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