Sweden-Number/server/async.c

182 lines
4.7 KiB
C
Raw Normal View History

/*
* Server-side support for async i/o operations
*
* Copyright (C) 1998 Alexandre Julliard
* Copyright (C) 2000 Mike McCormack
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include "config.h"
#include <assert.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <stdio.h>
#include "handle.h"
#include "thread.h"
#include "request.h"
#include "async.h"
void destroy_async( struct async *async )
{
struct async_queue *aq = async->q;
/*fprintf(stderr,"destroyed async %p\n",async->overlapped); */
if(async->timeout)
remove_timeout_user(async->timeout);
async->timeout = NULL;
if(async->prev)
async->prev->next = async->next;
else
aq->head = async->next;
if(async->next)
async->next->prev = async->prev;
else
aq->tail = async->prev;
async->q = NULL;
async->next = NULL;
async->prev = NULL;
free(async);
}
void async_notify(struct async *async, int status)
{
/* fprintf(stderr,"notifying %p!\n",async->overlapped); */
async->status = status;
thread_queue_apc(async->thread, NULL, NULL, APC_ASYNC_IO, 1, 2, async->overlapped, status);
}
void destroy_async_queue( struct async_queue *q )
{
while(q->head)
{
async_notify(q->head, STATUS_CANCELLED);
destroy_async(q->head);
}
}
struct async *find_async(struct async_queue *q, struct thread *thread, void *overlapped)
{
struct async *async;
/* fprintf(stderr,"find_async: %p\n",overlapped); */
if(!q)
return NULL;
for(async = q->head; async; async = async->next)
if((async->overlapped==overlapped) && (async->thread == thread))
return async;
return NULL;
}
void async_insert(struct async_queue *q, struct async *async)
{
async->q = q;
async->prev = q->tail;
async->next = NULL;
if(q->tail)
q->tail->next = async;
else
q->head = async;
q->tail = async;
}
static void async_callback(void *private)
{
struct async *async = (struct async *)private;
/* fprintf(stderr,"%p timeout out\n",async->overlapped); */
async->timeout = NULL;
async_notify(async, STATUS_TIMEOUT);
destroy_async(async);
}
struct async *create_async(struct object *obj, struct thread *thread,
void *overlapped)
{
struct async *async = (struct async *) malloc(sizeof(struct async));
if(!async)
{
set_error(STATUS_NO_MEMORY);
return NULL;
}
async->obj = obj;
async->thread = thread;
async->overlapped = overlapped;
async->next = NULL;
async->prev = NULL;
async->q = NULL;
async->status = STATUS_PENDING;
async->timeout = NULL;
return async;
}
void async_add_timeout(struct async *async, int timeout)
{
if(timeout)
{
gettimeofday( &async->when, 0 );
add_timeout( &async->when, timeout );
async->timeout = add_timeout_user( &async->when, async_callback, async );
}
}
DECL_HANDLER(register_async)
{
struct object *obj = get_handle_obj( current->process, req->handle, 0, NULL);
if ( !(obj) || !obj->ops->queue_async )
{
set_error(STATUS_INVALID_HANDLE);
return;
}
/*
* The queue_async method must do the following:
*
* 1. Get the async_queue for the request of given type.
* 2. Call find_async() to look for the specific client request in the queue (=> NULL if not found).
* 3. If status is STATUS_PENDING:
* a) If no async request found in step 2 (new request): call create_async() to initialize one.
* b) Set request's status to STATUS_PENDING.
* c) If the "queue" field of the async request is NULL: call async_insert() to put it into the queue.
* Otherwise:
* If the async request was found in step 2, destroy it by calling destroy_async().
* 4. Carry out any operations necessary to adjust the object's poll events
* Usually: set_elect_events (obj, obj->ops->get_poll_events()).
*
* See also the implementations in file.c, serial.c, and sock.c.
*/
obj->ops->queue_async (obj, req->overlapped, req->status, req->type, req->count);
release_object(obj);
}