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