TNS/R Native Application Migration Guide

Guardian API Migration Tasks

TNS/R Native Application Migration Guide—523745-001

9-5

XSTACKTEST

The XSTACKTEST procedure ensures that adequate stack space is available and

returns a set of constants to be used with the XBNDSTEST procedure.

If XSTACKTEST is called to return constants passed to the XBNDSTEST procedure,

delete the XSTACKTEST procedure, because native programs cannot call the

XBNDSTEST procedure. See the XBNDSTEST procedure in this section for more

details.

If XSTACKTEST is called to ensure that adequate stack space is available, replace

XSTACKTEST with calls to the HEADROOM_ENSURE_ procedure. The

HEADROOM_ENSURE_ procedure allows you to make sure that the current main

stack or privileged stack has enough room for the needs of your process. See the

Guardian Procedure Calls Reference Manual for details.

Using the INITIALIZER Procedure

The INITIALIZER procedure reads the startup message, and optionally, requests

receipt of the ASSIGN and PARAM messages sent by the starting process (which is

often a TACL process). The INITIALIZER procedure optionally initializes file control

blocks (FCBs) with the information read from the startup and ASSIGN messages.

Calls to the INITIALIZER procedure that pass the first parameter (the RUCB, run-unit

control block) must be changed. Such programs must specify two additional

parameters. Other callers to the INITIALIZER procedure do not need to be changed.

See the Guardian Procedure Calls Reference Manual for details.

Using Sequential I/O Procedures

Many of the sequential I/O procedures (SIO) take file control blocks (FCBs) as

parameters. TNS and native programs have FCBs of different sizes. The following SIO

procedures have separate TAL and pTAL declarations to support FCBs of different

sizes: CLOSE^WRITE, OPEN^FILE, READ^FILE, WAIT^FILE, and WRITE^FILE. You

do not need to change your programs for different FCB sizes. The TAL and pTAL

compilers automatically select the correct procedure version.

Callers to the CHECK^FILE and SET^FILE SIO procedures must make the changes

described in the following subsections.