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 Considerations

This routine may be called from 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).

PARAMETERS

zap

ZCOM address to be returned to the system.

RETURN VALUE

Routine zclos returns 0 if successful. Otherwise, a non-zero error code is returned. See /opt/acc/include/zcom/zcomsys.h for the list of ZCOM error codes and their meanings.

EXAMPLE

#include        <zcom/zcomsys.h>
#include        <zcom/zcomcall.h>
 
int32           ierr;
zaddr_type     zaddr;
 
if (ierr = zclos (&zaddr)) {
           /* error return code */
}
else {
           /* good return code */
}

FILES

/opt/acc/include/zcom/zcomsys.h	ZCOM subsystem general include file, containing data types, data structures, constants, error codes, masks, etc. Note that this must be the first include file before any other ZCOM include files.
/opt/acc/include/zcom/zcomcall.h	ZCOM routine function prototypes (requires ANSI C compilation).

ZCLOS (3X)

Technical documentation

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