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/*
* SCCS: @(#)sloop.c 1.9 (96/12/02)
*
* UniSoft Ltd., London, England
*
* (C) Copyright 1992 X/Open Company Limited
*
* All rights reserved. No part of this source code may be reproduced,
* stored in a retrieval system, or transmitted, in any form or by any
* means, electronic, mechanical, photocopying, recording or otherwise,
* except as stated in the end-user licence agreement, without the prior
* permission of the copyright owners.
*
* X/Open and the 'X' symbol are trademarks of X/Open Company Limited in
* the UK and other countries.
*/
#ifndef lint
static char sccsid[] = "@(#)sloop.c 1.9 (96/12/02) TET3 release 3.3";
#endif
/************************************************************************
SCCS: @(#)sloop.c 1.9 96/12/02 TETware release 3.3
NAME: sloop.c
PRODUCT: TETware
AUTHOR: Andrew Dingwall, UniSoft Ltd.
DATE CREATED: April 1992
DESCRIPTION:
generic server loop processing functions
MODIFICATIONS:
Andrew Dingwall, UniSoft Ltd., January 1994
added ptab tracing
Andrew Dingwall, UniSoft Ltd., December 1996
removed (time_t == unsigned long) assumption for n-bit portability
************************************************************************/
#include <stdio.h>
#include <stdlib.h>
#include <limits.h>
#include <sys/types.h>
#include <time.h>
#include "dtmac.h"
#include "dtmsg.h"
#include "ptab.h"
#include "error.h"
#include "server.h"
#include "servlib.h"
#include "tslib.h"
#ifndef NOTRACE
#include "ltoa.h"
#include "dtetlib.h"
#endif
#ifdef NEEDsrcFile
static char srcFile[] = __FILE__; /* file name for error reporting */
#endif
/* static function declarations */
static void si_procrun PROTOLIST((void));
static int si_timeouts PROTOLIST((void));
/*
** tet_si_serverloop() - perform a single server process loop iteration
**
** poll for incoming requests, then service any resulting events;
** do timeout processing, then service any resulting events
**
** the tet_ts_poll() routine should perform a poll of all connections to
** processes in states PS_IDLE, PS_RCVMSG, PS_SNDMSG and PS_CONNECT
** if data can be read (PS_IDLE or PS_RCVMSG) or written (PS_SNDMSG
** or PS_CONNECT) without blocking, raise PF_ATTENTION
** change the state to PS_RCVMSG or PS_SNDMSG as appropriate
** if the poll is implemented by doing a non-blocking read or write,
** set the state and flags as described for tet_ts_rcvmsg()
** or tet_ts_sndmsg()
**
** if a new connection request is received, a new ptab element should be
** allocated by tet_ptalloc() and linked to the ptab list by tet_ptadd() -
** if a connection is accepted without reading any data, set the state to
** PS_RCVMSG and raise PF_ATTENTION, otherwise set the state and flags as
** described for tet_ts_rcvmsg() below
**
** tet_ts_poll() should return 1 as soon as i/o is possible, or 0 after
** delay seconds if no i/o is possible
** if delay is -ve, tet_ts_poll() should not return until i/o is possible
*/
#define INFINITY ~((time_t) 1 << ((sizeof (time_t) * CHAR_BIT) - 1))
void tet_si_serverloop()
{
register struct ptab *pp;
register time_t timeout;
register int delay, rc;
extern struct ptab *tet_ptab;
/* see how long it is to the next timeout */
timeout = INFINITY;
for (pp = tet_ptab; pp; pp = pp->pt_next) {
ASSERT(pp->pt_magic == PT_MAGIC);
if (pp->pt_timeout && pp->pt_timeout < timeout)
timeout = pp->pt_timeout;
}
if (timeout == INFINITY)
delay = tet_ptab ? LONGDELAY : SHORTDELAY;
else if ((delay = (int) (timeout - time((time_t *) 0))) < 0 ||
delay > LONGDELAY)
delay = LONGDELAY;
TRACE3(tet_Tloop, 2,
"tet_si_serverloop TOP: tet_ptab = %s, poll timeout = %s",
tet_i2x(tet_ptab), tet_i2a(delay));
#ifndef NOTRACE
if (tet_Tloop) {
TRACE2(tet_Tloop, 10, "process table:%s",
tet_ptab ? "" : " empty");
for (pp = tet_ptab; pp; pp = pp->pt_next)
TRACE6(tet_Tloop, 10,
"pp = %s, next = %s, proc = %s, state = %s, flags = %s",
tet_i2x(pp), tet_i2x(pp->pt_next),
tet_r2a(&pp->pt_rid),
tet_ptstate(pp->pt_state),
tet_ptflags(pp->pt_flags));
}
#endif
/* perform the main loop */
if ((rc = tet_ts_poll(tet_ptab, delay)) > 0)
si_procrun();
else if (rc < 0)
exit(1);
if (si_timeouts() > 0)
si_procrun();
}
/*
** si_procrun() - scan the process table for processes that need servicing
** call the service routine for those that do
*/
static void si_procrun()
{
extern struct ptab *tet_ptab;
register struct ptab *pp;
register int done;
TRACE2(tet_Tloop, 8, "si_procrun START: tet_ptab = %s",
tet_i2x(tet_ptab));
do {
TRACE2(tet_Tloop, 8, "si_procrun RESTART: tet_ptab = %s",
tet_i2x(tet_ptab));
done = 1;
for (pp = tet_ptab; pp; pp = pp->pt_next) {
TRACE3(tet_Tloop, 8, "pp = %s, next = %s",
tet_i2x(pp), tet_i2x(pp->pt_next));
ASSERT(pp->pt_magic == PT_MAGIC);
if (pp->pt_flags & PF_ATTENTION) {
pp->pt_flags &= ~PF_ATTENTION;
tet_si_service(pp);
done = 0;
break;
}
}
} while (!done);
TRACE2(tet_Tloop, 8, "si_procrun END: tet_ptab = %s",
tet_i2x(tet_ptab));
/* call the server-specific end-procrun routine */
tet_ss_procrun();
}
/*
** si_timeouts() - process event timeouts
**
** return 1 if any events need to be serviced, 0 otherwise
*/
static int si_timeouts()
{
extern struct ptab *tet_ptab;
register struct ptab *pp;
register time_t now = time((time_t *) 0);
register int found = 0;
for (pp = tet_ptab; pp; pp = pp->pt_next) {
ASSERT(pp->pt_magic == PT_MAGIC);
if (pp->pt_timeout > 0 && pp->pt_timeout <= now) {
pp->pt_flags |= PF_TIMEDOUT;
pp->pt_timeout = 0;
TRACE4(tet_Tloop, 4, "%s: about to call tet_ss_timeout: state = %s, flags = %s",
tet_r2a(&pp->pt_rid),
tet_ptstate(pp->pt_state),
tet_ptflags(pp->pt_flags));
tet_ss_timeout(pp);
found = 1;
}
}
return(found);
}
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