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_close_handle,           /* close_handle */
  67     mutex_destroy              /* destroy */
  68 };
  69
  70
  71 static struct mutex *create_mutex( struct directory *root, const struct unicode_str *name,
  72                                    unsigned int attr, int owned )
  73 {
  74     struct mutex *mutex;
  75
  76     if ((mutex = create_named_object_dir( root, name, attr, &mutex_ops )))
  77     {
  78         if (get_error() != STATUS_OBJECT_NAME_EXISTS)
  79         {
  80             /* initialize it if it didn't already exist */
  81             mutex->count = 0;
  82             mutex->owner = NULL;
  83             mutex->abandoned = 0;
  84             if (owned) mutex_satisfied( &mutex->obj, current );
  85         }
  86     }
  87     return mutex;
  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 void abandon_mutexes( struct thread *thread )
 101 {
 102     struct list *ptr;
 103
 104     while ((ptr = list_head( &thread->mutex_list )) != NULL)
 105     {
 106         struct mutex *mutex = LIST_ENTRY( ptr, struct mutex, entry );
 107         assert( mutex->owner == thread );
 108         mutex->count = 0;
 109         mutex->abandoned = 1;
 110         do_release( mutex );
 111     }
 112 }
 113
 114 static void mutex_dump( struct object *obj, int verbose )
 115 {
 116     struct mutex *mutex = (struct mutex *)obj;
 117     assert( obj->ops == &mutex_ops );
 118     fprintf( stderr, "Mutex count=%u owner=%p ", mutex->count, mutex->owner );
 119     dump_object_name( &mutex->obj );
 120     fputc( '\n', stderr );
 121 }
 122
 123 static int mutex_signaled( struct object *obj, struct thread *thread )
 124 {
 125     struct mutex *mutex = (struct mutex *)obj;
 126     assert( obj->ops == &mutex_ops );
 127     return (!mutex->count || (mutex->owner == thread));
 128 }
 129
 130 static int mutex_satisfied( struct object *obj, struct thread *thread )
 131 {
 132     struct mutex *mutex = (struct mutex *)obj;
 133     assert( obj->ops == &mutex_ops );
 134     assert( !mutex->count || (mutex->owner == thread) );
 135
 136     if (!mutex->count++)  /* FIXME: avoid wrap-around */
 137     {
 138         assert( !mutex->owner );
 139         mutex->owner = thread;
 140         list_add_head( &thread->mutex_list, &mutex->entry );
 141     }
 142     if (!mutex->abandoned) return 0;
 143     mutex->abandoned = 0;
 144     return 1;
 145 }
 146
 147 static unsigned int mutex_map_access( struct object *obj, unsigned int access )
 148 {
 149     if (access & GENERIC_READ)    access |= STANDARD_RIGHTS_READ | SYNCHRONIZE;
 150     if (access & GENERIC_WRITE)   access |= STANDARD_RIGHTS_WRITE | MUTEX_MODIFY_STATE;
 151     if (access & GENERIC_EXECUTE) access |= STANDARD_RIGHTS_EXECUTE;
 152     if (access & GENERIC_ALL)     access |= STANDARD_RIGHTS_ALL | MUTEX_ALL_ACCESS;
 153     return access & ~(GENERIC_READ | GENERIC_WRITE | GENERIC_EXECUTE | GENERIC_ALL);
 154 }
 155
 156 static int mutex_signal( struct object *obj, unsigned int access )
 157 {
 158     struct mutex *mutex = (struct mutex *)obj;
 159     assert( obj->ops == &mutex_ops );
 160
 161     if (!(access & SYNCHRONIZE))  /* FIXME: MUTEX_MODIFY_STATE? */
 162     {
 163         set_error( STATUS_ACCESS_DENIED );
 164         return 0;
 165     }
 166     if (!mutex->count || (mutex->owner != current))
 167     {
 168         set_error( STATUS_MUTANT_NOT_OWNED );
 169         return 0;
 170     }
 171     if (!--mutex->count) do_release( mutex );
 172     return 1;
 173 }
 174
 175 static void mutex_destroy( struct object *obj )
 176 {
 177     struct mutex *mutex = (struct mutex *)obj;
 178     assert( obj->ops == &mutex_ops );
 179
 180     if (!mutex->count) return;
 181     mutex->count = 0;
 182     do_release( mutex );
 183 }
 184
 185 /* create a mutex */
 186 DECL_HANDLER(create_mutex)
 187 {
 188     struct mutex *mutex;
 189     struct unicode_str name;
 190     struct directory *root = NULL;
 191
 192     reply->handle = 0;
 193     get_req_unicode_str( &name );
 194     if (req->rootdir && !(root = get_directory_obj( current->process, req->rootdir, 0 )))
 195         return;
 196
 197     if ((mutex = create_mutex( root, &name, req->attributes, req->owned )))
 198     {
 199         reply->handle = alloc_handle( current->process, mutex, req->access, req->attributes );
 200         release_object( mutex );
 201     }
 202
 203     if (root) release_object( root );
 204 }
 205
 206 /* open a handle to a mutex */
 207 DECL_HANDLER(open_mutex)
 208 {
 209     struct unicode_str name;
 210     struct directory *root = NULL;
 211     struct mutex *mutex;
 212
 213     get_req_unicode_str( &name );
 214     if (req->rootdir && !(root = get_directory_obj( current->process, req->rootdir, 0 )))
 215         return;
 216
 217     if ((mutex = open_object_dir( root, &name, req->attributes, &mutex_ops )))
 218     {
 219         reply->handle = alloc_handle( current->process, &mutex->obj, req->access, req->attributes );
 220         release_object( mutex );
 221     }
 222
 223     if (root) release_object( root );
 224 }
 225
 226 /* release a mutex */
 227 DECL_HANDLER(release_mutex)
 228 {
 229     struct mutex *mutex;
 230
 231     if ((mutex = (struct mutex *)get_handle_obj( current->process, req->handle,
 232                                                  MUTEX_MODIFY_STATE, &mutex_ops )))
 233     {
 234         if (!mutex->count || (mutex->owner != current)) set_error( STATUS_MUTANT_NOT_OWNED );
 235         else
 236         {
 237             reply->prev_count = mutex->count;
 238             if (!--mutex->count) do_release( mutex );
 239         }
 240         release_object( mutex );
 241     }
 242 }