HP Advanced Communications Controllers (ACC) 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.

296 Chapter 4