HP UX 11i v1 I/O Cards manual Zread, Cancellation point

ZCOM C I/F Library Routines

ZREAD (3X)

	ZREAD (3X)
NAME	zread – Read from ZLU
SYNOPSIS
#include	<zcom/zcomsys.h>
#include	<zcom/zcomcall.h> /* if compiled with ANSI C (recommended) */

int32 zread (zap, mode, mhp, ibuf, len, rlen, rstat)

zaddr_type	*zap;
uint32	mode;
zmhd_type	*mhp;
char	*ibuf;
int32	len;
int32	*rlen;
int32	*rstat;

DESCRIPTION	Routine zread fetches the next message from the head of a program ZLU
	queue. The program has the option to wait (i.e., suspend) if there is no
	data on the queue specified. The actual length of the data message is
	returned in rlen.
	This routine is similar to zpeek(3X) except it removes the message after
	fetching it.
	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 a 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.
	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).

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