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