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     struct event        *event;
  49     async_data_t         data;            /* data for async I/O call */
  50     struct iosb         *iosb;            /* I/O status block */
  51     obj_handle_t         wait_handle;     /* pre-allocated wait handle */
  52     unsigned int         signaled :1;
  53     unsigned int         pending :1;      /* request successfully queued, but pending */
  54     unsigned int         direct_result :1;/* a flag if we're passing result directly from request instead of APC  */
  55     struct completion   *completion;      /* completion associated with fd */
  56     apc_param_t          comp_key;        /* completion key associated with fd */
  57     unsigned int         comp_flags;      /* completion flags */
  58     async_completion_callback completion_callback; /* callback to be called on completion */
  59     void                *completion_callback_private; /* argument to completion_callback */
  60 };
  61
  62 static void async_dump( struct object *obj, int verbose );
  63 static int async_signaled( struct object *obj, struct wait_queue_entry *entry );
  64 static void async_satisfied( struct object * obj, struct wait_queue_entry *entry );
  65 static void async_destroy( struct object *obj );
  66
  67 static const struct object_ops async_ops =
  68 {
  69     sizeof(struct async),      /* size */
  70     &no_type,                  /* type */
  71     async_dump,                /* dump */
  72     add_queue,                 /* add_queue */
  73     remove_queue,              /* remove_queue */
  74     async_signaled,            /* signaled */
  75     async_satisfied,           /* satisfied */
  76     no_signal,                 /* signal */
  77     no_get_fd,                 /* get_fd */
  78     default_map_access,        /* map_access */
  79     default_get_sd,            /* get_sd */
  80     default_set_sd,            /* set_sd */
  81     no_get_full_name,          /* get_full_name */
  82     no_lookup_name,            /* lookup_name */
  83     no_link_name,              /* link_name */
  84     NULL,                      /* unlink_name */
  85     no_open_file,              /* open_file */
  86     no_kernel_obj_list,        /* get_kernel_obj_list */
  87     no_close_handle,           /* close_handle */
  88     async_destroy              /* destroy */
  89 };
  90
  91 static inline void async_reselect( struct async *async )
  92 {
  93     if (async->queue && async->fd) fd_reselect_async( async->fd, async->queue );
  94 }
  95
  96 static void async_dump( struct object *obj, int verbose )
  97 {
  98     struct async *async = (struct async *)obj;
  99     assert( obj->ops == &async_ops );
 100     fprintf( stderr, "Async thread=%p\n", async->thread );
 101 }
 102
 103 static int async_signaled( struct object *obj, struct wait_queue_entry *entry )
 104 {
 105     struct async *async = (struct async *)obj;
 106     assert( obj->ops == &async_ops );
 107     return async->signaled;
 108 }
 109
 110 static void async_satisfied( struct object *obj, struct wait_queue_entry *entry )
 111 {
 112     struct async *async = (struct async *)obj;
 113     assert( obj->ops == &async_ops );
 114
 115     if (async->direct_result)
 116     {
 117         async_set_result( &async->obj, async->iosb->status, async->iosb->result );
 118         async->direct_result = 0;
 119     }
 120
 121     /* close wait handle here to avoid extra server round trip */
 122     if (async->wait_handle)
 123     {
 124         close_handle( async->thread->process, async->wait_handle );
 125         async->wait_handle = 0;
 126     }
 127
 128     if (async->status == STATUS_PENDING) make_wait_abandoned( entry );
 129 }
 130
 131 static void async_destroy( struct object *obj )
 132 {
 133     struct async *async = (struct async *)obj;
 134     assert( obj->ops == &async_ops );
 135
 136     list_remove( &async->process_entry );
 137
 138     if (async->queue)
 139     {
 140         list_remove( &async->queue_entry );
 141         async_reselect( async );
 142     }
 143     else if (async->fd) release_object( async->fd );
 144
 145     if (async->timeout) remove_timeout_user( async->timeout );
 146     if (async->completion) release_object( async->completion );
 147     if (async->event) release_object( async->event );
 148     if (async->iosb) release_object( async->iosb );
 149     release_object( async->thread );
 150 }
 151
 152 /* notifies client thread of new status of its async request */
 153 void async_terminate( struct async *async, unsigned int status )
 154 {
 155     assert( status != STATUS_PENDING );
 156
 157     if (async->status != STATUS_PENDING)
 158     {
 159         /* already terminated, just update status */
 160         async->status = status;
 161         return;
 162     }
 163
 164     async->status = status;
 165     if (async->iosb && async->iosb->status == STATUS_PENDING) async->iosb->status = status;
 166
 167     if (!async->direct_result)
 168     {
 169         if (async->data.user)
 170         {
 171             apc_call_t data;
 172
 173             memset( &data, 0, sizeof(data) );
 174             data.type            = APC_ASYNC_IO;
 175             data.async_io.user   = async->data.user;
 176             data.async_io.sb     = async->data.iosb;
 177             data.async_io.status = status;
 178             thread_queue_apc( async->thread->process, async->thread, &async->obj, &data );
 179         }
 180         else async_set_result( &async->obj, STATUS_SUCCESS, 0 );
 181     }
 182
 183     async_reselect( async );
 184     if (async->queue) release_object( async );  /* so that it gets destroyed when the async is done */
 185 }
 186
 187 /* callback for timeout on an async request */
 188 static void async_timeout( void *private )
 189 {
 190     struct async *async = private;
 191
 192     async->timeout = NULL;
 193     async_terminate( async, async->timeout_status );
 194 }
 195
 196 /* free an async queue, cancelling all async operations */
 197 void free_async_queue( struct async_queue *queue )
 198 {
 199     struct async *async, *next;
 200
 201     LIST_FOR_EACH_ENTRY_SAFE( async, next, &queue->queue, struct async, queue_entry )
 202     {
 203         grab_object( &async->obj );
 204         if (!async->completion) async->completion = fd_get_completion( async->fd, &async->comp_key );
 205         async->fd = NULL;
 206         async_terminate( async, STATUS_HANDLES_CLOSED );
 207         async->queue = NULL;
 208         release_object( &async->obj );
 209     }
 210 }
 211
 212 void queue_async( struct async_queue *queue, struct async *async )
 213 {
 214     /* fd will be set to NULL in free_async_queue when fd is destroyed */
 215     release_object( async->fd );
 216
 217     async->queue = queue;
 218     grab_object( async );
 219     list_add_tail( &queue->queue, &async->queue_entry );
 220
 221     set_fd_signaled( async->fd, 0 );
 222 }
 223
 224 /* create an async on a given queue of a fd */
 225 struct async *create_async( struct fd *fd, struct thread *thread, const async_data_t *data, struct iosb *iosb )
 226 {
 227     struct event *event = NULL;
 228     struct async *async;
 229
 230     if (data->event && !(event = get_event_obj( thread->process, data->event, EVENT_MODIFY_STATE )))
 231         return NULL;
 232
 233     if (!(async = alloc_object( &async_ops )))
 234     {
 235         if (event) release_object( event );
 236         return NULL;
 237     }
 238
 239     async->thread        = (struct thread *)grab_object( thread );
 240     async->event         = event;
 241     async->status        = STATUS_PENDING;
 242     async->data          = *data;
 243     async->timeout       = NULL;
 244     async->queue         = NULL;
 245     async->fd            = (struct fd *)grab_object( fd );
 246     async->signaled      = 0;
 247     async->pending       = 1;
 248     async->wait_handle   = 0;
 249     async->direct_result = 0;
 250     async->completion    = fd_get_completion( fd, &async->comp_key );
 251     async->comp_flags    = 0;
 252     async->completion_callback = NULL;
 253     async->completion_callback_private = NULL;
 254
 255     if (iosb) async->iosb = (struct iosb *)grab_object( iosb );
 256     else async->iosb = NULL;
 257
 258     list_add_head( &thread->process->asyncs, &async->process_entry );
 259     if (event) reset_event( event );
 260
 261     if (async->completion && data->apc)
 262     {
 263         release_object( async );
 264         set_error( STATUS_INVALID_PARAMETER );
 265         return NULL;
 266     }
 267
 268     return async;
 269 }
 270
 271 void set_async_pending( struct async *async, int signal )
 272 {
 273     if (async->status == STATUS_PENDING)
 274     {
 275         async->pending = 1;
 276         if (signal && !async->signaled)
 277         {
 278             async->signaled = 1;
 279             wake_up( &async->obj, 0 );
 280         }
 281     }
 282 }
 283
 284 /* create an async associated with iosb for async-based requests
 285  * returned async must be passed to async_handoff */
 286 struct async *create_request_async( struct fd *fd, unsigned int comp_flags, const async_data_t *data )
 287 {
 288     struct async *async;
 289     struct iosb *iosb;
 290
 291     if (!(iosb = create_iosb( get_req_data(), get_req_data_size(), get_reply_max_size() )))
 292         return NULL;
 293
 294     async = create_async( fd, current, data, iosb );
 295     release_object( iosb );
 296     if (async)
 297     {
 298         if (!(async->wait_handle = alloc_handle( current->process, async, SYNCHRONIZE, 0 )))
 299         {
 300             release_object( async );
 301             return NULL;
 302         }
 303         async->pending       = 0;
 304         async->direct_result = 1;
 305         async->comp_flags    = comp_flags;
 306     }
 307     return async;
 308 }
 309
 310 /* return async object status and wait handle to client */
 311 obj_handle_t async_handoff( struct async *async, int success, data_size_t *result, int force_blocking )
 312 {
 313     if (!success)
 314     {
 315         if (get_error() == STATUS_PENDING)
 316         {
 317             /* we don't know the result yet, so client needs to wait */
 318             async->direct_result = 0;
 319             return async->wait_handle;
 320         }
 321         close_handle( async->thread->process, async->wait_handle );
 322         async->wait_handle = 0;
 323         return 0;
 324     }
 325
 326     if (get_error() != STATUS_PENDING)
 327     {
 328         /* status and data are already set and returned */
 329         async_terminate( async, get_error() );
 330     }
 331     else if (async->iosb->status != STATUS_PENDING)
 332     {
 333         /* result is already available in iosb, return it */
 334         if (async->iosb->out_data)
 335         {
 336             set_reply_data_ptr( async->iosb->out_data, async->iosb->out_size );
 337             async->iosb->out_data = NULL;
 338         }
 339     }
 340
 341     if (async->iosb->status != STATUS_PENDING)
 342     {
 343         if (result) *result = async->iosb->result;
 344         async->signaled = 1;
 345     }
 346     else
 347     {
 348         async->direct_result = 0;
 349         async->pending = 1;
 350         if (!force_blocking && async->fd && is_fd_overlapped( async->fd ))
 351         {
 352             close_handle( async->thread->process, async->wait_handle);
 353             async->wait_handle = 0;
 354         }
 355     }
 356     set_error( async->iosb->status );
 357     return async->wait_handle;
 358 }
 359
 360 /* set the timeout of an async operation */
 361 void async_set_timeout( struct async *async, timeout_t timeout, unsigned int status )
 362 {
 363     if (async->timeout) remove_timeout_user( async->timeout );
 364     if (timeout != TIMEOUT_INFINITE) async->timeout = add_timeout_user( timeout, async_timeout, async );
 365     else async->timeout = NULL;
 366     async->timeout_status = status;
 367 }
 368
 369 /* set a callback to be notified when the async is completed */
 370 void async_set_completion_callback( struct async *async, async_completion_callback func, void *private )
 371 {
 372     async->completion_callback = func;
 373     async->completion_callback_private = private;
 374 }
 375
 376 static void add_async_completion( struct async *async, apc_param_t cvalue, unsigned int status,
 377                                   apc_param_t information )
 378 {
 379     if (async->fd && !async->completion) async->completion = fd_get_completion( async->fd, &async->comp_key );
 380     if (async->completion) add_completion( async->completion, async->comp_key, cvalue, status, information );
 381 }
 382
 383 /* store the result of the client-side async callback */
 384 void async_set_result( struct object *obj, unsigned int status, apc_param_t total )
 385 {
 386     struct async *async = (struct async *)obj;
 387
 388     if (obj->ops != &async_ops) return;  /* in case the client messed up the APC results */
 389
 390     assert( async->status != STATUS_PENDING );  /* it must have been woken up if we get a result */
 391
 392     if (status == STATUS_PENDING)  /* restart it */
 393     {
 394         status = async->status;
 395         async->status = STATUS_PENDING;
 396         grab_object( async );
 397
 398         if (status != STATUS_ALERTED)  /* it was terminated in the meantime */
 399             async_terminate( async, status );
 400         else
 401             async_reselect( async );
 402     }
 403     else
 404     {
 405         if (async->timeout) remove_timeout_user( async->timeout );
 406         async->timeout = NULL;
 407         async->status = status;
 408         if (status == STATUS_MORE_PROCESSING_REQUIRED) return;  /* don't report the completion */
 409
 410         if (async->data.apc)
 411         {
 412             apc_call_t data;
 413             memset( &data, 0, sizeof(data) );
 414             data.type              = APC_USER;
 415             data.user.user.func    = async->data.apc;
 416             data.user.user.args[0] = async->data.apc_context;
 417             data.user.user.args[1] = async->data.iosb;
 418             data.user.user.args[2] = 0;
 419             thread_queue_apc( NULL, async->thread, NULL, &data );
 420         }
 421         else if (async->data.apc_context && (async->pending ||
 422                  !(async->comp_flags & FILE_SKIP_COMPLETION_PORT_ON_SUCCESS)))
 423         {
 424             add_async_completion( async, async->data.apc_context, status, total );
 425         }
 426
 427         if (async->event) set_event( async->event );
 428         else if (async->fd) set_fd_signaled( async->fd, 1 );
 429         if (!async->signaled)
 430         {
 431             async->signaled = 1;
 432             wake_up( &async->obj, 0 );
 433         }
 434
 435         if (async->completion_callback)
 436             async->completion_callback( async->completion_callback_private );
 437         async->completion_callback = NULL;
 438     }
 439 }
 440
 441 /* check if an async operation is waiting to be alerted */
 442 int async_waiting( struct async_queue *queue )
 443 {
 444     struct list *ptr;
 445     struct async *async;
 446
 447     if (!(ptr = list_head( &queue->queue ))) return 0;
 448     async = LIST_ENTRY( ptr, struct async, queue_entry );
 449     return async->status == STATUS_PENDING;
 450 }
 451
 452 static int cancel_async( struct process *process, struct object *obj, struct thread *thread, client_ptr_t iosb )
 453 {
 454     struct async *async;
 455     int woken = 0;
 456
 457 restart:
 458     LIST_FOR_EACH_ENTRY( async, &process->asyncs, struct async, process_entry )
 459     {
 460         if (async->status == STATUS_CANCELLED) continue;
 461         if ((!obj || (async->fd && get_fd_user( async->fd ) == obj)) &&
 462             (!thread || async->thread == thread) &&
 463             (!iosb || async->data.iosb == iosb))
 464         {
 465             async_terminate( async, STATUS_CANCELLED );
 466             woken++;
 467             goto restart;
 468         }
 469     }
 470     return woken;
 471 }
 472
 473 void cancel_process_asyncs( struct process *process )
 474 {
 475     cancel_async( process, NULL, NULL, 0 );
 476 }
 477
 478 /* wake up async operations on the queue */
 479 void async_wake_up( struct async_queue *queue, unsigned int status )
 480 {
 481     struct list *ptr, *next;
 482
 483     LIST_FOR_EACH_SAFE( ptr, next, &queue->queue )
 484     {
 485         struct async *async = LIST_ENTRY( ptr, struct async, queue_entry );
 486         async_terminate( async, status );
 487         if (status == STATUS_ALERTED) break;  /* only wake up the first one */
 488     }
 489 }
 490
 491 static void iosb_dump( struct object *obj, int verbose );
 492 static void iosb_destroy( struct object *obj );
 493
 494 static const struct object_ops iosb_ops =
 495 {
 496     sizeof(struct iosb),      /* size */
 497     &no_type,                 /* type */
 498     iosb_dump,                /* dump */
 499     no_add_queue,             /* add_queue */
 500     NULL,                     /* remove_queue */
 501     NULL,                     /* signaled */
 502     NULL,                     /* satisfied */
 503     no_signal,                /* signal */
 504     no_get_fd,                /* get_fd */
 505     default_map_access,       /* map_access */
 506     default_get_sd,           /* get_sd */
 507     default_set_sd,           /* set_sd */
 508     no_get_full_name,         /* get_full_name */
 509     no_lookup_name,           /* lookup_name */
 510     no_link_name,             /* link_name */
 511     NULL,                     /* unlink_name */
 512     no_open_file,             /* open_file */
 513     no_kernel_obj_list,       /* get_kernel_obj_list */
 514     no_close_handle,          /* close_handle */
 515     iosb_destroy              /* destroy */
 516 };
 517
 518 static void iosb_dump( struct object *obj, int verbose )
 519 {
 520     assert( obj->ops == &iosb_ops );
 521     fprintf( stderr, "I/O status block\n" );
 522 }
 523
 524 static void iosb_destroy( struct object *obj )
 525 {
 526     struct iosb *iosb = (struct iosb *)obj;
 527
 528     free( iosb->in_data );
 529     free( iosb->out_data );
 530 }
 531
 532 /* allocate iosb struct */
 533 struct iosb *create_iosb( const void *in_data, data_size_t in_size, data_size_t out_size )
 534 {
 535     struct iosb *iosb;
 536
 537     if (!(iosb = alloc_object( &iosb_ops ))) return NULL;
 538
 539     iosb->status = STATUS_PENDING;
 540     iosb->result = 0;
 541     iosb->in_size = in_size;
 542     iosb->in_data = NULL;
 543     iosb->out_size = out_size;
 544     iosb->out_data = NULL;
 545
 546     if (in_size && !(iosb->in_data = memdup( in_data, in_size )))
 547     {
 548         release_object( iosb );
 549         iosb = NULL;
 550     }
 551
 552     return iosb;
 553 }
 554
 555 struct iosb *async_get_iosb( struct async *async )
 556 {
 557     return async->iosb ? (struct iosb *)grab_object( async->iosb ) : NULL;
 558 }
 559
 560 struct thread *async_get_thread( struct async *async )
 561 {
 562     return async->thread;
 563 }
 564
 565 int async_is_blocking( struct async *async )
 566 {
 567     return !async->event && !async->data.apc && !async->data.apc_context;
 568 }
 569
 570 /* find the first pending async in queue */
 571 struct async *find_pending_async( struct async_queue *queue )
 572 {
 573     struct async *async;
 574     LIST_FOR_EACH_ENTRY( async, &queue->queue, struct async, queue_entry )
 575         if (async->status == STATUS_PENDING) return (struct async *)grab_object( async );
 576     return NULL;
 577 }
 578
 579 /* cancels all async I/O */
 580 DECL_HANDLER(cancel_async)
 581 {
 582     struct object *obj = get_handle_obj( current->process, req->handle, 0, NULL );
 583     struct thread *thread = req->only_thread ? current : NULL;
 584
 585     if (obj)
 586     {
 587         int count = cancel_async( current->process, obj, thread, req->iosb );
 588         if (!count && req->iosb) set_error( STATUS_NOT_FOUND );
 589         release_object( obj );
 590     }
 591 }
 592
 593 /* get async result from associated iosb */
 594 DECL_HANDLER(get_async_result)
 595 {
 596     struct iosb *iosb = NULL;
 597     struct async *async;
 598
 599     LIST_FOR_EACH_ENTRY( async, &current->process->asyncs, struct async, process_entry )
 600         if (async->data.user == req->user_arg)
 601         {
 602             iosb = async->iosb;
 603             break;
 604         }
 605
 606     if (!iosb)
 607     {
 608         set_error( STATUS_INVALID_PARAMETER );
 609         return;
 610     }
 611
 612     if (iosb->out_data)
 613     {
 614         data_size_t size = min( iosb->out_size, get_reply_max_size() );
 615         if (size)
 616         {
 617             set_reply_data_ptr( iosb->out_data, size );
 618             iosb->out_data = NULL;
 619         }
 620     }
 621     reply->size = iosb->result;
 622     set_error( iosb->status );
 623 }