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         apc_call_t data;
 165
 166         memset( &data, 0, sizeof(data) );
 167         data.type            = APC_ASYNC_IO;
 168         data.async_io.user   = async->data.user;
 169         data.async_io.sb     = async->data.iosb;
 170         data.async_io.status = status;
 171         thread_queue_apc( async->thread->process, async->thread, &async->obj, &data );
 172     }
 173
 174     async_reselect( async );
 175     if (async->queue) release_object( async );  /* so that it gets destroyed when the async is done */
 176 }
 177
 178 /* callback for timeout on an async request */
 179 static void async_timeout( void *private )
 180 {
 181     struct async *async = private;
 182
 183     async->timeout = NULL;
 184     async_terminate( async, async->timeout_status );
 185 }
 186
 187 /* free an async queue, cancelling all async operations */
 188 void free_async_queue( struct async_queue *queue )
 189 {
 190     struct async *async, *next;
 191
 192     LIST_FOR_EACH_ENTRY_SAFE( async, next, &queue->queue, struct async, queue_entry )
 193     {
 194         grab_object( &async->obj );
 195         if (!async->completion) async->completion = fd_get_completion( async->fd, &async->comp_key );
 196         async->fd = NULL;
 197         async_terminate( async, STATUS_HANDLES_CLOSED );
 198         async->queue = NULL;
 199         release_object( &async->obj );
 200     }
 201 }
 202
 203 void queue_async( struct async_queue *queue, struct async *async )
 204 {
 205     /* fd will be set to NULL in free_async_queue when fd is destroyed */
 206     release_object( async->fd );
 207
 208     async->queue = queue;
 209     grab_object( async );
 210     list_add_tail( &queue->queue, &async->queue_entry );
 211
 212     set_fd_signaled( async->fd, 0 );
 213 }
 214
 215 /* create an async on a given queue of a fd */
 216 struct async *create_async( struct fd *fd, struct thread *thread, const async_data_t *data, struct iosb *iosb )
 217 {
 218     struct event *event = NULL;
 219     struct async *async;
 220
 221     if (data->event && !(event = get_event_obj( thread->process, data->event, EVENT_MODIFY_STATE )))
 222         return NULL;
 223
 224     if (!(async = alloc_object( &async_ops )))
 225     {
 226         if (event) release_object( event );
 227         return NULL;
 228     }
 229
 230     async->thread        = (struct thread *)grab_object( thread );
 231     async->event         = event;
 232     async->status        = STATUS_PENDING;
 233     async->data          = *data;
 234     async->timeout       = NULL;
 235     async->queue         = NULL;
 236     async->fd            = (struct fd *)grab_object( fd );
 237     async->signaled      = 0;
 238     async->pending       = 1;
 239     async->wait_handle   = 0;
 240     async->direct_result = 0;
 241     async->completion    = fd_get_completion( fd, &async->comp_key );
 242     async->comp_flags    = 0;
 243     async->completion_callback = NULL;
 244     async->completion_callback_private = NULL;
 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 void set_async_pending( struct async *async, int signal )
 263 {
 264     if (async->status == STATUS_PENDING)
 265     {
 266         async->pending = 1;
 267         if (signal && !async->signaled)
 268         {
 269             async->signaled = 1;
 270             wake_up( &async->obj, 0 );
 271         }
 272     }
 273 }
 274
 275 /* create an async associated with iosb for async-based requests
 276  * returned async must be passed to async_handoff */
 277 struct async *create_request_async( struct fd *fd, unsigned int comp_flags, const async_data_t *data )
 278 {
 279     struct async *async;
 280     struct iosb *iosb;
 281
 282     if (!(iosb = create_iosb( get_req_data(), get_req_data_size(), get_reply_max_size() )))
 283         return NULL;
 284
 285     async = create_async( fd, current, data, iosb );
 286     release_object( iosb );
 287     if (async)
 288     {
 289         if (!(async->wait_handle = alloc_handle( current->process, async, SYNCHRONIZE, 0 )))
 290         {
 291             release_object( async );
 292             return NULL;
 293         }
 294         async->pending       = 0;
 295         async->direct_result = 1;
 296         async->comp_flags    = comp_flags;
 297     }
 298     return async;
 299 }
 300
 301 /* return async object status and wait handle to client */
 302 obj_handle_t async_handoff( struct async *async, int success, data_size_t *result, int force_blocking )
 303 {
 304     if (!success)
 305     {
 306         if (get_error() == STATUS_PENDING)
 307         {
 308             /* we don't know the result yet, so client needs to wait */
 309             async->direct_result = 0;
 310             return async->wait_handle;
 311         }
 312         close_handle( async->thread->process, async->wait_handle );
 313         async->wait_handle = 0;
 314         return 0;
 315     }
 316
 317     if (get_error() != STATUS_PENDING)
 318     {
 319         /* status and data are already set and returned */
 320         async_terminate( async, get_error() );
 321     }
 322     else if (async->iosb->status != STATUS_PENDING)
 323     {
 324         /* result is already available in iosb, return it */
 325         if (async->iosb->out_data)
 326         {
 327             set_reply_data_ptr( async->iosb->out_data, async->iosb->out_size );
 328             async->iosb->out_data = NULL;
 329         }
 330     }
 331
 332     if (async->iosb->status != STATUS_PENDING)
 333     {
 334         if (result) *result = async->iosb->result;
 335         async->signaled = 1;
 336     }
 337     else
 338     {
 339         async->direct_result = 0;
 340         async->pending = 1;
 341         if (!force_blocking && async->fd && is_fd_overlapped( async->fd ))
 342         {
 343             close_handle( async->thread->process, async->wait_handle);
 344             async->wait_handle = 0;
 345         }
 346     }
 347     set_error( async->iosb->status );
 348     return async->wait_handle;
 349 }
 350
 351 /* set the timeout of an async operation */
 352 void async_set_timeout( struct async *async, timeout_t timeout, unsigned int status )
 353 {
 354     if (async->timeout) remove_timeout_user( async->timeout );
 355     if (timeout != TIMEOUT_INFINITE) async->timeout = add_timeout_user( timeout, async_timeout, async );
 356     else async->timeout = NULL;
 357     async->timeout_status = status;
 358 }
 359
 360 /* set a callback to be notified when the async is completed */
 361 void async_set_completion_callback( struct async *async, async_completion_callback func, void *private )
 362 {
 363     async->completion_callback = func;
 364     async->completion_callback_private = private;
 365 }
 366
 367 static void add_async_completion( struct async *async, apc_param_t cvalue, unsigned int status,
 368                                   apc_param_t information )
 369 {
 370     if (async->fd && !async->completion) async->completion = fd_get_completion( async->fd, &async->comp_key );
 371     if (async->completion) add_completion( async->completion, async->comp_key, cvalue, status, information );
 372 }
 373
 374 /* store the result of the client-side async callback */
 375 void async_set_result( struct object *obj, unsigned int status, apc_param_t total )
 376 {
 377     struct async *async = (struct async *)obj;
 378
 379     if (obj->ops != &async_ops) return;  /* in case the client messed up the APC results */
 380
 381     assert( async->status != STATUS_PENDING );  /* it must have been woken up if we get a result */
 382
 383     if (status == STATUS_PENDING)  /* restart it */
 384     {
 385         status = async->status;
 386         async->status = STATUS_PENDING;
 387         grab_object( async );
 388
 389         if (status != STATUS_ALERTED)  /* it was terminated in the meantime */
 390             async_terminate( async, status );
 391         else
 392             async_reselect( async );
 393     }
 394     else
 395     {
 396         if (async->timeout) remove_timeout_user( async->timeout );
 397         async->timeout = NULL;
 398         async->status = status;
 399
 400         if (async->data.apc)
 401         {
 402             apc_call_t data;
 403             memset( &data, 0, sizeof(data) );
 404             data.type         = APC_USER;
 405             data.user.func    = async->data.apc;
 406             data.user.args[0] = async->data.apc_context;
 407             data.user.args[1] = async->data.iosb;
 408             data.user.args[2] = 0;
 409             thread_queue_apc( NULL, async->thread, NULL, &data );
 410         }
 411         else if (async->data.apc_context && (async->pending ||
 412                  !(async->comp_flags & FILE_SKIP_COMPLETION_PORT_ON_SUCCESS)))
 413         {
 414             add_async_completion( async, async->data.apc_context, status, total );
 415         }
 416
 417         if (async->event) set_event( async->event );
 418         else if (async->fd) set_fd_signaled( async->fd, 1 );
 419         if (!async->signaled)
 420         {
 421             async->signaled = 1;
 422             wake_up( &async->obj, 0 );
 423         }
 424
 425         if (async->completion_callback)
 426             async->completion_callback( async->completion_callback_private );
 427         async->completion_callback = NULL;
 428     }
 429 }
 430
 431 /* check if an async operation is waiting to be alerted */
 432 int async_waiting( struct async_queue *queue )
 433 {
 434     struct list *ptr;
 435     struct async *async;
 436
 437     if (!(ptr = list_head( &queue->queue ))) return 0;
 438     async = LIST_ENTRY( ptr, struct async, queue_entry );
 439     return async->status == STATUS_PENDING;
 440 }
 441
 442 static int cancel_async( struct process *process, struct object *obj, struct thread *thread, client_ptr_t iosb )
 443 {
 444     struct async *async;
 445     int woken = 0;
 446
 447 restart:
 448     LIST_FOR_EACH_ENTRY( async, &process->asyncs, struct async, process_entry )
 449     {
 450         if (async->status != STATUS_PENDING) continue;
 451         if ((!obj || (async->fd && get_fd_user( async->fd ) == obj)) &&
 452             (!thread || async->thread == thread) &&
 453             (!iosb || async->data.iosb == iosb))
 454         {
 455             async_terminate( async, STATUS_CANCELLED );
 456             woken++;
 457             goto restart;
 458         }
 459     }
 460     return woken;
 461 }
 462
 463 void cancel_process_asyncs( struct process *process )
 464 {
 465     cancel_async( process, NULL, NULL, 0 );
 466 }
 467
 468 /* wake up async operations on the queue */
 469 void async_wake_up( struct async_queue *queue, unsigned int status )
 470 {
 471     struct list *ptr, *next;
 472
 473     LIST_FOR_EACH_SAFE( ptr, next, &queue->queue )
 474     {
 475         struct async *async = LIST_ENTRY( ptr, struct async, queue_entry );
 476         async_terminate( async, status );
 477         if (status == STATUS_ALERTED) break;  /* only wake up the first one */
 478     }
 479 }
 480
 481 static void iosb_dump( struct object *obj, int verbose );
 482 static void iosb_destroy( struct object *obj );
 483
 484 static const struct object_ops iosb_ops =
 485 {
 486     sizeof(struct iosb),      /* size */
 487     &no_type,                 /* type */
 488     iosb_dump,                /* dump */
 489     no_add_queue,             /* add_queue */
 490     NULL,                     /* remove_queue */
 491     NULL,                     /* signaled */
 492     NULL,                     /* satisfied */
 493     no_signal,                /* signal */
 494     no_get_fd,                /* get_fd */
 495     default_map_access,       /* map_access */
 496     default_get_sd,           /* get_sd */
 497     default_set_sd,           /* set_sd */
 498     no_get_full_name,         /* get_full_name */
 499     no_lookup_name,           /* lookup_name */
 500     no_link_name,             /* link_name */
 501     NULL,                     /* unlink_name */
 502     no_open_file,             /* open_file */
 503     no_kernel_obj_list,       /* get_kernel_obj_list */
 504     no_close_handle,          /* close_handle */
 505     iosb_destroy              /* destroy */
 506 };
 507
 508 static void iosb_dump( struct object *obj, int verbose )
 509 {
 510     assert( obj->ops == &iosb_ops );
 511     fprintf( stderr, "I/O status block\n" );
 512 }
 513
 514 static void iosb_destroy( struct object *obj )
 515 {
 516     struct iosb *iosb = (struct iosb *)obj;
 517
 518     free( iosb->in_data );
 519     free( iosb->out_data );
 520 }
 521
 522 /* allocate iosb struct */
 523 struct iosb *create_iosb( const void *in_data, data_size_t in_size, data_size_t out_size )
 524 {
 525     struct iosb *iosb;
 526
 527     if (!(iosb = alloc_object( &iosb_ops ))) return NULL;
 528
 529     iosb->status = STATUS_PENDING;
 530     iosb->result = 0;
 531     iosb->in_size = in_size;
 532     iosb->in_data = NULL;
 533     iosb->out_size = out_size;
 534     iosb->out_data = NULL;
 535
 536     if (in_size && !(iosb->in_data = memdup( in_data, in_size )))
 537     {
 538         release_object( iosb );
 539         iosb = NULL;
 540     }
 541
 542     return iosb;
 543 }
 544
 545 struct iosb *async_get_iosb( struct async *async )
 546 {
 547     return async->iosb ? (struct iosb *)grab_object( async->iosb ) : NULL;
 548 }
 549
 550 struct thread *async_get_thread( struct async *async )
 551 {
 552     return async->thread;
 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 }