HP Advanced Communications Controllers (ACC) manual Zclos, Cancellation point

ZCOM C I/F Library Routines

ZCLOS (3X)

	ZCLOS (3X)
NAME	zclos - Delete program input ZLU
SYNOPSIS
#include	<zcom/zcomsys.h>
#include	<zcom/zcomcall.h> /* if compiled with ANSI C (recommended) */
int32	zclos (zap)

zaddr_type *zap;

DESCRIPTION	Routine zclos closes the program ZLU set up by the zopen call and
	returns the ZLU back to the system for reuse. This call should normally
	always occur before a program terminates. If the program ZLU is not
	closed, then the ZCOM subsystem will continue to hold all of the
	resources associated with the ZLU and may add messages to the input
	queue. This feature allows a program to open a ZLU on another
	program’s behalf, or to be killed and rerun without losing any queued
	messages. It is the programmer’s responsibility to ensure that all
	unnecessary program ZLUs are closed before the program terminates.
	If zclos is called to close a program’s primary ZLU, the program will no
	longer have a primary ZLU. Usually, a program should open another
	ZLU as the primary ZLU because some APIs may return an error if the
	primary ZLU does not exist (e.g. zsend(3X)).
	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 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.

168 Chapter 4