ZCOM C I/F Library Routines

ZLTSTORE (3X)

 

ZLTSTORE (3X)

NAME

zltstore – Logical data storage allocation

SYNOPSIS

#include

<zcom/zcomsys.h>

#include

<zcom/zcomcall.h> /* if compiled with ANSI C (recommended) */

int32 zltstore (appln, label, size, offsetp

uint32 appln;

char *label; uint32 size; int32 *offsetp;

DESCRIPTION

Routine zltstore requests a data area in the logical terminal table

 

extension for terminals of a specific application number. Each data area

 

is identified by the terminal application group and a user defined label.

 

The returned offset (on successful completion) could then be used in

 

subsequent data storing and retrieval calls (zltup). For data update and

 

retrieval, using data storage is relatively more efficient than using a

 

data queue. However, due to the limited usable area in the terminal

 

tables, a data queue should be used for large amounts of data. See under

 

zltqueue for how to allocate a data queue.

 

The libraries libzcom_c.a and libpthread.a must be linked into the calling

 

program by giving the options “-lzcom_c -lpthread” to cc(1) or ld(1).

Threads

This routine may be called from a multi-threaded application using the

Considerations

POSIX (1003.1c) kernel threads API package. This routine has the

 

following characteristics when called by a multi-threaded application:

 

cancellation point

Thread cancellation can occur when a thread calls

 

 

this routine.

 

async-cancel unsafe

The calling thread’s cancelability type must be

 

 

PTHREAD_CANCEL_DEFERRED if

 

 

cancellation is enabled.

 

async-signal unsafe

It cannot be called from a signal handler.

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Chapter 4