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->process, 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         grab_object( &async->obj );
 196         if (!async->completion) async->completion = fd_get_completion( async->fd, &async->comp_key );
 197         async->fd = NULL;
 198         async_terminate( async, STATUS_HANDLES_CLOSED );
 199         async->queue = NULL;
 200         release_object( &async->obj );
 201     }
 202 }
 203
 204 void queue_async( struct async_queue *queue, struct async *async )
 205 {
 206     /* fd will be set to NULL in free_async_queue when fd is destroyed */
 207     release_object( async->fd );
 208
 209     async->queue = queue;
 210     grab_object( async );
 211     list_add_tail( &queue->queue, &async->queue_entry );
 212
 213     set_fd_signaled( async->fd, 0 );
 214 }
 215
 216 /* create an async on a given queue of a fd */
 217 struct async *create_async( struct fd *fd, struct thread *thread, const async_data_t *data, struct iosb *iosb )
 218 {
 219     struct event *event = NULL;
 220     struct async *async;
 221
 222     if (data->event && !(event = get_event_obj( thread->process, data->event, EVENT_MODIFY_STATE )))
 223         return NULL;
 224
 225     if (!(async = alloc_object( &async_ops )))
 226     {
 227         if (event) release_object( event );
 228         return NULL;
 229     }
 230
 231     async->thread        = (struct thread *)grab_object( thread );
 232     async->event         = event;
 233     async->status        = STATUS_PENDING;
 234     async->data          = *data;
 235     async->timeout       = NULL;
 236     async->queue         = NULL;
 237     async->fd            = (struct fd *)grab_object( fd );
 238     async->signaled      = 0;
 239     async->wait_handle   = 0;
 240     async->direct_result = 0;
 241     async->completion    = fd_get_completion( fd, &async->comp_key );
 242
 243     if (iosb) async->iosb = (struct iosb *)grab_object( iosb );
 244     else async->iosb = NULL;
 245
 246     list_add_head( &thread->process->asyncs, &async->process_entry );
 247     if (event) reset_event( event );
 248
 249     if (async->completion && data->apc)
 250     {
 251         release_object( async );
 252         set_error( STATUS_INVALID_PARAMETER );
 253         return NULL;
 254     }
 255
 256     return async;
 257 }
 258
 259 /* create an async associated with iosb for async-based requests
 260  * returned async must be passed to async_handoff */
 261 struct async *create_request_async( struct fd *fd, const async_data_t *data )
 262 {
 263     struct async *async;
 264     struct iosb *iosb;
 265
 266     if (!(iosb = create_iosb( get_req_data(), get_req_data_size(), get_reply_max_size() )))
 267         return NULL;
 268
 269     async = create_async( fd, current, data, iosb );
 270     release_object( iosb );
 271     if (async)
 272     {
 273         if (!(async->wait_handle = alloc_handle( current->process, async, SYNCHRONIZE, 0 )))
 274         {
 275             release_object( async );
 276             return NULL;
 277         }
 278         async->direct_result = 1;
 279     }
 280     return async;
 281 }
 282
 283 /* return async object status and wait handle to client */
 284 obj_handle_t async_handoff( struct async *async, int success, data_size_t *result )
 285 {
 286     if (!success)
 287     {
 288         close_handle( async->thread->process, async->wait_handle );
 289         async->wait_handle = 0;
 290         return 0;
 291     }
 292
 293     if (get_error() != STATUS_PENDING)
 294     {
 295         /* status and data are already set and returned */
 296         async_terminate( async, get_error() );
 297     }
 298     else if (async->iosb->status != STATUS_PENDING)
 299     {
 300         /* result is already available in iosb, return it */
 301         if (async->iosb->out_data)
 302         {
 303             set_reply_data_ptr( async->iosb->out_data, async->iosb->out_size );
 304             async->iosb->out_data = NULL;
 305         }
 306     }
 307
 308     if (async->iosb->status != STATUS_PENDING)
 309     {
 310         if (result) *result = async->iosb->result;
 311         async->signaled = 1;
 312     }
 313     else
 314     {
 315         async->direct_result = 0;
 316         if (!async_is_blocking( async ))
 317         {
 318             close_handle( async->thread->process, async->wait_handle);
 319             async->wait_handle = 0;
 320         }
 321     }
 322     set_error( async->iosb->status );
 323     return async->wait_handle;
 324 }
 325
 326 /* set the timeout of an async operation */
 327 void async_set_timeout( struct async *async, timeout_t timeout, unsigned int status )
 328 {
 329     if (async->timeout) remove_timeout_user( async->timeout );
 330     if (timeout != TIMEOUT_INFINITE) async->timeout = add_timeout_user( timeout, async_timeout, async );
 331     else async->timeout = NULL;
 332     async->timeout_status = status;
 333 }
 334
 335 static void add_async_completion( struct async *async, apc_param_t cvalue, unsigned int status,
 336                                   apc_param_t information )
 337 {
 338     if (async->fd && !async->completion) async->completion = fd_get_completion( async->fd, &async->comp_key );
 339     if (async->completion) add_completion( async->completion, async->comp_key, cvalue, status, information );
 340 }
 341
 342 /* store the result of the client-side async callback */
 343 void async_set_result( struct object *obj, unsigned int status, apc_param_t total )
 344 {
 345     struct async *async = (struct async *)obj;
 346
 347     if (obj->ops != &async_ops) return;  /* in case the client messed up the APC results */
 348
 349     assert( async->status != STATUS_PENDING );  /* it must have been woken up if we get a result */
 350
 351     if (status == STATUS_PENDING)  /* restart it */
 352     {
 353         status = async->status;
 354         async->status = STATUS_PENDING;
 355         grab_object( async );
 356
 357         if (status != STATUS_ALERTED)  /* it was terminated in the meantime */
 358             async_terminate( async, status );
 359         else
 360             async_reselect( async );
 361     }
 362     else
 363     {
 364         if (async->timeout) remove_timeout_user( async->timeout );
 365         async->timeout = NULL;
 366         async->status = status;
 367         if (status == STATUS_MORE_PROCESSING_REQUIRED) return;  /* don't report the completion */
 368
 369         if (async->data.apc)
 370         {
 371             apc_call_t data;
 372             memset( &data, 0, sizeof(data) );
 373             data.type         = APC_USER;
 374             data.user.func    = async->data.apc;
 375             data.user.args[0] = async->data.apc_context;
 376             data.user.args[1] = async->data.iosb;
 377             data.user.args[2] = 0;
 378             thread_queue_apc( NULL, async->thread, NULL, &data );
 379         }
 380         else if (async->data.apc_context)
 381             add_async_completion( async, async->data.apc_context, status, total );
 382
 383         if (async->event) set_event( async->event );
 384         else if (async->fd) set_fd_signaled( async->fd, 1 );
 385         if (!async->signaled)
 386         {
 387             async->signaled = 1;
 388             wake_up( &async->obj, 0 );
 389         }
 390     }
 391 }
 392
 393 /* check if an async operation is waiting to be alerted */
 394 int async_waiting( struct async_queue *queue )
 395 {
 396     struct list *ptr;
 397     struct async *async;
 398
 399     if (!(ptr = list_head( &queue->queue ))) return 0;
 400     async = LIST_ENTRY( ptr, struct async, queue_entry );
 401     return async->status == STATUS_PENDING;
 402 }
 403
 404 static int cancel_async( struct process *process, struct object *obj, struct thread *thread, client_ptr_t iosb )
 405 {
 406     struct async *async;
 407     int woken = 0;
 408
 409 restart:
 410     LIST_FOR_EACH_ENTRY( async, &process->asyncs, struct async, process_entry )
 411     {
 412         if (async->status == STATUS_CANCELLED) continue;
 413         if ((!obj || (async->fd && get_fd_user( async->fd ) == obj)) &&
 414             (!thread || async->thread == thread) &&
 415             (!iosb || async->data.iosb == iosb))
 416         {
 417             async_terminate( async, STATUS_CANCELLED );
 418             woken++;
 419             goto restart;
 420         }
 421     }
 422     return woken;
 423 }
 424
 425 void cancel_process_asyncs( struct process *process )
 426 {
 427     cancel_async( process, NULL, NULL, 0 );
 428 }
 429
 430 /* wake up async operations on the queue */
 431 void async_wake_up( struct async_queue *queue, unsigned int status )
 432 {
 433     struct list *ptr, *next;
 434
 435     LIST_FOR_EACH_SAFE( ptr, next, &queue->queue )
 436     {
 437         struct async *async = LIST_ENTRY( ptr, struct async, queue_entry );
 438         async_terminate( async, status );
 439         if (status == STATUS_ALERTED) break;  /* only wake up the first one */
 440     }
 441 }
 442
 443 static void iosb_dump( struct object *obj, int verbose );
 444 static void iosb_destroy( struct object *obj );
 445
 446 static const struct object_ops iosb_ops =
 447 {
 448     sizeof(struct iosb),      /* size */
 449     iosb_dump,                /* dump */
 450     no_get_type,              /* get_type */
 451     no_add_queue,             /* add_queue */
 452     NULL,                     /* remove_queue */
 453     NULL,                     /* signaled */
 454     NULL,                     /* satisfied */
 455     no_signal,                /* signal */
 456     no_get_fd,                /* get_fd */
 457     no_map_access,            /* map_access */
 458     default_get_sd,           /* get_sd */
 459     default_set_sd,           /* set_sd */
 460     no_lookup_name,           /* lookup_name */
 461     no_link_name,             /* link_name */
 462     NULL,                     /* unlink_name */
 463     no_open_file,             /* open_file */
 464     no_close_handle,          /* close_handle */
 465     iosb_destroy              /* destroy */
 466 };
 467
 468 static void iosb_dump( struct object *obj, int verbose )
 469 {
 470     assert( obj->ops == &iosb_ops );
 471     fprintf( stderr, "I/O status block\n" );
 472 }
 473
 474 static void iosb_destroy( struct object *obj )
 475 {
 476     struct iosb *iosb = (struct iosb *)obj;
 477
 478     free( iosb->in_data );
 479     free( iosb->out_data );
 480 }
 481
 482 /* allocate iosb struct */
 483 struct iosb *create_iosb( const void *in_data, data_size_t in_size, data_size_t out_size )
 484 {
 485     struct iosb *iosb;
 486
 487     if (!(iosb = alloc_object( &iosb_ops ))) return NULL;
 488
 489     iosb->status = STATUS_PENDING;
 490     iosb->result = 0;
 491     iosb->in_size = in_size;
 492     iosb->in_data = NULL;
 493     iosb->out_size = out_size;
 494     iosb->out_data = NULL;
 495
 496     if (in_size && !(iosb->in_data = memdup( in_data, in_size )))
 497     {
 498         release_object( iosb );
 499         iosb = NULL;
 500     }
 501
 502     return iosb;
 503 }
 504
 505 struct iosb *async_get_iosb( struct async *async )
 506 {
 507     return async->iosb ? (struct iosb *)grab_object( async->iosb ) : NULL;
 508 }
 509
 510 int async_is_blocking( struct async *async )
 511 {
 512     return !async->event && !async->data.apc && !async->data.apc_context;
 513 }
 514
 515 /* find the first pending async in queue */
 516 struct async *find_pending_async( struct async_queue *queue )
 517 {
 518     struct async *async;
 519     LIST_FOR_EACH_ENTRY( async, &queue->queue, struct async, queue_entry )
 520         if (async->status == STATUS_PENDING) return (struct async *)grab_object( async );
 521     return NULL;
 522 }
 523
 524 /* cancels all async I/O */
 525 DECL_HANDLER(cancel_async)
 526 {
 527     struct object *obj = get_handle_obj( current->process, req->handle, 0, NULL );
 528     struct thread *thread = req->only_thread ? current : NULL;
 529
 530     if (obj)
 531     {
 532         int count = cancel_async( current->process, obj, thread, req->iosb );
 533         if (!count && req->iosb) set_error( STATUS_NOT_FOUND );
 534         release_object( obj );
 535     }
 536 }
 537
 538 /* get async result from associated iosb */
 539 DECL_HANDLER(get_async_result)
 540 {
 541     struct iosb *iosb = NULL;
 542     struct async *async;
 543
 544     LIST_FOR_EACH_ENTRY( async, &current->process->asyncs, struct async, process_entry )
 545         if (async->data.user == req->user_arg)
 546         {
 547             iosb = async->iosb;
 548             break;
 549         }
 550
 551     if (!iosb)
 552     {
 553         set_error( STATUS_INVALID_PARAMETER );
 554         return;
 555     }
 556
 557     if (iosb->out_data)
 558     {
 559         data_size_t size = min( iosb->out_size, get_reply_max_size() );
 560         if (size)
 561         {
 562             set_reply_data_ptr( iosb->out_data, size );
 563             iosb->out_data = NULL;
 564         }
 565     }
 566     reply->size = iosb->result;
 567     set_error( iosb->status );
 568 }