server/async.c

   1 /*
   2  * Server-side async I/O support
   3  *
   4  * Copyright (C) 2007 Alexandre Julliard
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
  19  */
  20
  21 #include <assert.h>
  22 #include <stdio.h>
  23 #include <stdlib.h>
  24 #include <stdarg.h>
  25
  26 #include "ntstatus.h"
  27 #define WIN32_NO_STATUS
  28 #include "windef.h"
  29 #include "winternl.h"
  30
  31 #include "object.h"
  32 #include "file.h"
  33 #include "request.h"
  34 #include "process.h"
  35 #include "handle.h"
  36
  37 struct async
  38 {
  39     struct object        obj;             /* object header */
  40     struct thread       *thread;          /* owning thread */
  41     struct list          queue_entry;     /* entry in async queue list */
  42     struct list          process_entry;   /* entry in process list */
  43     struct async_queue  *queue;           /* queue containing this async */
  44     struct fd           *fd;              /* fd associated with an unqueued async */
  45     unsigned int         status;          /* current status */
  46     struct timeout_user *timeout;
  47     unsigned int         timeout_status;  /* status to report upon timeout */
  48     int                  signaled;
  49     struct event        *event;
  50     async_data_t         data;            /* data for async I/O call */
  51     struct iosb         *iosb;            /* I/O status block */
  52     obj_handle_t         wait_handle;     /* pre-allocated wait handle */
  53     int                  direct_result;   /* a flag if we're passing result directly from request instead of APC  */
  54     struct completion   *completion;      /* completion associated with fd */
  55     apc_param_t          comp_key;        /* completion key associated with fd */
  56     unsigned int         comp_flags;      /* completion flags */
  57 };
  58
  59 static void async_dump( struct object *obj, int verbose );
  60 static int async_signaled( struct object *obj, struct wait_queue_entry *entry );
  61 static void async_satisfied( struct object * obj, struct wait_queue_entry *entry );
  62 static void async_destroy( struct object *obj );
  63
  64 static const struct object_ops async_ops =
  65 {
  66     sizeof(struct async),      /* size */
  67     async_dump,                /* dump */
  68     no_get_type,               /* get_type */
  69     add_queue,                 /* add_queue */
  70     remove_queue,              /* remove_queue */
  71     async_signaled,            /* signaled */
  72     async_satisfied,           /* satisfied */
  73     no_signal,                 /* signal */
  74     no_get_fd,                 /* get_fd */
  75     no_map_access,             /* map_access */
  76     default_get_sd,            /* get_sd */
  77     default_set_sd,            /* set_sd */
  78     no_lookup_name,            /* lookup_name */
  79     no_link_name,              /* link_name */
  80     NULL,                      /* unlink_name */
  81     no_open_file,              /* open_file */
  82     no_close_handle,           /* close_handle */
  83     async_destroy              /* destroy */
  84 };
  85
  86 static inline void async_reselect( struct async *async )
  87 {
  88     if (async->queue && async->fd) fd_reselect_async( async->fd, async->queue );
  89 }
  90
  91 static void async_dump( struct object *obj, int verbose )
  92 {
  93     struct async *async = (struct async *)obj;
  94     assert( obj->ops == &async_ops );
  95     fprintf( stderr, "Async thread=%p\n", async->thread );
  96 }
  97
  98 static int async_signaled( struct object *obj, struct wait_queue_entry *entry )
  99 {
 100     struct async *async = (struct async *)obj;
 101     assert( obj->ops == &async_ops );
 102     return async->signaled;
 103 }
 104
 105 static void async_satisfied( struct object *obj, struct wait_queue_entry *entry )
 106 {
 107     struct async *async = (struct async *)obj;
 108     assert( obj->ops == &async_ops );
 109
 110     if (async->direct_result)
 111     {
 112         async_set_result( &async->obj, async->iosb->status, async->iosb->result );
 113         async->direct_result = 0;
 114     }
 115
 116     /* close wait handle here to avoid extra server round trip */
 117     if (async->wait_handle)
 118     {
 119         close_handle( async->thread->process, async->wait_handle );
 120         async->wait_handle = 0;
 121     }
 122 }
 123
 124 static void async_destroy( struct object *obj )
 125 {
 126     struct async *async = (struct async *)obj;
 127     assert( obj->ops == &async_ops );
 128
 129     list_remove( &async->process_entry );
 130
 131     if (async->queue)
 132     {
 133         list_remove( &async->queue_entry );
 134         async_reselect( async );
 135     }
 136     else if (async->fd) release_object( async->fd );
 137
 138     if (async->timeout) remove_timeout_user( async->timeout );
 139     if (async->completion) release_object( async->completion );
 140     if (async->event) release_object( async->event );
 141     if (async->iosb) release_object( async->iosb );
 142     release_object( async->thread );
 143 }
 144
 145 /* notifies client thread of new status of its async request */
 146 void async_terminate( struct async *async, unsigned int status )
 147 {
 148     assert( status != STATUS_PENDING );
 149
 150     if (async->status != STATUS_PENDING)
 151     {
 152         /* already terminated, just update status */
 153         async->status = status;
 154         return;
 155     }
 156
 157     async->status = status;
 158     if (async->iosb && async->iosb->status == STATUS_PENDING) async->iosb->status = status;
 159
 160     if (!async->direct_result)
 161     {
 162         if (async->data.user)
 163         {
 164             apc_call_t data;
 165
 166             memset( &data, 0, sizeof(data) );
 167             data.type            = APC_ASYNC_IO;
 168             data.async_io.user   = async->data.user;
 169             data.async_io.sb     = async->data.iosb;
 170             data.async_io.status = status;
 171             thread_queue_apc( async->thread->process, async->thread, &async->obj, &data );
 172         }
 173         else async_set_result( &async->obj, STATUS_SUCCESS, 0 );
 174     }
 175
 176     async_reselect( async );
 177     if (async->queue) release_object( async );  /* so that it gets destroyed when the async is done */
 178 }
 179
 180 /* callback for timeout on an async request */
 181 static void async_timeout( void *private )
 182 {
 183     struct async *async = private;
 184
 185     async->timeout = NULL;
 186     async_terminate( async, async->timeout_status );
 187 }
 188
 189 /* free an async queue, cancelling all async operations */
 190 void free_async_queue( struct async_queue *queue )
 191 {
 192     struct async *async, *next;
 193
 194     LIST_FOR_EACH_ENTRY_SAFE( async, next, &queue->queue, struct async, queue_entry )
 195     {
 196         grab_object( &async->obj );
 197         if (!async->completion) async->completion = fd_get_completion( async->fd, &async->comp_key );
 198         async->fd = NULL;
 199         async_terminate( async, STATUS_HANDLES_CLOSED );
 200         async->queue = NULL;
 201         release_object( &async->obj );
 202     }
 203 }
 204
 205 void queue_async( struct async_queue *queue, struct async *async )
 206 {
 207     /* fd will be set to NULL in free_async_queue when fd is destroyed */
 208     release_object( async->fd );
 209
 210     async->queue = queue;
 211     grab_object( async );
 212     list_add_tail( &queue->queue, &async->queue_entry );
 213
 214     set_fd_signaled( async->fd, 0 );
 215 }
 216
 217 /* create an async on a given queue of a fd */
 218 struct async *create_async( struct fd *fd, struct thread *thread, const async_data_t *data, struct iosb *iosb )
 219 {
 220     struct event *event = NULL;
 221     struct async *async;
 222
 223     if (data->event && !(event = get_event_obj( thread->process, data->event, EVENT_MODIFY_STATE )))
 224         return NULL;
 225
 226     if (!(async = alloc_object( &async_ops )))
 227     {
 228         if (event) release_object( event );
 229         return NULL;
 230     }
 231
 232     async->thread        = (struct thread *)grab_object( thread );
 233     async->event         = event;
 234     async->status        = STATUS_PENDING;
 235     async->data          = *data;
 236     async->timeout       = NULL;
 237     async->queue         = NULL;
 238     async->fd            = (struct fd *)grab_object( fd );
 239     async->signaled      = 0;
 240     async->wait_handle   = 0;
 241     async->direct_result = 0;
 242     async->completion    = fd_get_completion( fd, &async->comp_key );
 243     async->comp_flags    = 0;
 244
 245     if (iosb) async->iosb = (struct iosb *)grab_object( iosb );
 246     else async->iosb = NULL;
 247
 248     list_add_head( &thread->process->asyncs, &async->process_entry );
 249     if (event) reset_event( event );
 250
 251     if (async->completion && data->apc)
 252     {
 253         release_object( async );
 254         set_error( STATUS_INVALID_PARAMETER );
 255         return NULL;
 256     }
 257
 258     return async;
 259 }
 260
 261 /* create an async associated with iosb for async-based requests
 262  * returned async must be passed to async_handoff */
 263 struct async *create_request_async( struct fd *fd, unsigned int comp_flags, const async_data_t *data )
 264 {
 265     struct async *async;
 266     struct iosb *iosb;
 267
 268     if (!(iosb = create_iosb( get_req_data(), get_req_data_size(), get_reply_max_size() )))
 269         return NULL;
 270
 271     async = create_async( fd, current, data, iosb );
 272     release_object( iosb );
 273     if (async)
 274     {
 275         if (!(async->wait_handle = alloc_handle( current->process, async, SYNCHRONIZE, 0 )))
 276         {
 277             release_object( async );
 278             return NULL;
 279         }
 280         async->direct_result = 1;
 281         async->comp_flags = comp_flags;
 282     }
 283     return async;
 284 }
 285
 286 /* return async object status and wait handle to client */
 287 obj_handle_t async_handoff( struct async *async, int success, data_size_t *result, int force_blocking )
 288 {
 289     if (!success)
 290     {
 291         close_handle( async->thread->process, async->wait_handle );
 292         async->wait_handle = 0;
 293         return 0;
 294     }
 295
 296     if (get_error() != STATUS_PENDING)
 297     {
 298         /* status and data are already set and returned */
 299         async_terminate( async, get_error() );
 300     }
 301     else if (async->iosb->status != STATUS_PENDING)
 302     {
 303         /* result is already available in iosb, return it */
 304         if (async->iosb->out_data)
 305         {
 306             set_reply_data_ptr( async->iosb->out_data, async->iosb->out_size );
 307             async->iosb->out_data = NULL;
 308         }
 309     }
 310
 311     if (async->iosb->status != STATUS_PENDING)
 312     {
 313         if (result) *result = async->iosb->result;
 314         async->signaled = 1;
 315     }
 316     else
 317     {
 318         async->direct_result = 0;
 319         if (!force_blocking && async->fd && is_fd_overlapped( async->fd ))
 320         {
 321             close_handle( async->thread->process, async->wait_handle);
 322             async->wait_handle = 0;
 323         }
 324     }
 325     set_error( async->iosb->status );
 326     return async->wait_handle;
 327 }
 328
 329 /* set the timeout of an async operation */
 330 void async_set_timeout( struct async *async, timeout_t timeout, unsigned int status )
 331 {
 332     if (async->timeout) remove_timeout_user( async->timeout );
 333     if (timeout != TIMEOUT_INFINITE) async->timeout = add_timeout_user( timeout, async_timeout, async );
 334     else async->timeout = NULL;
 335     async->timeout_status = status;
 336 }
 337
 338 static void add_async_completion( struct async *async, apc_param_t cvalue, unsigned int status,
 339                                   apc_param_t information )
 340 {
 341     if (async->fd && !async->completion) async->completion = fd_get_completion( async->fd, &async->comp_key );
 342     if (async->completion) add_completion( async->completion, async->comp_key, cvalue, status, information );
 343 }
 344
 345 /* store the result of the client-side async callback */
 346 void async_set_result( struct object *obj, unsigned int status, apc_param_t total )
 347 {
 348     struct async *async = (struct async *)obj;
 349
 350     if (obj->ops != &async_ops) return;  /* in case the client messed up the APC results */
 351
 352     assert( async->status != STATUS_PENDING );  /* it must have been woken up if we get a result */
 353
 354     if (status == STATUS_PENDING)  /* restart it */
 355     {
 356         status = async->status;
 357         async->status = STATUS_PENDING;
 358         grab_object( async );
 359
 360         if (status != STATUS_ALERTED)  /* it was terminated in the meantime */
 361             async_terminate( async, status );
 362         else
 363             async_reselect( async );
 364     }
 365     else
 366     {
 367         if (async->timeout) remove_timeout_user( async->timeout );
 368         async->timeout = NULL;
 369         async->status = status;
 370         if (status == STATUS_MORE_PROCESSING_REQUIRED) return;  /* don't report the completion */
 371
 372         if (async->data.apc)
 373         {
 374             apc_call_t data;
 375             memset( &data, 0, sizeof(data) );
 376             data.type         = APC_USER;
 377             data.user.func    = async->data.apc;
 378             data.user.args[0] = async->data.apc_context;
 379             data.user.args[1] = async->data.iosb;
 380             data.user.args[2] = 0;
 381             thread_queue_apc( NULL, async->thread, NULL, &data );
 382         }
 383         else if (async->data.apc_context && (!async->direct_result ||
 384                  !(async->comp_flags & FILE_SKIP_COMPLETION_PORT_ON_SUCCESS)))
 385         {
 386             add_async_completion( async, async->data.apc_context, status, total );
 387         }
 388
 389         if (async->event) set_event( async->event );
 390         else if (async->fd) set_fd_signaled( async->fd, 1 );
 391         if (!async->signaled)
 392         {
 393             async->signaled = 1;
 394             wake_up( &async->obj, 0 );
 395         }
 396     }
 397 }
 398
 399 /* check if an async operation is waiting to be alerted */
 400 int async_waiting( struct async_queue *queue )
 401 {
 402     struct list *ptr;
 403     struct async *async;
 404
 405     if (!(ptr = list_head( &queue->queue ))) return 0;
 406     async = LIST_ENTRY( ptr, struct async, queue_entry );
 407     return async->status == STATUS_PENDING;
 408 }
 409
 410 static int cancel_async( struct process *process, struct object *obj, struct thread *thread, client_ptr_t iosb )
 411 {
 412     struct async *async;
 413     int woken = 0;
 414
 415 restart:
 416     LIST_FOR_EACH_ENTRY( async, &process->asyncs, struct async, process_entry )
 417     {
 418         if (async->status == STATUS_CANCELLED) continue;
 419         if ((!obj || (async->fd && get_fd_user( async->fd ) == obj)) &&
 420             (!thread || async->thread == thread) &&
 421             (!iosb || async->data.iosb == iosb))
 422         {
 423             async_terminate( async, STATUS_CANCELLED );
 424             woken++;
 425             goto restart;
 426         }
 427     }
 428     return woken;
 429 }
 430
 431 void cancel_process_asyncs( struct process *process )
 432 {
 433     cancel_async( process, NULL, NULL, 0 );
 434 }
 435
 436 /* wake up async operations on the queue */
 437 void async_wake_up( struct async_queue *queue, unsigned int status )
 438 {
 439     struct list *ptr, *next;
 440
 441     LIST_FOR_EACH_SAFE( ptr, next, &queue->queue )
 442     {
 443         struct async *async = LIST_ENTRY( ptr, struct async, queue_entry );
 444         async_terminate( async, status );
 445         if (status == STATUS_ALERTED) break;  /* only wake up the first one */
 446     }
 447 }
 448
 449 static void iosb_dump( struct object *obj, int verbose );
 450 static void iosb_destroy( struct object *obj );
 451
 452 static const struct object_ops iosb_ops =
 453 {
 454     sizeof(struct iosb),      /* size */
 455     iosb_dump,                /* dump */
 456     no_get_type,              /* get_type */
 457     no_add_queue,             /* add_queue */
 458     NULL,                     /* remove_queue */
 459     NULL,                     /* signaled */
 460     NULL,                     /* satisfied */
 461     no_signal,                /* signal */
 462     no_get_fd,                /* get_fd */
 463     no_map_access,            /* map_access */
 464     default_get_sd,           /* get_sd */
 465     default_set_sd,           /* set_sd */
 466     no_lookup_name,           /* lookup_name */
 467     no_link_name,             /* link_name */
 468     NULL,                     /* unlink_name */
 469     no_open_file,             /* open_file */
 470     no_close_handle,          /* close_handle */
 471     iosb_destroy              /* destroy */
 472 };
 473
 474 static void iosb_dump( struct object *obj, int verbose )
 475 {
 476     assert( obj->ops == &iosb_ops );
 477     fprintf( stderr, "I/O status block\n" );
 478 }
 479
 480 static void iosb_destroy( struct object *obj )
 481 {
 482     struct iosb *iosb = (struct iosb *)obj;
 483
 484     free( iosb->in_data );
 485     free( iosb->out_data );
 486 }
 487
 488 /* allocate iosb struct */
 489 struct iosb *create_iosb( const void *in_data, data_size_t in_size, data_size_t out_size )
 490 {
 491     struct iosb *iosb;
 492
 493     if (!(iosb = alloc_object( &iosb_ops ))) return NULL;
 494
 495     iosb->status = STATUS_PENDING;
 496     iosb->result = 0;
 497     iosb->in_size = in_size;
 498     iosb->in_data = NULL;
 499     iosb->out_size = out_size;
 500     iosb->out_data = NULL;
 501
 502     if (in_size && !(iosb->in_data = memdup( in_data, in_size )))
 503     {
 504         release_object( iosb );
 505         iosb = NULL;
 506     }
 507
 508     return iosb;
 509 }
 510
 511 struct iosb *async_get_iosb( struct async *async )
 512 {
 513     return async->iosb ? (struct iosb *)grab_object( async->iosb ) : NULL;
 514 }
 515
 516 int async_is_blocking( struct async *async )
 517 {
 518     return !async->event && !async->data.apc && !async->data.apc_context;
 519 }
 520
 521 /* find the first pending async in queue */
 522 struct async *find_pending_async( struct async_queue *queue )
 523 {
 524     struct async *async;
 525     LIST_FOR_EACH_ENTRY( async, &queue->queue, struct async, queue_entry )
 526         if (async->status == STATUS_PENDING) return (struct async *)grab_object( async );
 527     return NULL;
 528 }
 529
 530 /* cancels all async I/O */
 531 DECL_HANDLER(cancel_async)
 532 {
 533     struct object *obj = get_handle_obj( current->process, req->handle, 0, NULL );
 534     struct thread *thread = req->only_thread ? current : NULL;
 535
 536     if (obj)
 537     {
 538         int count = cancel_async( current->process, obj, thread, req->iosb );
 539         if (!count && req->iosb) set_error( STATUS_NOT_FOUND );
 540         release_object( obj );
 541     }
 542 }
 543
 544 /* get async result from associated iosb */
 545 DECL_HANDLER(get_async_result)
 546 {
 547     struct iosb *iosb = NULL;
 548     struct async *async;
 549
 550     LIST_FOR_EACH_ENTRY( async, &current->process->asyncs, struct async, process_entry )
 551         if (async->data.user == req->user_arg)
 552         {
 553             iosb = async->iosb;
 554             break;
 555         }
 556
 557     if (!iosb)
 558     {
 559         set_error( STATUS_INVALID_PARAMETER );
 560         return;
 561     }
 562
 563     if (iosb->out_data)
 564     {
 565         data_size_t size = min( iosb->out_size, get_reply_max_size() );
 566         if (size)
 567         {
 568             set_reply_data_ptr( iosb->out_data, size );
 569             iosb->out_data = NULL;
 570         }
 571     }
 572     reply->size = iosb->result;
 573     set_error( iosb->status );
 574 }