ZQSZE (3X)

NAME

zqsze - Read ZLU input queue size

SYNOPSIS

#include  <zcom/zcomsys.h>
#include  <zcom/zcomcall.h> /* if compiled with ANSI C (recommended) */
 
int32 zqsze (zap, zqhdp)
 
zaddr_type  *zap; 
zqhd_type   *zqhdp;

DESCRIPTION

Routine zqsze will return the queue header information, which includes the number of messages, i.e., the number of buffers (zqhd_type->qnmsg) queued to the specified program ZLU. An error is returned if the ZLU is not a program ZLU.

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).

PARAMETERS

zap	ZCOM address
zqhdp (Return param)
	ZCOM queue header data structure. This structure has the following definition:
	typedef struct {
		uint32 qnmsg;	/* Number of msgs on queue */
		uint32 qlimit;	/* Max # of msgs allowed on queue */
		zbhd_type *qhead;	/* Pointer to 1st msg on queue */
		zbhd_type *qtail;	/* Pointer to last msg on queue */
		uint32 qmmax;	/* Historical max # of msgs on queue */
		uint32 qtmsg;	/* Total # of msgs through queue */
		uint32 qbytes;	/* Number of bytes on queue */
		uint16 qwaiter;	/* Number of waiters on this queue */
		uint16 qflag;	/* Queue flags */
		uint32 qfdata;	/* Queue function data */
		uint32 spare1;	/* Reserved, not used */
		void (*qfunc)();	/* Queue function to call */
	}	zqhd_type;

	Note that in 32-bit mode, 32-bit padding fields are inserted before the pointer fields. These are to maintain the same layout in both 32/64-bit modes. Such padding fields are not shown here and also should not be referenced directly.

RETURN VALUE

Routine zqsze 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;
zqhd_type      zqhd;
 
if (ierr = zqsze (&zaddr, &zqhd)) {
       /* 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).