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     set_wait_status( entry, async->status );
 122
 123     /* close wait handle here to avoid extra server round trip */
 124     if (async->wait_handle)
 125     {
 126         close_handle( async->thread->process, async->wait_handle );
 127         async->wait_handle = 0;
 128     }
 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) return; /* already terminated */
 158
 159     async->status = status;
 160     if (async->iosb && async->iosb->status == STATUS_PENDING) async->iosb->status = status;
 161
 162     if (!async->direct_result)
 163     {
 164         if (async->data.user)
 165         {
 166             apc_call_t data;
 167
 168             memset( &data, 0, sizeof(data) );
 169             data.type            = APC_ASYNC_IO;
 170             data.async_io.user   = async->data.user;
 171             data.async_io.sb     = async->data.iosb;
 172             data.async_io.status = status;
 173             thread_queue_apc( async->thread->process, async->thread, &async->obj, &data );
 174         }
 175         else async_set_result( &async->obj, STATUS_SUCCESS, 0 );
 176     }
 177
 178     async_reselect( async );
 179     if (async->queue) release_object( async );  /* so that it gets destroyed when the async is done */
 180 }
 181
 182 /* callback for timeout on an async request */
 183 static void async_timeout( void *private )
 184 {
 185     struct async *async = private;
 186
 187     async->timeout = NULL;
 188     async_terminate( async, async->timeout_status );
 189 }
 190
 191 /* free an async queue, cancelling all async operations */
 192 void free_async_queue( struct async_queue *queue )
 193 {
 194     struct async *async, *next;
 195
 196     LIST_FOR_EACH_ENTRY_SAFE( async, next, &queue->queue, struct async, queue_entry )
 197     {
 198         grab_object( &async->obj );
 199         if (!async->completion) async->completion = fd_get_completion( async->fd, &async->comp_key );
 200         async->fd = NULL;
 201         async_terminate( async, STATUS_HANDLES_CLOSED );
 202         async->queue = NULL;
 203         release_object( &async->obj );
 204     }
 205 }
 206
 207 void queue_async( struct async_queue *queue, struct async *async )
 208 {
 209     /* fd will be set to NULL in free_async_queue when fd is destroyed */
 210     release_object( async->fd );
 211
 212     async->queue = queue;
 213     grab_object( async );
 214     list_add_tail( &queue->queue, &async->queue_entry );
 215
 216     set_fd_signaled( async->fd, 0 );
 217 }
 218
 219 /* create an async on a given queue of a fd */
 220 struct async *create_async( struct fd *fd, struct thread *thread, const async_data_t *data, struct iosb *iosb )
 221 {
 222     struct event *event = NULL;
 223     struct async *async;
 224
 225     if (data->event && !(event = get_event_obj( thread->process, data->event, EVENT_MODIFY_STATE )))
 226         return NULL;
 227
 228     if (!(async = alloc_object( &async_ops )))
 229     {
 230         if (event) release_object( event );
 231         return NULL;
 232     }
 233
 234     async->thread        = (struct thread *)grab_object( thread );
 235     async->event         = event;
 236     async->status        = STATUS_PENDING;
 237     async->data          = *data;
 238     async->timeout       = NULL;
 239     async->queue         = NULL;
 240     async->fd            = (struct fd *)grab_object( fd );
 241     async->signaled      = 0;
 242     async->pending       = 1;
 243     async->wait_handle   = 0;
 244     async->direct_result = 0;
 245     async->completion    = fd_get_completion( fd, &async->comp_key );
 246     async->comp_flags    = 0;
 247     async->completion_callback = NULL;
 248     async->completion_callback_private = NULL;
 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 /* set a callback to be notified when the async is completed */
 365 void async_set_completion_callback( struct async *async, async_completion_callback func, void *private )
 366 {
 367     async->completion_callback = func;
 368     async->completion_callback_private = private;
 369 }
 370
 371 static void add_async_completion( struct async *async, apc_param_t cvalue, unsigned int status,
 372                                   apc_param_t information )
 373 {
 374     if (async->fd && !async->completion) async->completion = fd_get_completion( async->fd, &async->comp_key );
 375     if (async->completion) add_completion( async->completion, async->comp_key, cvalue, status, information );
 376 }
 377
 378 /* store the result of the client-side async callback */
 379 void async_set_result( struct object *obj, unsigned int status, apc_param_t total )
 380 {
 381     struct async *async = (struct async *)obj;
 382
 383     if (obj->ops != &async_ops) return;  /* in case the client messed up the APC results */
 384
 385     assert( async->status != STATUS_PENDING );  /* it must have been woken up if we get a result */
 386
 387     if (status == STATUS_PENDING)  /* restart it */
 388     {
 389         status = async->status;
 390         async->status = STATUS_PENDING;
 391         grab_object( async );
 392
 393         if (status != STATUS_ALERTED)  /* it was terminated in the meantime */
 394             async_terminate( async, status );
 395         else
 396             async_reselect( async );
 397     }
 398     else
 399     {
 400         if (async->timeout) remove_timeout_user( async->timeout );
 401         async->timeout = NULL;
 402         async->status = status;
 403         if (status == STATUS_MORE_PROCESSING_REQUIRED) return;  /* don't report the completion */
 404
 405         if (async->data.apc)
 406         {
 407             apc_call_t data;
 408             memset( &data, 0, sizeof(data) );
 409             data.type         = APC_USER;
 410             data.user.func    = async->data.apc;
 411             data.user.args[0] = async->data.apc_context;
 412             data.user.args[1] = async->data.iosb;
 413             data.user.args[2] = 0;
 414             thread_queue_apc( NULL, async->thread, NULL, &data );
 415         }
 416         else if (async->data.apc_context && (async->pending ||
 417                  !(async->comp_flags & FILE_SKIP_COMPLETION_PORT_ON_SUCCESS)))
 418         {
 419             add_async_completion( async, async->data.apc_context, status, total );
 420         }
 421
 422         if (async->event) set_event( async->event );
 423         else if (async->fd) set_fd_signaled( async->fd, 1 );
 424         if (!async->signaled)
 425         {
 426             async->signaled = 1;
 427             wake_up( &async->obj, 0 );
 428         }
 429
 430         if (async->completion_callback)
 431             async->completion_callback( async->completion_callback_private );
 432         async->completion_callback = NULL;
 433     }
 434 }
 435
 436 /* check if an async operation is waiting to be alerted */
 437 int async_waiting( struct async_queue *queue )
 438 {
 439     struct list *ptr;
 440     struct async *async;
 441
 442     if (!(ptr = list_head( &queue->queue ))) return 0;
 443     async = LIST_ENTRY( ptr, struct async, queue_entry );
 444     return async->status == STATUS_PENDING;
 445 }
 446
 447 static int cancel_async( struct process *process, struct object *obj, struct thread *thread, client_ptr_t iosb )
 448 {
 449     struct async *async;
 450     int woken = 0;
 451
 452 restart:
 453     LIST_FOR_EACH_ENTRY( async, &process->asyncs, struct async, process_entry )
 454     {
 455         if (async->status != STATUS_PENDING) continue;
 456         if ((!obj || (async->fd && get_fd_user( async->fd ) == obj)) &&
 457             (!thread || async->thread == thread) &&
 458             (!iosb || async->data.iosb == iosb))
 459         {
 460             async_terminate( async, STATUS_CANCELLED );
 461             woken++;
 462             goto restart;
 463         }
 464     }
 465     return woken;
 466 }
 467
 468 void cancel_process_asyncs( struct process *process )
 469 {
 470     cancel_async( process, NULL, NULL, 0 );
 471 }
 472
 473 /* wake up async operations on the queue */
 474 void async_wake_up( struct async_queue *queue, unsigned int status )
 475 {
 476     struct list *ptr, *next;
 477
 478     LIST_FOR_EACH_SAFE( ptr, next, &queue->queue )
 479     {
 480         struct async *async = LIST_ENTRY( ptr, struct async, queue_entry );
 481         async_terminate( async, status );
 482         if (status == STATUS_ALERTED) break;  /* only wake up the first one */
 483     }
 484 }
 485
 486 static void iosb_dump( struct object *obj, int verbose );
 487 static void iosb_destroy( struct object *obj );
 488
 489 static const struct object_ops iosb_ops =
 490 {
 491     sizeof(struct iosb),      /* size */
 492     &no_type,                 /* type */
 493     iosb_dump,                /* dump */
 494     no_add_queue,             /* add_queue */
 495     NULL,                     /* remove_queue */
 496     NULL,                     /* signaled */
 497     NULL,                     /* satisfied */
 498     no_signal,                /* signal */
 499     no_get_fd,                /* get_fd */
 500     default_map_access,       /* map_access */
 501     default_get_sd,           /* get_sd */
 502     default_set_sd,           /* set_sd */
 503     no_get_full_name,         /* get_full_name */
 504     no_lookup_name,           /* lookup_name */
 505     no_link_name,             /* link_name */
 506     NULL,                     /* unlink_name */
 507     no_open_file,             /* open_file */
 508     no_kernel_obj_list,       /* get_kernel_obj_list */
 509     no_close_handle,          /* close_handle */
 510     iosb_destroy              /* destroy */
 511 };
 512
 513 static void iosb_dump( struct object *obj, int verbose )
 514 {
 515     assert( obj->ops == &iosb_ops );
 516     fprintf( stderr, "I/O status block\n" );
 517 }
 518
 519 static void iosb_destroy( struct object *obj )
 520 {
 521     struct iosb *iosb = (struct iosb *)obj;
 522
 523     free( iosb->in_data );
 524     free( iosb->out_data );
 525 }
 526
 527 /* allocate iosb struct */
 528 struct iosb *create_iosb( const void *in_data, data_size_t in_size, data_size_t out_size )
 529 {
 530     struct iosb *iosb;
 531
 532     if (!(iosb = alloc_object( &iosb_ops ))) return NULL;
 533
 534     iosb->status = STATUS_PENDING;
 535     iosb->result = 0;
 536     iosb->in_size = in_size;
 537     iosb->in_data = NULL;
 538     iosb->out_size = out_size;
 539     iosb->out_data = NULL;
 540
 541     if (in_size && !(iosb->in_data = memdup( in_data, in_size )))
 542     {
 543         release_object( iosb );
 544         iosb = NULL;
 545     }
 546
 547     return iosb;
 548 }
 549
 550 struct iosb *async_get_iosb( struct async *async )
 551 {
 552     return async->iosb ? (struct iosb *)grab_object( async->iosb ) : NULL;
 553 }
 554
 555 struct thread *async_get_thread( struct async *async )
 556 {
 557     return async->thread;
 558 }
 559
 560 /* find the first pending async in queue */
 561 struct async *find_pending_async( struct async_queue *queue )
 562 {
 563     struct async *async;
 564     LIST_FOR_EACH_ENTRY( async, &queue->queue, struct async, queue_entry )
 565         if (async->status == STATUS_PENDING) return (struct async *)grab_object( async );
 566     return NULL;
 567 }
 568
 569 /* cancels all async I/O */
 570 DECL_HANDLER(cancel_async)
 571 {
 572     struct object *obj = get_handle_obj( current->process, req->handle, 0, NULL );
 573     struct thread *thread = req->only_thread ? current : NULL;
 574
 575     if (obj)
 576     {
 577         int count = cancel_async( current->process, obj, thread, req->iosb );
 578         if (!count && req->iosb) set_error( STATUS_NOT_FOUND );
 579         release_object( obj );
 580     }
 581 }
 582
 583 /* get async result from associated iosb */
 584 DECL_HANDLER(get_async_result)
 585 {
 586     struct iosb *iosb = NULL;
 587     struct async *async;
 588
 589     LIST_FOR_EACH_ENTRY( async, &current->process->asyncs, struct async, process_entry )
 590         if (async->data.user == req->user_arg)
 591         {
 592             iosb = async->iosb;
 593             break;
 594         }
 595
 596     if (!iosb)
 597     {
 598         set_error( STATUS_INVALID_PARAMETER );
 599         return;
 600     }
 601
 602     if (iosb->out_data)
 603     {
 604         data_size_t size = min( iosb->out_size, get_reply_max_size() );
 605         if (size)
 606         {
 607             set_reply_data_ptr( iosb->out_data, size );
 608             iosb->out_data = NULL;
 609         }
 610     }
 611     reply->size = iosb->result;
 612     set_error( iosb->status );
 613 }