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 wait_queue_entry *entry );
  51 static void mutex_satisfied( struct object *obj, struct wait_queue_entry *entry );
  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     directory_link_name,       /* link_name */
  72     default_unlink_name,       /* unlink_name */
  73     no_open_file,              /* open_file */
  74     no_close_handle,           /* close_handle */
  75     mutex_destroy              /* destroy */
  76 };
  77
  78
  79 /* grab a mutex for a given thread */
  80 static void do_grab( struct mutex *mutex, struct thread *thread )
  81 {
  82     assert( !mutex->count || (mutex->owner == thread) );
  83
  84     if (!mutex->count++)  /* FIXME: avoid wrap-around */
  85     {
  86         assert( !mutex->owner );
  87         mutex->owner = thread;
  88         list_add_head( &thread->mutex_list, &mutex->entry );
  89     }
  90 }
  91
  92 /* release a mutex once the recursion count is 0 */
  93 static void do_release( struct mutex *mutex )
  94 {
  95     assert( !mutex->count );
  96     /* remove the mutex from the thread list of owned mutexes */
  97     list_remove( &mutex->entry );
  98     mutex->owner = NULL;
  99     wake_up( &mutex->obj, 0 );
 100 }
 101
 102 static struct mutex *create_mutex( struct object *root, const struct unicode_str *name,
 103                                    unsigned int attr, int owned, const struct security_descriptor *sd )
 104 {
 105     struct mutex *mutex;
 106
 107     if ((mutex = create_named_object( root, &mutex_ops, name, attr, sd )))
 108     {
 109         if (get_error() != STATUS_OBJECT_NAME_EXISTS)
 110         {
 111             /* initialize it if it didn't already exist */
 112             mutex->count = 0;
 113             mutex->owner = NULL;
 114             mutex->abandoned = 0;
 115             if (owned) do_grab( mutex, current );
 116         }
 117     }
 118     return mutex;
 119 }
 120
 121 void abandon_mutexes( struct thread *thread )
 122 {
 123     struct list *ptr;
 124
 125     while ((ptr = list_head( &thread->mutex_list )) != NULL)
 126     {
 127         struct mutex *mutex = LIST_ENTRY( ptr, struct mutex, entry );
 128         assert( mutex->owner == thread );
 129         mutex->count = 0;
 130         mutex->abandoned = 1;
 131         do_release( mutex );
 132     }
 133 }
 134
 135 static void mutex_dump( struct object *obj, int verbose )
 136 {
 137     struct mutex *mutex = (struct mutex *)obj;
 138     assert( obj->ops == &mutex_ops );
 139     fprintf( stderr, "Mutex count=%u owner=%p\n", mutex->count, mutex->owner );
 140 }
 141
 142 static struct object_type *mutex_get_type( struct object *obj )
 143 {
 144     static const WCHAR name[] = {'M','u','t','a','n','t'};
 145     static const struct unicode_str str = { name, sizeof(name) };
 146     return get_object_type( &str );
 147 }
 148
 149 static int mutex_signaled( struct object *obj, struct wait_queue_entry *entry )
 150 {
 151     struct mutex *mutex = (struct mutex *)obj;
 152     assert( obj->ops == &mutex_ops );
 153     return (!mutex->count || (mutex->owner == get_wait_queue_thread( entry )));
 154 }
 155
 156 static void mutex_satisfied( struct object *obj, struct wait_queue_entry *entry )
 157 {
 158     struct mutex *mutex = (struct mutex *)obj;
 159     assert( obj->ops == &mutex_ops );
 160
 161     do_grab( mutex, get_wait_queue_thread( entry ));
 162     if (mutex->abandoned) make_wait_abandoned( entry );
 163     mutex->abandoned = 0;
 164 }
 165
 166 static unsigned int mutex_map_access( struct object *obj, unsigned int access )
 167 {
 168     if (access & GENERIC_READ)    access |= STANDARD_RIGHTS_READ | MUTANT_QUERY_STATE;
 169     if (access & GENERIC_WRITE)   access |= STANDARD_RIGHTS_WRITE;
 170     if (access & GENERIC_EXECUTE) access |= STANDARD_RIGHTS_EXECUTE | SYNCHRONIZE;
 171     if (access & GENERIC_ALL)     access |= STANDARD_RIGHTS_ALL | MUTEX_ALL_ACCESS;
 172     return access & ~(GENERIC_READ | GENERIC_WRITE | GENERIC_EXECUTE | GENERIC_ALL);
 173 }
 174
 175 static int mutex_signal( struct object *obj, unsigned int access )
 176 {
 177     struct mutex *mutex = (struct mutex *)obj;
 178     assert( obj->ops == &mutex_ops );
 179
 180     if (!(access & SYNCHRONIZE))
 181     {
 182         set_error( STATUS_ACCESS_DENIED );
 183         return 0;
 184     }
 185     if (!mutex->count || (mutex->owner != current))
 186     {
 187         set_error( STATUS_MUTANT_NOT_OWNED );
 188         return 0;
 189     }
 190     if (!--mutex->count) do_release( mutex );
 191     return 1;
 192 }
 193
 194 static void mutex_destroy( struct object *obj )
 195 {
 196     struct mutex *mutex = (struct mutex *)obj;
 197     assert( obj->ops == &mutex_ops );
 198
 199     if (!mutex->count) return;
 200     mutex->count = 0;
 201     do_release( mutex );
 202 }
 203
 204 /* create a mutex */
 205 DECL_HANDLER(create_mutex)
 206 {
 207     struct mutex *mutex;
 208     struct unicode_str name;
 209     struct object *root;
 210     const struct security_descriptor *sd;
 211     const struct object_attributes *objattr = get_req_object_attributes( &sd, &name, &root );
 212
 213     if (!objattr) return;
 214
 215     if ((mutex = create_mutex( root, &name, objattr->attributes, req->owned, sd )))
 216     {
 217         if (get_error() == STATUS_OBJECT_NAME_EXISTS)
 218             reply->handle = alloc_handle( current->process, mutex, req->access, objattr->attributes );
 219         else
 220             reply->handle = alloc_handle_no_access_check( current->process, mutex,
 221                                                           req->access, objattr->attributes );
 222         release_object( mutex );
 223     }
 224
 225     if (root) release_object( root );
 226 }
 227
 228 /* open a handle to a mutex */
 229 DECL_HANDLER(open_mutex)
 230 {
 231     struct unicode_str name = get_req_unicode_str();
 232
 233     reply->handle = open_object( current->process, req->rootdir, req->access,
 234                                  &mutex_ops, &name, req->attributes );
 235 }
 236
 237 /* release a mutex */
 238 DECL_HANDLER(release_mutex)
 239 {
 240     struct mutex *mutex;
 241
 242     if ((mutex = (struct mutex *)get_handle_obj( current->process, req->handle,
 243                                                  0, &mutex_ops )))
 244     {
 245         if (!mutex->count || (mutex->owner != current)) set_error( STATUS_MUTANT_NOT_OWNED );
 246         else
 247         {
 248             reply->prev_count = mutex->count;
 249             if (!--mutex->count) do_release( mutex );
 250         }
 251         release_object( mutex );
 252     }
 253 }
 254
 255 /* return details about the mutex */
 256 DECL_HANDLER(query_mutex)
 257 {
 258     struct mutex *mutex;
 259
 260     if ((mutex = (struct mutex *)get_handle_obj( current->process, req->handle,
 261                                                  MUTANT_QUERY_STATE, &mutex_ops )))
 262     {
 263         reply->count = mutex->count;
 264         reply->owned = (mutex->owner == current);
 265         reply->abandoned = mutex->abandoned;
 266
 267         release_object( mutex );
 268     }
 269 }