Sweden-Number/server/object.c

147 lines
3.5 KiB
C

/*
* Server-side objects
* These are the server equivalent of K32OBJ
*
* Copyright (C) 1998 Alexandre Julliard
*/
#include <assert.h>
#include <limits.h>
#include <stdlib.h>
#include <string.h>
#include "winerror.h"
#include "server.h"
#include "server/thread.h"
int debug_level = 0;
struct object_name
{
struct object_name *next;
struct object *obj;
int len;
char name[1];
};
#define NAME_HASH_SIZE 37
static struct object_name *names[NAME_HASH_SIZE];
/*****************************************************************/
void *mem_alloc( size_t size )
{
void *ptr = malloc( size );
if (ptr) memset( ptr, 0x55, size );
else if (current) SET_ERROR( ERROR_OUTOFMEMORY );
return ptr;
}
/*****************************************************************/
static int get_name_hash( const char *name )
{
int hash = 0;
while (*name) hash ^= *name++;
return hash % NAME_HASH_SIZE;
}
static struct object_name *add_name( struct object *obj, const char *name )
{
struct object_name *ptr;
int hash = get_name_hash( name );
int len = strlen( name );
if (!(ptr = (struct object_name *)mem_alloc( sizeof(*ptr) + len )))
return NULL;
ptr->next = names[hash];
ptr->obj = obj;
ptr->len = len;
strcpy( ptr->name, name );
names[hash] = ptr;
return ptr;
}
static void free_name( struct object *obj )
{
int hash = get_name_hash( obj->name->name );
struct object_name **pptr = &names[hash];
while (*pptr && *pptr != obj->name) pptr = &(*pptr)->next;
assert( *pptr );
*pptr = (*pptr)->next;
free( obj->name );
}
/* initialize an already allocated object */
/* return 1 if OK, 0 on error */
int init_object( struct object *obj, const struct object_ops *ops,
const char *name )
{
obj->refcount = 1;
obj->ops = ops;
obj->head = NULL;
obj->tail = NULL;
if (!name) obj->name = NULL;
else if (!(obj->name = add_name( obj, name ))) return 0;
return 1;
}
struct object *create_named_object( const char *name, const struct object_ops *ops, size_t size )
{
struct object *obj;
if ((obj = find_object( name )))
{
if (obj->ops == ops)
{
SET_ERROR( ERROR_ALREADY_EXISTS );
return obj;
}
SET_ERROR( ERROR_INVALID_HANDLE );
return NULL;
}
if (!(obj = mem_alloc( size ))) return NULL;
if (!init_object( obj, ops, name ))
{
free( obj );
return NULL;
}
CLEAR_ERROR();
return obj;
}
/* grab an object (i.e. increment its refcount) and return the object */
struct object *grab_object( void *ptr )
{
struct object *obj = (struct object *)ptr;
assert( obj->refcount < INT_MAX );
obj->refcount++;
return obj;
}
/* release an object (i.e. decrement its refcount) */
void release_object( void *ptr )
{
struct object *obj = (struct object *)ptr;
assert( obj->refcount );
if (!--obj->refcount)
{
/* if the refcount is 0, nobody can be in the wait queue */
assert( !obj->head );
assert( !obj->tail );
if (obj->name) free_name( obj );
obj->ops->destroy( obj );
}
}
/* find an object by its name; the refcount is incremented */
struct object *find_object( const char *name )
{
struct object_name *ptr;
if (!name) return NULL;
ptr = names[ get_name_hash( name ) ];
while (ptr && strcmp( ptr->name, name )) ptr = ptr->next;
if (!ptr) return NULL;
return grab_object( ptr->obj );
}