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 };
  57
  58 static void async_dump( struct object *obj, int verbose );
  59 static int async_signaled( struct object *obj, struct wait_queue_entry *entry );
  60 static void async_satisfied( struct object * obj, struct wait_queue_entry *entry );
  61 static void async_destroy( struct object *obj );
  62
  63 static const struct object_ops async_ops =
  64 {
  65     sizeof(struct async),      /* size */
  66     async_dump,                /* dump */
  67     no_get_type,               /* get_type */
  68     add_queue,                 /* add_queue */
  69     remove_queue,              /* remove_queue */
  70     async_signaled,            /* signaled */
  71     async_satisfied,           /* satisfied */
  72     no_signal,                 /* signal */
  73     no_get_fd,                 /* get_fd */
  74     no_map_access,             /* map_access */
  75     default_get_sd,            /* get_sd */
  76     default_set_sd,            /* set_sd */
  77     no_lookup_name,            /* lookup_name */
  78     no_link_name,              /* link_name */
  79     NULL,                      /* unlink_name */
  80     no_open_file,              /* open_file */
  81     no_close_handle,           /* close_handle */
  82     async_destroy              /* destroy */
  83 };
  84
  85 static inline void async_reselect( struct async *async )
  86 {
  87     if (async->queue && async->fd) fd_reselect_async( async->fd, async->queue );
  88 }
  89
  90 static void async_dump( struct object *obj, int verbose )
  91 {
  92     struct async *async = (struct async *)obj;
  93     assert( obj->ops == &async_ops );
  94     fprintf( stderr, "Async thread=%p\n", async->thread );
  95 }
  96
  97 static int async_signaled( struct object *obj, struct wait_queue_entry *entry )
  98 {
  99     struct async *async = (struct async *)obj;
 100     assert( obj->ops == &async_ops );
 101     return async->signaled;
 102 }
 103
 104 static void async_satisfied( struct object *obj, struct wait_queue_entry *entry )
 105 {
 106     struct async *async = (struct async *)obj;
 107     assert( obj->ops == &async_ops );
 108
 109     if (async->direct_result)
 110     {
 111         async_set_result( &async->obj, async->iosb->status, async->iosb->result );
 112         async->direct_result = 0;
 113     }
 114
 115     /* close wait handle here to avoid extra server round trip */
 116     if (async->wait_handle)
 117     {
 118         close_handle( async->thread->process, async->wait_handle );
 119         async->wait_handle = 0;
 120     }
 121 }
 122
 123 static void async_destroy( struct object *obj )
 124 {
 125     struct async *async = (struct async *)obj;
 126     assert( obj->ops == &async_ops );
 127
 128     list_remove( &async->process_entry );
 129
 130     if (async->queue)
 131     {
 132         list_remove( &async->queue_entry );
 133         async_reselect( async );
 134     }
 135     else if (async->fd) release_object( async->fd );
 136
 137     if (async->timeout) remove_timeout_user( async->timeout );
 138     if (async->completion) release_object( async->completion );
 139     if (async->event) release_object( async->event );
 140     if (async->iosb) release_object( async->iosb );
 141     release_object( async->thread );
 142 }
 143
 144 /* notifies client thread of new status of its async request */
 145 void async_terminate( struct async *async, unsigned int status )
 146 {
 147     assert( status != STATUS_PENDING );
 148
 149     if (async->status != STATUS_PENDING)
 150     {
 151         /* already terminated, just update status */
 152         async->status = status;
 153         return;
 154     }
 155
 156     async->status = status;
 157     if (async->iosb && async->iosb->status == STATUS_PENDING) async->iosb->status = status;
 158
 159     if (!async->direct_result)
 160     {
 161         if (async->data.user)
 162         {
 163             apc_call_t data;
 164
 165             memset( &data, 0, sizeof(data) );
 166             data.type            = APC_ASYNC_IO;
 167             data.async_io.user   = async->data.user;
 168             data.async_io.sb     = async->data.iosb;
 169             data.async_io.status = status;
 170             thread_queue_apc( async->thread, &async->obj, &data );
 171         }
 172         else async_set_result( &async->obj, STATUS_SUCCESS, 0 );
 173     }
 174
 175     async_reselect( async );
 176     if (async->queue) release_object( async );  /* so that it gets destroyed when the async is done */
 177 }
 178
 179 /* callback for timeout on an async request */
 180 static void async_timeout( void *private )
 181 {
 182     struct async *async = private;
 183
 184     async->timeout = NULL;
 185     async_terminate( async, async->timeout_status );
 186 }
 187
 188 /* free an async queue, cancelling all async operations */
 189 void free_async_queue( struct async_queue *queue )
 190 {
 191     struct async *async, *next;
 192
 193     LIST_FOR_EACH_ENTRY_SAFE( async, next, &queue->queue, struct async, queue_entry )
 194     {
 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     }
 200 }
 201
 202 void queue_async( struct async_queue *queue, struct async *async )
 203 {
 204     /* fd will be set to NULL in free_async_queue when fd is destroyed */
 205     release_object( async->fd );
 206
 207     async->queue = queue;
 208     grab_object( async );
 209     list_add_tail( &queue->queue, &async->queue_entry );
 210
 211     set_fd_signaled( async->fd, 0 );
 212 }
 213
 214 /* create an async on a given queue of a fd */
 215 struct async *create_async( struct fd *fd, struct thread *thread, const async_data_t *data, struct iosb *iosb )
 216 {
 217     struct event *event = NULL;
 218     struct async *async;
 219
 220     if (data->event && !(event = get_event_obj( thread->process, data->event, EVENT_MODIFY_STATE )))
 221         return NULL;
 222
 223     if (!(async = alloc_object( &async_ops )))
 224     {
 225         if (event) release_object( event );
 226         return NULL;
 227     }
 228
 229     async->thread        = (struct thread *)grab_object( thread );
 230     async->event         = event;
 231     async->status        = STATUS_PENDING;
 232     async->data          = *data;
 233     async->timeout       = NULL;
 234     async->queue         = NULL;
 235     async->fd            = (struct fd *)grab_object( fd );
 236     async->signaled      = 0;
 237     async->wait_handle   = 0;
 238     async->direct_result = 0;
 239     async->completion    = fd_get_completion( fd, &async->comp_key );
 240
 241     if (iosb) async->iosb = (struct iosb *)grab_object( iosb );
 242     else async->iosb = NULL;
 243
 244     list_add_head( &thread->process->asyncs, &async->process_entry );
 245     if (event) reset_event( event );
 246
 247     if (async->completion && data->apc)
 248     {
 249         release_object( async );
 250         set_error( STATUS_INVALID_PARAMETER );
 251         return NULL;
 252     }
 253
 254     return async;
 255 }
 256
 257 /* create an async associated with iosb for async-based requests
 258  * returned async must be passed to async_handoff */
 259 struct async *create_request_async( struct fd *fd, const async_data_t *data )
 260 {
 261     struct async *async;
 262     struct iosb *iosb;
 263
 264     if (!(iosb = create_iosb( get_req_data(), get_req_data_size(), get_reply_max_size() )))
 265         return NULL;
 266
 267     async = create_async( fd, current, data, iosb );
 268     release_object( iosb );
 269     if (async)
 270     {
 271         if (!(async->wait_handle = alloc_handle( current->process, async, SYNCHRONIZE, 0 )))
 272         {
 273             release_object( async );
 274             return NULL;
 275         }
 276         async->direct_result = 1;
 277     }
 278     return async;
 279 }
 280
 281 /* return async object status and wait handle to client */
 282 obj_handle_t async_handoff( struct async *async, int success, data_size_t *result )
 283 {
 284     if (!success)
 285     {
 286         close_handle( async->thread->process, async->wait_handle );
 287         async->wait_handle = 0;
 288         return 0;
 289     }
 290
 291     if (get_error() != STATUS_PENDING)
 292     {
 293         /* status and data are already set and returned */
 294         async_terminate( async, get_error() );
 295     }
 296     else if (async->iosb->status != STATUS_PENDING)
 297     {
 298         /* result is already available in iosb, return it */
 299         if (async->iosb->out_data)
 300         {
 301             set_reply_data_ptr( async->iosb->out_data, async->iosb->out_size );
 302             async->iosb->out_data = NULL;
 303         }
 304     }
 305
 306     if (async->iosb->status != STATUS_PENDING)
 307     {
 308         if (result) *result = async->iosb->result;
 309         async->signaled = 1;
 310     }
 311     else
 312     {
 313         async->direct_result = 0;
 314         if (!async_is_blocking( async ))
 315         {
 316             close_handle( async->thread->process, async->wait_handle);
 317             async->wait_handle = 0;
 318         }
 319     }
 320     set_error( async->iosb->status );
 321     return async->wait_handle;
 322 }
 323
 324 /* set the timeout of an async operation */
 325 void async_set_timeout( struct async *async, timeout_t timeout, unsigned int status )
 326 {
 327     if (async->timeout) remove_timeout_user( async->timeout );
 328     if (timeout != TIMEOUT_INFINITE) async->timeout = add_timeout_user( timeout, async_timeout, async );
 329     else async->timeout = NULL;
 330     async->timeout_status = status;
 331 }
 332
 333 static void add_async_completion( struct async *async, apc_param_t cvalue, unsigned int status,
 334                                   apc_param_t information )
 335 {
 336     if (async->fd && !async->completion) async->completion = fd_get_completion( async->fd, &async->comp_key );
 337     if (async->completion) add_completion( async->completion, async->comp_key, cvalue, status, information );
 338 }
 339
 340 /* store the result of the client-side async callback */
 341 void async_set_result( struct object *obj, unsigned int status, apc_param_t total )
 342 {
 343     struct async *async = (struct async *)obj;
 344
 345     if (obj->ops != &async_ops) return;  /* in case the client messed up the APC results */
 346
 347     assert( async->status != STATUS_PENDING );  /* it must have been woken up if we get a result */
 348
 349     if (status == STATUS_PENDING)  /* restart it */
 350     {
 351         status = async->status;
 352         async->status = STATUS_PENDING;
 353         grab_object( async );
 354
 355         if (status != STATUS_ALERTED)  /* it was terminated in the meantime */
 356             async_terminate( async, status );
 357         else
 358             async_reselect( async );
 359     }
 360     else
 361     {
 362         if (async->timeout) remove_timeout_user( async->timeout );
 363         async->timeout = NULL;
 364         async->status = status;
 365         if (status == STATUS_MORE_PROCESSING_REQUIRED) return;  /* don't report the completion */
 366
 367         if (async->data.apc)
 368         {
 369             apc_call_t data;
 370             memset( &data, 0, sizeof(data) );
 371             data.type         = APC_USER;
 372             data.user.func    = async->data.apc;
 373             data.user.args[0] = async->data.apc_context;
 374             data.user.args[1] = async->data.iosb;
 375             data.user.args[2] = 0;
 376             thread_queue_apc( async->thread, NULL, &data );
 377         }
 378         else if (async->data.apc_context)
 379             add_async_completion( async, async->data.apc_context, status, total );
 380
 381         if (async->event) set_event( async->event );
 382         else if (async->fd) set_fd_signaled( async->fd, 1 );
 383         if (!async->signaled)
 384         {
 385             async->signaled = 1;
 386             wake_up( &async->obj, 0 );
 387         }
 388     }
 389 }
 390
 391 /* check if an async operation is waiting to be alerted */
 392 int async_waiting( struct async_queue *queue )
 393 {
 394     struct list *ptr;
 395     struct async *async;
 396
 397     if (!(ptr = list_head( &queue->queue ))) return 0;
 398     async = LIST_ENTRY( ptr, struct async, queue_entry );
 399     return async->status == STATUS_PENDING;
 400 }
 401
 402 static int cancel_async( struct process *process, struct object *obj, struct thread *thread, client_ptr_t iosb )
 403 {
 404     struct async *async;
 405     int woken = 0;
 406
 407 restart:
 408     LIST_FOR_EACH_ENTRY( async, &process->asyncs, struct async, process_entry )
 409     {
 410         if (async->status == STATUS_CANCELLED) continue;
 411         if ((!obj || (async->fd && get_fd_user( async->fd ) == obj)) &&
 412             (!thread || async->thread == thread) &&
 413             (!iosb || async->data.iosb == iosb))
 414         {
 415             async_terminate( async, STATUS_CANCELLED );
 416             woken++;
 417             goto restart;
 418         }
 419     }
 420     return woken;
 421 }
 422
 423 void cancel_process_asyncs( struct process *process )
 424 {
 425     cancel_async( process, NULL, NULL, 0 );
 426 }
 427
 428 /* wake up async operations on the queue */
 429 void async_wake_up( struct async_queue *queue, unsigned int status )
 430 {
 431     struct list *ptr, *next;
 432
 433     LIST_FOR_EACH_SAFE( ptr, next, &queue->queue )
 434     {
 435         struct async *async = LIST_ENTRY( ptr, struct async, queue_entry );
 436         async_terminate( async, status );
 437         if (status == STATUS_ALERTED) break;  /* only wake up the first one */
 438     }
 439 }
 440
 441 static void iosb_dump( struct object *obj, int verbose );
 442 static void iosb_destroy( struct object *obj );
 443
 444 static const struct object_ops iosb_ops =
 445 {
 446     sizeof(struct iosb),      /* size */
 447     iosb_dump,                /* dump */
 448     no_get_type,              /* get_type */
 449     no_add_queue,             /* add_queue */
 450     NULL,                     /* remove_queue */
 451     NULL,                     /* signaled */
 452     NULL,                     /* satisfied */
 453     no_signal,                /* signal */
 454     no_get_fd,                /* get_fd */
 455     no_map_access,            /* map_access */
 456     default_get_sd,           /* get_sd */
 457     default_set_sd,           /* set_sd */
 458     no_lookup_name,           /* lookup_name */
 459     no_link_name,             /* link_name */
 460     NULL,                     /* unlink_name */
 461     no_open_file,             /* open_file */
 462     no_close_handle,          /* close_handle */
 463     iosb_destroy              /* destroy */
 464 };
 465
 466 static void iosb_dump( struct object *obj, int verbose )
 467 {
 468     assert( obj->ops == &iosb_ops );
 469     fprintf( stderr, "I/O status block\n" );
 470 }
 471
 472 static void iosb_destroy( struct object *obj )
 473 {
 474     struct iosb *iosb = (struct iosb *)obj;
 475
 476     free( iosb->in_data );
 477     free( iosb->out_data );
 478 }
 479
 480 /* allocate iosb struct */
 481 struct iosb *create_iosb( const void *in_data, data_size_t in_size, data_size_t out_size )
 482 {
 483     struct iosb *iosb;
 484
 485     if (!(iosb = alloc_object( &iosb_ops ))) return NULL;
 486
 487     iosb->status = STATUS_PENDING;
 488     iosb->result = 0;
 489     iosb->in_size = in_size;
 490     iosb->in_data = NULL;
 491     iosb->out_size = out_size;
 492     iosb->out_data = NULL;
 493
 494     if (in_size && !(iosb->in_data = memdup( in_data, in_size )))
 495     {
 496         release_object( iosb );
 497         iosb = NULL;
 498     }
 499
 500     return iosb;
 501 }
 502
 503 struct iosb *async_get_iosb( struct async *async )
 504 {
 505     return async->iosb ? (struct iosb *)grab_object( async->iosb ) : NULL;
 506 }
 507
 508 int async_is_blocking( struct async *async )
 509 {
 510     return !async->event && !async->data.apc && !async->data.apc_context;
 511 }
 512
 513 /* find the first pending async in queue */
 514 struct async *find_pending_async( struct async_queue *queue )
 515 {
 516     struct async *async;
 517     LIST_FOR_EACH_ENTRY( async, &queue->queue, struct async, queue_entry )
 518         if (async->status == STATUS_PENDING) return (struct async *)grab_object( async );
 519     return NULL;
 520 }
 521
 522 /* cancels all async I/O */
 523 DECL_HANDLER(cancel_async)
 524 {
 525     struct object *obj = get_handle_obj( current->process, req->handle, 0, NULL );
 526     struct thread *thread = req->only_thread ? current : NULL;
 527
 528     if (obj)
 529     {
 530         int count = cancel_async( current->process, obj, thread, req->iosb );
 531         if (!count && req->iosb) set_error( STATUS_NOT_FOUND );
 532         release_object( obj );
 533     }
 534 }
 535
 536 /* get async result from associated iosb */
 537 DECL_HANDLER(get_async_result)
 538 {
 539     struct iosb *iosb = NULL;
 540     struct async *async;
 541
 542     LIST_FOR_EACH_ENTRY( async, &current->process->asyncs, struct async, process_entry )
 543         if (async->data.user == req->user_arg)
 544         {
 545             iosb = async->iosb;
 546             break;
 547         }
 548
 549     if (!iosb)
 550     {
 551         set_error( STATUS_INVALID_PARAMETER );
 552         return;
 553     }
 554
 555     if (iosb->out_data)
 556     {
 557         data_size_t size = min( iosb->out_size, get_reply_max_size() );
 558         if (size)
 559         {
 560             set_reply_data_ptr( iosb->out_data, size );
 561             iosb->out_data = NULL;
 562         }
 563     }
 564     reply->size = iosb->result;
 565     set_error( iosb->status );
 566 }