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 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;
 167     if (access & GENERIC_WRITE)   access |= STANDARD_RIGHTS_WRITE;
 168     if (access & GENERIC_EXECUTE) access |= STANDARD_RIGHTS_EXECUTE | SYNCHRONIZE;
 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))
 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                                                  0, &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 }