1 /* -*- mode: C; c-file-style: "gnu" -*- */
2 /* dbus-pending-call.c Object representing a call in progress.
4 * Copyright (C) 2002, 2003 Red Hat Inc.
6 * Licensed under the Academic Free License version 2.1
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.
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.
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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
24 #include "dbus-internals.h"
25 #include "dbus-connection-internal.h"
26 #include "dbus-pending-call.h"
27 #include "dbus-list.h"
28 #include "dbus-threads.h"
29 #include "dbus-test.h"
32 * @defgroup DBusPendingCallInternals DBusPendingCall implementation details
33 * @ingroup DBusInternals
34 * @brief DBusPendingCall private implementation details.
36 * The guts of DBusPendingCall and its methods.
41 static dbus_int32_t notify_user_data_slot = -1;
44 * Creates a new pending reply object.
46 * @param connection connection where reply will arrive
47 * @param timeout_milliseconds length of timeout, -1 for default
48 * @param timeout_handler timeout handler, takes pending call as data
49 * @returns a new #DBusPendingCall or #NULL if no memory.
52 _dbus_pending_call_new (DBusConnection *connection,
53 int timeout_milliseconds,
54 DBusTimeoutHandler timeout_handler)
56 DBusPendingCall *pending;
59 _dbus_assert (timeout_milliseconds >= 0 || timeout_milliseconds == -1);
61 if (timeout_milliseconds == -1)
62 timeout_milliseconds = _DBUS_DEFAULT_TIMEOUT_VALUE;
64 /* it would probably seem logical to pass in _DBUS_INT_MAX for
65 * infinite timeout, but then math in
66 * _dbus_connection_block_for_reply would get all overflow-prone, so
69 if (timeout_milliseconds > _DBUS_ONE_HOUR_IN_MILLISECONDS * 6)
70 timeout_milliseconds = _DBUS_ONE_HOUR_IN_MILLISECONDS * 6;
72 if (!dbus_pending_call_allocate_data_slot (¬ify_user_data_slot))
75 pending = dbus_new0 (DBusPendingCall, 1);
79 dbus_pending_call_free_data_slot (¬ify_user_data_slot);
83 timeout = _dbus_timeout_new (timeout_milliseconds,
89 dbus_pending_call_free_data_slot (¬ify_user_data_slot);
94 pending->refcount.value = 1;
95 pending->connection = connection;
96 pending->timeout = timeout;
98 _dbus_data_slot_list_init (&pending->slot_list);
104 * Calls notifier function for the pending call
105 * and sets the call to completed.
107 * @param pending the pending call
111 _dbus_pending_call_notify (DBusPendingCall *pending)
113 _dbus_assert (!pending->completed);
115 pending->completed = TRUE;
117 if (pending->function)
120 user_data = dbus_pending_call_get_data (pending,
121 notify_user_data_slot);
123 (* pending->function) (pending, user_data);
130 * @defgroup DBusPendingCall DBusPendingCall
132 * @brief Pending reply to a method call message
134 * A DBusPendingCall is an object representing an
135 * expected reply. A #DBusPendingCall can be created
136 * when you send a message that should have a reply.
142 * @typedef DBusPendingCall
144 * Opaque data type representing a message pending.
148 * Increments the reference count on a pending call.
150 * @param pending the pending call object
151 * @returns the pending call object
154 dbus_pending_call_ref (DBusPendingCall *pending)
156 _dbus_return_val_if_fail (pending != NULL, NULL);
158 _dbus_atomic_inc (&pending->refcount);
164 * Decrements the reference count on a pending call,
165 * freeing it if the count reaches 0.
167 * @param pending the pending call object
170 dbus_pending_call_unref (DBusPendingCall *pending)
172 dbus_bool_t last_unref;
174 _dbus_return_if_fail (pending != NULL);
176 last_unref = (_dbus_atomic_dec (&pending->refcount) == 1);
180 /* If we get here, we should be already detached
181 * from the connection, or never attached.
183 _dbus_assert (pending->connection == NULL);
184 _dbus_assert (!pending->timeout_added);
186 /* this assumes we aren't holding connection lock... */
187 _dbus_data_slot_list_free (&pending->slot_list);
189 if (pending->timeout != NULL)
190 _dbus_timeout_unref (pending->timeout);
192 if (pending->timeout_link)
194 dbus_message_unref ((DBusMessage *)pending->timeout_link->data);
195 _dbus_list_free_link (pending->timeout_link);
196 pending->timeout_link = NULL;
201 dbus_message_unref (pending->reply);
202 pending->reply = NULL;
207 dbus_pending_call_free_data_slot (¬ify_user_data_slot);
212 * Sets a notification function to be called when the reply is
213 * received or the pending call times out.
215 * @param pending the pending call
216 * @param function notifier function
217 * @param user_data data to pass to notifier function
218 * @param free_user_data function to free the user data
219 * @returns #FALSE if not enough memory
222 dbus_pending_call_set_notify (DBusPendingCall *pending,
223 DBusPendingCallNotifyFunction function,
225 DBusFreeFunction free_user_data)
227 _dbus_return_val_if_fail (pending != NULL, FALSE);
229 /* could invoke application code! */
230 if (!dbus_pending_call_set_data (pending, notify_user_data_slot,
231 user_data, free_user_data))
234 pending->function = function;
240 * Cancels the pending call, such that any reply or error received
241 * will just be ignored. Drops the dbus library's internal reference
242 * to the #DBusPendingCall so will free the call if nobody else is
243 * holding a reference. However you usually get a reference
244 * from dbus_connection_send() so probably your app owns a ref also.
246 * @param pending the pending call
249 dbus_pending_call_cancel (DBusPendingCall *pending)
251 if (pending->connection)
252 _dbus_connection_remove_pending_call (pending->connection,
257 * Checks whether the pending call has received a reply
260 * @todo not thread safe? I guess it has to lock though it sucks
262 * @param pending the pending call
263 * @returns #TRUE if a reply has been received */
265 dbus_pending_call_get_completed (DBusPendingCall *pending)
267 return pending->completed;
271 * Gets the reply, or returns #NULL if none has been received
272 * yet. Ownership of the reply message passes to the caller. This
273 * function can only be called once per pending call, since the reply
274 * message is tranferred to the caller.
276 * @param pending the pending call
277 * @returns the reply message or #NULL.
280 dbus_pending_call_steal_reply (DBusPendingCall *pending)
282 DBusMessage *message;
284 _dbus_return_val_if_fail (pending->completed, NULL);
285 _dbus_return_val_if_fail (pending->reply != NULL, NULL);
287 message = pending->reply;
288 pending->reply = NULL;
294 * Block until the pending call is completed. The blocking is as with
295 * dbus_connection_send_with_reply_and_block(); it does not enter the
296 * main loop or process other messages, it simply waits for the reply
299 * If the pending call is already completed, this function returns
302 * @todo when you start blocking, the timeout is reset, but it should
303 * really only use time remaining since the pending call was created.
305 * @param pending the pending call
308 dbus_pending_call_block (DBusPendingCall *pending)
310 _dbus_connection_block_pending_call (pending);
313 static DBusDataSlotAllocator slot_allocator;
314 _DBUS_DEFINE_GLOBAL_LOCK (pending_call_slots);
317 * Allocates an integer ID to be used for storing application-specific
318 * data on any DBusPendingCall. The allocated ID may then be used
319 * with dbus_pending_call_set_data() and dbus_pending_call_get_data().
320 * The passed-in slot must be initialized to -1, and is filled in
321 * with the slot ID. If the passed-in slot is not -1, it's assumed
322 * to be already allocated, and its refcount is incremented.
324 * The allocated slot is global, i.e. all DBusPendingCall objects will
325 * have a slot with the given integer ID reserved.
327 * @param slot_p address of a global variable storing the slot
328 * @returns #FALSE on failure (no memory)
331 dbus_pending_call_allocate_data_slot (dbus_int32_t *slot_p)
333 return _dbus_data_slot_allocator_alloc (&slot_allocator,
334 _DBUS_LOCK_NAME (pending_call_slots),
339 * Deallocates a global ID for #DBusPendingCall data slots.
340 * dbus_pending_call_get_data() and dbus_pending_call_set_data() may
341 * no longer be used with this slot. Existing data stored on existing
342 * DBusPendingCall objects will be freed when the #DBusPendingCall is
343 * finalized, but may not be retrieved (and may only be replaced if
344 * someone else reallocates the slot). When the refcount on the
345 * passed-in slot reaches 0, it is set to -1.
347 * @param slot_p address storing the slot to deallocate
350 dbus_pending_call_free_data_slot (dbus_int32_t *slot_p)
352 _dbus_return_if_fail (*slot_p >= 0);
354 _dbus_data_slot_allocator_free (&slot_allocator, slot_p);
358 * Stores a pointer on a #DBusPendingCall, along
359 * with an optional function to be used for freeing
360 * the data when the data is set again, or when
361 * the pending call is finalized. The slot number
362 * must have been allocated with dbus_pending_call_allocate_data_slot().
364 * @param pending the pending_call
365 * @param slot the slot number
366 * @param data the data to store
367 * @param free_data_func finalizer function for the data
368 * @returns #TRUE if there was enough memory to store the data
371 dbus_pending_call_set_data (DBusPendingCall *pending,
374 DBusFreeFunction free_data_func)
376 DBusFreeFunction old_free_func;
380 _dbus_return_val_if_fail (pending != NULL, FALSE);
381 _dbus_return_val_if_fail (slot >= 0, FALSE);
383 retval = _dbus_data_slot_list_set (&slot_allocator,
385 slot, data, free_data_func,
386 &old_free_func, &old_data);
391 (* old_free_func) (old_data);
398 * Retrieves data previously set with dbus_pending_call_set_data().
399 * The slot must still be allocated (must not have been freed).
401 * @param pending the pending_call
402 * @param slot the slot to get data from
403 * @returns the data, or #NULL if not found
406 dbus_pending_call_get_data (DBusPendingCall *pending,
411 _dbus_return_val_if_fail (pending != NULL, NULL);
413 res = _dbus_data_slot_list_get (&slot_allocator,
422 #ifdef DBUS_BUILD_TESTS
425 * @ingroup DBusPendingCallInternals
426 * Unit test for DBusPendingCall.
428 * @returns #TRUE on success.
431 _dbus_pending_call_test (const char *test_data_dir)
436 #endif /* DBUS_BUILD_TESTS */