Sweden-Number/server/object.c

318 lines
7.8 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 <unistd.h>
#include "thread.h"
#include "unicode.h"
struct object_name
{
struct object_name *next;
struct object_name *prev;
struct object *obj;
size_t len;
WCHAR 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 set_error( STATUS_NO_MEMORY );
return ptr;
}
/* duplicate a block of memory */
void *memdup( const void *data, size_t len )
{
void *ptr = malloc( len );
if (ptr) memcpy( ptr, data, len );
else set_error( STATUS_NO_MEMORY );
return ptr;
}
/*****************************************************************/
static int get_name_hash( const WCHAR *name, size_t len )
{
WCHAR hash = 0;
len /= sizeof(WCHAR);
while (len--) hash ^= *name++;
return hash % NAME_HASH_SIZE;
}
/* allocate a name for an object */
static struct object_name *alloc_name( const WCHAR *name, size_t len )
{
struct object_name *ptr;
if ((ptr = mem_alloc( sizeof(*ptr) + len - sizeof(ptr->name) )))
{
ptr->len = len;
memcpy( ptr->name, name, len );
}
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 */
/* if the function fails the fd is closed */
void *alloc_object( const struct object_ops *ops, int fd )
{
struct object *obj = mem_alloc( ops->size );
if (obj)
{
obj->refcount = 1;
obj->fd = fd;
obj->select = -1;
obj->ops = ops;
obj->head = NULL;
obj->tail = NULL;
obj->name = NULL;
if ((fd != -1) && (add_select_user( obj ) == -1))
{
close( fd );
free( obj );
return NULL;
}
#ifdef DEBUG_OBJECTS
obj->prev = NULL;
if ((obj->next = first) != NULL) obj->next->prev = obj;
first = obj;
#endif
return obj;
}
if (fd != -1) close( fd );
return NULL;
}
void *create_named_object( const struct object_ops *ops, const WCHAR *name, size_t len )
{
struct object *obj;
struct object_name *name_ptr;
if (!name || !len) return alloc_object( ops, -1 );
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( STATUS_OBJECT_NAME_COLLISION );
return obj;
}
set_error( STATUS_OBJECT_TYPE_MISMATCH );
return NULL;
}
if ((obj = alloc_object( ops, -1 )))
{
set_object_name( obj, name_ptr );
clear_error();
}
else free( name_ptr );
return obj;
}
/* dump the name of an object to stderr */
void dump_object_name( struct object *obj )
{
if (!obj->name) fprintf( stderr, "name=\"\"" );
else
{
fprintf( stderr, "name=L\"" );
dump_strW( obj->name->name, obj->name->len/sizeof(WCHAR), stderr, "\"\"" );
fputc( '\"', stderr );
}
}
/* 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 );
obj->ops->destroy( obj );
if (obj->name) free_name( obj );
if (obj->select != -1) remove_select_user( obj );
if (obj->fd != -1) close( obj->fd );
#ifdef DEBUG_OBJECTS
if (obj->next) obj->next->prev = obj->prev;
if (obj->prev) obj->prev->next = obj->next;
else first = obj->next;
memset( obj, 0xaa, obj->ops->size );
#endif
free( obj );
}
}
/* find an object by its name; the refcount is incremented */
struct object *find_object( const WCHAR *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/default object operations */
int no_add_queue( struct object *obj, struct wait_queue_entry *entry )
{
set_error( STATUS_OBJECT_TYPE_MISMATCH );
return 0;
}
int no_satisfied( struct object *obj, struct thread *thread )
{
return 0; /* not abandoned */
}
int no_get_fd( struct object *obj )
{
set_error( STATUS_OBJECT_TYPE_MISMATCH );
return -1;
}
int no_flush( struct object *obj )
{
set_error( STATUS_OBJECT_TYPE_MISMATCH );
return 0;
}
int no_get_file_info( struct object *obj, struct get_file_info_reply *info )
{
set_error( STATUS_OBJECT_TYPE_MISMATCH );
return FD_TYPE_INVALID;
}
void no_destroy( struct object *obj )
{
}
/* default add_queue() routine for objects that poll() on an fd */
int default_poll_add_queue( struct object *obj, struct wait_queue_entry *entry )
{
if (!obj->head) /* first on the queue */
set_select_events( obj, obj->ops->get_poll_events( obj ) );
add_queue( obj, entry );
return 1;
}
/* default remove_queue() routine for objects that poll() on an fd */
void default_poll_remove_queue( struct object *obj, struct wait_queue_entry *entry )
{
grab_object(obj);
remove_queue( obj, entry );
if (!obj->head) /* last on the queue is gone */
set_select_events( obj, 0 );
release_object( obj );
}
/* default signaled() routine for objects that poll() on an fd */
int default_poll_signaled( struct object *obj, struct thread *thread )
{
int events = obj->ops->get_poll_events( obj );
if (check_select_events( obj->fd, events ))
{
/* stop waiting on select() if we are signaled */
set_select_events( obj, 0 );
return 1;
}
/* restart waiting on select() if we are no longer signaled */
if (obj->head) set_select_events( obj, events );
return 0;
}
/* default handler for poll() events */
void default_poll_event( struct object *obj, int event )
{
/* an error occurred, stop polling this fd to avoid busy-looping */
if (event & (POLLERR | POLLHUP)) set_select_events( obj, -1 );
wake_up( obj, 0 );
}