1 /* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
2 /* dbus-pending-call.c Object representing a call in progress.
3 *
4 * Copyright (C) 2002, 2003 Red Hat Inc.
5 *
6 * Licensed under the Academic Free License version 2.1
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21 *
22 */
23
24 #include <config.h>
25 #include "dbus-internals.h"
26 #include "dbus-connection-internal.h"
27 #include "dbus-message-internal.h"
28 #include "dbus-pending-call-internal.h"
29 #include "dbus-pending-call.h"
30 #include "dbus-list.h"
31 #include "dbus-threads.h"
32 #include "dbus-test.h"
33
34 /**
35 * @defgroup DBusPendingCallInternals DBusPendingCall implementation details
36 * @ingroup DBusInternals
37 * @brief DBusPendingCall private implementation details.
38 *
39 * The guts of DBusPendingCall and its methods.
40 *
41 * @{
42 */
43
44 /**
45 * @brief Internals of DBusPendingCall
46 *
47 * Opaque object representing a reply message that we're waiting for.
48 */
49
50 /**
51 * shorter and more visible way to write _dbus_connection_lock()
52 */
53 #define CONNECTION_LOCK(connection) _dbus_connection_lock(connection)
54 /**
55 * shorter and more visible way to write _dbus_connection_unlock()
56 */
57 #define CONNECTION_UNLOCK(connection) _dbus_connection_unlock(connection)
58
59 /**
60 * Implementation details of #DBusPendingCall - all fields are private.
61 */
62 struct DBusPendingCall
63 {
64 DBusAtomic refcount; /**< reference count */
65
66 DBusDataSlotList slot_list; /**< Data stored by allocated integer ID */
67
68 DBusPendingCallNotifyFunction function; /**< Notifier when reply arrives. */
69
70 DBusConnection *connection; /**< Connections we're associated with */
71 DBusMessage *reply; /**< Reply (after we've received it) */
72 DBusTimeout *timeout; /**< Timeout */
73
74 DBusList *timeout_link; /**< Preallocated timeout response */
75
76 dbus_uint32_t reply_serial; /**< Expected serial of reply */
77
78 /**
79 * TRUE if some thread has taken responsibility for completing this
80 * pending call: either the pending call has completed, or it is about
81 * to be completed. Protected by the connection lock.
82 */
83 unsigned int completed : 1;
84 /**
85 * TRUE if we have added the timeout. Protected by the connection lock.
86 */
87 unsigned int timeout_added : 1;
88 };
89
90 static void
_dbus_pending_call_trace_ref(DBusPendingCall * pending_call,int old_refcount,int new_refcount,const char * why)91 _dbus_pending_call_trace_ref (DBusPendingCall *pending_call,
92 int old_refcount,
93 int new_refcount,
94 const char *why)
95 {
96 #ifdef DBUS_ENABLE_VERBOSE_MODE
97 static int enabled = -1;
98
99 _dbus_trace_ref ("DBusPendingCall", pending_call, old_refcount,
100 new_refcount, why, "DBUS_PENDING_CALL_TRACE", &enabled);
101 #endif
102 }
103
104 static dbus_int32_t notify_user_data_slot = -1;
105
106 /**
107 * Creates a new pending reply object.
108 *
109 * @param connection connection where reply will arrive
110 * @param timeout_milliseconds length of timeout, -1 (or
111 * #DBUS_TIMEOUT_USE_DEFAULT) for default,
112 * #DBUS_TIMEOUT_INFINITE for no timeout
113 * @param timeout_handler timeout handler, takes pending call as data
114 * @returns a new #DBusPendingCall or #NULL if no memory.
115 */
116 DBusPendingCall*
_dbus_pending_call_new_unlocked(DBusConnection * connection,int timeout_milliseconds,DBusTimeoutHandler timeout_handler)117 _dbus_pending_call_new_unlocked (DBusConnection *connection,
118 int timeout_milliseconds,
119 DBusTimeoutHandler timeout_handler)
120 {
121 DBusPendingCall *pending;
122 DBusTimeout *timeout;
123
124 _dbus_assert (timeout_milliseconds >= 0 || timeout_milliseconds == -1);
125
126 if (timeout_milliseconds == -1)
127 timeout_milliseconds = _DBUS_DEFAULT_TIMEOUT_VALUE;
128
129 if (!dbus_pending_call_allocate_data_slot (¬ify_user_data_slot))
130 return NULL;
131
132 pending = dbus_new0 (DBusPendingCall, 1);
133
134 if (pending == NULL)
135 {
136 dbus_pending_call_free_data_slot (¬ify_user_data_slot);
137 return NULL;
138 }
139
140 if (timeout_milliseconds != DBUS_TIMEOUT_INFINITE)
141 {
142 timeout = _dbus_timeout_new (timeout_milliseconds,
143 timeout_handler,
144 pending, NULL);
145
146 if (timeout == NULL)
147 {
148 dbus_pending_call_free_data_slot (¬ify_user_data_slot);
149 dbus_free (pending);
150 return NULL;
151 }
152
153 pending->timeout = timeout;
154 }
155 else
156 {
157 pending->timeout = NULL;
158 }
159
160 _dbus_atomic_inc (&pending->refcount);
161 pending->connection = connection;
162 _dbus_connection_ref_unlocked (pending->connection);
163
164 _dbus_data_slot_list_init (&pending->slot_list);
165
166 _dbus_pending_call_trace_ref (pending, 0, 1, "new_unlocked");
167
168 return pending;
169 }
170
171 /**
172 * Sets the reply of a pending call with the given message,
173 * or if the message is #NULL, by timing out the pending call.
174 *
175 * @param pending the pending call
176 * @param message the message to complete the call with, or #NULL
177 * to time out the call
178 */
179 void
_dbus_pending_call_set_reply_unlocked(DBusPendingCall * pending,DBusMessage * message)180 _dbus_pending_call_set_reply_unlocked (DBusPendingCall *pending,
181 DBusMessage *message)
182 {
183 if (message == NULL)
184 {
185 message = pending->timeout_link->data;
186 _dbus_list_clear (&pending->timeout_link);
187 }
188 else
189 dbus_message_ref (message);
190
191 _dbus_verbose (" handing message %p (%s) to pending call serial %u\n",
192 message,
193 dbus_message_get_type (message) == DBUS_MESSAGE_TYPE_METHOD_RETURN ?
194 "method return" :
195 dbus_message_get_type (message) == DBUS_MESSAGE_TYPE_ERROR ?
196 "error" : "other type",
197 pending->reply_serial);
198
199 _dbus_assert (pending->reply == NULL);
200 _dbus_assert (pending->reply_serial == dbus_message_get_reply_serial (message));
201 pending->reply = message;
202 }
203
204 /**
205 * Sets the pending call to completed
206 *
207 * This method is called with the connection lock held, to protect
208 * pending->completed. It must be paired with a call to
209 * _dbus_pending_call_finish_completion() after the connection lock has
210 * been released.
211 *
212 * @param pending the pending call
213 */
214 void
_dbus_pending_call_start_completion_unlocked(DBusPendingCall * pending)215 _dbus_pending_call_start_completion_unlocked (DBusPendingCall *pending)
216 {
217 _dbus_assert (!pending->completed);
218
219 pending->completed = TRUE;
220 }
221
222 /**
223 * Call the notifier function for the pending call.
224 *
225 * This method must be called after the connection lock has been
226 * released, and must be paired with a call to
227 * _dbus_pending_call_start_completion_unlocked().
228 *
229 * @param pending the pending call
230 */
231 void
_dbus_pending_call_finish_completion(DBusPendingCall * pending)232 _dbus_pending_call_finish_completion (DBusPendingCall *pending)
233 {
234 _dbus_assert (pending->completed);
235
236 if (pending->function)
237 {
238 void *user_data;
239 user_data = dbus_pending_call_get_data (pending,
240 notify_user_data_slot);
241
242 (* pending->function) (pending, user_data);
243 }
244 }
245
246 /**
247 * If the pending call hasn't been timed out, add its timeout
248 * error reply to the connection's incoming message queue.
249 *
250 * @param pending the pending call
251 * @param connection the connection the call was sent to
252 */
253 void
_dbus_pending_call_queue_timeout_error_unlocked(DBusPendingCall * pending,DBusConnection * connection)254 _dbus_pending_call_queue_timeout_error_unlocked (DBusPendingCall *pending,
255 DBusConnection *connection)
256 {
257 _dbus_assert (connection == pending->connection);
258
259 if (pending->timeout_link)
260 {
261 _dbus_connection_queue_synthesized_message_link (connection,
262 pending->timeout_link);
263 pending->timeout_link = NULL;
264 }
265 }
266
267 /**
268 * Checks to see if a timeout has been added
269 *
270 * @param pending the pending_call
271 * @returns #TRUE if there is a timeout or #FALSE if not
272 */
273 dbus_bool_t
_dbus_pending_call_is_timeout_added_unlocked(DBusPendingCall * pending)274 _dbus_pending_call_is_timeout_added_unlocked (DBusPendingCall *pending)
275 {
276 _dbus_assert (pending != NULL);
277
278 return pending->timeout_added;
279 }
280
281
282 /**
283 * Sets wether the timeout has been added
284 *
285 * @param pending the pending_call
286 * @param is_added whether or not a timeout is added
287 */
288 void
_dbus_pending_call_set_timeout_added_unlocked(DBusPendingCall * pending,dbus_bool_t is_added)289 _dbus_pending_call_set_timeout_added_unlocked (DBusPendingCall *pending,
290 dbus_bool_t is_added)
291 {
292 _dbus_assert (pending != NULL);
293
294 pending->timeout_added = is_added;
295 }
296
297
298 /**
299 * Retrives the timeout
300 *
301 * @param pending the pending_call
302 * @returns a timeout object or NULL if call has no timeout
303 */
304 DBusTimeout *
_dbus_pending_call_get_timeout_unlocked(DBusPendingCall * pending)305 _dbus_pending_call_get_timeout_unlocked (DBusPendingCall *pending)
306 {
307 _dbus_assert (pending != NULL);
308
309 return pending->timeout;
310 }
311
312 /**
313 * Gets the reply's serial number
314 *
315 * @param pending the pending_call
316 * @returns a serial number for the reply or 0
317 */
318 dbus_uint32_t
_dbus_pending_call_get_reply_serial_unlocked(DBusPendingCall * pending)319 _dbus_pending_call_get_reply_serial_unlocked (DBusPendingCall *pending)
320 {
321 _dbus_assert (pending != NULL);
322
323 return pending->reply_serial;
324 }
325
326 /**
327 * Sets the reply's serial number
328 *
329 * @param pending the pending_call
330 * @param serial the serial number
331 */
332 void
_dbus_pending_call_set_reply_serial_unlocked(DBusPendingCall * pending,dbus_uint32_t serial)333 _dbus_pending_call_set_reply_serial_unlocked (DBusPendingCall *pending,
334 dbus_uint32_t serial)
335 {
336 _dbus_assert (pending != NULL);
337 _dbus_assert (pending->reply_serial == 0);
338
339 pending->reply_serial = serial;
340 }
341
342 /**
343 * Gets the connection associated with this pending call.
344 *
345 * @param pending the pending_call
346 * @returns the connection associated with the pending call
347 */
348 DBusConnection *
_dbus_pending_call_get_connection_and_lock(DBusPendingCall * pending)349 _dbus_pending_call_get_connection_and_lock (DBusPendingCall *pending)
350 {
351 _dbus_assert (pending != NULL);
352
353 CONNECTION_LOCK (pending->connection);
354 return pending->connection;
355 }
356
357 /**
358 * Gets the connection associated with this pending call.
359 *
360 * @param pending the pending_call
361 * @returns the connection associated with the pending call
362 */
363 DBusConnection *
_dbus_pending_call_get_connection_unlocked(DBusPendingCall * pending)364 _dbus_pending_call_get_connection_unlocked (DBusPendingCall *pending)
365 {
366 _dbus_assert (pending != NULL);
367
368 return pending->connection;
369 }
370
371 /**
372 * Sets the reply message associated with the pending call to a timeout error
373 *
374 * @param pending the pending_call
375 * @param message the message we are sending the error reply to
376 * @param serial serial number for the reply
377 * @return #FALSE on OOM
378 */
379 dbus_bool_t
_dbus_pending_call_set_timeout_error_unlocked(DBusPendingCall * pending,DBusMessage * message,dbus_uint32_t serial)380 _dbus_pending_call_set_timeout_error_unlocked (DBusPendingCall *pending,
381 DBusMessage *message,
382 dbus_uint32_t serial)
383 {
384 DBusList *reply_link;
385 DBusMessage *reply;
386
387 reply = dbus_message_new_error (message, DBUS_ERROR_NO_REPLY,
388 "Did not receive a reply. Possible causes include: "
389 "the remote application did not send a reply, "
390 "the message bus security policy blocked the reply, "
391 "the reply timeout expired, or "
392 "the network connection was broken.");
393 if (reply == NULL)
394 return FALSE;
395
396 reply_link = _dbus_list_alloc_link (reply);
397 if (reply_link == NULL)
398 {
399 /* it's OK to unref this, nothing that could have attached a callback
400 * has ever seen it */
401 dbus_message_unref (reply);
402 return FALSE;
403 }
404
405 pending->timeout_link = reply_link;
406
407 _dbus_pending_call_set_reply_serial_unlocked (pending, serial);
408
409 return TRUE;
410 }
411
412 /**
413 * Increments the reference count on a pending call,
414 * while the lock on its connection is already held.
415 *
416 * @param pending the pending call object
417 * @returns the pending call object
418 */
419 DBusPendingCall *
_dbus_pending_call_ref_unlocked(DBusPendingCall * pending)420 _dbus_pending_call_ref_unlocked (DBusPendingCall *pending)
421 {
422 dbus_int32_t old_refcount;
423
424 old_refcount = _dbus_atomic_inc (&pending->refcount);
425 _dbus_pending_call_trace_ref (pending, old_refcount, old_refcount + 1,
426 "ref_unlocked");
427
428 return pending;
429 }
430
431
432 static void
_dbus_pending_call_last_unref(DBusPendingCall * pending)433 _dbus_pending_call_last_unref (DBusPendingCall *pending)
434 {
435 DBusConnection *connection;
436
437 /* If we get here, we should be already detached
438 * from the connection, or never attached.
439 */
440 _dbus_assert (!pending->timeout_added);
441
442 connection = pending->connection;
443
444 /* this assumes we aren't holding connection lock... */
445 _dbus_data_slot_list_free (&pending->slot_list);
446
447 if (pending->timeout != NULL)
448 _dbus_timeout_unref (pending->timeout);
449
450 if (pending->timeout_link)
451 {
452 dbus_message_unref ((DBusMessage *)pending->timeout_link->data);
453 _dbus_list_free_link (pending->timeout_link);
454 pending->timeout_link = NULL;
455 }
456
457 if (pending->reply)
458 {
459 dbus_message_unref (pending->reply);
460 pending->reply = NULL;
461 }
462
463 dbus_free (pending);
464
465 dbus_pending_call_free_data_slot (¬ify_user_data_slot);
466
467 /* connection lock should not be held. */
468 /* Free the connection last to avoid a weird state while
469 * calling out to application code where the pending exists
470 * but not the connection.
471 */
472 dbus_connection_unref (connection);
473 }
474
475 /**
476 * Decrements the reference count on a pending call,
477 * freeing it if the count reaches 0. Assumes
478 * connection lock is already held.
479 *
480 * @param pending the pending call object
481 */
482 void
_dbus_pending_call_unref_and_unlock(DBusPendingCall * pending)483 _dbus_pending_call_unref_and_unlock (DBusPendingCall *pending)
484 {
485 dbus_int32_t old_refcount;
486
487 old_refcount = _dbus_atomic_dec (&pending->refcount);
488 _dbus_assert (old_refcount > 0);
489 _dbus_pending_call_trace_ref (pending, old_refcount,
490 old_refcount - 1, "unref_and_unlock");
491
492 CONNECTION_UNLOCK (pending->connection);
493
494 if (old_refcount == 1)
495 _dbus_pending_call_last_unref (pending);
496 }
497
498 /**
499 * Checks whether the pending call has received a reply
500 * yet, or not. Assumes connection lock is held.
501 *
502 * @param pending the pending call
503 * @returns #TRUE if a reply has been received
504 */
505 dbus_bool_t
_dbus_pending_call_get_completed_unlocked(DBusPendingCall * pending)506 _dbus_pending_call_get_completed_unlocked (DBusPendingCall *pending)
507 {
508 return pending->completed;
509 }
510
511 static DBusDataSlotAllocator slot_allocator =
512 _DBUS_DATA_SLOT_ALLOCATOR_INIT (_DBUS_LOCK_NAME (pending_call_slots));
513
514 /**
515 * Stores a pointer on a #DBusPendingCall, along
516 * with an optional function to be used for freeing
517 * the data when the data is set again, or when
518 * the pending call is finalized. The slot number
519 * must have been allocated with dbus_pending_call_allocate_data_slot().
520 *
521 * @param pending the pending_call
522 * @param slot the slot number
523 * @param data the data to store
524 * @param free_data_func finalizer function for the data
525 * @returns #TRUE if there was enough memory to store the data
526 */
527 dbus_bool_t
_dbus_pending_call_set_data_unlocked(DBusPendingCall * pending,dbus_int32_t slot,void * data,DBusFreeFunction free_data_func)528 _dbus_pending_call_set_data_unlocked (DBusPendingCall *pending,
529 dbus_int32_t slot,
530 void *data,
531 DBusFreeFunction free_data_func)
532 {
533 DBusFreeFunction old_free_func;
534 void *old_data;
535 dbus_bool_t retval;
536
537 retval = _dbus_data_slot_list_set (&slot_allocator,
538 &pending->slot_list,
539 slot, data, free_data_func,
540 &old_free_func, &old_data);
541
542 /* Drop locks to call out to app code */
543 CONNECTION_UNLOCK (pending->connection);
544
545 if (retval)
546 {
547 if (old_free_func)
548 (* old_free_func) (old_data);
549 }
550
551 CONNECTION_LOCK (pending->connection);
552
553 return retval;
554 }
555
556 /** @} */
557
558 /**
559 * @defgroup DBusPendingCall DBusPendingCall
560 * @ingroup DBus
561 * @brief Pending reply to a method call message
562 *
563 * A DBusPendingCall is an object representing an
564 * expected reply. A #DBusPendingCall can be created
565 * when you send a message that should have a reply.
566 *
567 * @{
568 */
569
570 /**
571 * @def DBUS_TIMEOUT_INFINITE
572 *
573 * An integer constant representing an infinite timeout. This has the
574 * numeric value 0x7fffffff (the largest 32-bit signed integer).
575 *
576 * For source compatibility with D-Bus versions earlier than 1.4.12, use
577 * 0x7fffffff, or INT32_MAX (assuming your platform has it).
578 */
579
580 /**
581 * @def DBUS_TIMEOUT_USE_DEFAULT
582 *
583 * An integer constant representing a request to use the default timeout.
584 * This has numeric value -1.
585 *
586 * For source compatibility with D-Bus versions earlier than 1.4.12, use a
587 * literal -1.
588 */
589
590 /**
591 * @typedef DBusPendingCall
592 *
593 * Opaque data type representing a message pending.
594 */
595
596 /**
597 * Increments the reference count on a pending call.
598 *
599 * @param pending the pending call object
600 * @returns the pending call object
601 */
602 DBusPendingCall *
dbus_pending_call_ref(DBusPendingCall * pending)603 dbus_pending_call_ref (DBusPendingCall *pending)
604 {
605 dbus_int32_t old_refcount;
606
607 _dbus_return_val_if_fail (pending != NULL, NULL);
608
609 old_refcount = _dbus_atomic_inc (&pending->refcount);
610 _dbus_pending_call_trace_ref (pending, old_refcount, old_refcount + 1,
611 "ref");
612
613 return pending;
614 }
615
616 /**
617 * Decrements the reference count on a pending call,
618 * freeing it if the count reaches 0.
619 *
620 * @param pending the pending call object
621 */
622 void
dbus_pending_call_unref(DBusPendingCall * pending)623 dbus_pending_call_unref (DBusPendingCall *pending)
624 {
625 dbus_int32_t old_refcount;
626
627 _dbus_return_if_fail (pending != NULL);
628
629 old_refcount = _dbus_atomic_dec (&pending->refcount);
630 _dbus_pending_call_trace_ref (pending, old_refcount, old_refcount - 1,
631 "unref");
632
633 if (old_refcount == 1)
634 _dbus_pending_call_last_unref(pending);
635 }
636
637 /**
638 * Sets a notification function to be called when the reply is
639 * received or the pending call times out.
640 *
641 * @param pending the pending call
642 * @param function notifier function
643 * @param user_data data to pass to notifier function
644 * @param free_user_data function to free the user data
645 * @returns #FALSE if not enough memory
646 */
647 dbus_bool_t
dbus_pending_call_set_notify(DBusPendingCall * pending,DBusPendingCallNotifyFunction function,void * user_data,DBusFreeFunction free_user_data)648 dbus_pending_call_set_notify (DBusPendingCall *pending,
649 DBusPendingCallNotifyFunction function,
650 void *user_data,
651 DBusFreeFunction free_user_data)
652 {
653 dbus_bool_t ret = FALSE;
654
655 _dbus_return_val_if_fail (pending != NULL, FALSE);
656
657 CONNECTION_LOCK (pending->connection);
658
659 /* could invoke application code! */
660 if (!_dbus_pending_call_set_data_unlocked (pending, notify_user_data_slot,
661 user_data, free_user_data))
662 goto out;
663
664 pending->function = function;
665 ret = TRUE;
666
667 out:
668 CONNECTION_UNLOCK (pending->connection);
669
670 return ret;
671 }
672
673 /**
674 * Cancels the pending call, such that any reply or error received
675 * will just be ignored. Drops the dbus library's internal reference
676 * to the #DBusPendingCall so will free the call if nobody else is
677 * holding a reference. However you usually get a reference from
678 * dbus_connection_send_with_reply() so probably your app owns a ref
679 * also.
680 *
681 * Note that canceling a pending call will <em>not</em> simulate a
682 * timed-out call; if a call times out, then a timeout error reply is
683 * received. If you cancel the call, no reply is received unless the
684 * the reply was already received before you canceled.
685 *
686 * @param pending the pending call
687 */
688 void
dbus_pending_call_cancel(DBusPendingCall * pending)689 dbus_pending_call_cancel (DBusPendingCall *pending)
690 {
691 _dbus_return_if_fail (pending != NULL);
692
693 _dbus_connection_remove_pending_call (pending->connection,
694 pending);
695 }
696
697 /**
698 * Checks whether the pending call has received a reply
699 * yet, or not.
700 *
701 * @param pending the pending call
702 * @returns #TRUE if a reply has been received
703 */
704 dbus_bool_t
dbus_pending_call_get_completed(DBusPendingCall * pending)705 dbus_pending_call_get_completed (DBusPendingCall *pending)
706 {
707 dbus_bool_t completed;
708
709 _dbus_return_val_if_fail (pending != NULL, FALSE);
710
711 CONNECTION_LOCK (pending->connection);
712 completed = pending->completed;
713 CONNECTION_UNLOCK (pending->connection);
714
715 return completed;
716 }
717
718 /**
719 * Gets the reply, or returns #NULL if none has been received
720 * yet. Ownership of the reply message passes to the caller. This
721 * function can only be called once per pending call, since the reply
722 * message is tranferred to the caller.
723 *
724 * @param pending the pending call
725 * @returns the reply message or #NULL.
726 */
727 DBusMessage*
dbus_pending_call_steal_reply(DBusPendingCall * pending)728 dbus_pending_call_steal_reply (DBusPendingCall *pending)
729 {
730 DBusMessage *message;
731
732 _dbus_return_val_if_fail (pending != NULL, NULL);
733 _dbus_return_val_if_fail (pending->completed, NULL);
734 _dbus_return_val_if_fail (pending->reply != NULL, NULL);
735
736 CONNECTION_LOCK (pending->connection);
737
738 message = pending->reply;
739 pending->reply = NULL;
740
741 CONNECTION_UNLOCK (pending->connection);
742
743 _dbus_message_trace_ref (message, -1, -1, "dbus_pending_call_steal_reply");
744 return message;
745 }
746
747 /**
748 * Block until the pending call is completed. The blocking is as with
749 * dbus_connection_send_with_reply_and_block(); it does not enter the
750 * main loop or process other messages, it simply waits for the reply
751 * in question.
752 *
753 * If the pending call is already completed, this function returns
754 * immediately.
755 *
756 * @todo when you start blocking, the timeout is reset, but it should
757 * really only use time remaining since the pending call was created.
758 * This requires storing timestamps instead of intervals in the timeout
759 *
760 * @param pending the pending call
761 */
762 void
dbus_pending_call_block(DBusPendingCall * pending)763 dbus_pending_call_block (DBusPendingCall *pending)
764 {
765 _dbus_return_if_fail (pending != NULL);
766
767 _dbus_connection_block_pending_call (pending);
768 }
769
770 /**
771 * Allocates an integer ID to be used for storing application-specific
772 * data on any DBusPendingCall. The allocated ID may then be used
773 * with dbus_pending_call_set_data() and dbus_pending_call_get_data().
774 * The passed-in slot must be initialized to -1, and is filled in
775 * with the slot ID. If the passed-in slot is not -1, it's assumed
776 * to be already allocated, and its refcount is incremented.
777 *
778 * The allocated slot is global, i.e. all DBusPendingCall objects will
779 * have a slot with the given integer ID reserved.
780 *
781 * @param slot_p address of a global variable storing the slot
782 * @returns #FALSE on failure (no memory)
783 */
784 dbus_bool_t
dbus_pending_call_allocate_data_slot(dbus_int32_t * slot_p)785 dbus_pending_call_allocate_data_slot (dbus_int32_t *slot_p)
786 {
787 _dbus_return_val_if_fail (slot_p != NULL, FALSE);
788
789 return _dbus_data_slot_allocator_alloc (&slot_allocator,
790 slot_p);
791 }
792
793 /**
794 * Deallocates a global ID for #DBusPendingCall data slots.
795 * dbus_pending_call_get_data() and dbus_pending_call_set_data() may
796 * no longer be used with this slot. Existing data stored on existing
797 * DBusPendingCall objects will be freed when the #DBusPendingCall is
798 * finalized, but may not be retrieved (and may only be replaced if
799 * someone else reallocates the slot). When the refcount on the
800 * passed-in slot reaches 0, it is set to -1.
801 *
802 * @param slot_p address storing the slot to deallocate
803 */
804 void
dbus_pending_call_free_data_slot(dbus_int32_t * slot_p)805 dbus_pending_call_free_data_slot (dbus_int32_t *slot_p)
806 {
807 _dbus_return_if_fail (slot_p != NULL);
808 _dbus_return_if_fail (*slot_p >= 0);
809
810 _dbus_data_slot_allocator_free (&slot_allocator, slot_p);
811 }
812
813 /**
814 * Stores a pointer on a #DBusPendingCall, along
815 * with an optional function to be used for freeing
816 * the data when the data is set again, or when
817 * the pending call is finalized. The slot number
818 * must have been allocated with dbus_pending_call_allocate_data_slot().
819 *
820 * @param pending the pending_call
821 * @param slot the slot number
822 * @param data the data to store
823 * @param free_data_func finalizer function for the data
824 * @returns #TRUE if there was enough memory to store the data
825 */
826 dbus_bool_t
dbus_pending_call_set_data(DBusPendingCall * pending,dbus_int32_t slot,void * data,DBusFreeFunction free_data_func)827 dbus_pending_call_set_data (DBusPendingCall *pending,
828 dbus_int32_t slot,
829 void *data,
830 DBusFreeFunction free_data_func)
831 {
832 dbus_bool_t retval;
833
834 _dbus_return_val_if_fail (pending != NULL, FALSE);
835 _dbus_return_val_if_fail (slot >= 0, FALSE);
836
837
838 CONNECTION_LOCK (pending->connection);
839 retval = _dbus_pending_call_set_data_unlocked (pending, slot, data, free_data_func);
840 CONNECTION_UNLOCK (pending->connection);
841 return retval;
842 }
843
844 /**
845 * Retrieves data previously set with dbus_pending_call_set_data().
846 * The slot must still be allocated (must not have been freed).
847 *
848 * @param pending the pending_call
849 * @param slot the slot to get data from
850 * @returns the data, or #NULL if not found
851 */
852 void*
dbus_pending_call_get_data(DBusPendingCall * pending,dbus_int32_t slot)853 dbus_pending_call_get_data (DBusPendingCall *pending,
854 dbus_int32_t slot)
855 {
856 void *res;
857
858 _dbus_return_val_if_fail (pending != NULL, NULL);
859
860 CONNECTION_LOCK (pending->connection);
861 res = _dbus_data_slot_list_get (&slot_allocator,
862 &pending->slot_list,
863 slot);
864 CONNECTION_UNLOCK (pending->connection);
865
866 return res;
867 }
868
869 /** @} */
870