Appendix D

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?"