Reference Guide

ZCOM C I/F Library Routines
ZLTMX (3X)
Chapter 4 245
ZLTMX (3X)
NAME zltmx – Control logical terminal multiplexing
SYNOPSIS
#include <zcom/zcomsys.h>
#include <zcom/zcomcall.h> /* if compiled with ANSI C (recommended) */
int32 zltmx (zap, mode)
zaddr_type *zap;
int32 mode;
DESCRIPTION Routine zltmx is used to enable or disable the multiplexing of logical
terminals. This routine allows dynamic control of the
ZCOM_LTFLAG_OMX and ZCOM_LTFLAG_IMX logical terminal flag
bits. These flag bits are initialized for each terminal ZLU by TTGEN, and
may be changed by use of this call.
After calling this routine, the subsequent zrcvr and zsend calls will work
according to the new settings.
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
Considerations
This routine may be called from a multi-threaded application using the
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.
fork unsafe It cannot be called by a child process after fork(2)
but before exec(2).