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/*
* SCCS: @(#)poll.c 1.9 (98/09/01)
*
* 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.
*/
/************************************************************************
SCCS: @(#)poll.c 1.9 98/09/01 TETware release 3.3
NAME: poll.c
PRODUCT: TETware
AUTHOR: Andrew Dingwall, UniSoft Ltd.
DATE CREATED: April 1992
DESCRIPTION:
required transport-specific library interface
poll remote process connections for the posibility of i/o
MODIFICATIONS:
Andrew Dingwall, UniSoft Ltd., November 1992
AIX-specific modifications.
Andrew Dingwall, UniSoft Ltd., July 1998
Now that AIX is UNIX98-compliant we don't need the AIX-specific
modifications any more.
Provision of FD_SET macro and friends now only if _XOPEN_SOURCE
is not defined.
Aaron Plattner, April 2010
Fixed warnings when compiled with GCC's -Wall option.
************************************************************************/
#include <errno.h>
#include <sys/types.h>
# if defined(_AIX) && !defined(_XOPEN_SOURCE)
# include <sys/select.h>
# endif /* _AIX */
# include <sys/time.h>
# include <netinet/in.h>
#include "dtmac.h"
#include "dtmsg.h"
#include "ptab.h"
#include "error.h"
#include "tptab_in.h"
#include "server_in.h"
#include "tslib.h"
#ifndef NOTRACE
#include "ltoa.h"
#endif
/*
** compatability for systems with pre-BSD4.3 select() call -
** only one long in fd_set
**
** in UniPlus V.2, fd_set is already typedefed in <sys/types.h>
** on systems where this is not done, you will need something like
**
** typedef struct { long fd_bits[1]; } fd_set;
**
** here as well
*/
#ifndef _XOPEN_SOURCE
# ifndef FD_SET
# define FD_SET(n, p) ((p)->fds_bits[0] |= (1L << (n)))
# define FD_CLR(n, p) ((p)->fds_bits[0] &= ~(1L << (n)))
# define FD_ISSET(n, p) ((p)->fds_bits[0] & (1L << (n)))
# define FD_ZERO(p) ((p)->fds_bits[0] = 0L)
# endif /* FD_SET */
#endif /* !_XOPEN_SOURCE */
/*
** tet_ts_poll() - poll for connection attempts, and pending i/o
** to/from connected processes in the ptab list at *pp
**
** return 1 if there is at least one i/o request to service
** 0 if no requests arrive before the timeout expires
** -1 on error
*/
int tet_ts_poll(pp, timeout)
struct ptab *pp;
int timeout;
{
register struct ptab *q;
register struct tptab *tp;
fd_set rfds, wfds, rd, wd;
int nfds, nfound, err;
struct timeval tv;
register struct timeval *tvp;
extern SOCKET tet_listen_sd;
TRACE2(tet_Tio, 4, "tet_ts_poll: timeout = %s", tet_i2a(timeout));
/* clear descriptor masks for select -
arrange to receive new connection notification */
FD_ZERO(&rfds);
FD_ZERO(&wfds);
if (tet_listen_sd != INVALID_SOCKET) {
TRACE2(tet_Tio, 6, "poll listen sd %s for reading",
tet_i2a(tet_listen_sd));
FD_SET(tet_listen_sd, &rfds);
nfds = tet_listen_sd + 1;
}
else
nfds = 0;
/* set fd_set bits according to process state */
for (q = pp; q; q = q->pt_next) {
ASSERT(q->pt_magic == PT_MAGIC);
tp = (struct tptab *) q->pt_tdata;
if (tp->tp_sd == INVALID_SOCKET)
continue;
switch (q->pt_state) {
case PS_IDLE:
q->pt_state = PS_RCVMSG;
/* fall through */
case PS_RCVMSG:
TRACE2(tet_Tio, 6, "poll sd %s for reading",
tet_i2a(tp->tp_sd));
FD_SET(tp->tp_sd, &rfds);
if (tp->tp_sd >= nfds)
nfds = tp->tp_sd + 1;
break;
case PS_CONNECT:
case PS_SNDMSG:
TRACE2(tet_Tio, 6, "poll sd %s for writing",
tet_i2a(tp->tp_sd));
FD_SET(tp->tp_sd, &wfds);
if (tp->tp_sd >= nfds)
nfds = tp->tp_sd + 1;
break;
}
}
/* set select timeout */
if (timeout >= 0) {
tv.tv_sec = timeout;
tv.tv_usec = 0;
tvp = &tv;
}
else
tvp = (struct timeval *) 0;
/* do the select operation -
we use temporary copies of rfds and wfds because they
get trashed if select returns with EINTR */
do {
TRACE3(tet_Tio, 8, "select: rfds = %s, wfds = %s",
tet_l2x(rfds.fds_bits[0]), tet_l2x(wfds.fds_bits[0]));
rd = rfds;
wd = wfds;
err = 0;
if ((nfound = select(nfds, &rd, &wd, (fd_set *) 0, tvp)) == SOCKET_ERROR)
err = SOCKET_ERRNO;
} while (nfound == SOCKET_ERROR && err == SOCKET_EINTR);
rfds = rd;
wfds = wd;
if (nfound >= 0)
TRACE2(tet_Tio, 6, "select returns %s", tet_i2a(nfound));
if (nfound == SOCKET_ERROR) {
error(err, "select() failed", (char *) 0);
return(-1);
}
else if (nfound == 0)
return(0);
/* accept a new connection if one is pending on the listen socket */
if (tet_listen_sd != INVALID_SOCKET && FD_ISSET(tet_listen_sd, &rfds)) {
TRACE1(tet_Tio, 6, "i/o possible on listen sd");
FD_CLR(tet_listen_sd, &rfds);
tet_ss_tsaccept();
nfound--;
}
/* arrange to service processes where i/o is possible */
for (q = pp; q && nfound >= 0; q = q->pt_next) {
ASSERT(q->pt_magic == PT_MAGIC);
tp = (struct tptab *) q->pt_tdata;
if (FD_ISSET(tp->tp_sd, &wfds)) {
TRACE2(tet_Tio, 6, "i/o possible on write sd %s",
tet_i2a(tp->tp_sd));
nfound--;
if (q->pt_state == PS_CONNECT) {
q->pt_state = PS_SNDMSG;
q->pt_flags = (q->pt_flags & ~PF_INPROGRESS) | PF_CONNECTED;
}
q->pt_flags |= PF_ATTENTION;
}
if (FD_ISSET(tp->tp_sd, &rfds)) {
TRACE2(tet_Tio, 6, "i/o possible on read sd %s",
tet_i2a(tp->tp_sd));
nfound--;
q->pt_flags |= PF_ATTENTION;
}
}
return(1);
}
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