access_check( current
->process
, sem
, req
->access
, req
->attributes
);
202 release_object( sem
);
205 if (root
) release_object( root
);
208 /* open a handle to a semaphore */
209 DECL_HANDLER(open_semaphore
)
211 struct unicode_str name
;
212 struct directory
*root
= NULL
;
213 struct semaphore
*sem
;
215 get_req_unicode_str( &name
);
216 if (req
->rootdir
&& !(root
= get_directory_obj( current
->process
, req
->rootdir
, 0 )))
219 if ((sem
= open_object_dir( root
, &name
, req
->attributes
, &semaphore_ops
)))
221 reply
->handle
= alloc_handle( current
->process
, &sem
->obj
, req
->access
, req
->attributes
);
222 release_object( sem
);
225 if (root
) release_object( root
);
228 /* release a semaphore */
229 DECL_HANDLER(release_semaphore
)
231 struct semaphore
*sem
;
233 if ((sem
= (struct semaphore
*)get_handle_obj( current
->process
, req
->handle
,
234 SEMAPHORE_MODIFY_STATE
, &semaphore_ops
)))
236 release_semaphore( sem
, req
->count
, &reply
->prev_count
);
237 release_object( sem
);
241 /* query details about the semaphore */
242 DECL_HANDLER(query_semaphore
)
244 struct semaphore
*sem
;
246 if ((sem
= (struct semaphore
*)get_handle_obj( current
->process
, req
->handle
,
247 SEMAPHORE_QUERY_STATE
, &semaphore_ops
)))
249 reply
->current
= sem
->count
;
250 reply
->max
= sem
->max
;
251 release_object( sem
);