gtpi1m0jSystem Installation Support Reference

C Debugger Initialization

User exit routine UCCCDBI allows you to initialize a C debugger other than the TPF C Debugger for VisualAge Client. UCCCDBI is called before initializing a C debugger if the exit point named CDBI is active. Exit point CDBI is located in the object code only segment CDBINT, which is part of the library load module CISO.

General Conditions at Entry

The registers at entry to UCCCDBI are:

R0-R8, R10
Contents are unknown.

R9
Address of the ECB.

R11-R15
See User Exit Routines - Common Entry Conditions.

The C debugger state indicators in page 2 of the ECB are:

CE2DBENBL
Indicates if the ECB is enabled for debugging. If it is, one of the following fields in the TPF process block (IPROC) will contain a pointer to the trace entry; the other will contain a zero to indicate that it is not being used:

IPROC_TBT_PTR
The address of the trace-by-terminal entry.

IPROC_TBP_PTR
The address of the trace-by-program entry.

Each trace entry contains the following information:

  • Debug workstation IP address
  • Port number of the debug workstation
  • Entry state flag
  • Option flags
  • Number of ECBs using this entry
  • Created ECB trace token
  • Programs to be traced
  • User token.
Note:
A trace-by-terminal entry also contains a field that identifies the terminal information. A terminal can be a TCP/IP address, a fully qualified LU Name, or an LNIATA.

CE2DBHOOK
Indicates if the ECB has entered a program that matches the trace entry information and, therefore, should initialize the debugger.

CE2DBINIT
Indicates if the debugger has been initialized.

CE2DBFLAG
This byte holds several internal flags that are used by debuggers. One of the bits indicate that the debugger has issued an input/output (I/O) command to the workstation and is waiting for a response. This bit is set before writing to the socket and is cleared after reading the socket.

System Conditions at Entry

System state
Inherited from application

System mask
Inherited from application

Protect key
Inherited from application

Address Space
EVM.

Programming Considerations at Entry

  1. UCCCDBI can use the data stored in the user token field of the trace entry, or any other information accessible by the ECB to determine if it should delay the initialization of the debugger until the ECB enters another C program. To delay the initialization of the debugger until the ECB enters another C program, set the CE2DBINIT field to CE2DBINIT_OFF.
  2. See User Exit Routines - Common Entry Conditions.
  3. See User Exit Routines - Common Programming Considerations for other considerations.

Programming Considerations on Return

See User Exit Routines - Common Return Conditions.

General Conditions on Return

See User Exit Routines - Common Return Conditions.