Reference Guide

ZCOM C I/F Library Routines
LTQDPUT (3X)
Chapter 4 155
LTQDPUT (3X)
NAME ltqdput – Store data buffer in terminal data queue
SYNOPSIS
#include <zcom/zcomsys.h>
#include <zcom/zcomcall.h> /* if compiled with ANSI C (recommended)
*/
int32 ltqdput (zap, queue, ibuf, len)
zaddr_type *zap;
uint32 queue;
char *ibuf;
int32 len;
DESCRIPTION Routine ltqdput stores a data message in the data queue of the logical
terminal tables. It links the message to the end of the specified queue.
Retrieval occurs on a First-In-First-Out basis. See the man page for
ltqdget on how to retrieve a message in the data queue.
The data queue is designed to store a relatively large or unpredictable
amount of terminal data in FIFO order. When compared to logical data
storage (refer to zltstore and zltup), the data queues allow terminal data
to be stored dynamically, that is, memory is used only when data is
stored. However, it is penalized by incurring more processing overhead
during data update and retrieval. In addition, access is restricted to a
FIFO order.
The libraries libzcom_c.a and libpthread.a must be linked into the calling
program by giving the options “-lzx25 -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.