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Diffstat (limited to 'dbus/dbus-pending-call.c')
| -rw-r--r-- | dbus/dbus-pending-call.c | 429 |
1 files changed, 429 insertions, 0 deletions
diff --git a/dbus/dbus-pending-call.c b/dbus/dbus-pending-call.c new file mode 100644 index 00000000..dad444e3 --- /dev/null +++ b/dbus/dbus-pending-call.c @@ -0,0 +1,429 @@ +/* -*- mode: C; c-file-style: "gnu" -*- */ +/* dbus-pending-call.c Object representing a call in progress. + * + * Copyright (C) 2002, 2003 Red Hat Inc. + * + * Licensed under the Academic Free License version 1.2 + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + */ + +#include "dbus-internals.h" +#include "dbus-connection-internal.h" +#include "dbus-pending-call.h" +#include "dbus-list.h" +#include "dbus-threads.h" +#include "dbus-test.h" + +/** + * @defgroup DBusPendingCallInternals DBusPendingCall implementation details + * @ingroup DBusInternals + * @brief DBusPendingCall private implementation details. + * + * The guts of DBusPendingCall and its methods. + * + * @{ + */ + +static dbus_int32_t notify_user_data_slot = -1; + +/** + * Creates a new pending reply object. + * + * @param connection connection where reply will arrive + * @param timeout_milliseconds length of timeout, -1 for default + * @param timeout_handler timeout handler, takes pending call as data + * @returns a new #DBusPendingCall or #NULL if no memory. + */ +DBusPendingCall* +_dbus_pending_call_new (DBusConnection *connection, + int timeout_milliseconds, + DBusTimeoutHandler timeout_handler) +{ + DBusPendingCall *pending; + DBusTimeout *timeout; + + _dbus_return_val_if_fail (timeout_milliseconds >= 0 || timeout_milliseconds == -1, FALSE); + + if (timeout_milliseconds == -1) + timeout_milliseconds = _DBUS_DEFAULT_TIMEOUT_VALUE; + + if (!dbus_pending_call_allocate_data_slot (¬ify_user_data_slot)) + return NULL; + + pending = dbus_new (DBusPendingCall, 1); + + if (pending == NULL) + { + dbus_pending_call_free_data_slot (¬ify_user_data_slot); + return NULL; + } + + timeout = _dbus_timeout_new (timeout_milliseconds, + timeout_handler, + pending, NULL); + + if (timeout == NULL) + { + dbus_pending_call_free_data_slot (¬ify_user_data_slot); + dbus_free (pending); + return NULL; + } + + pending->refcount.value = 1; + pending->connection = connection; + pending->timeout = timeout; + + _dbus_data_slot_list_init (&pending->slot_list); + + return pending; +} + +/** + * Calls notifier function for the pending call + * and sets the call to completed. + * + * @param pending the pending call + * + */ +void +_dbus_pending_call_notify (DBusPendingCall *pending) +{ + pending->completed = TRUE; + + if (pending->function) + { + void *user_data; + user_data = dbus_pending_call_get_data (pending, + notify_user_data_slot); + + (* pending->function) (pending, user_data); + } +} + +/** @} */ + +/** + * @defgroup DBusPendingCall DBusPendingCall + * @ingroup DBus + * @brief Pending reply to a method call message + * + * A DBusPendingCall is an object representing an + * expected reply. A #DBusPendingCall can be created + * when you send a message that should have a reply. + * + * @{ + */ + +/** + * @typedef DBusPendingCall + * + * Opaque data type representing a message pending. + */ + +/** + * Increments the reference count on a pending call. + * + * @param pending the pending call object + */ +void +dbus_pending_call_ref (DBusPendingCall *pending) +{ + _dbus_return_if_fail (pending != NULL); + + _dbus_atomic_inc (&pending->refcount); +} + +/** + * Decrements the reference count on a pending call, + * freeing it if the count reaches 0. + * + * @param pending the pending call object + */ +void +dbus_pending_call_unref (DBusPendingCall *pending) +{ + dbus_bool_t last_unref; + + _dbus_return_if_fail (pending != NULL); + + last_unref = (_dbus_atomic_dec (&pending->refcount) == 1); + + if (last_unref) + { + /* If we get here, we should be already detached + * from the connection, or never attached. + */ + _dbus_assert (pending->connection == NULL); + _dbus_assert (!pending->timeout_added); + + /* this assumes we aren't holding connection lock... */ + _dbus_data_slot_list_free (&pending->slot_list); + + if (pending->timeout != NULL) + _dbus_timeout_unref (pending->timeout); + + if (pending->timeout_link) + { + dbus_message_unref ((DBusMessage *)pending->timeout_link->data); + _dbus_list_free_link (pending->timeout_link); + pending->timeout_link = NULL; + } + + if (pending->reply) + { + dbus_message_unref (pending->reply); + pending->reply = NULL; + } + + dbus_free (pending); + + dbus_pending_call_free_data_slot (¬ify_user_data_slot); + } +} + +/** + * Sets a notification function to be called when the reply is + * received or the pending call times out. + * + * @param pending the pending call + * @param function notifier function + * @param user_data data to pass to notifier function + * @param free_user_data function to free the user data + * @returns #FALSE if not enough memory + */ +dbus_bool_t +dbus_pending_call_set_notify (DBusPendingCall *pending, + DBusPendingCallNotifyFunction function, + void *user_data, + DBusFreeFunction free_user_data) +{ + _dbus_return_val_if_fail (pending != NULL, FALSE); + + /* could invoke application code! */ + if (!dbus_pending_call_set_data (pending, notify_user_data_slot, + user_data, free_user_data)) + return FALSE; + + pending->function = function; + + return TRUE; +} + +/** + * Cancels the pending call, such that any reply + * or error received will just be ignored. + * Drops at least one reference to the #DBusPendingCall + * so will free the call if nobody else is holding + * a reference. + * + * @param pending the pending call + */ +void +dbus_pending_call_cancel (DBusPendingCall *pending) +{ + if (pending->connection) + _dbus_connection_remove_pending_call (pending->connection, + pending); +} + +/** + * Checks whether the pending call has received a reply + * yet, or not. + * + * @todo not thread safe? I guess it has to lock though it sucks + * + * @param pending the pending call + * @returns #TRUE if a reply has been received */ +dbus_bool_t +dbus_pending_call_get_completed (DBusPendingCall *pending) +{ + return pending->completed; +} + +/** + * Gets the reply, or returns #NULL if none has been received yet. The + * reference count is not incremented on the returned message, so you + * have to keep a reference count on the pending call (or add one + * to the message). + * + * @todo not thread safe? I guess it has to lock though it sucks + * @todo maybe to make this threadsafe, it should be steal_reply(), i.e. only one thread can ever get the message + * + * @param pending the pending call + * @returns the reply message or #NULL. + */ +DBusMessage* +dbus_pending_call_get_reply (DBusPendingCall *pending) +{ + return pending->reply; +} + +/** + * Block until the pending call is completed. The blocking is as with + * dbus_connection_send_with_reply_and_block(); it does not enter the + * main loop or process other messages, it simply waits for the reply + * in question. + * + * If the pending call is already completed, this function returns + * immediately. + * + * @todo when you start blocking, the timeout is reset, but it should + * really only use time remaining since the pending call was created. + * + * @param pending the pending call + */ +void +dbus_pending_call_block (DBusPendingCall *pending) +{ + DBusMessage *message; + + if (dbus_pending_call_get_completed (pending)) + return; + + message = _dbus_connection_block_for_reply (pending->connection, + pending->reply_serial, + dbus_timeout_get_interval (pending->timeout)); + + _dbus_connection_lock (pending->connection); + _dbus_pending_call_complete_and_unlock (pending, message); + dbus_message_unref (message); +} + +static DBusDataSlotAllocator slot_allocator; +_DBUS_DEFINE_GLOBAL_LOCK (pending_call_slots); + +/** + * Allocates an integer ID to be used for storing application-specific + * data on any DBusPendingCall. The allocated ID may then be used + * with dbus_pending_call_set_data() and dbus_pending_call_get_data(). + * The passed-in slot must be initialized to -1, and is filled in + * with the slot ID. If the passed-in slot is not -1, it's assumed + * to be already allocated, and its refcount is incremented. + * + * The allocated slot is global, i.e. all DBusPendingCall objects will + * have a slot with the given integer ID reserved. + * + * @param slot_p address of a global variable storing the slot + * @returns #FALSE on failure (no memory) + */ +dbus_bool_t +dbus_pending_call_allocate_data_slot (dbus_int32_t *slot_p) +{ + return _dbus_data_slot_allocator_alloc (&slot_allocator, + _DBUS_LOCK_NAME (pending_call_slots), + slot_p); +} + +/** + * Deallocates a global ID for #DBusPendingCall data slots. + * dbus_pending_call_get_data() and dbus_pending_call_set_data() may + * no longer be used with this slot. Existing data stored on existing + * DBusPendingCall objects will be freed when the #DBusPendingCall is + * finalized, but may not be retrieved (and may only be replaced if + * someone else reallocates the slot). When the refcount on the + * passed-in slot reaches 0, it is set to -1. + * + * @param slot_p address storing the slot to deallocate + */ +void +dbus_pending_call_free_data_slot (dbus_int32_t *slot_p) +{ + _dbus_return_if_fail (*slot_p >= 0); + + _dbus_data_slot_allocator_free (&slot_allocator, slot_p); +} + +/** + * Stores a pointer on a #DBusPendingCall, along + * with an optional function to be used for freeing + * the data when the data is set again, or when + * the pending call is finalized. The slot number + * must have been allocated with dbus_pending_call_allocate_data_slot(). + * + * @param pending the pending_call + * @param slot the slot number + * @param data the data to store + * @param free_data_func finalizer function for the data + * @returns #TRUE if there was enough memory to store the data + */ +dbus_bool_t +dbus_pending_call_set_data (DBusPendingCall *pending, + dbus_int32_t slot, + void *data, + DBusFreeFunction free_data_func) +{ + DBusFreeFunction old_free_func; + void *old_data; + dbus_bool_t retval; + + _dbus_return_val_if_fail (pending != NULL, FALSE); + _dbus_return_val_if_fail (slot >= 0, FALSE); + + retval = _dbus_data_slot_list_set (&slot_allocator, + &pending->slot_list, + slot, data, free_data_func, + &old_free_func, &old_data); + + if (retval) + { + if (old_free_func) + (* old_free_func) (old_data); + } + + return retval; +} + +/** + * Retrieves data previously set with dbus_pending_call_set_data(). + * The slot must still be allocated (must not have been freed). + * + * @param pending the pending_call + * @param slot the slot to get data from + * @returns the data, or #NULL if not found + */ +void* +dbus_pending_call_get_data (DBusPendingCall *pending, + dbus_int32_t slot) +{ + void *res; + + _dbus_return_val_if_fail (pending != NULL, NULL); + + res = _dbus_data_slot_list_get (&slot_allocator, + &pending->slot_list, + slot); + + return res; +} + +/** @} */ + +#ifdef DBUS_BUILD_TESTS + +/** + * @ingroup DBusPendingCallInternals + * Unit test for DBusPendingCall. + * + * @returns #TRUE on success. + */ +dbus_bool_t +_dbus_pending_call_test (const char *test_data_dir) +{ + + return TRUE; +} +#endif /* DBUS_BUILD_TESTS */ |