Frequently Asked Questions

This appendix contains answers to the following questions about the ToolTalk service:

• What is the ToolTalk service?

• Is the ToolTalk Service the Sun implementation of the Common Object Request Broker Architecture (CORBA)?

• What files are part of the ToolTalk service?

• Where is the initial X-based ttsession started?

• Where is rpc.ttdbserverd started?

• Where are the ToolTalk type databases stored?

• Do I need X Windows to use the ToolTalk service?

• Can I use the ToolTalk service with MIT X?

• Where is the session id of the X-session?

• How does tt_open connect to a ttsession?

• After calling tt_open, when does a session actually begin?

• If another session is attached, does the first session get killed?

• How can processes on different machines communicate using the ToolTalk service?

• What is the purpose of tt_default_session_set?

• How can a process connect to more than one session?

• Can you start a ttsession with a known session id?

• What information does a session id contain?

• Is there a standard way to announce that a new program has joined a session?

• Where is my message going?

• What is the basic flow of a message?

• What happens when a message arrives to my application?

• How can I differentiate between messages?

• Can a process send a request to itself?

• Can I pass my own data to a function registered by tt_message_callback_add?

• How can I send arbitrary data in a message?

• Can I transfer files with the ToolTalk service?

• How are memory (byte) ordering issues handled by the ToolTalk service?

• Can I re-use messages?

• What happens when I destroy a message?

• Can I have more than one handler per message?

• Can I run more than one handler of a given ptype?

• What value is disposition in a message?

• What are the message status elements?

• When should I use tt_free?

• What does the ptype represent?

• Why are my new types not recognized?

• Is ptype information used if a process of that ptype already exists?

• Can the ptype definition be modified to always start an instance (whether or not one is already running)?

• What does tt_ptype_declare do?

• What is TT_TOKEN?

• When are my patterns active?

• Must I register patterns to get replies?

• How can I observe requests?

• How do I match to attribute values in static patterns?

• Why am I unable to wildcard a pattern for TT_HANDLER?

• Can I set a pattern to watch for any file scoped message?

• Is file scope in static patterns the same as file_in_session scope?

• What is the difference between arg_add, barg_add, and iarg_add?

• What is the type or vtype in a message argument?

• How do I use contexts?

• How does ttsession check for matches?

• How many kinds of scope does the ToolTalk service have?

• What are the TT_DB directories, and what is the difference between the types database and the TT_DB directories?

• What should the tt_db databases contain?

• What does rpc.ttdbserverd do?

• Do ttsession and rpc.ttdbserverdever communicate?

• What message bandwidth can be supported?

• Is there a limit to the message size or the number of arguments?

• What is the most time efficient method to send a message?

• What network overhead is involved?

• Does the ToolTalk service use load balancing to handle requests?

• What resources are required by a ToolTalk application?

• What happens if the ttsession exits unexpectedly?

• What happens if rpc.ttdbserverd exits unexpectedly?

• What happens if a host or a link is down?

• What does tt_close do?

• Is message delivery guaranteed on a network?

• Is there a temporal sequence of message delivery?

• What is unix, xauth, and des?

• Can my applications hide messages from each other?

• Is there protection against interception or imitation?

• Where are queued messages stored and how secure is the storage?

• Is the ToolTalk service C2 qualified?

• How can I trace my message's progress?

• How can I isolate my debugging tool from all the other tools using the ToolTalk service?

• Can I use the ToolTalk service with C++?

• Should I qualify my filenames?

• Can you tell me about ToolTalk objects?

• Is there a ToolTalk news group?