diff options
Diffstat (limited to 'dbus/dbus-connection.c')
| -rw-r--r-- | dbus/dbus-connection.c | 364 |
1 files changed, 200 insertions, 164 deletions
diff --git a/dbus/dbus-connection.c b/dbus/dbus-connection.c index ba5601e3..3af00ed0 100644 --- a/dbus/dbus-connection.c +++ b/dbus/dbus-connection.c @@ -37,6 +37,7 @@ #include "dbus-dataslot.h" #include "dbus-object-registry.h" #include "dbus-string.h" +#include "dbus-pending-call.h" #if 0 #define CONNECTION_LOCK(connection) do { \ @@ -124,9 +125,6 @@ * @{ */ -/** default timeout value when waiting for a message reply */ -#define DEFAULT_TIMEOUT_VALUE (15 * 1000) - static dbus_bool_t _dbus_modify_sigpipe = TRUE; /** @@ -163,7 +161,7 @@ struct DBusConnection DBusDataSlotList slot_list; /**< Data stored by allocated integer ID */ - DBusHashTable *pending_replies; /**< Hash of message serials and their message handlers. */ + DBusHashTable *pending_replies; /**< Hash of message serials to #DBusPendingCall. */ dbus_uint32_t client_serial; /**< Client serial. Increments each time a message is sent */ DBusList *disconnect_message_link; /**< Preallocated list node for queueing the disconnection message */ @@ -184,21 +182,6 @@ struct DBusConnection DBusObjectRegistry *objects; /**< Objects registered with this connection */ }; -typedef struct -{ - DBusConnection *connection; - DBusMessageHandler *handler; - DBusTimeout *timeout; - int serial; - - DBusList *timeout_link; /* Preallocated timeout response */ - - dbus_bool_t timeout_added; - dbus_bool_t connection_added; -} ReplyHandlerData; - -static void reply_handler_data_free (ReplyHandlerData *data); - static void _dbus_connection_remove_timeout_locked (DBusConnection *connection, DBusTimeout *timeout); static DBusDispatchStatus _dbus_connection_get_dispatch_status_unlocked (DBusConnection *connection); @@ -283,7 +266,7 @@ void _dbus_connection_queue_received_message_link (DBusConnection *connection, DBusList *link) { - ReplyHandlerData *reply_handler_data; + DBusPendingCall *pending; dbus_int32_t reply_serial; DBusMessage *message; @@ -297,14 +280,15 @@ _dbus_connection_queue_received_message_link (DBusConnection *connection, reply_serial = dbus_message_get_reply_serial (message); if (reply_serial != -1) { - reply_handler_data = _dbus_hash_table_lookup_int (connection->pending_replies, - reply_serial); - if (reply_handler_data != NULL) + pending = _dbus_hash_table_lookup_int (connection->pending_replies, + reply_serial); + if (pending != NULL) { - if (reply_handler_data->timeout_added) + if (pending->timeout_added) _dbus_connection_remove_timeout_locked (connection, - reply_handler_data->timeout); - reply_handler_data->timeout_added = FALSE; + pending->timeout); + + pending->timeout_added = FALSE; } } @@ -555,6 +539,86 @@ _dbus_connection_notify_disconnected (DBusConnection *connection) } } +static dbus_bool_t +_dbus_connection_attach_pending_call_unlocked (DBusConnection *connection, + DBusPendingCall *pending) +{ + _dbus_assert (pending->reply_serial != 0); + + if (!_dbus_connection_add_timeout (connection, pending->timeout)) + return FALSE; + + if (!_dbus_hash_table_insert_int (connection->pending_replies, + pending->reply_serial, + pending)) + { + _dbus_connection_remove_timeout (connection, pending->timeout); + return FALSE; + } + + pending->timeout_added = TRUE; + pending->connection = connection; + + dbus_pending_call_ref (pending); + + return TRUE; +} + +static void +free_pending_call_on_hash_removal (void *data) +{ + DBusPendingCall *pending; + + if (data == NULL) + return; + + pending = data; + + if (pending->connection) + { + if (pending->timeout_added) + { + _dbus_connection_remove_timeout (pending->connection, + pending->timeout); + pending->timeout_added = FALSE; + } + + pending->connection = NULL; + + dbus_pending_call_unref (pending); + } +} + +static void +_dbus_connection_detach_pending_call_and_unlock (DBusConnection *connection, + DBusPendingCall *pending) +{ + /* The idea here is to avoid finalizing the pending call + * with the lock held, since there's a destroy notifier + * in pending call that goes out to application code. + */ + dbus_pending_call_ref (pending); + _dbus_hash_table_remove_int (connection->pending_replies, + pending->reply_serial); + CONNECTION_UNLOCK (connection); + dbus_pending_call_unref (pending); +} + +/** + * Removes a pending call from the connection, such that + * the pending reply will be ignored. May drop the last + * reference to the pending call. + * + * @param connection the connection + * @param pending the pending call + */ +void +_dbus_connection_remove_pending_call (DBusConnection *connection, + DBusPendingCall *pending) +{ + CONNECTION_LOCK (connection); + _dbus_connection_detach_pending_call_and_unlock (connection, pending); +} /** * Acquire the transporter I/O path. This must be done before @@ -699,7 +763,8 @@ _dbus_connection_new_for_transport (DBusTransport *transport) pending_replies = _dbus_hash_table_new (DBUS_HASH_INT, - NULL, (DBusFreeFunction)reply_handler_data_free); + NULL, + (DBusFreeFunction)free_pending_call_on_hash_removal); if (pending_replies == NULL) goto error; @@ -1442,6 +1507,28 @@ dbus_connection_send_preallocated (DBusConnection *connection, CONNECTION_UNLOCK (connection); } +static dbus_bool_t +_dbus_connection_send_unlocked (DBusConnection *connection, + DBusMessage *message, + dbus_uint32_t *client_serial) +{ + DBusPreallocatedSend *preallocated; + + _dbus_assert (connection != NULL); + _dbus_assert (message != NULL); + + preallocated = _dbus_connection_preallocate_send_unlocked (connection); + if (preallocated == NULL) + return FALSE; + + + _dbus_connection_send_preallocated_unlocked (connection, + preallocated, + message, + client_serial); + return TRUE; +} + /** * Adds a message to the outgoing message queue. Does not block to * write the message to the network; that happens asynchronously. To @@ -1465,50 +1552,41 @@ dbus_connection_send (DBusConnection *connection, DBusMessage *message, dbus_uint32_t *client_serial) { - DBusPreallocatedSend *preallocated; - _dbus_return_val_if_fail (connection != NULL, FALSE); _dbus_return_val_if_fail (message != NULL, FALSE); CONNECTION_LOCK (connection); - - preallocated = _dbus_connection_preallocate_send_unlocked (connection); - if (preallocated == NULL) + + if (!_dbus_connection_send_unlocked (connection, message, client_serial)) { CONNECTION_UNLOCK (connection); return FALSE; } - else - { - _dbus_connection_send_preallocated_unlocked (connection, - preallocated, - message, - client_serial); - CONNECTION_UNLOCK (connection); - return TRUE; - } + + CONNECTION_UNLOCK (connection); + return TRUE; } static dbus_bool_t reply_handler_timeout (void *data) { DBusConnection *connection; - ReplyHandlerData *reply_handler_data = data; DBusDispatchStatus status; + DBusPendingCall *pending = data; - connection = reply_handler_data->connection; + connection = pending->connection; CONNECTION_LOCK (connection); - if (reply_handler_data->timeout_link) + if (pending->timeout_link) { _dbus_connection_queue_synthesized_message_link (connection, - reply_handler_data->timeout_link); - reply_handler_data->timeout_link = NULL; + pending->timeout_link); + pending->timeout_link = NULL; } _dbus_connection_remove_timeout (connection, - reply_handler_data->timeout); - reply_handler_data->timeout_added = FALSE; + pending->timeout); + pending->timeout_added = FALSE; status = _dbus_connection_get_dispatch_status_unlocked (connection); @@ -1518,52 +1596,29 @@ reply_handler_timeout (void *data) return TRUE; } -static void -reply_handler_data_free (ReplyHandlerData *data) -{ - if (!data) - return; - - if (data->timeout_added) - _dbus_connection_remove_timeout_locked (data->connection, - data->timeout); - - if (data->connection_added) - _dbus_message_handler_remove_connection (data->handler, - data->connection); - - if (data->timeout_link) - { - dbus_message_unref ((DBusMessage *)data->timeout_link->data); - _dbus_list_free_link (data->timeout_link); - } - - dbus_message_handler_unref (data->handler); - - dbus_free (data); -} - /** * Queues a message to send, as with dbus_connection_send_message(), - * but also sets up a DBusMessageHandler to receive a reply to the + * but also returns a #DBusPendingCall used to receive a reply to the * message. If no reply is received in the given timeout_milliseconds, - * expires the pending reply and sends the DBusMessageHandler a - * synthetic error reply (generated in-process, not by the remote - * application) indicating that a timeout occurred. - * - * Reply handlers see their replies after message filters see them, - * but before message handlers added with - * dbus_connection_register_handler() see them, regardless of the - * reply message's name. Reply handlers are only handed a single - * message as a reply, after one reply has been seen the handler is - * removed. If a filter filters out the reply before the handler sees - * it, the reply is immediately timed out and a timeout error reply is + * this function expires the pending reply and generates a synthetic + * error reply (generated in-process, not by the remote application) + * indicating that a timeout occurred. + * + * A #DBusPendingCall will see a reply message after any filters, but + * before any object instances or other handlers. A #DBusPendingCall + * will always see exactly one reply message, unless it's cancelled + * with dbus_pending_call_cancel(). + * + * If a filter filters out the reply before the handler sees it, the + * reply is immediately timed out and a timeout error reply is * generated. If a filter removes the timeout error reply then the - * reply handler will never be called. Filters should not do this. + * #DBusPendingCall will get confused. Filtering the timeout error + * is thus considered a bug and will print a warning. * - * If #NULL is passed for the reply_handler, the timeout reply will - * still be generated and placed into the message queue, but no - * specific message handler will receive the reply. + * If #NULL is passed for the pending_return, the #DBusPendingCall + * will still be generated internally, and used to track + * the message reply timeout. This means a timeout error will + * occur if no reply arrives, unlike with dbus_connection_send(). * * If -1 is passed for the timeout, a sane default timeout is used. -1 * is typically the best value for the timeout for this reason, unless @@ -1573,7 +1628,7 @@ reply_handler_data_free (ReplyHandlerData *data) * * @param connection the connection * @param message the message to send - * @param reply_handler message handler expecting the reply, or #NULL + * @param pending_return return location for a #DBusPendingCall object, or #NULL * @param timeout_milliseconds timeout in milliseconds or -1 for default * @returns #TRUE if the message is successfully queued, #FALSE if no memory. * @@ -1581,63 +1636,30 @@ reply_handler_data_free (ReplyHandlerData *data) dbus_bool_t dbus_connection_send_with_reply (DBusConnection *connection, DBusMessage *message, - DBusMessageHandler *reply_handler, + DBusPendingCall **pending_return, int timeout_milliseconds) { - DBusTimeout *timeout; - ReplyHandlerData *data; + DBusPendingCall *pending; DBusMessage *reply; DBusList *reply_link; dbus_int32_t serial = -1; _dbus_return_val_if_fail (connection != NULL, FALSE); _dbus_return_val_if_fail (message != NULL, FALSE); - _dbus_return_val_if_fail (reply_handler != NULL, FALSE); _dbus_return_val_if_fail (timeout_milliseconds >= 0 || timeout_milliseconds == -1, FALSE); - - if (timeout_milliseconds == -1) - timeout_milliseconds = DEFAULT_TIMEOUT_VALUE; - data = dbus_new0 (ReplyHandlerData, 1); - - if (!data) - return FALSE; + if (pending_return) + *pending_return = NULL; - timeout = _dbus_timeout_new (timeout_milliseconds, reply_handler_timeout, - data, NULL); + pending = _dbus_pending_call_new (connection, + timeout_milliseconds, + reply_handler_timeout); - if (!timeout) - { - reply_handler_data_free (data); - return FALSE; - } + if (pending == NULL) + return FALSE; CONNECTION_LOCK (connection); - /* Add timeout */ - if (!_dbus_connection_add_timeout (connection, timeout)) - { - reply_handler_data_free (data); - _dbus_timeout_unref (timeout); - CONNECTION_UNLOCK (connection); - return FALSE; - } - - /* The connection now owns the reference to the timeout. */ - _dbus_timeout_unref (timeout); - - data->timeout_added = TRUE; - data->timeout = timeout; - data->connection = connection; - - if (!_dbus_message_handler_add_connection (reply_handler, connection)) - { - CONNECTION_UNLOCK (connection); - reply_handler_data_free (data); - return FALSE; - } - data->connection_added = TRUE; - /* Assign a serial to the message */ if (dbus_message_get_serial (message) == 0) { @@ -1645,17 +1667,14 @@ dbus_connection_send_with_reply (DBusConnection *connection, _dbus_message_set_serial (message, serial); } - data->handler = reply_handler; - data->serial = serial; - - dbus_message_handler_ref (reply_handler); + pending->reply_serial = serial; reply = dbus_message_new_error (message, DBUS_ERROR_NO_REPLY, "No reply within specified time"); if (!reply) { CONNECTION_UNLOCK (connection); - reply_handler_data_free (data); + dbus_pending_call_unref (pending); return FALSE; } @@ -1664,33 +1683,42 @@ dbus_connection_send_with_reply (DBusConnection *connection, { CONNECTION_UNLOCK (connection); dbus_message_unref (reply); - reply_handler_data_free (data); + dbus_pending_call_unref (pending); return FALSE; } - data->timeout_link = reply_link; - - /* Insert the serial in the pending replies hash. */ - if (!_dbus_hash_table_insert_int (connection->pending_replies, serial, data)) + pending->timeout_link = reply_link; + + /* Insert the serial in the pending replies hash; + * hash takes a refcount on DBusPendingCall. + * Also, add the timeout. + */ + if (!_dbus_connection_attach_pending_call_unlocked (connection, + pending)) { CONNECTION_UNLOCK (connection); - reply_handler_data_free (data); + dbus_pending_call_unref (pending); return FALSE; } - - CONNECTION_UNLOCK (connection); - if (!dbus_connection_send (connection, message, NULL)) + if (!_dbus_connection_send_unlocked (connection, message, NULL)) { - /* This will free the handler data too */ - _dbus_hash_table_remove_int (connection->pending_replies, serial); + _dbus_connection_detach_pending_call_and_unlock (connection, + pending); return FALSE; } + if (pending_return) + { + dbus_pending_call_ref (pending); + *pending_return = pending; + } + + CONNECTION_UNLOCK (connection); + return TRUE; } - static DBusMessage* check_for_reply_unlocked (DBusConnection *connection, dbus_uint32_t client_serial) @@ -1755,7 +1783,7 @@ dbus_connection_send_with_reply_and_block (DBusConnection *connection, _dbus_return_val_if_error_is_set (error, NULL); if (timeout_milliseconds == -1) - timeout_milliseconds = DEFAULT_TIMEOUT_VALUE; + timeout_milliseconds = _DBUS_DEFAULT_TIMEOUT_VALUE; /* it would probably seem logical to pass in _DBUS_INT_MAX * for infinite timeout, but then math below would get @@ -2283,7 +2311,7 @@ dbus_connection_dispatch (DBusConnection *connection) DBusMessage *message; DBusList *link, *filter_list_copy, *message_link; DBusHandlerResult result; - ReplyHandlerData *reply_handler_data; + DBusPendingCall *pending; dbus_int32_t reply_serial; DBusDispatchStatus status; @@ -2332,8 +2360,8 @@ dbus_connection_dispatch (DBusConnection *connection) result = DBUS_HANDLER_RESULT_NOT_YET_HANDLED; reply_serial = dbus_message_get_reply_serial (message); - reply_handler_data = _dbus_hash_table_lookup_int (connection->pending_replies, - reply_serial); + pending = _dbus_hash_table_lookup_int (connection->pending_replies, + reply_serial); if (!_dbus_list_copy (&connection->filter_list, &filter_list_copy)) { @@ -2386,34 +2414,42 @@ dbus_connection_dispatch (DBusConnection *connection) goto out; /* Did a reply we were waiting on get filtered? */ - if (reply_handler_data && result == DBUS_HANDLER_RESULT_HANDLED) + if (pending && result == DBUS_HANDLER_RESULT_HANDLED) { /* Queue the timeout immediately! */ - if (reply_handler_data->timeout_link) + if (pending->timeout_link) { _dbus_connection_queue_synthesized_message_link (connection, - reply_handler_data->timeout_link); - reply_handler_data->timeout_link = NULL; + pending->timeout_link); + pending->timeout_link = NULL; } else { /* We already queued the timeout? Then it was filtered! */ - _dbus_warn ("The timeout error with reply serial %d was filtered, so the reply handler will never be called.\n", reply_serial); + _dbus_warn ("The timeout error with reply serial %d was filtered, so the DBusPendingCall will never stop pending.\n", reply_serial); } } if (result == DBUS_HANDLER_RESULT_HANDLED) goto out; - if (reply_handler_data) + if (pending) { - CONNECTION_UNLOCK (connection); + _dbus_verbose (" handing message %p to pending call\n", message); + + _dbus_assert (pending->reply == NULL); + pending->reply = message; + dbus_message_ref (pending->reply); + + dbus_pending_call_ref (pending); /* in case there's no app with a ref held */ + _dbus_connection_detach_pending_call_and_unlock (connection, pending); + + /* Must be called unlocked since it invokes app callback */ + _dbus_pending_call_notify (pending); + dbus_pending_call_unref (pending); - _dbus_verbose (" running reply handler on message %p\n", message); + pending = NULL; - result = _dbus_message_handler_handle_message (reply_handler_data->handler, - connection, message); - reply_handler_data_free (reply_handler_data); CONNECTION_LOCK (connection); goto out; } |