Sweden-Number/server/object.c

259 lines
5.8 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 <stdio.h>
#include <string.h>
#include "winerror.h"
#include "thread.h"
int debug_level = 0;
struct object_name
{
struct object_name *next;
struct object_name *prev;
struct object *obj;
size_t len;
char name[1];
};
#define NAME_HASH_SIZE 37
static struct object_name *names[NAME_HASH_SIZE];
#ifdef DEBUG_OBJECTS
static struct object *first;
void dump_objects(void)
{
struct object *ptr = first;
while (ptr)
{
fprintf( stderr, "%p:%d: ", ptr, ptr->refcount );
ptr->ops->dump( ptr, 1 );
ptr = ptr->next;
}
}
#endif
/*****************************************************************/
/* malloc replacement */
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, size_t len )
{
char hash = 0;
while (len--) hash ^= *name++;
return hash % NAME_HASH_SIZE;
}
/* allocate a name for an object */
static struct object_name *alloc_name( const char *name, size_t len )
{
struct object_name *ptr;
if ((ptr = mem_alloc( sizeof(*ptr) + len )))
{
ptr->len = len;
memcpy( ptr->name, name, len );
ptr->name[len] = 0;
}
return ptr;
}
/* free the name of an object */
static void free_name( struct object *obj )
{
struct object_name *ptr = obj->name;
if (ptr->next) ptr->next->prev = ptr->prev;
if (ptr->prev) ptr->prev->next = ptr->next;
else
{
int hash;
for (hash = 0; hash < NAME_HASH_SIZE; hash++)
if (names[hash] == ptr)
{
names[hash] = ptr->next;
break;
}
}
free( ptr );
}
/* set the name of an existing object */
static void set_object_name( struct object *obj, struct object_name *ptr )
{
int hash = get_name_hash( ptr->name, ptr->len );
if ((ptr->next = names[hash]) != NULL) ptr->next->prev = ptr;
ptr->obj = obj;
ptr->prev = NULL;
names[hash] = ptr;
assert( !obj->name );
obj->name = ptr;
}
/* allocate and initialize an object */
void *alloc_object( const struct object_ops *ops )
{
struct object *obj = mem_alloc( ops->size );
if (obj)
{
obj->refcount = 1;
obj->ops = ops;
obj->head = NULL;
obj->tail = NULL;
obj->name = NULL;
#ifdef DEBUG_OBJECTS
obj->prev = NULL;
if ((obj->next = first) != NULL) obj->next->prev = obj;
first = obj;
#endif
}
return obj;
}
void *create_named_object( const struct object_ops *ops, const char *name, size_t len )
{
struct object *obj;
struct object_name *name_ptr;
if (!name || !len) return alloc_object( ops );
if (!(name_ptr = alloc_name( name, len ))) return NULL;
if ((obj = find_object( name_ptr->name, name_ptr->len )))
{
free( name_ptr ); /* we no longer need it */
if (obj->ops == ops)
{
set_error( ERROR_ALREADY_EXISTS );
return obj;
}
set_error( ERROR_INVALID_HANDLE );
return NULL;
}
if ((obj = alloc_object( ops )))
{
set_object_name( obj, name_ptr );
clear_error();
}
else free( name_ptr );
return obj;
}
/* return a pointer to the object name, or to an empty string */
const char *get_object_name( struct object *obj )
{
if (!obj->name) return "";
return obj->name->name;
}
/* 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 );
#ifdef DEBUG_OBJECTS
if (obj->next) obj->next->prev = obj->prev;
if (obj->prev) obj->prev->next = obj->next;
else first = obj->next;
#endif
obj->ops->destroy( obj );
memset( obj, 0xaa, obj->ops->size );
free( obj );
}
}
/* find an object by its name; the refcount is incremented */
struct object *find_object( const char *name, size_t len )
{
struct object_name *ptr;
if (!name || !len) return NULL;
for (ptr = names[ get_name_hash( name, len ) ]; ptr; ptr = ptr->next)
{
if (ptr->len != len) continue;
if (!memcmp( ptr->name, name, len )) return grab_object( ptr->obj );
}
return NULL;
}
/* functions for unimplemented object operations */
int no_add_queue( struct object *obj, struct wait_queue_entry *entry )
{
set_error( ERROR_INVALID_HANDLE );
return 0;
}
int no_satisfied( struct object *obj, struct thread *thread )
{
return 0; /* not abandoned */
}
int no_read_fd( struct object *obj )
{
set_error( ERROR_INVALID_HANDLE );
return -1;
}
int no_write_fd( struct object *obj )
{
set_error( ERROR_INVALID_HANDLE );
return -1;
}
int no_flush( struct object *obj )
{
set_error( ERROR_INVALID_HANDLE );
return 0;
}
int no_get_file_info( struct object *obj, struct get_file_info_request *info )
{
set_error( ERROR_INVALID_HANDLE );
return 0;
}
void no_destroy( struct object *obj )
{
}
void default_select_event( int event, void *private )
{
struct object *obj = (struct object *)private;
assert( obj );
wake_up( obj, 0 );
}