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