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