1 /*
2 * Server-side mutex management
3 *
4 * Copyright (C) 1998 Alexandre Julliard
5 *
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.
10 *
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.
15 *
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
19 */
20
21 #include "config.h"
22 #include "wine/port.h"
23
24 #include <assert.h>
25 #include <stdio.h>
26 #include <stdlib.h>
27 #include <stdarg.h>
28
29 #include "ntstatus.h"
30 #define WIN32_NO_STATUS
31 #include "windef.h"
32 #include "winternl.h"
33
34 #include "handle.h"
35 #include "thread.h"
36 #include "request.h"
37 #include "security.h"
38
39 struct mutex
40 {
41 struct object obj; /* object header */
42 struct thread *owner; /* mutex owner */
43 unsigned int count; /* recursion count */
44 int abandoned; /* has it been abandoned? */
45 struct list entry; /* entry in owner thread mutex list */
46 };
47
48 static void mutex_dump( struct object *obj, int verbose );
49 static struct object_type *mutex_get_type( struct object *obj );
50 static int mutex_signaled( struct object *obj, struct thread *thread );
51 static int mutex_satisfied( struct object *obj, struct thread *thread );
52 static unsigned int mutex_map_access( struct object *obj, unsigned int access );
53 static void mutex_destroy( struct object *obj );
54 static int mutex_signal( struct object *obj, unsigned int access );
55
56 static const struct object_ops mutex_ops =
57 {
58 sizeof(struct mutex), /* size */
59 mutex_dump, /* dump */
60 mutex_get_type, /* get_type */
61 add_queue, /* add_queue */
62 remove_queue, /* remove_queue */
63 mutex_signaled, /* signaled */
64 mutex_satisfied, /* satisfied */
65 mutex_signal, /* signal */
66 no_get_fd, /* get_fd */
67 mutex_map_access, /* map_access */
68 default_get_sd, /* get_sd */
69 default_set_sd, /* set_sd */
70 no_lookup_name, /* lookup_name */
71 no_open_file, /* open_file */
72 no_close_handle, /* close_handle */
73 mutex_destroy /* destroy */
74 };
75
76
77 static struct mutex *create_mutex( struct directory *root, const struct unicode_str *name,
78 unsigned int attr, int owned, const struct security_descriptor *sd )
79 {
80 struct mutex *mutex;
81
82 if ((mutex = create_named_object_dir( root, name, attr, &mutex_ops )))
83 {
84 if (get_error() != STATUS_OBJECT_NAME_EXISTS)
85 {
86 /* initialize it if it didn't already exist */
87 mutex->count = 0;
88 mutex->owner = NULL;
89 mutex->abandoned = 0;
90 if (owned) mutex_satisfied( &mutex->obj, current );
91 if (sd) default_set_sd( &mutex->obj, sd, OWNER_SECURITY_INFORMATION|
92 GROUP_SECURITY_INFORMATION|
93 DACL_SECURITY_INFORMATION|
94 SACL_SECURITY_INFORMATION );
95 }
96 }
97 return mutex;
98 }
99
100 /* release a mutex once the recursion count is 0 */
101 static void do_release( struct mutex *mutex )
102 {
103 assert( !mutex->count );
104 /* remove the mutex from the thread list of owned mutexes */
105 list_remove( &mutex->entry );
106 mutex->owner = NULL;
107 wake_up( &mutex->obj, 0 );
108 }
109
110 void abandon_mutexes( struct thread *thread )
111 {
112 struct list *ptr;
113
114 while ((ptr = list_head( &thread->mutex_list )) != NULL)
115 {
116 struct mutex *mutex = LIST_ENTRY( ptr, struct mutex, entry );
117 assert( mutex->owner == thread );
118 mutex->count = 0;
119 mutex->abandoned = 1;
120 do_release( mutex );
121 }
122 }
123
124 static void mutex_dump( struct object *obj, int verbose )
125 {
126 struct mutex *mutex = (struct mutex *)obj;
127 assert( obj->ops == &mutex_ops );
128 fprintf( stderr, "Mutex count=%u owner=%p ", mutex->count, mutex->owner );
129 dump_object_name( &mutex->obj );
130 fputc( '\n', stderr );
131 }
132
133 static struct object_type *mutex_get_type( struct object *obj )
134 {
135 static const WCHAR name[] = {'M','u','t','a','n','t'};
136 static const struct unicode_str str = { name, sizeof(name) };
137 return get_object_type( &str );
138 }
139
140 static int mutex_signaled( struct object *obj, struct thread *thread )
141 {
142 struct mutex *mutex = (struct mutex *)obj;
143 assert( obj->ops == &mutex_ops );
144 return (!mutex->count || (mutex->owner == thread));
145 }
146
147 static int mutex_satisfied( struct object *obj, struct thread *thread )
148 {
149 struct mutex *mutex = (struct mutex *)obj;
150 assert( obj->ops == &mutex_ops );
151 assert( !mutex->count || (mutex->owner == thread) );
152
153 if (!mutex->count++) /* FIXME: avoid wrap-around */
154 {
155 assert( !mutex->owner );
156 mutex->owner = thread;
157 list_add_head( &thread->mutex_list, &mutex->entry );
158 }
159 if (!mutex->abandoned) return 0;
160 mutex->abandoned = 0;
161 return 1;
162 }
163
164 static unsigned int mutex_map_access( struct object *obj, unsigned int access )
165 {
166 if (access & GENERIC_READ) access |= STANDARD_RIGHTS_READ | SYNCHRONIZE;
167 if (access & GENERIC_WRITE) access |= STANDARD_RIGHTS_WRITE | MUTEX_MODIFY_STATE;
168 if (access & GENERIC_EXECUTE) access |= STANDARD_RIGHTS_EXECUTE;
169 if (access & GENERIC_ALL) access |= STANDARD_RIGHTS_ALL | MUTEX_ALL_ACCESS;
170 return access & ~(GENERIC_READ | GENERIC_WRITE | GENERIC_EXECUTE | GENERIC_ALL);
171 }
172
173 static int mutex_signal( struct object *obj, unsigned int access )
174 {
175 struct mutex *mutex = (struct mutex *)obj;
176 assert( obj->ops == &mutex_ops );
177
178 if (!(access & SYNCHRONIZE)) /* FIXME: MUTEX_MODIFY_STATE? */
179 {
180 set_error( STATUS_ACCESS_DENIED );
181 return 0;
182 }
183 if (!mutex->count || (mutex->owner != current))
184 {
185 set_error( STATUS_MUTANT_NOT_OWNED );
186 return 0;
187 }
188 if (!--mutex->count) do_release( mutex );
189 return 1;
190 }
191
192 static void mutex_destroy( struct object *obj )
193 {
194 struct mutex *mutex = (struct mutex *)obj;
195 assert( obj->ops == &mutex_ops );
196
197 if (!mutex->count) return;
198 mutex->count = 0;
199 do_release( mutex );
200 }
201
202 /* create a mutex */
203 DECL_HANDLER(create_mutex)
204 {
205 struct mutex *mutex;
206 struct unicode_str name;
207 struct directory *root = NULL;
208 const struct object_attributes *objattr = get_req_data();
209 const struct security_descriptor *sd;
210
211 reply->handle = 0;
212
213 if (!objattr_is_valid( objattr, get_req_data_size() ))
214 return;
215
216 sd = objattr->sd_len ? (const struct security_descriptor *)(objattr + 1) : NULL;
217 objattr_get_name( objattr, &name );
218
219 if (objattr->rootdir && !(root = get_directory_obj( current->process, objattr->rootdir, 0 )))
220 return;
221
222 if ((mutex = create_mutex( root, &name, req->attributes, req->owned, sd )))
223 {
224 if (get_error() == STATUS_OBJECT_NAME_EXISTS)
225 reply->handle = alloc_handle( current->process, mutex, req->access, req->attributes );
226 else
227 reply->handle = alloc_handle_no_access_check( current->process, mutex, req->access, req->attributes );
228 release_object( mutex );
229 }
230
231 if (root) release_object( root );
232 }
233
234 /* open a handle to a mutex */
235 DECL_HANDLER(open_mutex)
236 {
237 struct unicode_str name;
238 struct directory *root = NULL;
239 struct mutex *mutex;
240
241 get_req_unicode_str( &name );
242 if (req->rootdir && !(root = get_directory_obj( current->process, req->rootdir, 0 )))
243 return;
244
245 if ((mutex = open_object_dir( root, &name, req->attributes, &mutex_ops )))
246 {
247 reply->handle = alloc_handle( current->process, &mutex->obj, req->access, req->attributes );
248 release_object( mutex );
249 }
250
251 if (root) release_object( root );
252 }
253
254 /* release a mutex */
255 DECL_HANDLER(release_mutex)
256 {
257 struct mutex *mutex;
258
259 if ((mutex = (struct mutex *)get_handle_obj( current->process, req->handle,
260 MUTEX_MODIFY_STATE, &mutex_ops )))
261 {
262 if (!mutex->count || (mutex->owner != current)) set_error( STATUS_MUTANT_NOT_OWNED );
263 else
264 {
265 reply->prev_count = mutex->count;
266 if (!--mutex->count) do_release( mutex );
267 }
268 release_object( mutex );
269 }
270 }
271
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