mono/io-layer/events.c

   1 /*
   2  * events.c:  Event handles
   3  *
   4  * Author:
   5  *      Dick Porter (dick@ximian.com)
   6  *
   7  * (C) 2002 Ximian, Inc.
   8  */
   9
  10 #include <config.h>
  11 #include <glib.h>
  12 #include <pthread.h>
  13 #include <string.h>
  14
  15 #include <mono/io-layer/wapi.h>
  16 #include <mono/io-layer/wapi-private.h>
  17 #include <mono/io-layer/handles-private.h>
  18 #include <mono/io-layer/misc-private.h>
  19
  20 #include <mono/io-layer/mono-mutex.h>
  21
  22 #include <mono/io-layer/event-private.h>
  23
  24 #undef DEBUG
  25
  26 static void event_signal(gpointer handle);
  27 static gboolean event_own (gpointer handle);
  28
  29 static void namedevent_signal (gpointer handle);
  30 static gboolean namedevent_own (gpointer handle);
  31
  32 struct _WapiHandleOps _wapi_event_ops = {
  33         NULL,                   /* close */
  34         event_signal,           /* signal */
  35         event_own,              /* own */
  36         NULL,                   /* is_owned */
  37         NULL,                   /* special_wait */
  38         NULL                    /* prewait */
  39 };
  40
  41 struct _WapiHandleOps _wapi_namedevent_ops = {
  42         NULL,                   /* close */
  43         namedevent_signal,      /* signal */
  44         namedevent_own,         /* own */
  45         NULL,                   /* is_owned */
  46 };
  47
  48 static gboolean event_pulse (gpointer handle);
  49 static gboolean event_reset (gpointer handle);
  50 static gboolean event_set (gpointer handle);
  51
  52 static gboolean namedevent_pulse (gpointer handle);
  53 static gboolean namedevent_reset (gpointer handle);
  54 static gboolean namedevent_set (gpointer handle);
  55
  56 static struct
  57 {
  58         gboolean (*pulse)(gpointer handle);
  59         gboolean (*reset)(gpointer handle);
  60         gboolean (*set)(gpointer handle);
  61 } event_ops[WAPI_HANDLE_COUNT] = {
  62                 {NULL},
  63                 {NULL},
  64                 {NULL},
  65                 {NULL},
  66                 {NULL},
  67                 {NULL},
  68                 {event_pulse, event_reset, event_set},
  69                 {NULL},
  70                 {NULL},
  71                 {NULL},
  72                 {NULL},
  73                 {NULL},
  74                 {NULL},
  75                 {namedevent_pulse, namedevent_reset, namedevent_set},
  76 };
  77
  78 void _wapi_event_details (gpointer handle_info)
  79 {
  80         struct _WapiHandle_event *event = (struct _WapiHandle_event *)handle_info;
  81
  82         g_print ("manual: %s", event->manual?"TRUE":"FALSE");
  83 }
  84
  85 static mono_once_t event_ops_once=MONO_ONCE_INIT;
  86
  87 static void event_ops_init (void)
  88 {
  89         _wapi_handle_register_capabilities (WAPI_HANDLE_EVENT,
  90                                             WAPI_HANDLE_CAP_WAIT |
  91                                             WAPI_HANDLE_CAP_SIGNAL);
  92         _wapi_handle_register_capabilities (WAPI_HANDLE_NAMEDEVENT,
  93                                             WAPI_HANDLE_CAP_WAIT |
  94                                             WAPI_HANDLE_CAP_SIGNAL);
  95 }
  96
  97 static void event_signal(gpointer handle)
  98 {
  99         SetEvent(handle);
 100 }
 101
 102 static gboolean event_own (gpointer handle)
 103 {
 104         struct _WapiHandle_event *event_handle;
 105         gboolean ok;
 106
 107         ok=_wapi_lookup_handle (handle, WAPI_HANDLE_EVENT,
 108                                 (gpointer *)&event_handle);
 109         if(ok==FALSE) {
 110                 g_warning ("%s: error looking up event handle %p", __func__,
 111                            handle);
 112                 return (FALSE);
 113         }
 114
 115 #ifdef DEBUG
 116         g_message("%s: owning event handle %p", __func__, handle);
 117 #endif
 118
 119         if(event_handle->manual==FALSE) {
 120                 g_assert (event_handle->set_count > 0);
 121
 122                 if (--event_handle->set_count == 0) {
 123                         _wapi_handle_set_signal_state (handle, FALSE, FALSE);
 124                 }
 125         }
 126
 127         return(TRUE);
 128 }
 129
 130 static void namedevent_signal (gpointer handle)
 131 {
 132         SetEvent (handle);
 133 }
 134
 135 /* NB, always called with the shared handle lock held */
 136 static gboolean namedevent_own (gpointer handle)
 137 {
 138         struct _WapiHandle_namedevent *namedevent_handle;
 139         gboolean ok;
 140
 141 #ifdef DEBUG
 142         g_message ("%s: owning named event handle %p", __func__, handle);
 143 #endif
 144
 145         ok = _wapi_lookup_handle (handle, WAPI_HANDLE_NAMEDEVENT,
 146                                   (gpointer *)&namedevent_handle);
 147         if (ok == FALSE) {
 148                 g_warning ("%s: error looking up named event handle %p",
 149                            __func__, handle);
 150                 return(FALSE);
 151         }
 152
 153         if (namedevent_handle->manual == FALSE) {
 154                 g_assert (namedevent_handle->set_count > 0);
 155
 156                 if (--namedevent_handle->set_count == 0) {
 157                         _wapi_shared_handle_set_signal_state (handle, FALSE);
 158                 }
 159         }
 160
 161         return (TRUE);
 162 }
 163 static gpointer event_create (WapiSecurityAttributes *security G_GNUC_UNUSED,
 164                               gboolean manual, gboolean initial)
 165 {
 166         struct _WapiHandle_event event_handle = {0};
 167         gpointer handle;
 168         int thr_ret;
 169
 170         /* Need to blow away any old errors here, because code tests
 171          * for ERROR_ALREADY_EXISTS on success (!) to see if an event
 172          * was freshly created
 173          */
 174         SetLastError (ERROR_SUCCESS);
 175
 176 #ifdef DEBUG
 177         g_message ("%s: Creating unnamed event", __func__);
 178 #endif
 179
 180         event_handle.manual = manual;
 181         event_handle.set_count = 0;
 182
 183         if (initial == TRUE) {
 184                 if (manual == FALSE) {
 185                         event_handle.set_count = 1;
 186                 }
 187         }
 188
 189         handle = _wapi_handle_new (WAPI_HANDLE_EVENT, &event_handle);
 190         if (handle == _WAPI_HANDLE_INVALID) {
 191                 g_warning ("%s: error creating event handle", __func__);
 192                 SetLastError (ERROR_GEN_FAILURE);
 193                 return(NULL);
 194         }
 195
 196         pthread_cleanup_push ((void(*)(void *))_wapi_handle_unlock_handle,
 197                               handle);
 198         thr_ret = _wapi_handle_lock_handle (handle);
 199         g_assert (thr_ret == 0);
 200
 201         if (initial == TRUE) {
 202                 _wapi_handle_set_signal_state (handle, TRUE, FALSE);
 203         }
 204
 205 #ifdef DEBUG
 206         g_message("%s: created new event handle %p", __func__, handle);
 207 #endif
 208
 209         thr_ret = _wapi_handle_unlock_handle (handle);
 210         g_assert (thr_ret == 0);
 211         pthread_cleanup_pop (0);
 212
 213         return(handle);
 214 }
 215
 216 static gpointer namedevent_create (WapiSecurityAttributes *security G_GNUC_UNUSED,
 217                                    gboolean manual, gboolean initial,
 218                                    const gunichar2 *name G_GNUC_UNUSED)
 219 {
 220         struct _WapiHandle_namedevent namedevent_handle = {{{0}}, 0};
 221         gpointer handle;
 222         gchar *utf8_name;
 223         int thr_ret;
 224         gpointer ret = NULL;
 225         guint32 namelen;
 226         gint32 offset;
 227
 228         /* w32 seems to guarantee that opening named objects can't
 229          * race each other
 230          */
 231         thr_ret = _wapi_namespace_lock ();
 232         g_assert (thr_ret == 0);
 233
 234         /* Need to blow away any old errors here, because code tests
 235          * for ERROR_ALREADY_EXISTS on success (!) to see if an event
 236          * was freshly created
 237          */
 238         SetLastError (ERROR_SUCCESS);
 239
 240         utf8_name = g_utf16_to_utf8 (name, -1, NULL, NULL, NULL);
 241
 242 #ifdef DEBUG
 243         g_message ("%s: Creating named event [%s]", __func__, utf8_name);
 244 #endif
 245
 246         offset = _wapi_search_handle_namespace (WAPI_HANDLE_NAMEDEVENT,
 247                                                 utf8_name);
 248         if (offset == -1) {
 249                 /* The name has already been used for a different
 250                  * object.
 251                  */
 252                 SetLastError (ERROR_INVALID_HANDLE);
 253                 goto cleanup;
 254         } else if (offset != 0) {
 255                 /* Not an error, but this is how the caller is
 256                  * informed that the event wasn't freshly created
 257                  */
 258                 SetLastError (ERROR_ALREADY_EXISTS);
 259         }
 260         /* Fall through to create the event handle. */
 261
 262         if (offset == 0) {
 263                 /* A new named event, so create both the private and
 264                  * shared parts
 265                  */
 266
 267                 if (strlen (utf8_name) < MAX_PATH) {
 268                         namelen = strlen (utf8_name);
 269                 } else {
 270                         namelen = MAX_PATH;
 271                 }
 272
 273                 memcpy (&namedevent_handle.sharedns.name, utf8_name, namelen);
 274
 275                 namedevent_handle.manual = manual;
 276                 namedevent_handle.set_count = 0;
 277
 278                 if (initial == TRUE) {
 279                         if (manual == FALSE) {
 280                                 namedevent_handle.set_count = 1;
 281                         }
 282                 }
 283
 284                 handle = _wapi_handle_new (WAPI_HANDLE_NAMEDEVENT,
 285                                            &namedevent_handle);
 286         } else {
 287                 /* A new reference to an existing named event, so just
 288                  * create the private part
 289                  */
 290                 handle = _wapi_handle_new_from_offset (WAPI_HANDLE_NAMEDEVENT,
 291                                                        offset, TRUE);
 292         }
 293
 294         if (handle == _WAPI_HANDLE_INVALID) {
 295                 g_warning ("%s: error creating event handle", __func__);
 296                 SetLastError (ERROR_GEN_FAILURE);
 297                 goto cleanup;
 298         }
 299         ret = handle;
 300
 301         if (offset == 0) {
 302                 /* Set the initial state, as this is a completely new
 303                  * handle
 304                  */
 305                 thr_ret = _wapi_handle_lock_shared_handles ();
 306                 g_assert (thr_ret == 0);
 307
 308                 if (initial == TRUE) {
 309                         _wapi_shared_handle_set_signal_state (handle, TRUE);
 310                 }
 311
 312                 _wapi_handle_unlock_shared_handles ();
 313         }
 314
 315 #ifdef DEBUG
 316         g_message ("%s: returning event handle %p", __func__, handle);
 317 #endif
 318
 319 cleanup:
 320         g_free (utf8_name);
 321
 322         _wapi_namespace_unlock (NULL);
 323
 324         return(ret);
 325
 326 }
 327
 328
 329 /**
 330  * CreateEvent:
 331  * @security: Ignored for now.
 332  * @manual: Specifies whether the new event handle has manual or auto
 333  * reset behaviour.
 334  * @initial: Specifies whether the new event handle is initially
 335  * signalled or not.
 336  * @name:Pointer to a string specifying the name of this name, or
 337  * %NULL.  Currently ignored.
 338  *
 339  * Creates a new event handle.
 340  *
 341  * An event handle is signalled with SetEvent().  If the new handle is
 342  * a manual reset event handle, it remains signalled until it is reset
 343  * with ResetEvent().  An auto reset event remains signalled until a
 344  * single thread has waited for it, at which time the event handle is
 345  * automatically reset to unsignalled.
 346  *
 347  * Return value: A new handle, or %NULL on error.
 348  */
 349 gpointer CreateEvent(WapiSecurityAttributes *security G_GNUC_UNUSED,
 350                      gboolean manual, gboolean initial,
 351                      const gunichar2 *name G_GNUC_UNUSED)
 352 {
 353         mono_once (&event_ops_once, event_ops_init);
 354
 355         if (name == NULL) {
 356                 return(event_create (security, manual, initial));
 357         } else {
 358                 return(namedevent_create (security, manual, initial, name));
 359         }
 360 }
 361
 362 static gboolean event_pulse (gpointer handle)
 363 {
 364         struct _WapiHandle_event *event_handle;
 365         gboolean ok;
 366         int thr_ret;
 367
 368         ok = _wapi_lookup_handle (handle, WAPI_HANDLE_EVENT,
 369                                   (gpointer *)&event_handle);
 370         if (ok == FALSE) {
 371                 g_warning ("%s: error looking up event handle %p", __func__,
 372                            handle);
 373                 return(FALSE);
 374         }
 375
 376         pthread_cleanup_push ((void(*)(void *))_wapi_handle_unlock_handle,
 377                               handle);
 378         thr_ret = _wapi_handle_lock_handle (handle);
 379         g_assert (thr_ret == 0);
 380
 381 #ifdef DEBUG
 382         g_message ("%s: Pulsing event handle %p", __func__, handle);
 383 #endif
 384
 385         if (event_handle->manual == TRUE) {
 386                 _wapi_handle_set_signal_state (handle, TRUE, TRUE);
 387         } else {
 388                 event_handle->set_count = 1;
 389                 _wapi_handle_set_signal_state (handle, TRUE, FALSE);
 390         }
 391
 392         thr_ret = _wapi_handle_unlock_handle (handle);
 393         g_assert (thr_ret == 0);
 394
 395         pthread_cleanup_pop (0);
 396
 397         if (event_handle->manual == TRUE) {
 398                 /* For a manual-reset event, we're about to try and
 399                  * get the handle lock again, so give other threads a
 400                  * chance
 401                  */
 402                 sched_yield ();
 403
 404                 /* Reset the handle signal state */
 405                 /* I'm not sure whether or not we need a barrier here
 406                  * to make sure that all threads waiting on the event
 407                  * have proceeded.  Currently we rely on broadcasting
 408                  * a condition.
 409                  */
 410 #ifdef DEBUG
 411                 g_message ("%s: Obtained write lock on event handle %p",
 412                            __func__, handle);
 413 #endif
 414
 415                 pthread_cleanup_push ((void(*)(void *))_wapi_handle_unlock_handle, handle);
 416                 thr_ret = _wapi_handle_lock_handle (handle);
 417                 g_assert (thr_ret == 0);
 418
 419                 _wapi_handle_set_signal_state (handle, FALSE, FALSE);
 420
 421                 thr_ret = _wapi_handle_unlock_handle (handle);
 422                 g_assert (thr_ret == 0);
 423                 pthread_cleanup_pop (0);
 424         }
 425
 426         return(TRUE);
 427 }
 428
 429 static gboolean namedevent_pulse (gpointer handle)
 430 {
 431         struct _WapiHandle_namedevent *namedevent_handle;
 432         gboolean ok;
 433         int thr_ret;
 434
 435         ok = _wapi_lookup_handle (handle, WAPI_HANDLE_NAMEDEVENT,
 436                                   (gpointer *)&namedevent_handle);
 437         if (ok == FALSE) {
 438                 g_warning ("%s: error looking up named event handle %p",
 439                            __func__, handle);
 440                 return(FALSE);
 441         }
 442
 443         thr_ret = _wapi_handle_lock_shared_handles ();
 444         g_assert (thr_ret == 0);
 445
 446 #ifdef DEBUG
 447         g_message ("%s: Pulsing named event handle %p", __func__, handle);
 448 #endif
 449
 450         if (namedevent_handle->manual == TRUE) {
 451                 _wapi_shared_handle_set_signal_state (handle, TRUE);
 452         } else {
 453                 namedevent_handle->set_count = 1;
 454                 _wapi_shared_handle_set_signal_state (handle, TRUE);
 455         }
 456
 457         _wapi_handle_unlock_shared_handles ();
 458
 459         if (namedevent_handle->manual == TRUE) {
 460                 /* For a manual-reset event, we're about to try and
 461                  * get the handle lock again, so give other processes
 462                  * a chance
 463                  */
 464                 _wapi_handle_spin (200);
 465
 466                 /* Reset the handle signal state */
 467                 /* I'm not sure whether or not we need a barrier here
 468                  * to make sure that all threads waiting on the event
 469                  * have proceeded.  Currently we rely on waiting for
 470                  * twice the shared handle poll interval.
 471                  */
 472 #ifdef DEBUG
 473                 g_message ("%s: Obtained write lock on event handle %p",
 474                            __func__, handle);
 475 #endif
 476
 477                 thr_ret = _wapi_handle_lock_shared_handles ();
 478                 g_assert (thr_ret == 0);
 479
 480                 _wapi_shared_handle_set_signal_state (handle, FALSE);
 481
 482                 _wapi_handle_unlock_shared_handles ();
 483         }
 484
 485         return(TRUE);
 486 }
 487
 488 /**
 489  * PulseEvent:
 490  * @handle: The event handle.
 491  *
 492  * Sets the event handle @handle to the signalled state, and then
 493  * resets it to unsignalled after informing any waiting threads.
 494  *
 495  * If @handle is a manual reset event, all waiting threads that can be
 496  * released immediately are released.  @handle is then reset.  If
 497  * @handle is an auto reset event, one waiting thread is released even
 498  * if multiple threads are waiting.
 499  *
 500  * Return value: %TRUE on success, %FALSE otherwise.  (Currently only
 501  * ever returns %TRUE).
 502  */
 503 gboolean PulseEvent(gpointer handle)
 504 {
 505         WapiHandleType type;
 506
 507         if (handle == NULL) {
 508                 SetLastError (ERROR_INVALID_HANDLE);
 509                 return(FALSE);
 510         }
 511
 512         type = _wapi_handle_type (handle);
 513
 514         if (event_ops[type].pulse == NULL) {
 515                 SetLastError (ERROR_INVALID_HANDLE);
 516                 return(FALSE);
 517         }
 518
 519         return(event_ops[type].pulse (handle));
 520 }
 521
 522 static gboolean event_reset (gpointer handle)
 523 {
 524         struct _WapiHandle_event *event_handle;
 525         gboolean ok;
 526         int thr_ret;
 527
 528         ok = _wapi_lookup_handle (handle, WAPI_HANDLE_EVENT,
 529                                   (gpointer *)&event_handle);
 530         if (ok == FALSE) {
 531                 g_warning ("%s: error looking up event handle %p",
 532                            __func__, handle);
 533                 return(FALSE);
 534         }
 535
 536 #ifdef DEBUG
 537         g_message ("%s: Resetting event handle %p", __func__, handle);
 538 #endif
 539
 540         pthread_cleanup_push ((void(*)(void *))_wapi_handle_unlock_handle,
 541                               handle);
 542         thr_ret = _wapi_handle_lock_handle (handle);
 543         g_assert (thr_ret == 0);
 544
 545         if (_wapi_handle_issignalled (handle) == FALSE) {
 546 #ifdef DEBUG
 547                 g_message ("%s: No need to reset event handle %p", __func__,
 548                            handle);
 549 #endif
 550         } else {
 551 #ifdef DEBUG
 552                 g_message ("%s: Obtained write lock on event handle %p",
 553                            __func__, handle);
 554 #endif
 555
 556                 _wapi_handle_set_signal_state (handle, FALSE, FALSE);
 557         }
 558
 559         event_handle->set_count = 0;
 560
 561         thr_ret = _wapi_handle_unlock_handle (handle);
 562         g_assert (thr_ret == 0);
 563
 564         pthread_cleanup_pop (0);
 565
 566         return(TRUE);
 567 }
 568
 569 static gboolean namedevent_reset (gpointer handle)
 570 {
 571         struct _WapiHandle_namedevent *namedevent_handle;
 572         gboolean ok;
 573         int thr_ret;
 574
 575         ok = _wapi_lookup_handle (handle, WAPI_HANDLE_NAMEDEVENT,
 576                                   (gpointer *)&namedevent_handle);
 577         if (ok == FALSE) {
 578                 g_warning ("%s: error looking up named event handle %p",
 579                            __func__, handle);
 580                 return(FALSE);
 581         }
 582
 583 #ifdef DEBUG
 584         g_message ("%s: Resetting named event handle %p", __func__, handle);
 585 #endif
 586
 587         thr_ret = _wapi_handle_lock_shared_handles ();
 588         g_assert (thr_ret == 0);
 589
 590         if (_wapi_handle_issignalled (handle) == FALSE) {
 591 #ifdef DEBUG
 592                 g_message ("%s: No need to reset named event handle %p",
 593                            __func__, handle);
 594 #endif
 595         } else {
 596 #ifdef DEBUG
 597                 g_message ("%s: Obtained write lock on named event handle %p",
 598                            __func__, handle);
 599 #endif
 600
 601                 _wapi_shared_handle_set_signal_state (handle, FALSE);
 602         }
 603
 604         namedevent_handle->set_count = 0;
 605
 606         _wapi_handle_unlock_shared_handles ();
 607
 608         return(TRUE);
 609 }
 610
 611 /**
 612  * ResetEvent:
 613  * @handle: The event handle.
 614  *
 615  * Resets the event handle @handle to the unsignalled state.
 616  *
 617  * Return value: %TRUE on success, %FALSE otherwise.  (Currently only
 618  * ever returns %TRUE).
 619  */
 620 gboolean ResetEvent(gpointer handle)
 621 {
 622         WapiHandleType type;
 623
 624         if (handle == NULL) {
 625                 SetLastError (ERROR_INVALID_HANDLE);
 626                 return(FALSE);
 627         }
 628
 629         type = _wapi_handle_type (handle);
 630
 631         if (event_ops[type].reset == NULL) {
 632                 SetLastError (ERROR_INVALID_HANDLE);
 633                 return(FALSE);
 634         }
 635
 636         return(event_ops[type].reset (handle));
 637 }
 638
 639 static gboolean event_set (gpointer handle)
 640 {
 641         struct _WapiHandle_event *event_handle;
 642         gboolean ok;
 643         int thr_ret;
 644
 645         ok = _wapi_lookup_handle (handle, WAPI_HANDLE_EVENT,
 646                                   (gpointer *)&event_handle);
 647         if (ok == FALSE) {
 648                 g_warning ("%s: error looking up event handle %p", __func__,
 649                            handle);
 650                 return(FALSE);
 651         }
 652
 653         pthread_cleanup_push ((void(*)(void *))_wapi_handle_unlock_handle,
 654                               handle);
 655         thr_ret = _wapi_handle_lock_handle (handle);
 656         g_assert (thr_ret == 0);
 657
 658 #ifdef DEBUG
 659         g_message ("%s: Setting event handle %p", __func__, handle);
 660 #endif
 661
 662         if (event_handle->manual == TRUE) {
 663                 _wapi_handle_set_signal_state (handle, TRUE, TRUE);
 664         } else {
 665                 event_handle->set_count = 1;
 666                 _wapi_handle_set_signal_state (handle, TRUE, FALSE);
 667         }
 668
 669         thr_ret = _wapi_handle_unlock_handle (handle);
 670         g_assert (thr_ret == 0);
 671
 672         pthread_cleanup_pop (0);
 673
 674         return(TRUE);
 675 }
 676
 677 static gboolean namedevent_set (gpointer handle)
 678 {
 679         struct _WapiHandle_namedevent *namedevent_handle;
 680         gboolean ok;
 681         int thr_ret;
 682
 683         ok = _wapi_lookup_handle (handle, WAPI_HANDLE_NAMEDEVENT,
 684                                   (gpointer *)&namedevent_handle);
 685         if (ok == FALSE) {
 686                 g_warning ("%s: error looking up named event handle %p",
 687                            __func__, handle);
 688                 return(FALSE);
 689         }
 690
 691         thr_ret = _wapi_handle_lock_shared_handles ();
 692         g_assert (thr_ret == 0);
 693
 694 #ifdef DEBUG
 695         g_message ("%s: Setting named event handle %p", __func__, handle);
 696 #endif
 697
 698         if (namedevent_handle->manual == TRUE) {
 699                 _wapi_shared_handle_set_signal_state (handle, TRUE);
 700         } else {
 701                 namedevent_handle->set_count = 1;
 702                 _wapi_shared_handle_set_signal_state (handle, TRUE);
 703         }
 704
 705         _wapi_handle_unlock_shared_handles ();
 706
 707         return(TRUE);
 708 }
 709
 710 /**
 711  * SetEvent:
 712  * @handle: The event handle
 713  *
 714  * Sets the event handle @handle to the signalled state.
 715  *
 716  * If @handle is a manual reset event, it remains signalled until it
 717  * is reset with ResetEvent().  An auto reset event remains signalled
 718  * until a single thread has waited for it, at which time @handle is
 719  * automatically reset to unsignalled.
 720  *
 721  * Return value: %TRUE on success, %FALSE otherwise.  (Currently only
 722  * ever returns %TRUE).
 723  */
 724 gboolean SetEvent(gpointer handle)
 725 {
 726         WapiHandleType type;
 727
 728         if (handle == NULL) {
 729                 SetLastError (ERROR_INVALID_HANDLE);
 730                 return(FALSE);
 731         }
 732
 733         type = _wapi_handle_type (handle);
 734
 735         if (event_ops[type].set == NULL) {
 736                 SetLastError (ERROR_INVALID_HANDLE);
 737                 return(FALSE);
 738         }
 739
 740         return(event_ops[type].set (handle));
 741 }
 742
 743 gpointer OpenEvent (guint32 access G_GNUC_UNUSED, gboolean inherit G_GNUC_UNUSED, const gunichar2 *name)
 744 {
 745         gpointer handle;
 746         gchar *utf8_name;
 747         int thr_ret;
 748         gpointer ret = NULL;
 749         gint32 offset;
 750
 751         mono_once (&event_ops_once, event_ops_init);
 752
 753         /* w32 seems to guarantee that opening named objects can't
 754          * race each other
 755          */
 756         thr_ret = _wapi_namespace_lock ();
 757         g_assert (thr_ret == 0);
 758
 759         utf8_name = g_utf16_to_utf8 (name, -1, NULL, NULL, NULL);
 760
 761 #ifdef DEBUG
 762         g_message ("%s: Opening named event [%s]", __func__, utf8_name);
 763 #endif
 764
 765         offset = _wapi_search_handle_namespace (WAPI_HANDLE_NAMEDEVENT,
 766                                                 utf8_name);
 767         if (offset == -1) {
 768                 /* The name has already been used for a different
 769                  * object.
 770                  */
 771                 SetLastError (ERROR_INVALID_HANDLE);
 772                 goto cleanup;
 773         } else if (offset == 0) {
 774                 /* This name doesn't exist */
 775                 SetLastError (ERROR_FILE_NOT_FOUND);    /* yes, really */
 776                 goto cleanup;
 777         }
 778
 779         /* A new reference to an existing named event, so just create
 780          * the private part
 781          */
 782         handle = _wapi_handle_new_from_offset (WAPI_HANDLE_NAMEDEVENT, offset,
 783                                                TRUE);
 784
 785         if (handle == _WAPI_HANDLE_INVALID) {
 786                 g_warning ("%s: error opening named event handle", __func__);
 787                 SetLastError (ERROR_GEN_FAILURE);
 788                 goto cleanup;
 789         }
 790         ret = handle;
 791
 792 #ifdef DEBUG
 793         g_message ("%s: returning named event handle %p", __func__, handle);
 794 #endif
 795
 796 cleanup:
 797         g_free (utf8_name);
 798
 799         _wapi_namespace_unlock (NULL);
 800
 801         return(ret);
 802
 803 }