
Universal Debugger Interface Specification
5-1
Chapter 5
5
UDI IPC Methods for UNIX Hosts
This chapter specifies how UDI DFEs and TIPs communicate using the
socket–based IPC mechanism. The UDI version covered is UDI 1.4 but
compatibility with previous versions of UDI (back to version 1.2) is also
discussed. (For complete information on compatibility and interoperability of
different version TIPs and DFEs, please see page D–1.)
NOTE:
Refer back to Chapter 3 for semantics on most of the fields of the
messages.
In the socket–based IPC mechanism, the DFE establishes a socket connection
to the TIP. The DFE and TIP then exchange requests and responses by sending
messages over that socket. Also, for a few unusual asynchronous situations, the
DFE can send a signal to the TIP.
The sections below describe how the DFE connects to the TIP, the format of
the request and response messages that are sent between the DFE and TIP on
the socket, and the signals that the DFE can send to the TIP.
NOTE
: In this chapter, when a reference is made to a UDIConnect request
message, it means "either a
UDIConnect_12
request message or a
UDIConnect_14
request message" unless otherwise noted.
Establishing the Connection
The TIP and DFE communicate over a socket. The socket may be based on
any of the socket address families. The method by which the TIP chooses a
socket to listen on and the way the DFE learns the socket address and address
family of the TIP is outside the scope of this specification. (As an example, the
TIP and DFE could take the socket name as a startup parameter. In some
cases, the DFE might actually spawn the TIP.)
The TIP calls
socket()
,
bind()
,
listen()
, and
accept()
. After an
accept()
establishes a socket descriptor, the TIP expects all data for that connection
from the DFE to arrive on that same socket descriptor.