D-Bus 1.15.12
dbus-pending-call.c
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 * SPDX-License-Identifier: AFL-2.1 OR GPL-2.0-or-later
7 *
8 * Licensed under the Academic Free License version 2.1
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2 of the License, or
13 * (at your option) any later version.
14 *
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
19 *
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
23 *
24 */
25
26#include <config.h>
27#include "dbus-internals.h"
28#include "dbus-connection-internal.h"
29#include "dbus-message-internal.h"
30#include "dbus-pending-call-internal.h"
31#include "dbus-pending-call.h"
32#include "dbus-list.h"
33#include "dbus-threads.h"
34#include "dbus-test.h"
35
55#define CONNECTION_LOCK(connection) _dbus_connection_lock(connection)
59#define CONNECTION_UNLOCK(connection) _dbus_connection_unlock(connection)
60
91
92static void
93_dbus_pending_call_trace_ref (DBusPendingCall *pending_call,
94 int old_refcount,
95 int new_refcount,
96 const char *why)
97{
98#ifdef DBUS_ENABLE_VERBOSE_MODE
99 static int enabled = -1;
100
101 _dbus_trace_ref ("DBusPendingCall", pending_call, old_refcount,
102 new_refcount, why, "DBUS_PENDING_CALL_TRACE", &enabled);
103#endif
104}
105
106/* protected by _DBUS_LOCK_pending_call_slots */
107static dbus_int32_t notify_user_data_slot = -1;
108
121 int timeout_milliseconds,
122 DBusTimeoutHandler timeout_handler)
123{
124 DBusPendingCall *pending;
125 DBusTimeout *timeout;
126
127 _dbus_assert (timeout_milliseconds >= 0 || timeout_milliseconds == -1);
128
129 if (timeout_milliseconds == -1)
130 timeout_milliseconds = _DBUS_DEFAULT_TIMEOUT_VALUE;
131
132 if (!dbus_pending_call_allocate_data_slot (&notify_user_data_slot))
133 return NULL;
134
135 pending = dbus_new0 (DBusPendingCall, 1);
136
137 if (pending == NULL)
138 {
139 dbus_pending_call_free_data_slot (&notify_user_data_slot);
140 return NULL;
141 }
142
143 if (timeout_milliseconds != DBUS_TIMEOUT_INFINITE)
144 {
145 timeout = _dbus_timeout_new (timeout_milliseconds,
146 timeout_handler,
147 pending, NULL);
148
149 if (timeout == NULL)
150 {
151 dbus_pending_call_free_data_slot (&notify_user_data_slot);
152 dbus_free (pending);
153 return NULL;
154 }
155
156 pending->timeout = timeout;
157 }
158 else
159 {
160 pending->timeout = NULL;
161 }
162
163 _dbus_atomic_inc (&pending->refcount);
164 pending->connection = connection;
166
168
169 _dbus_pending_call_trace_ref (pending, 0, 1, "new_unlocked");
170
171 return pending;
172}
173
182void
184 DBusMessage *message)
185{
186 if (message == NULL)
187 {
188 message = pending->timeout_link->data;
189 _dbus_list_clear (&pending->timeout_link);
190 }
191 else
192 dbus_message_ref (message);
193
194 _dbus_verbose (" handing message %p (%s) to pending call serial %u\n",
195 message,
197 "method return" :
199 "error" : "other type",
200 pending->reply_serial);
201
202 _dbus_assert (pending->reply == NULL);
204 pending->reply = message;
205}
206
217void
224
234void
236{
237 _dbus_assert (pending->completed);
238
239 if (pending->function)
240 {
241 void *user_data;
242 user_data = dbus_pending_call_get_data (pending,
243 notify_user_data_slot);
244
245 (* pending->function) (pending, user_data);
246 }
247}
248
256void
258 DBusConnection *connection)
259{
260 _dbus_assert (connection == pending->connection);
261
262 if (pending->timeout_link)
263 {
265 pending->timeout_link);
266 pending->timeout_link = NULL;
267 }
268}
269
276dbus_bool_t
278{
279 _dbus_assert (pending != NULL);
280
281 return pending->timeout_added;
282}
283
284
291void
293 dbus_bool_t is_added)
294{
295 _dbus_assert (pending != NULL);
296
297 pending->timeout_added = is_added;
298}
299
300
309{
310 _dbus_assert (pending != NULL);
311
312 return pending->timeout;
313}
314
321dbus_uint32_t
323{
324 _dbus_assert (pending != NULL);
325
326 return pending->reply_serial;
327}
328
335void
337 dbus_uint32_t serial)
338{
339 _dbus_assert (pending != NULL);
340 _dbus_assert (pending->reply_serial == 0);
341
342 pending->reply_serial = serial;
343}
344
353{
354 _dbus_assert (pending != NULL);
355
356 CONNECTION_LOCK (pending->connection);
357 return pending->connection;
358}
359
368{
369 _dbus_assert (pending != NULL);
370
371 return pending->connection;
372}
373
382dbus_bool_t
384 DBusMessage *message,
385 dbus_uint32_t serial)
386{
387 DBusList *reply_link;
388 DBusMessage *reply;
389
391 "Did not receive a reply. Possible causes include: "
392 "the remote application did not send a reply, "
393 "the message bus security policy blocked the reply, "
394 "the reply timeout expired, or "
395 "the network connection was broken.");
396 if (reply == NULL)
397 return FALSE;
398
399 reply_link = _dbus_list_alloc_link (reply);
400 if (reply_link == NULL)
401 {
402 /* it's OK to unref this, nothing that could have attached a callback
403 * has ever seen it */
404 dbus_message_unref (reply);
405 return FALSE;
406 }
407
408 pending->timeout_link = reply_link;
409
411
412 return TRUE;
413}
414
424{
425 dbus_int32_t old_refcount;
426
427 old_refcount = _dbus_atomic_inc (&pending->refcount);
428 _dbus_pending_call_trace_ref (pending, old_refcount, old_refcount + 1,
429 "ref_unlocked");
430
431 return pending;
432}
433
434
435static void
436_dbus_pending_call_last_unref (DBusPendingCall *pending)
437{
438 DBusConnection *connection;
439
440 /* If we get here, we should be already detached
441 * from the connection, or never attached.
442 */
443 _dbus_assert (!pending->timeout_added);
444
445 connection = pending->connection;
446
447 /* this assumes we aren't holding connection lock... */
449
450 if (pending->timeout != NULL)
451 _dbus_timeout_unref (pending->timeout);
452
453 if (pending->timeout_link)
454 {
457 pending->timeout_link = NULL;
458 }
459
460 if (pending->reply)
461 {
462 dbus_message_unref (pending->reply);
463 pending->reply = NULL;
464 }
465
466 dbus_free (pending);
467
468 dbus_pending_call_free_data_slot (&notify_user_data_slot);
469
470 /* connection lock should not be held. */
471 /* Free the connection last to avoid a weird state while
472 * calling out to application code where the pending exists
473 * but not the connection.
474 */
475 dbus_connection_unref (connection);
476}
477
485void
487{
488 dbus_int32_t old_refcount;
489
490 old_refcount = _dbus_atomic_dec (&pending->refcount);
491 _dbus_assert (old_refcount > 0);
492 _dbus_pending_call_trace_ref (pending, old_refcount,
493 old_refcount - 1, "unref_and_unlock");
494
495 CONNECTION_UNLOCK (pending->connection);
496
497 if (old_refcount == 1)
498 _dbus_pending_call_last_unref (pending);
499}
500
508dbus_bool_t
513
514static DBusDataSlotAllocator slot_allocator =
515 _DBUS_DATA_SLOT_ALLOCATOR_INIT (_DBUS_LOCK_NAME (pending_call_slots));
516
530dbus_bool_t
532 dbus_int32_t slot,
533 void *data,
534 DBusFreeFunction free_data_func)
535{
536 DBusFreeFunction old_free_func;
537 void *old_data;
538 dbus_bool_t retval;
539
540 retval = _dbus_data_slot_list_set (&slot_allocator,
541 &pending->slot_list,
542 slot, data, free_data_func,
543 &old_free_func, &old_data);
544
545 /* Drop locks to call out to app code */
546 CONNECTION_UNLOCK (pending->connection);
547
548 if (retval)
549 {
550 if (old_free_func)
551 (* old_free_func) (old_data);
552 }
553
554 CONNECTION_LOCK (pending->connection);
555
556 return retval;
557}
558
607{
608 dbus_int32_t old_refcount;
609
610 _dbus_return_val_if_fail (pending != NULL, NULL);
611
612 old_refcount = _dbus_atomic_inc (&pending->refcount);
613 _dbus_pending_call_trace_ref (pending, old_refcount, old_refcount + 1,
614 "ref");
615
616 return pending;
617}
618
625void
627{
628 dbus_int32_t old_refcount;
629
630 _dbus_return_if_fail (pending != NULL);
631
632 old_refcount = _dbus_atomic_dec (&pending->refcount);
633 _dbus_pending_call_trace_ref (pending, old_refcount, old_refcount - 1,
634 "unref");
635
636 if (old_refcount == 1)
637 _dbus_pending_call_last_unref(pending);
638}
639
650dbus_bool_t
653 void *user_data,
654 DBusFreeFunction free_user_data)
655{
656 dbus_bool_t ret = FALSE;
657
658 _dbus_return_val_if_fail (pending != NULL, FALSE);
659
660 CONNECTION_LOCK (pending->connection);
661
662 /* could invoke application code! */
663 if (!_dbus_pending_call_set_data_unlocked (pending, notify_user_data_slot,
664 user_data, free_user_data))
665 goto out;
666
667 pending->function = function;
668 ret = TRUE;
669
670out:
671 CONNECTION_UNLOCK (pending->connection);
672
673 return ret;
674}
675
691void
693{
694 _dbus_return_if_fail (pending != NULL);
695
697 pending);
698}
699
707dbus_bool_t
709{
710 dbus_bool_t completed;
711
712 _dbus_return_val_if_fail (pending != NULL, FALSE);
713
714 CONNECTION_LOCK (pending->connection);
715 completed = pending->completed;
716 CONNECTION_UNLOCK (pending->connection);
717
718 return completed;
719}
720
732{
733 DBusMessage *message;
734
735 _dbus_return_val_if_fail (pending != NULL, NULL);
736 _dbus_return_val_if_fail (pending->completed, NULL);
737 _dbus_return_val_if_fail (pending->reply != NULL, NULL);
738
739 CONNECTION_LOCK (pending->connection);
740
741 message = pending->reply;
742 pending->reply = NULL;
743
744 CONNECTION_UNLOCK (pending->connection);
745
746 _dbus_message_trace_ref (message, -1, -1, "dbus_pending_call_steal_reply");
747 return message;
748}
749
765void
767{
768 _dbus_return_if_fail (pending != NULL);
769
771}
772
787dbus_bool_t
789{
790 _dbus_return_val_if_fail (slot_p != NULL, FALSE);
791
792 return _dbus_data_slot_allocator_alloc (&slot_allocator,
793 slot_p);
794}
795
807void
809{
810 _dbus_return_if_fail (slot_p != NULL);
811 _dbus_return_if_fail (*slot_p >= 0);
812
813 _dbus_data_slot_allocator_free (&slot_allocator, slot_p);
814}
815
829dbus_bool_t
831 dbus_int32_t slot,
832 void *data,
833 DBusFreeFunction free_data_func)
834{
835 dbus_bool_t retval;
836
837 _dbus_return_val_if_fail (pending != NULL, FALSE);
838 _dbus_return_val_if_fail (slot >= 0, FALSE);
839
840
841 CONNECTION_LOCK (pending->connection);
842 retval = _dbus_pending_call_set_data_unlocked (pending, slot, data, free_data_func);
843 CONNECTION_UNLOCK (pending->connection);
844 return retval;
845}
846
855void*
857 dbus_int32_t slot)
858{
859 void *res;
860
861 _dbus_return_val_if_fail (pending != NULL, NULL);
862
863 CONNECTION_LOCK (pending->connection);
864 res = _dbus_data_slot_list_get (&slot_allocator,
865 &pending->slot_list,
866 slot);
867 CONNECTION_UNLOCK (pending->connection);
868
869 return res;
870}
871
void _dbus_connection_remove_pending_call(DBusConnection *connection, DBusPendingCall *pending)
Removes a pending call from the connection, such that the pending reply will be ignored.
void _dbus_connection_block_pending_call(DBusPendingCall *pending)
Blocks until a pending call times out or gets a reply.
void _dbus_connection_queue_synthesized_message_link(DBusConnection *connection, DBusList *link)
Adds a link + message to the incoming message queue.
DBUS_PRIVATE_EXPORT DBusConnection * _dbus_connection_ref_unlocked(DBusConnection *connection)
Increments the reference count of a DBusConnection.
void dbus_connection_unref(DBusConnection *connection)
Decrements the reference count of a DBusConnection, and finalizes it if the count reaches zero.
void(* DBusPendingCallNotifyFunction)(DBusPendingCall *pending, void *user_data)
Called when a pending call now has a reply available.
void _dbus_data_slot_allocator_free(DBusDataSlotAllocator *allocator, dbus_int32_t *slot_id_p)
Deallocates an ID previously allocated with _dbus_data_slot_allocator_alloc().
void _dbus_data_slot_list_init(DBusDataSlotList *list)
Initializes a slot list.
void _dbus_data_slot_list_free(DBusDataSlotList *list)
Frees the data slot list and all data slots contained in it, calling application-provided free functi...
void * _dbus_data_slot_list_get(DBusDataSlotAllocator *allocator, DBusDataSlotList *list, int slot)
Retrieves data previously set with _dbus_data_slot_list_set_data().
dbus_bool_t _dbus_data_slot_list_set(DBusDataSlotAllocator *allocator, DBusDataSlotList *list, int slot, void *data, DBusFreeFunction free_data_func, DBusFreeFunction *old_free_func, void **old_data)
Stores a pointer in the data slot list, along with an optional function to be used for freeing the da...
dbus_bool_t _dbus_data_slot_allocator_alloc(DBusDataSlotAllocator *allocator, dbus_int32_t *slot_id_p)
Allocates an integer ID to be used for storing data in a DBusDataSlotList.
#define _dbus_assert(condition)
Aborts with an error message if the condition is false.
#define _DBUS_LOCK_NAME(name)
Expands to name of a global lock variable.
void _dbus_list_free_link(DBusList *link)
Frees a linked list node allocated with _dbus_list_alloc_link.
Definition dbus-list.c:257
void _dbus_list_clear(DBusList **list)
Frees all links in the list and sets the list head to NULL.
Definition dbus-list.c:545
DBusList * _dbus_list_alloc_link(void *data)
Allocates a linked list node.
Definition dbus-list.c:245
#define NULL
A null pointer, defined appropriately for C or C++.
Definition dbus-macros.h:51
#define TRUE
Expands to "1".
Definition dbus-macros.h:41
#define FALSE
Expands to "0".
Definition dbus-macros.h:44
void(* DBusFreeFunction)(void *memory)
The type of a function which frees a block of memory.
Definition dbus-memory.h:65
void dbus_free(void *memory)
Frees a block of memory previously allocated by dbus_malloc() or dbus_malloc0().
#define dbus_new0(type, count)
Safe macro for using dbus_malloc0().
Definition dbus-memory.h:60
DBusMessage * dbus_message_new_error(DBusMessage *reply_to, const char *error_name, const char *error_message)
Creates a new message that is an error reply to another message.
int dbus_message_get_type(DBusMessage *message)
Gets the type of a message.
DBusMessage * dbus_message_ref(DBusMessage *message)
Increments the reference count of a DBusMessage.
dbus_uint32_t dbus_message_get_reply_serial(DBusMessage *message)
Returns the serial that the message is a reply to or 0 if none.
void dbus_message_unref(DBusMessage *message)
Decrements the reference count of a DBusMessage, freeing the message if the count reaches 0.
void _dbus_pending_call_finish_completion(DBusPendingCall *pending)
Call the notifier function for the pending call.
DBusConnection * _dbus_pending_call_get_connection_and_lock(DBusPendingCall *pending)
Gets the connection associated with this pending call.
DBusPendingCall * _dbus_pending_call_ref_unlocked(DBusPendingCall *pending)
Increments the reference count on a pending call, while the lock on its connection is already held.
void _dbus_pending_call_queue_timeout_error_unlocked(DBusPendingCall *pending, DBusConnection *connection)
If the pending call hasn't been timed out, add its timeout error reply to the connection's incoming m...
void _dbus_pending_call_unref_and_unlock(DBusPendingCall *pending)
Decrements the reference count on a pending call, freeing it if the count reaches 0.
dbus_bool_t _dbus_pending_call_get_completed_unlocked(DBusPendingCall *pending)
Checks whether the pending call has received a reply yet, or not.
void _dbus_pending_call_set_reply_unlocked(DBusPendingCall *pending, DBusMessage *message)
Sets the reply of a pending call with the given message, or if the message is NULL,...
void _dbus_pending_call_set_reply_serial_unlocked(DBusPendingCall *pending, dbus_uint32_t serial)
Sets the reply's serial number.
dbus_bool_t _dbus_pending_call_set_data_unlocked(DBusPendingCall *pending, dbus_int32_t slot, void *data, DBusFreeFunction free_data_func)
Stores a pointer on a DBusPendingCall, along with an optional function to be used for freeing the dat...
DBusPendingCall * _dbus_pending_call_new_unlocked(DBusConnection *connection, int timeout_milliseconds, DBusTimeoutHandler timeout_handler)
Creates a new pending reply object.
dbus_bool_t _dbus_pending_call_set_timeout_error_unlocked(DBusPendingCall *pending, DBusMessage *message, dbus_uint32_t serial)
Sets the reply message associated with the pending call to a timeout error.
#define CONNECTION_LOCK(connection)
Internals of DBusPendingCall.
#define CONNECTION_UNLOCK(connection)
shorter and more visible way to write _dbus_connection_unlock()
void _dbus_pending_call_start_completion_unlocked(DBusPendingCall *pending)
Sets the pending call to completed.
dbus_bool_t _dbus_pending_call_is_timeout_added_unlocked(DBusPendingCall *pending)
Checks to see if a timeout has been added.
dbus_uint32_t _dbus_pending_call_get_reply_serial_unlocked(DBusPendingCall *pending)
Gets the reply's serial number.
DBusConnection * _dbus_pending_call_get_connection_unlocked(DBusPendingCall *pending)
Gets the connection associated with this pending call.
DBusTimeout * _dbus_pending_call_get_timeout_unlocked(DBusPendingCall *pending)
Retrives the timeout.
void _dbus_pending_call_set_timeout_added_unlocked(DBusPendingCall *pending, dbus_bool_t is_added)
Sets wether the timeout has been added.
dbus_bool_t dbus_pending_call_set_notify(DBusPendingCall *pending, DBusPendingCallNotifyFunction function, void *user_data, DBusFreeFunction free_user_data)
Sets a notification function to be called when the reply is received or the pending call times out.
void dbus_pending_call_free_data_slot(dbus_int32_t *slot_p)
Deallocates a global ID for DBusPendingCall data slots.
#define DBUS_TIMEOUT_INFINITE
An integer constant representing an infinite timeout.
DBusPendingCall * dbus_pending_call_ref(DBusPendingCall *pending)
Increments the reference count on a pending call.
void * dbus_pending_call_get_data(DBusPendingCall *pending, dbus_int32_t slot)
Retrieves data previously set with dbus_pending_call_set_data().
DBusMessage * dbus_pending_call_steal_reply(DBusPendingCall *pending)
Gets the reply, or returns NULL if none has been received yet.
void dbus_pending_call_cancel(DBusPendingCall *pending)
Cancels the pending call, such that any reply or error received will just be ignored.
void dbus_pending_call_block(DBusPendingCall *pending)
Block until the pending call is completed.
dbus_bool_t dbus_pending_call_set_data(DBusPendingCall *pending, dbus_int32_t slot, void *data, DBusFreeFunction free_data_func)
Stores a pointer on a DBusPendingCall, along with an optional function to be used for freeing the dat...
dbus_bool_t dbus_pending_call_allocate_data_slot(dbus_int32_t *slot_p)
Allocates an integer ID to be used for storing application-specific data on any DBusPendingCall.
dbus_bool_t dbus_pending_call_get_completed(DBusPendingCall *pending)
Checks whether the pending call has received a reply yet, or not.
void dbus_pending_call_unref(DBusPendingCall *pending)
Decrements the reference count on a pending call, freeing it if the count reaches 0.
#define DBUS_MESSAGE_TYPE_ERROR
Message type of an error reply message, see dbus_message_get_type()
#define DBUS_MESSAGE_TYPE_METHOD_RETURN
Message type of a method return message, see dbus_message_get_type()
#define DBUS_ERROR_NO_REPLY
No reply to a message expecting one, usually means a timeout occurred.
dbus_int32_t _dbus_atomic_dec(DBusAtomic *atomic)
Atomically decrement an integer.
dbus_int32_t _dbus_atomic_inc(DBusAtomic *atomic)
Atomically increments an integer.
void _dbus_timeout_unref(DBusTimeout *timeout)
Decrements the reference count of a DBusTimeout object and finalizes the object if the count reaches ...
DBusTimeout * _dbus_timeout_new(int interval, DBusTimeoutHandler handler, void *data, DBusFreeFunction free_data_function)
Creates a new DBusTimeout, enabled by default.
dbus_bool_t(* DBusTimeoutHandler)(void *data)
function to run when the timeout is handled
An atomic integer safe to increment or decrement from multiple threads.
Implementation details of DBusConnection.
An allocator that tracks a set of slot IDs.
Data structure that stores the actual user data set at a given slot.
A node in a linked list.
Definition dbus-list.h:37
void * data
Data stored at this element.
Definition dbus-list.h:40
Internals of DBusMessage.
Implementation details of DBusPendingCall - all fields are private.
DBusPendingCallNotifyFunction function
Notifier when reply arrives.
DBusMessage * reply
Reply (after we've received it)
DBusList * timeout_link
Preallocated timeout response.
DBusAtomic refcount
reference count
unsigned int timeout_added
TRUE if we have added the timeout.
dbus_uint32_t reply_serial
Expected serial of reply.
unsigned int completed
TRUE if some thread has taken responsibility for completing this pending call: either the pending cal...
DBusDataSlotList slot_list
Data stored by allocated integer ID.
DBusConnection * connection
Connections we're associated with.
DBusTimeout * timeout
Timeout.
Internals of DBusTimeout.