Sweden-Number/server/async.c

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/*
* Server-side async I/O support
*
* Copyright (C) 2007 Alexandre Julliard
*
* 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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
*/
#include <assert.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include "ntstatus.h"
#define WIN32_NO_STATUS
#include "windef.h"
#include "winternl.h"
#include "object.h"
#include "file.h"
#include "request.h"
#include "process.h"
#include "handle.h"
struct async
{
struct object obj; /* object header */
struct thread *thread; /* owning thread */
struct list queue_entry; /* entry in async queue list */
struct list process_entry; /* entry in process list */
struct async_queue *queue; /* queue containing this async */
struct fd *fd; /* fd associated with an unqueued async */
struct timeout_user *timeout;
unsigned int timeout_status; /* status to report upon timeout */
struct event *event;
async_data_t data; /* data for async I/O call */
struct iosb *iosb; /* I/O status block */
obj_handle_t wait_handle; /* pre-allocated wait handle */
unsigned int initial_status; /* status returned from initial request */
unsigned int signaled :1;
unsigned int pending :1; /* request successfully queued, but pending */
unsigned int direct_result :1;/* a flag if we're passing result directly from request instead of APC */
unsigned int alerted :1; /* fd is signaled, but we are waiting for client-side I/O */
unsigned int terminated :1; /* async has been terminated */
unsigned int canceled :1; /* have we already queued cancellation for this async? */
unsigned int unknown_status :1; /* initial status is not known yet */
unsigned int blocking :1; /* async is blocking */
struct completion *completion; /* completion associated with fd */
apc_param_t comp_key; /* completion key associated with fd */
unsigned int comp_flags; /* completion flags */
async_completion_callback completion_callback; /* callback to be called on completion */
void *completion_callback_private; /* argument to completion_callback */
};
static void async_dump( struct object *obj, int verbose );
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static int async_signaled( struct object *obj, struct wait_queue_entry *entry );
static void async_satisfied( struct object * obj, struct wait_queue_entry *entry );
static void async_destroy( struct object *obj );
static const struct object_ops async_ops =
{
sizeof(struct async), /* size */
&no_type, /* type */
async_dump, /* dump */
2015-05-08 10:32:06 +02:00
add_queue, /* add_queue */
remove_queue, /* remove_queue */
async_signaled, /* signaled */
async_satisfied, /* satisfied */
no_signal, /* signal */
no_get_fd, /* get_fd */
default_map_access, /* map_access */
default_get_sd, /* get_sd */
default_set_sd, /* set_sd */
no_get_full_name, /* get_full_name */
no_lookup_name, /* lookup_name */
no_link_name, /* link_name */
NULL, /* unlink_name */
no_open_file, /* open_file */
no_kernel_obj_list, /* get_kernel_obj_list */
no_close_handle, /* close_handle */
async_destroy /* destroy */
};
static inline void async_reselect( struct async *async )
{
if (async->queue && async->fd) fd_reselect_async( async->fd, async->queue );
}
static void async_dump( struct object *obj, int verbose )
{
struct async *async = (struct async *)obj;
assert( obj->ops == &async_ops );
fprintf( stderr, "Async thread=%p\n", async->thread );
}
2015-05-08 10:32:06 +02:00
static int async_signaled( struct object *obj, struct wait_queue_entry *entry )
{
struct async *async = (struct async *)obj;
assert( obj->ops == &async_ops );
return async->signaled;
}
static void async_satisfied( struct object *obj, struct wait_queue_entry *entry )
{
struct async *async = (struct async *)obj;
assert( obj->ops == &async_ops );
/* we only return an async handle for asyncs created via create_request_async() */
assert( async->iosb );
if (async->direct_result)
{
async_set_result( &async->obj, async->iosb->status, async->iosb->result );
async->direct_result = 0;
}
if (async->initial_status == STATUS_PENDING && async->blocking)
set_wait_status( entry, async->iosb->status );
else
set_wait_status( entry, async->initial_status );
/* close wait handle here to avoid extra server round trip */
if (async->wait_handle)
{
close_handle( async->thread->process, async->wait_handle );
async->wait_handle = 0;
}
}
static void async_destroy( struct object *obj )
{
struct async *async = (struct async *)obj;
assert( obj->ops == &async_ops );
list_remove( &async->process_entry );
if (async->queue)
{
list_remove( &async->queue_entry );
async_reselect( async );
}
else if (async->fd) release_object( async->fd );
if (async->timeout) remove_timeout_user( async->timeout );
if (async->completion) release_object( async->completion );
if (async->event) release_object( async->event );
if (async->iosb) release_object( async->iosb );
release_object( async->thread );
}
/* notifies client thread of new status of its async request */
void async_terminate( struct async *async, unsigned int status )
{
struct iosb *iosb = async->iosb;
if (async->terminated) return;
async->terminated = 1;
if (async->iosb && async->iosb->status == STATUS_PENDING) async->iosb->status = status;
if (status == STATUS_ALERTED)
async->alerted = 1;
/* if no APC could be queued (e.g. the process is terminated),
* thread_queue_apc() may trigger async_set_result(), which may drop the
* last reference to the async, so grab a temporary reference here */
grab_object( async );
if (!async->direct_result)
{
apc_call_t data;
memset( &data, 0, sizeof(data) );
data.type = APC_ASYNC_IO;
data.async_io.user = async->data.user;
data.async_io.result = iosb ? iosb->result : 0;
/* this can happen if the initial status was unknown (i.e. for device
* files). the client should not fill the IOSB in this case; pass it as
* NULL to communicate that.
* note that we check the IOSB status and not the initial status */
if (NT_ERROR( status ) && (!is_fd_overlapped( async->fd ) || !async->pending))
data.async_io.sb = 0;
else
data.async_io.sb = async->data.iosb;
/* if there is output data, the client needs to make an extra request
* to retrieve it; use STATUS_ALERTED to signal this case */
if (iosb && iosb->out_data)
data.async_io.status = STATUS_ALERTED;
else
data.async_io.status = status;
thread_queue_apc( async->thread->process, async->thread, &async->obj, &data );
}
async_reselect( async );
release_object( async );
}
/* callback for timeout on an async request */
static void async_timeout( void *private )
{
struct async *async = private;
async->timeout = NULL;
async_terminate( async, async->timeout_status );
}
/* free an async queue, cancelling all async operations */
void free_async_queue( struct async_queue *queue )
{
struct async *async, *next;
LIST_FOR_EACH_ENTRY_SAFE( async, next, &queue->queue, struct async, queue_entry )
{
if (!async->completion) async->completion = fd_get_completion( async->fd, &async->comp_key );
async->fd = NULL;
async_terminate( async, STATUS_HANDLES_CLOSED );
async->queue = NULL;
release_object( &async->obj );
}
}
void queue_async( struct async_queue *queue, struct async *async )
{
/* fd will be set to NULL in free_async_queue when fd is destroyed */
release_object( async->fd );
async->queue = queue;
grab_object( async );
list_add_tail( &queue->queue, &async->queue_entry );
set_fd_signaled( async->fd, 0 );
}
/* create an async on a given queue of a fd */
struct async *create_async( struct fd *fd, struct thread *thread, const async_data_t *data, struct iosb *iosb )
{
struct event *event = NULL;
struct async *async;
if (data->event && !(event = get_event_obj( thread->process, data->event, EVENT_MODIFY_STATE )))
return NULL;
if (!(async = alloc_object( &async_ops )))
{
if (event) release_object( event );
return NULL;
}
async->thread = (struct thread *)grab_object( thread );
async->event = event;
async->data = *data;
async->timeout = NULL;
async->queue = NULL;
async->fd = (struct fd *)grab_object( fd );
async->initial_status = STATUS_PENDING;
async->signaled = 0;
async->pending = 1;
async->wait_handle = 0;
async->direct_result = 0;
async->alerted = 0;
async->terminated = 0;
async->canceled = 0;
async->unknown_status = 0;
async->blocking = !is_fd_overlapped( fd );
async->completion = fd_get_completion( fd, &async->comp_key );
async->comp_flags = 0;
async->completion_callback = NULL;
async->completion_callback_private = NULL;
if (iosb) async->iosb = (struct iosb *)grab_object( iosb );
else async->iosb = NULL;
list_add_head( &thread->process->asyncs, &async->process_entry );
if (event) reset_event( event );
if (async->completion && data->apc)
{
release_object( async );
set_error( STATUS_INVALID_PARAMETER );
return NULL;
}
return async;
}
/* set the initial status of an async whose status was previously unknown
* the initial status may be STATUS_PENDING */
void async_set_initial_status( struct async *async, unsigned int status )
{
assert( async->unknown_status );
if (!async->terminated)
{
async->initial_status = status;
async->unknown_status = 0;
}
}
void set_async_pending( struct async *async )
{
if (!async->terminated)
async->pending = 1;
}
void async_wake_obj( struct async *async )
{
assert( !async->unknown_status );
if (!async->blocking)
{
async->signaled = 1;
wake_up( &async->obj, 0 );
}
}
/* return async object status and wait handle to client */
obj_handle_t async_handoff( struct async *async, data_size_t *result, int force_blocking )
{
async->blocking = force_blocking || async->blocking;
if (async->unknown_status)
{
/* even the initial status is not known yet */
set_error( STATUS_PENDING );
return async->wait_handle;
}
async->initial_status = get_error();
if (!async->pending && NT_ERROR( get_error() ))
{
close_handle( async->thread->process, async->wait_handle );
async->wait_handle = 0;
return 0;
}
if (get_error() != STATUS_PENDING)
{
/* status and data are already set and returned */
async_terminate( async, get_error() );
}
else if (async->iosb->status != STATUS_PENDING)
{
/* result is already available in iosb, return it */
if (async->iosb->out_data)
{
set_reply_data_ptr( async->iosb->out_data, async->iosb->out_size );
async->iosb->out_data = NULL;
}
}
if (async->iosb->status != STATUS_PENDING)
{
if (result) *result = async->iosb->result;
async->signaled = 1;
}
else
{
async->direct_result = 0;
async->pending = 1;
if (!async->blocking)
{
close_handle( async->thread->process, async->wait_handle);
async->wait_handle = 0;
}
}
async->initial_status = async->iosb->status;
set_error( async->iosb->status );
return async->wait_handle;
}
/* complete a request-based async with a pre-allocated buffer */
void async_request_complete( struct async *async, unsigned int status, data_size_t result,
data_size_t out_size, void *out_data )
{
struct iosb *iosb = async_get_iosb( async );
/* the async may have already been canceled */
if (iosb->status != STATUS_PENDING)
{
release_object( iosb );
free( out_data );
return;
}
iosb->status = status;
iosb->result = result;
iosb->out_data = out_data;
iosb->out_size = out_size;
release_object( iosb );
async_terminate( async, status );
}
/* complete a request-based async */
void async_request_complete_alloc( struct async *async, unsigned int status, data_size_t result,
data_size_t out_size, const void *out_data )
{
void *out_data_copy = NULL;
if (out_size && !(out_data_copy = memdup( out_data, out_size )))
{
async_terminate( async, STATUS_NO_MEMORY );
return;
}
async_request_complete( async, status, result, out_size, out_data_copy );
}
/* mark an async as having unknown initial status */
void async_set_unknown_status( struct async *async )
{
async->unknown_status = 1;
async->direct_result = 0;
}
/* set the timeout of an async operation */
void async_set_timeout( struct async *async, timeout_t timeout, unsigned int status )
{
if (async->timeout) remove_timeout_user( async->timeout );
if (timeout != TIMEOUT_INFINITE) async->timeout = add_timeout_user( timeout, async_timeout, async );
else async->timeout = NULL;
async->timeout_status = status;
}
/* set a callback to be notified when the async is completed */
void async_set_completion_callback( struct async *async, async_completion_callback func, void *private )
{
async->completion_callback = func;
async->completion_callback_private = private;
}
static void add_async_completion( struct async *async, apc_param_t cvalue, unsigned int status,
apc_param_t information )
{
if (async->fd && !async->completion) async->completion = fd_get_completion( async->fd, &async->comp_key );
if (async->completion) add_completion( async->completion, async->comp_key, cvalue, status, information );
}
/* store the result of the client-side async callback */
void async_set_result( struct object *obj, unsigned int status, apc_param_t total )
{
struct async *async = (struct async *)obj;
if (obj->ops != &async_ops) return; /* in case the client messed up the APC results */
assert( async->terminated ); /* it must have been woken up if we get a result */
if (async->alerted && status == STATUS_PENDING) /* restart it */
{
async->terminated = 0;
async->alerted = 0;
async_reselect( async );
}
else
{
if (async->timeout) remove_timeout_user( async->timeout );
async->timeout = NULL;
async->terminated = 1;
if (async->iosb) async->iosb->status = status;
/* don't signal completion if the async failed synchronously
* this can happen if the initial status was unknown (i.e. for device files)
* note that we check the IOSB status here, not the initial status */
if (async->pending || !NT_ERROR( status ))
{
if (async->data.apc)
{
apc_call_t data;
memset( &data, 0, sizeof(data) );
data.type = APC_USER;
data.user.func = async->data.apc;
data.user.args[0] = async->data.apc_context;
data.user.args[1] = async->data.iosb;
data.user.args[2] = 0;
thread_queue_apc( NULL, async->thread, NULL, &data );
}
else if (async->data.apc_context && (async->pending ||
!(async->comp_flags & FILE_SKIP_COMPLETION_PORT_ON_SUCCESS)))
{
add_async_completion( async, async->data.apc_context, status, total );
}
if (async->event) set_event( async->event );
else if (async->fd) set_fd_signaled( async->fd, 1 );
}
if (!async->signaled)
{
async->signaled = 1;
wake_up( &async->obj, 0 );
}
if (async->completion_callback)
async->completion_callback( async->completion_callback_private );
async->completion_callback = NULL;
if (async->queue)
{
list_remove( &async->queue_entry );
async_reselect( async );
async->fd = NULL;
async->queue = NULL;
release_object( async );
}
}
}
/* check if an async operation is waiting to be alerted */
int async_waiting( struct async_queue *queue )
{
struct list *ptr;
struct async *async;
if (!(ptr = list_head( &queue->queue ))) return 0;
async = LIST_ENTRY( ptr, struct async, queue_entry );
return !async->terminated;
}
static int cancel_async( struct process *process, struct object *obj, struct thread *thread, client_ptr_t iosb )
{
struct async *async;
int woken = 0;
/* FIXME: it would probably be nice to replace the "canceled" flag with a
* single LIST_FOR_EACH_ENTRY_SAFE, but currently cancelling an async can
* cause other asyncs to be removed via async_reselect() */
restart:
LIST_FOR_EACH_ENTRY( async, &process->asyncs, struct async, process_entry )
{
if (async->terminated || async->canceled) continue;
if ((!obj || (get_fd_user( async->fd ) == obj)) &&
(!thread || async->thread == thread) &&
(!iosb || async->data.iosb == iosb))
{
async->canceled = 1;
fd_cancel_async( async->fd, async );
woken++;
goto restart;
}
}
return woken;
}
void cancel_process_asyncs( struct process *process )
{
cancel_async( process, NULL, NULL, 0 );
}
/* wake up async operations on the queue */
void async_wake_up( struct async_queue *queue, unsigned int status )
{
struct list *ptr, *next;
LIST_FOR_EACH_SAFE( ptr, next, &queue->queue )
{
struct async *async = LIST_ENTRY( ptr, struct async, queue_entry );
async_terminate( async, status );
if (status == STATUS_ALERTED) break; /* only wake up the first one */
}
}
static void iosb_dump( struct object *obj, int verbose );
static void iosb_destroy( struct object *obj );
static const struct object_ops iosb_ops =
{
sizeof(struct iosb), /* size */
&no_type, /* type */
iosb_dump, /* dump */
no_add_queue, /* add_queue */
NULL, /* remove_queue */
NULL, /* signaled */
NULL, /* satisfied */
no_signal, /* signal */
no_get_fd, /* get_fd */
default_map_access, /* map_access */
default_get_sd, /* get_sd */
default_set_sd, /* set_sd */
no_get_full_name, /* get_full_name */
no_lookup_name, /* lookup_name */
no_link_name, /* link_name */
NULL, /* unlink_name */
no_open_file, /* open_file */
no_kernel_obj_list, /* get_kernel_obj_list */
no_close_handle, /* close_handle */
iosb_destroy /* destroy */
};
static void iosb_dump( struct object *obj, int verbose )
{
assert( obj->ops == &iosb_ops );
fprintf( stderr, "I/O status block\n" );
}
static void iosb_destroy( struct object *obj )
{
struct iosb *iosb = (struct iosb *)obj;
free( iosb->in_data );
free( iosb->out_data );
}
/* allocate iosb struct */
static struct iosb *create_iosb( const void *in_data, data_size_t in_size, data_size_t out_size )
{
struct iosb *iosb;
if (!(iosb = alloc_object( &iosb_ops ))) return NULL;
iosb->status = STATUS_PENDING;
iosb->result = 0;
iosb->in_size = in_size;
iosb->in_data = NULL;
iosb->out_size = out_size;
iosb->out_data = NULL;
if (in_size && !(iosb->in_data = memdup( in_data, in_size )))
{
release_object( iosb );
iosb = NULL;
}
return iosb;
}
/* create an async associated with iosb for async-based requests
* returned async must be passed to async_handoff */
struct async *create_request_async( struct fd *fd, unsigned int comp_flags, const async_data_t *data )
{
struct async *async;
struct iosb *iosb;
if (!(iosb = create_iosb( get_req_data(), get_req_data_size(), get_reply_max_size() )))
return NULL;
async = create_async( fd, current, data, iosb );
release_object( iosb );
if (async)
{
if (!(async->wait_handle = alloc_handle( current->process, async, SYNCHRONIZE, 0 )))
{
release_object( async );
return NULL;
}
async->pending = 0;
async->direct_result = 1;
async->comp_flags = comp_flags;
}
return async;
}
struct iosb *async_get_iosb( struct async *async )
{
return async->iosb ? (struct iosb *)grab_object( async->iosb ) : NULL;
}
struct thread *async_get_thread( struct async *async )
{
return async->thread;
}
/* find the first pending async in queue */
struct async *find_pending_async( struct async_queue *queue )
{
struct async *async;
LIST_FOR_EACH_ENTRY( async, &queue->queue, struct async, queue_entry )
if (!async->terminated) return (struct async *)grab_object( async );
return NULL;
}
/* cancels all async I/O */
DECL_HANDLER(cancel_async)
{
struct object *obj = get_handle_obj( current->process, req->handle, 0, NULL );
struct thread *thread = req->only_thread ? current : NULL;
if (obj)
{
int count = cancel_async( current->process, obj, thread, req->iosb );
if (!count && req->iosb) set_error( STATUS_NOT_FOUND );
release_object( obj );
}
}
/* get async result from associated iosb */
DECL_HANDLER(get_async_result)
{
struct iosb *iosb = NULL;
struct async *async;
LIST_FOR_EACH_ENTRY( async, &current->process->asyncs, struct async, process_entry )
if (async->data.user == req->user_arg)
{
iosb = async->iosb;
break;
}
if (!iosb)
{
set_error( STATUS_INVALID_PARAMETER );
return;
}
if (iosb->out_data)
{
data_size_t size = min( iosb->out_size, get_reply_max_size() );
if (size)
{
set_reply_data_ptr( iosb->out_data, size );
iosb->out_data = NULL;
}
}
set_error( iosb->status );
}