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_kernel_obj_list,        /* get_kernel_obj_list */
  75     no_close_handle,           /* close_handle */
  76     mutex_destroy              /* destroy */
  77 };
  78
  79
  80 /* grab a mutex for a given thread */
  81 static void do_grab( struct mutex *mutex, struct thread *thread )
  82 {
  83     assert( !mutex->count || (mutex->owner == thread) );
  84
  85     if (!mutex->count++)  /* FIXME: avoid wrap-around */
  86     {
  87         assert( !mutex->owner );
  88         mutex->owner = thread;
  89         list_add_head( &thread->mutex_list, &mutex->entry );
  90     }
  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 static struct mutex *create_mutex( struct object *root, const struct unicode_str *name,
 104                                    unsigned int attr, int owned, const struct security_descriptor *sd )
 105 {
 106     struct mutex *mutex;
 107
 108     if ((mutex = create_named_object( root, &mutex_ops, name, attr, sd )))
 109     {
 110         if (get_error() != STATUS_OBJECT_NAME_EXISTS)
 111         {
 112             /* initialize it if it didn't already exist */
 113             mutex->count = 0;
 114             mutex->owner = NULL;
 115             mutex->abandoned = 0;
 116             if (owned) do_grab( mutex, current );
 117         }
 118     }
 119     return mutex;
 120 }
 121
 122 void abandon_mutexes( struct thread *thread )
 123 {
 124     struct list *ptr;
 125
 126     while ((ptr = list_head( &thread->mutex_list )) != NULL)
 127     {
 128         struct mutex *mutex = LIST_ENTRY( ptr, struct mutex, entry );
 129         assert( mutex->owner == thread );
 130         mutex->count = 0;
 131         mutex->abandoned = 1;
 132         do_release( mutex );
 133     }
 134 }
 135
 136 static void mutex_dump( struct object *obj, int verbose )
 137 {
 138     struct mutex *mutex = (struct mutex *)obj;
 139     assert( obj->ops == &mutex_ops );
 140     fprintf( stderr, "Mutex count=%u owner=%p\n", mutex->count, mutex->owner );
 141 }
 142
 143 static struct object_type *mutex_get_type( struct object *obj )
 144 {
 145     static const WCHAR name[] = {'M','u','t','a','n','t'};
 146     static const struct unicode_str str = { name, sizeof(name) };
 147     return get_object_type( &str );
 148 }
 149
 150 static int mutex_signaled( struct object *obj, struct wait_queue_entry *entry )
 151 {
 152     struct mutex *mutex = (struct mutex *)obj;
 153     assert( obj->ops == &mutex_ops );
 154     return (!mutex->count || (mutex->owner == get_wait_queue_thread( entry )));
 155 }
 156
 157 static void mutex_satisfied( struct object *obj, struct wait_queue_entry *entry )
 158 {
 159     struct mutex *mutex = (struct mutex *)obj;
 160     assert( obj->ops == &mutex_ops );
 161
 162     do_grab( mutex, get_wait_queue_thread( entry ));
 163     if (mutex->abandoned) make_wait_abandoned( entry );
 164     mutex->abandoned = 0;
 165 }
 166
 167 static unsigned int mutex_map_access( struct object *obj, unsigned int access )
 168 {
 169     if (access & GENERIC_READ)    access |= STANDARD_RIGHTS_READ | MUTANT_QUERY_STATE;
 170     if (access & GENERIC_WRITE)   access |= STANDARD_RIGHTS_WRITE;
 171     if (access & GENERIC_EXECUTE) access |= STANDARD_RIGHTS_EXECUTE | SYNCHRONIZE;
 172     if (access & GENERIC_ALL)     access |= STANDARD_RIGHTS_ALL | MUTEX_ALL_ACCESS;
 173     return access & ~(GENERIC_READ | GENERIC_WRITE | GENERIC_EXECUTE | GENERIC_ALL);
 174 }
 175
 176 static int mutex_signal( struct object *obj, unsigned int access )
 177 {
 178     struct mutex *mutex = (struct mutex *)obj;
 179     assert( obj->ops == &mutex_ops );
 180
 181     if (!(access & SYNCHRONIZE))
 182     {
 183         set_error( STATUS_ACCESS_DENIED );
 184         return 0;
 185     }
 186     if (!mutex->count || (mutex->owner != current))
 187     {
 188         set_error( STATUS_MUTANT_NOT_OWNED );
 189         return 0;
 190     }
 191     if (!--mutex->count) do_release( mutex );
 192     return 1;
 193 }
 194
 195 static void mutex_destroy( struct object *obj )
 196 {
 197     struct mutex *mutex = (struct mutex *)obj;
 198     assert( obj->ops == &mutex_ops );
 199
 200     if (!mutex->count) return;
 201     mutex->count = 0;
 202     do_release( mutex );
 203 }
 204
 205 /* create a mutex */
 206 DECL_HANDLER(create_mutex)
 207 {
 208     struct mutex *mutex;
 209     struct unicode_str name;
 210     struct object *root;
 211     const struct security_descriptor *sd;
 212     const struct object_attributes *objattr = get_req_object_attributes( &sd, &name, &root );
 213
 214     if (!objattr) return;
 215
 216     if ((mutex = create_mutex( root, &name, objattr->attributes, req->owned, sd )))
 217     {
 218         if (get_error() == STATUS_OBJECT_NAME_EXISTS)
 219             reply->handle = alloc_handle( current->process, mutex, req->access, objattr->attributes );
 220         else
 221             reply->handle = alloc_handle_no_access_check( current->process, mutex,
 222                                                           req->access, objattr->attributes );
 223         release_object( mutex );
 224     }
 225
 226     if (root) release_object( root );
 227 }
 228
 229 /* open a handle to a mutex */
 230 DECL_HANDLER(open_mutex)
 231 {
 232     struct unicode_str name = get_req_unicode_str();
 233
 234     reply->handle = open_object( current->process, req->rootdir, req->access,
 235                                  &mutex_ops, &name, req->attributes );
 236 }
 237
 238 /* release a mutex */
 239 DECL_HANDLER(release_mutex)
 240 {
 241     struct mutex *mutex;
 242
 243     if ((mutex = (struct mutex *)get_handle_obj( current->process, req->handle,
 244                                                  0, &mutex_ops )))
 245     {
 246         if (!mutex->count || (mutex->owner != current)) set_error( STATUS_MUTANT_NOT_OWNED );
 247         else
 248         {
 249             reply->prev_count = mutex->count;
 250             if (!--mutex->count) do_release( mutex );
 251         }
 252         release_object( mutex );
 253     }
 254 }
 255
 256 /* return details about the mutex */
 257 DECL_HANDLER(query_mutex)
 258 {
 259     struct mutex *mutex;
 260
 261     if ((mutex = (struct mutex *)get_handle_obj( current->process, req->handle,
 262                                                  MUTANT_QUERY_STATE, &mutex_ops )))
 263     {
 264         reply->count = mutex->count;
 265         reply->owned = (mutex->owner == current);
 266         reply->abandoned = mutex->abandoned;
 267
 268         release_object( mutex );
 269     }
 270 }