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
  38 struct mutex
  39 {
  40     struct object  obj;             /* object header */
  41     struct thread *owner;           /* mutex owner */
  42     unsigned int   count;           /* recursion count */
  43     int            abandoned;       /* has it been abandoned? */
  44     struct list    entry;           /* entry in owner thread mutex list */
  45 };
  46
  47 static void mutex_dump( struct object *obj, int verbose );
  48 static int mutex_signaled( struct object *obj, struct thread *thread );
  49 static int mutex_satisfied( struct object *obj, struct thread *thread );
  50 static unsigned int mutex_map_access( struct object *obj, unsigned int access );
  51 static void mutex_destroy( struct object *obj );
  52 static int mutex_signal( struct object *obj, unsigned int access );
  53
  54 static const struct object_ops mutex_ops =
  55 {
  56     sizeof(struct mutex),      /* size */
  57     mutex_dump,                /* dump */
  58     add_queue,                 /* add_queue */
  59     remove_queue,              /* remove_queue */
  60     mutex_signaled,            /* signaled */
  61     mutex_satisfied,           /* satisfied */
  62     mutex_signal,              /* signal */
  63     no_get_fd,                 /* get_fd */
  64     mutex_map_access,          /* map_access */
  65     no_lookup_name,            /* lookup_name */
  66     no_open_file,              /* open_file */
  67     no_close_handle,           /* close_handle */
  68     mutex_destroy              /* destroy */
  69 };
  70
  71
  72 static struct mutex *create_mutex( struct directory *root, const struct unicode_str *name,
  73                                    unsigned int attr, int owned )
  74 {
  75     struct mutex *mutex;
  76
  77     if ((mutex = create_named_object_dir( root, name, attr, &mutex_ops )))
  78     {
  79         if (get_error() != STATUS_OBJECT_NAME_EXISTS)
  80         {
  81             /* initialize it if it didn't already exist */
  82             mutex->count = 0;
  83             mutex->owner = NULL;
  84             mutex->abandoned = 0;
  85             if (owned) mutex_satisfied( &mutex->obj, current );
  86         }
  87     }
  88     return mutex;
  89 }
  90
  91 /* release a mutex once the recursion count is 0 */
  92 static void do_release( struct mutex *mutex )
  93 {
  94     assert( !mutex->count );
  95     /* remove the mutex from the thread list of owned mutexes */
  96     list_remove( &mutex->entry );
  97     mutex->owner = NULL;
  98     wake_up( &mutex->obj, 0 );
  99 }
 100
 101 void abandon_mutexes( struct thread *thread )
 102 {
 103     struct list *ptr;
 104
 105     while ((ptr = list_head( &thread->mutex_list )) != NULL)
 106     {
 107         struct mutex *mutex = LIST_ENTRY( ptr, struct mutex, entry );
 108         assert( mutex->owner == thread );
 109         mutex->count = 0;
 110         mutex->abandoned = 1;
 111         do_release( mutex );
 112     }
 113 }
 114
 115 static void mutex_dump( struct object *obj, int verbose )
 116 {
 117     struct mutex *mutex = (struct mutex *)obj;
 118     assert( obj->ops == &mutex_ops );
 119     fprintf( stderr, "Mutex count=%u owner=%p ", mutex->count, mutex->owner );
 120     dump_object_name( &mutex->obj );
 121     fputc( '\n', stderr );
 122 }
 123
 124 static int mutex_signaled( struct object *obj, struct thread *thread )
 125 {
 126     struct mutex *mutex = (struct mutex *)obj;
 127     assert( obj->ops == &mutex_ops );
 128     return (!mutex->count || (mutex->owner == thread));
 129 }
 130
 131 static int mutex_satisfied( struct object *obj, struct thread *thread )
 132 {
 133     struct mutex *mutex = (struct mutex *)obj;
 134     assert( obj->ops == &mutex_ops );
 135     assert( !mutex->count || (mutex->owner == thread) );
 136
 137     if (!mutex->count++)  /* FIXME: avoid wrap-around */
 138     {
 139         assert( !mutex->owner );
 140         mutex->owner = thread;
 141         list_add_head( &thread->mutex_list, &mutex->entry );
 142     }
 143     if (!mutex->abandoned) return 0;
 144     mutex->abandoned = 0;
 145     return 1;
 146 }
 147
 148 static unsigned int mutex_map_access( struct object *obj, unsigned int access )
 149 {
 150     if (access & GENERIC_READ)    access |= STANDARD_RIGHTS_READ | SYNCHRONIZE;
 151     if (access & GENERIC_WRITE)   access |= STANDARD_RIGHTS_WRITE | MUTEX_MODIFY_STATE;
 152     if (access & GENERIC_EXECUTE) access |= STANDARD_RIGHTS_EXECUTE;
 153     if (access & GENERIC_ALL)     access |= STANDARD_RIGHTS_ALL | MUTEX_ALL_ACCESS;
 154     return access & ~(GENERIC_READ | GENERIC_WRITE | GENERIC_EXECUTE | GENERIC_ALL);
 155 }
 156
 157 static int mutex_signal( struct object *obj, unsigned int access )
 158 {
 159     struct mutex *mutex = (struct mutex *)obj;
 160     assert( obj->ops == &mutex_ops );
 161
 162     if (!(access & SYNCHRONIZE))  /* FIXME: MUTEX_MODIFY_STATE? */
 163     {
 164         set_error( STATUS_ACCESS_DENIED );
 165         return 0;
 166     }
 167     if (!mutex->count || (mutex->owner != current))
 168     {
 169         set_error( STATUS_MUTANT_NOT_OWNED );
 170         return 0;
 171     }
 172     if (!--mutex->count) do_release( mutex );
 173     return 1;
 174 }
 175
 176 static void mutex_destroy( struct object *obj )
 177 {
 178     struct mutex *mutex = (struct mutex *)obj;
 179     assert( obj->ops == &mutex_ops );
 180
 181     if (!mutex->count) return;
 182     mutex->count = 0;
 183     do_release( mutex );
 184 }
 185
 186 /* create a mutex */
 187 DECL_HANDLER(create_mutex)
 188 {
 189     struct mutex *mutex;
 190     struct unicode_str name;
 191     struct directory *root = NULL;
 192
 193     reply->handle = 0;
 194     get_req_unicode_str( &name );
 195     if (req->rootdir && !(root = get_directory_obj( current->process, req->rootdir, 0 )))
 196         return;
 197
 198     if ((mutex = create_mutex( root, &name, req->attributes, req->owned )))
 199     {
 200         reply->handle = alloc_handle( current->process, mutex, req->access, req->attributes );
 201         release_object( mutex );
 202     }
 203
 204     if (root) release_object( root );
 205 }
 206
 207 /* open a handle to a mutex */
 208 DECL_HANDLER(open_mutex)
 209 {
 210     struct unicode_str name;
 211     struct directory *root = NULL;
 212     struct mutex *mutex;
 213
 214     get_req_unicode_str( &name );
 215     if (req->rootdir && !(root = get_directory_obj( current->process, req->rootdir, 0 )))
 216         return;
 217
 218     if ((mutex = open_object_dir( root, &name, req->attributes, &mutex_ops )))
 219     {
 220         reply->handle = alloc_handle( current->process, &mutex->obj, req->access, req->attributes );
 221         release_object( mutex );
 222     }
 223
 224     if (root) release_object( root );
 225 }
 226
 227 /* release a mutex */
 228 DECL_HANDLER(release_mutex)
 229 {
 230     struct mutex *mutex;
 231
 232     if ((mutex = (struct mutex *)get_handle_obj( current->process, req->handle,
 233                                                  MUTEX_MODIFY_STATE, &mutex_ops )))
 234     {
 235         if (!mutex->count || (mutex->owner != current)) set_error( STATUS_MUTANT_NOT_OWNED );
 236         else
 237         {
 238             reply->prev_count = mutex->count;
 239             if (!--mutex->count) do_release( mutex );
 240         }
 241         release_object( mutex );
 242     }
 243 }