TNS/E Native Application Conversion Guide

C and C++ Conversion Tasks

TNS/E Native Application Conversion Guide—529659-003

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Using Active Backup Programming in C

To convert a TNS program that uses the active backup programming functions to

native mode:

•

Replace the header file nonstop.h with crtlns.h.

•

Instead of binding in cnonstop, link the active backup support library:

For more details on writing programs that use the active backup functions, see the

Guardian Programmer’s Guide

Replacing Obsolete C++ Library Operations

The TNS C++ run-time library uses the TNS Guardian C library alternate-model I/O

functions to provide an I/O facility similar to but not identical to the UNIX file descriptor

model. To improve interoperability between the Guardian and OSS environments, the

native environment does not support the Guardian alternate-model I/O functions.

Because of this change, the Guardian native C++ run-time library filebuf and

fstream classes cannot be used to specify an existing open file stream with the

attach function. Two options are available to programs that use the alternate-model

I/O functions:

•

Rewrite your code to use the OSS versions of these classes.

•

Open the file stream instead of using a file descriptor to attach to an existing open

stream.

The attach function’s use of file descriptors is nonstandard behavior.

Using the Tools.h++ Class Library

Two product versions of Tools.h++ (version 6.1 and version 7) are available since the

D45.00 and G05.00 RVUs. Only version 7 is available in H-series RVUs. If you are

converting a TNS program that uses an earlier version of Tools.h++ to TNS/E native

mode, you must convert to Tools.h++ version 7. Version 7 offers many new features

over earlier versions, but converting to version 7 requires extensive source code

changes. The

C/C++ Programmer’s Guide

provides an overview of Tools.h++ version 7

along with a summary of conversion tasks. See the

Tools.h++ 7.0 User’s Guide

for

detailed conversion information.

Environment Active Backup Support Library

Guardian CRTLNS

OSS or PC crtlns.o