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
  35
  36 struct object_name
  37 {
  38     struct list         entry;    /* entry in the hash list */
  39     struct object      *obj;
  40     size_t              len;
  41     WCHAR               name[1];
  42 };
  43
  44 struct namespace
  45 {
  46     unsigned int        hash_size;       /* size of hash table */
  47     int                 case_sensitive;  /* are names case sensitive? */
  48     struct list         names[1];        /* array of hash entry lists */
  49 };
  50
  51
  52 #ifdef DEBUG_OBJECTS
  53 static struct list object_list = LIST_INIT(object_list);
  54
  55 void dump_objects(void)
  56 {
  57     struct list *p;
  58
  59     LIST_FOR_EACH( p, &object_list )
  60     {
  61         struct object *ptr = LIST_ENTRY( p, struct object, obj_list );
  62         fprintf( stderr, "%p:%d: ", ptr, ptr->refcount );
  63         ptr->ops->dump( ptr, 1 );
  64     }
  65 }
  66 #endif
  67
  68 /*****************************************************************/
  69
  70 /* malloc replacement */
  71 void *mem_alloc( size_t size )
  72 {
  73     void *ptr = malloc( size );
  74     if (ptr) memset( ptr, 0x55, size );
  75     else set_error( STATUS_NO_MEMORY );
  76     return ptr;
  77 }
  78
  79 /* duplicate a block of memory */
  80 void *memdup( const void *data, size_t len )
  81 {
  82     void *ptr = malloc( len );
  83     if (ptr) memcpy( ptr, data, len );
  84     else set_error( STATUS_NO_MEMORY );
  85     return ptr;
  86 }
  87
  88
  89 /*****************************************************************/
  90
  91 static int get_name_hash( const struct namespace *namespace, const WCHAR *name, size_t len )
  92 {
  93     WCHAR hash = 0;
  94     len /= sizeof(WCHAR);
  95     if (namespace->case_sensitive) while (len--) hash ^= *name++;
  96     else while (len--) hash ^= tolowerW(*name++);
  97     return hash % namespace->hash_size;
  98 }
  99
 100 /* allocate a name for an object */
 101 static struct object_name *alloc_name( const WCHAR *name, size_t len )
 102 {
 103     struct object_name *ptr;
 104
 105     if ((ptr = mem_alloc( sizeof(*ptr) + len - sizeof(ptr->name) )))
 106     {
 107         ptr->len = len;
 108         memcpy( ptr->name, name, len );
 109     }
 110     return ptr;
 111 }
 112
 113 /* free the name of an object */
 114 static void free_name( struct object *obj )
 115 {
 116     struct object_name *ptr = obj->name;
 117     list_remove( &ptr->entry );
 118     free( ptr );
 119 }
 120
 121 /* set the name of an existing object */
 122 static void set_object_name( struct namespace *namespace,
 123                              struct object *obj, struct object_name *ptr )
 124 {
 125     int hash = get_name_hash( namespace, ptr->name, ptr->len );
 126
 127     list_add_head( &namespace->names[hash], &ptr->entry );
 128     ptr->obj = obj;
 129     obj->name = ptr;
 130 }
 131
 132 /* allocate and initialize an object */
 133 void *alloc_object( const struct object_ops *ops )
 134 {
 135     struct object *obj = mem_alloc( ops->size );
 136     if (obj)
 137     {
 138         obj->refcount = 1;
 139         obj->ops      = ops;
 140         obj->head     = NULL;
 141         obj->tail     = NULL;
 142         obj->name     = NULL;
 143 #ifdef DEBUG_OBJECTS
 144         list_add_head( &object_list, &obj->obj_list );
 145 #endif
 146         return obj;
 147     }
 148     return NULL;
 149 }
 150
 151 void *create_named_object( struct namespace *namespace, const struct object_ops *ops,
 152                            const WCHAR *name, size_t len )
 153 {
 154     struct object *obj;
 155     struct object_name *name_ptr;
 156
 157     if (!name || !len) return alloc_object( ops );
 158
 159     if ((obj = find_object( namespace, name, len )))
 160     {
 161         if (obj->ops == ops)
 162         {
 163             set_error( STATUS_OBJECT_NAME_COLLISION );
 164             return obj;
 165         }
 166         set_error( STATUS_OBJECT_TYPE_MISMATCH );
 167         return NULL;
 168     }
 169     if (!(name_ptr = alloc_name( name, len ))) return NULL;
 170     if ((obj = alloc_object( ops )))
 171     {
 172         set_object_name( namespace, obj, name_ptr );
 173         clear_error();
 174     }
 175     else free( name_ptr );
 176     return obj;
 177 }
 178
 179 /* dump the name of an object to stderr */
 180 void dump_object_name( struct object *obj )
 181 {
 182     if (!obj->name) fprintf( stderr, "name=\"\"" );
 183     else
 184     {
 185         fprintf( stderr, "name=L\"" );
 186         dump_strW( obj->name->name, obj->name->len/sizeof(WCHAR), stderr, "\"\"" );
 187         fputc( '\"', stderr );
 188     }
 189 }
 190
 191 /* grab an object (i.e. increment its refcount) and return the object */
 192 struct object *grab_object( void *ptr )
 193 {
 194     struct object *obj = (struct object *)ptr;
 195     assert( obj->refcount < INT_MAX );
 196     obj->refcount++;
 197     return obj;
 198 }
 199
 200 /* release an object (i.e. decrement its refcount) */
 201 void release_object( void *ptr )
 202 {
 203     struct object *obj = (struct object *)ptr;
 204     assert( obj->refcount );
 205     if (!--obj->refcount)
 206     {
 207         /* if the refcount is 0, nobody can be in the wait queue */
 208         assert( !obj->head );
 209         assert( !obj->tail );
 210         obj->ops->destroy( obj );
 211         if (obj->name) free_name( obj );
 212 #ifdef DEBUG_OBJECTS
 213         list_remove( &obj->obj_list );
 214         memset( obj, 0xaa, obj->ops->size );
 215 #endif
 216         free( obj );
 217     }
 218 }
 219
 220 /* find an object by its name; the refcount is incremented */
 221 struct object *find_object( const struct namespace *namespace, const WCHAR *name, size_t len )
 222 {
 223     const struct list *list, *p;
 224
 225     if (!name || !len) return NULL;
 226
 227     list = &namespace->names[ get_name_hash( namespace, name, len ) ];
 228     if (namespace->case_sensitive)
 229     {
 230         LIST_FOR_EACH( p, list )
 231         {
 232             const struct object_name *ptr = LIST_ENTRY( p, const struct object_name, entry );
 233             if (ptr->len != len) continue;
 234             if (!memcmp( ptr->name, name, len )) return grab_object( ptr->obj );
 235         }
 236     }
 237     else
 238     {
 239         LIST_FOR_EACH( p, list )
 240         {
 241             const struct object_name *ptr = LIST_ENTRY( p, const struct object_name, entry );
 242             if (ptr->len != len) continue;
 243             if (!strncmpiW( ptr->name, name, len/sizeof(WCHAR) )) return grab_object( ptr->obj );
 244         }
 245     }
 246     return NULL;
 247 }
 248
 249 /* allocate a namespace */
 250 struct namespace *create_namespace( unsigned int hash_size, int case_sensitive )
 251 {
 252     struct namespace *namespace;
 253     unsigned int i;
 254
 255     namespace = mem_alloc( sizeof(*namespace) + (hash_size - 1) * sizeof(namespace->names[0]) );
 256     if (namespace)
 257     {
 258         namespace->hash_size      = hash_size;
 259         namespace->case_sensitive = case_sensitive;
 260         for (i = 0; i < hash_size; i++) list_init( &namespace->names[i] );
 261     }
 262     return namespace;
 263 }
 264
 265 /* functions for unimplemented/default object operations */
 266
 267 int no_add_queue( struct object *obj, struct wait_queue_entry *entry )
 268 {
 269     set_error( STATUS_OBJECT_TYPE_MISMATCH );
 270     return 0;
 271 }
 272
 273 int no_satisfied( struct object *obj, struct thread *thread )
 274 {
 275     return 0;  /* not abandoned */
 276 }
 277
 278 struct fd *no_get_fd( struct object *obj )
 279 {
 280     set_error( STATUS_OBJECT_TYPE_MISMATCH );
 281     return NULL;
 282 }
 283
 284 void no_destroy( struct object *obj )
 285 {
 286 }