server/mutex.c

   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 wait_queue_entry *entry );
  51 static void mutex_satisfied( struct object *obj, struct wait_queue_entry *entry );
  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 /* grab a mutex for a given thread */
  78 static void do_grab( struct mutex *mutex, struct thread *thread )
  79 {
  80     assert( !mutex->count || (mutex->owner == thread) );
  81
  82     if (!mutex->count++)  /* FIXME: avoid wrap-around */
  83     {
  84         assert( !mutex->owner );
  85         mutex->owner = thread;
  86         list_add_head( &thread->mutex_list, &mutex->entry );
  87     }
  88 }
  89
  90 /* release a mutex once the recursion count is 0 */
  91 static void do_release( struct mutex *mutex )
  92 {
  93     assert( !mutex->count );
  94     /* remove the mutex from the thread list of owned mutexes */
  95     list_remove( &mutex->entry );
  96     mutex->owner = NULL;
  97     wake_up( &mutex->obj, 0 );
  98 }
  99
 100 static struct mutex *create_mutex( struct directory *root, const struct unicode_str *name,
 101                                    unsigned int attr, int owned, const struct security_descriptor *sd )
 102 {
 103     struct mutex *mutex;
 104
 105     if ((mutex = create_named_object_dir( root, name, attr, &mutex_ops )))
 106     {
 107         if (get_error() != STATUS_OBJECT_NAME_EXISTS)
 108         {
 109             /* initialize it if it didn't already exist */
 110             mutex->count = 0;
 111             mutex->owner = NULL;
 112             mutex->abandoned = 0;
 113             if (owned) do_grab( mutex, current );
 114             if (sd) default_set_sd( &mutex->obj, sd, OWNER_SECURITY_INFORMATION|
 115                                                      GROUP_SECURITY_INFORMATION|
 116                                                      DACL_SECURITY_INFORMATION|
 117                                                      SACL_SECURITY_INFORMATION );
 118         }
 119     }
 120     return mutex;
 121 }
 122
 123 void abandon_mutexes( struct thread *thread )
 124 {
 125     struct list *ptr;
 126
 127     while ((ptr = list_head( &thread->mutex_list )) != NULL)
 128     {
 129         struct mutex *mutex = LIST_ENTRY( ptr, struct mutex, entry );
 130         assert( mutex->owner == thread );
 131         mutex->count = 0;
 132         mutex->abandoned = 1;
 133         do_release( mutex );
 134     }
 135 }
 136
 137 static void mutex_dump( struct object *obj, int verbose )
 138 {
 139     struct mutex *mutex = (struct mutex *)obj;
 140     assert( obj->ops == &mutex_ops );
 141     fprintf( stderr, "Mutex count=%u owner=%p ", mutex->count, mutex->owner );
 142     dump_object_name( &mutex->obj );
 143     fputc( '\n', stderr );
 144 }
 145
 146 static struct object_type *mutex_get_type( struct object *obj )
 147 {
 148     static const WCHAR name[] = {'M','u','t','a','n','t'};
 149     static const struct unicode_str str = { name, sizeof(name) };
 150     return get_object_type( &str );
 151 }
 152
 153 static int mutex_signaled( struct object *obj, struct wait_queue_entry *entry )
 154 {
 155     struct mutex *mutex = (struct mutex *)obj;
 156     assert( obj->ops == &mutex_ops );
 157     return (!mutex->count || (mutex->owner == get_wait_queue_thread( entry )));
 158 }
 159
 160 static void mutex_satisfied( struct object *obj, struct wait_queue_entry *entry )
 161 {
 162     struct mutex *mutex = (struct mutex *)obj;
 163     assert( obj->ops == &mutex_ops );
 164
 165     do_grab( mutex, get_wait_queue_thread( entry ));
 166     if (mutex->abandoned) make_wait_abandoned( entry );
 167     mutex->abandoned = 0;
 168 }
 169
 170 static unsigned int mutex_map_access( struct object *obj, unsigned int access )
 171 {
 172     if (access & GENERIC_READ)    access |= STANDARD_RIGHTS_READ;
 173     if (access & GENERIC_WRITE)   access |= STANDARD_RIGHTS_WRITE;
 174     if (access & GENERIC_EXECUTE) access |= STANDARD_RIGHTS_EXECUTE | SYNCHRONIZE;
 175     if (access & GENERIC_ALL)     access |= STANDARD_RIGHTS_ALL | MUTEX_ALL_ACCESS;
 176     return access & ~(GENERIC_READ | GENERIC_WRITE | GENERIC_EXECUTE | GENERIC_ALL);
 177 }
 178
 179 static int mutex_signal( struct object *obj, unsigned int access )
 180 {
 181     struct mutex *mutex = (struct mutex *)obj;
 182     assert( obj->ops == &mutex_ops );
 183
 184     if (!(access & SYNCHRONIZE))
 185     {
 186         set_error( STATUS_ACCESS_DENIED );
 187         return 0;
 188     }
 189     if (!mutex->count || (mutex->owner != current))
 190     {
 191         set_error( STATUS_MUTANT_NOT_OWNED );
 192         return 0;
 193     }
 194     if (!--mutex->count) do_release( mutex );
 195     return 1;
 196 }
 197
 198 static void mutex_destroy( struct object *obj )
 199 {
 200     struct mutex *mutex = (struct mutex *)obj;
 201     assert( obj->ops == &mutex_ops );
 202
 203     if (!mutex->count) return;
 204     mutex->count = 0;
 205     do_release( mutex );
 206 }
 207
 208 /* create a mutex */
 209 DECL_HANDLER(create_mutex)
 210 {
 211     struct mutex *mutex;
 212     struct unicode_str name;
 213     struct directory *root = NULL;
 214     const struct object_attributes *objattr = get_req_data();
 215     const struct security_descriptor *sd;
 216
 217     reply->handle = 0;
 218
 219     if (!objattr_is_valid( objattr, get_req_data_size() ))
 220         return;
 221
 222     sd = objattr->sd_len ? (const struct security_descriptor *)(objattr + 1) : NULL;
 223     objattr_get_name( objattr, &name );
 224
 225     if (objattr->rootdir && !(root = get_directory_obj( current->process, objattr->rootdir, 0 )))
 226         return;
 227
 228     if ((mutex = create_mutex( root, &name, req->attributes, req->owned, sd )))
 229     {
 230         if (get_error() == STATUS_OBJECT_NAME_EXISTS)
 231             reply->handle = alloc_handle( current->process, mutex, req->access, req->attributes );
 232         else
 233             reply->handle = alloc_handle_no_access_check( current->process, mutex, req->access, req->attributes );
 234         release_object( mutex );
 235     }
 236
 237     if (root) release_object( root );
 238 }
 239
 240 /* open a handle to a mutex */
 241 DECL_HANDLER(open_mutex)
 242 {
 243     struct unicode_str name;
 244     struct directory *root = NULL;
 245     struct mutex *mutex;
 246
 247     get_req_unicode_str( &name );
 248     if (req->rootdir && !(root = get_directory_obj( current->process, req->rootdir, 0 )))
 249         return;
 250
 251     if ((mutex = open_object_dir( root, &name, req->attributes, &mutex_ops )))
 252     {
 253         reply->handle = alloc_handle( current->process, &mutex->obj, req->access, req->attributes );
 254         release_object( mutex );
 255     }
 256
 257     if (root) release_object( root );
 258 }
 259
 260 /* release a mutex */
 261 DECL_HANDLER(release_mutex)
 262 {
 263     struct mutex *mutex;
 264
 265     if ((mutex = (struct mutex *)get_handle_obj( current->process, req->handle,
 266                                                  0, &mutex_ops )))
 267     {
 268         if (!mutex->count || (mutex->owner != current)) set_error( STATUS_MUTANT_NOT_OWNED );
 269         else
 270         {
 271             reply->prev_count = mutex->count;
 272             if (!--mutex->count) do_release( mutex );
 273         }
 274         release_object( mutex );
 275     }
 276 }