server/object.c

   1 /*
   2  * Server-side objects
   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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  19  */
  20
  21 #include "config.h"
  22 #include "wine/port.h"
  23
  24 #include <assert.h>
  25 #include <limits.h>
  26 #include <stdlib.h>
  27 #include <stdio.h>
  28 #include <string.h>
  29 #include <unistd.h>
  30
  31 #include "file.h"
  32 #include "thread.h"
  33 #include "unicode.h"
  34 #include "list.h"
  35
  36
  37 struct object_name
  38 {
  39     struct list         entry;    /* entry in the hash list */
  40     struct object      *obj;
  41     size_t              len;
  42     WCHAR               name[1];
  43 };
  44
  45 struct namespace
  46 {
  47     unsigned int        hash_size;       /* size of hash table */
  48     int                 case_sensitive;  /* are names case sensitive? */
  49     struct list         names[1];        /* array of hash entry lists */
  50 };
  51
  52
  53 #ifdef DEBUG_OBJECTS
  54 static struct list object_list = LIST_INIT(object_list);
  55
  56 void dump_objects(void)
  57 {
  58     struct list *p;
  59
  60     LIST_FOR_EACH( p, &object_list )
  61     {
  62         struct object *ptr = LIST_ENTRY( p, struct object, obj_list );
  63         fprintf( stderr, "%p:%d: ", ptr, ptr->refcount );
  64         ptr->ops->dump( ptr, 1 );
  65     }
  66 }
  67 #endif
  68
  69 /*****************************************************************/
  70
  71 /* malloc replacement */
  72 void *mem_alloc( size_t size )
  73 {
  74     void *ptr = malloc( size );
  75     if (ptr) memset( ptr, 0x55, size );
  76     else set_error( STATUS_NO_MEMORY );
  77     return ptr;
  78 }
  79
  80 /* duplicate a block of memory */
  81 void *memdup( const void *data, size_t len )
  82 {
  83     void *ptr = malloc( len );
  84     if (ptr) memcpy( ptr, data, len );
  85     else set_error( STATUS_NO_MEMORY );
  86     return ptr;
  87 }
  88
  89
  90 /*****************************************************************/
  91
  92 static int get_name_hash( const struct namespace *namespace, const WCHAR *name, size_t len )
  93 {
  94     WCHAR hash = 0;
  95     len /= sizeof(WCHAR);
  96     if (namespace->case_sensitive) while (len--) hash ^= *name++;
  97     else while (len--) hash ^= tolowerW(*name++);
  98     return hash % namespace->hash_size;
  99 }
 100
 101 /* allocate a name for an object */
 102 static struct object_name *alloc_name( const WCHAR *name, size_t len )
 103 {
 104     struct object_name *ptr;
 105
 106     if ((ptr = mem_alloc( sizeof(*ptr) + len - sizeof(ptr->name) )))
 107     {
 108         ptr->len = len;
 109         memcpy( ptr->name, name, len );
 110     }
 111     return ptr;
 112 }
 113
 114 /* free the name of an object */
 115 static void free_name( struct object *obj )
 116 {
 117     struct object_name *ptr = obj->name;
 118     list_remove( &ptr->entry );
 119     free( ptr );
 120 }
 121
 122 /* set the name of an existing object */
 123 static void set_object_name( struct namespace *namespace,
 124                              struct object *obj, struct object_name *ptr )
 125 {
 126     int hash = get_name_hash( namespace, ptr->name, ptr->len );
 127
 128     list_add_head( &namespace->names[hash], &ptr->entry );
 129     ptr->obj = obj;
 130     obj->name = ptr;
 131 }
 132
 133 /* allocate and initialize an object */
 134 /* if the function fails the fd is closed */
 135 void *alloc_object( const struct object_ops *ops, int fd )
 136 {
 137     struct object *obj = mem_alloc( ops->size );
 138     if (obj)
 139     {
 140         obj->refcount = 1;
 141         obj->fd_obj   = NULL;
 142         obj->fd       = fd;
 143         obj->select   = -1;
 144         obj->ops      = ops;
 145         obj->head     = NULL;
 146         obj->tail     = NULL;
 147         obj->name     = NULL;
 148         if ((fd != -1) && (add_select_user( obj ) == -1))
 149         {
 150             close( fd );
 151             free( obj );
 152             return NULL;
 153         }
 154 #ifdef DEBUG_OBJECTS
 155         list_add_head( &object_list, &obj->obj_list );
 156 #endif
 157         return obj;
 158     }
 159     if (fd != -1) close( fd );
 160     return NULL;
 161 }
 162
 163 void *create_named_object( struct namespace *namespace, const struct object_ops *ops,
 164                            const WCHAR *name, size_t len )
 165 {
 166     struct object *obj;
 167     struct object_name *name_ptr;
 168
 169     if (!name || !len) return alloc_object( ops, -1 );
 170
 171     if ((obj = find_object( namespace, name, len )))
 172     {
 173         if (obj->ops == ops)
 174         {
 175             set_error( STATUS_OBJECT_NAME_COLLISION );
 176             return obj;
 177         }
 178         set_error( STATUS_OBJECT_TYPE_MISMATCH );
 179         return NULL;
 180     }
 181     if (!(name_ptr = alloc_name( name, len ))) return NULL;
 182     if ((obj = alloc_object( ops, -1 )))
 183     {
 184         set_object_name( namespace, obj, name_ptr );
 185         clear_error();
 186     }
 187     else free( name_ptr );
 188     return obj;
 189 }
 190
 191 /* dump the name of an object to stderr */
 192 void dump_object_name( struct object *obj )
 193 {
 194     if (!obj->name) fprintf( stderr, "name=\"\"" );
 195     else
 196     {
 197         fprintf( stderr, "name=L\"" );
 198         dump_strW( obj->name->name, obj->name->len/sizeof(WCHAR), stderr, "\"\"" );
 199         fputc( '\"', stderr );
 200     }
 201 }
 202
 203 /* grab an object (i.e. increment its refcount) and return the object */
 204 struct object *grab_object( void *ptr )
 205 {
 206     struct object *obj = (struct object *)ptr;
 207     assert( obj->refcount < INT_MAX );
 208     obj->refcount++;
 209     return obj;
 210 }
 211
 212 /* release an object (i.e. decrement its refcount) */
 213 void release_object( void *ptr )
 214 {
 215     struct object *obj = (struct object *)ptr;
 216     assert( obj->refcount );
 217     if (!--obj->refcount)
 218     {
 219         /* if the refcount is 0, nobody can be in the wait queue */
 220         assert( !obj->head );
 221         assert( !obj->tail );
 222         obj->ops->destroy( obj );
 223         if (obj->fd_obj) close_fd( obj->fd_obj );
 224         if (obj->name) free_name( obj );
 225         if (obj->select != -1) remove_select_user( obj );
 226         if (obj->fd != -1) close( obj->fd );
 227 #ifdef DEBUG_OBJECTS
 228         list_remove( &obj->obj_list );
 229         memset( obj, 0xaa, obj->ops->size );
 230 #endif
 231         free( obj );
 232     }
 233 }
 234
 235 /* find an object by its name; the refcount is incremented */
 236 struct object *find_object( const struct namespace *namespace, const WCHAR *name, size_t len )
 237 {
 238     const struct list *list, *p;
 239
 240     if (!name || !len) return NULL;
 241
 242     list = &namespace->names[ get_name_hash( namespace, name, len ) ];
 243     if (namespace->case_sensitive)
 244     {
 245         LIST_FOR_EACH( p, list )
 246         {
 247             struct object_name *ptr = LIST_ENTRY( p, struct object_name, entry );
 248             if (ptr->len != len) continue;
 249             if (!memcmp( ptr->name, name, len )) return grab_object( ptr->obj );
 250         }
 251     }
 252     else
 253     {
 254         LIST_FOR_EACH( p, list )
 255         {
 256             struct object_name *ptr = LIST_ENTRY( p, struct object_name, entry );
 257             if (ptr->len != len) continue;
 258             if (!strncmpiW( ptr->name, name, len/sizeof(WCHAR) )) return grab_object( ptr->obj );
 259         }
 260     }
 261     return NULL;
 262 }
 263
 264 /* allocate a namespace */
 265 struct namespace *create_namespace( unsigned int hash_size, int case_sensitive )
 266 {
 267     struct namespace *namespace;
 268     unsigned int i;
 269
 270     namespace = mem_alloc( sizeof(*namespace) + (hash_size - 1) * sizeof(namespace->names[0]) );
 271     if (namespace)
 272     {
 273         namespace->hash_size      = hash_size;
 274         namespace->case_sensitive = case_sensitive;
 275         for (i = 0; i < hash_size; i++) list_init( &namespace->names[i] );
 276     }
 277     return namespace;
 278 }
 279
 280 /* functions for unimplemented/default object operations */
 281
 282 int no_add_queue( struct object *obj, struct wait_queue_entry *entry )
 283 {
 284     set_error( STATUS_OBJECT_TYPE_MISMATCH );
 285     return 0;
 286 }
 287
 288 int no_satisfied( struct object *obj, struct thread *thread )
 289 {
 290     return 0;  /* not abandoned */
 291 }
 292
 293 struct fd *no_get_fd( struct object *obj )
 294 {
 295     set_error( STATUS_OBJECT_TYPE_MISMATCH );
 296     return NULL;
 297 }
 298
 299 struct fd *default_get_fd( struct object *obj )
 300 {
 301     if (obj->fd_obj) return (struct fd *)grab_object( obj->fd_obj );
 302     set_error( STATUS_OBJECT_TYPE_MISMATCH );
 303     return NULL;
 304 }
 305
 306 int no_get_file_info( struct object *obj, struct get_file_info_reply *info, int *flags )
 307 {
 308     set_error( STATUS_OBJECT_TYPE_MISMATCH );
 309     *flags = 0;
 310     return FD_TYPE_INVALID;
 311 }
 312
 313 void no_destroy( struct object *obj )
 314 {
 315 }
 316
 317 /* default handler for poll() events */
 318 void default_poll_event( struct object *obj, int event )
 319 {
 320     /* an error occurred, stop polling this fd to avoid busy-looping */
 321     if (event & (POLLERR | POLLHUP)) set_select_events( obj, -1 );
 322     wake_up( obj, 0 );
 323 }