Dbus method call sent but no reply got

Fei Zheng Fei.Zheng at csr.com
Sun Sep 15 22:59:27 PDT 2013


I need your help to resolve a problem about making method call but no reply got.

In Dbus_send.c, method call is the sent to remote and block to wait the reply.

1.        dbus_bus_get()

2.       dbus_message_new_method_call()

3.       dbus_connection_send_with_reply_and_block()

in dbus_recv.c,  message_handler () is registered to handle the method call, then enter the main loop to dispatch the message.

1.       dbus_bus_get()

2.       dbus_bus_request_name()

3.       dbus_connection_register_object_path()

4.       dbus_connection_read_write_dispatch()

In message_handler, if signal_handler() is called to send the reply in the this function, In Dbus_send.c the caller could get the reply correctly. But if the reply is sent asynchronously in a signal handler,  the reply could not be got by the caller.

static DBusHandlerResult  message_handler (DBusConnection *connection, DBusMessage *message, void *user_data)
                dmsg  = message;
                dconn = connection;

#if 1
                //reply cannot be got by sender when reply is sent in a signal handler.

                printf("Create signal\n");
                incb = 0;
                signal(SIGALRM, sigHandler);
                printf("Start timer \n");
                printf("Increase the reference\n");

// it is ok to send the reply here.

                return DBUS_HANDLER_RESULT_HANDLED;

The two file is attached, could you help check what's wrong with it? Thanks.

Best regards
Fei Zheng

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