/*    Unix SMB/Netbios implementation.   Version 3.0   Samba select/poll implementation   Copyright (C) Andrew Tridgell 1992-1998   Copyright (C) Derrell Lipman 2003-2005      This program is free software; you can redistribute it and/or modify   it under the terms of the GNU General Public License as published by   the Free Software Foundation; either version 2 of the License, or   (at your option) any later version.      This program is distributed in the hope that it will be useful,   but WITHOUT ANY WARRANTY; without even the implied warranty of   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the   GNU General Public License for more details.      You should have received a copy of the GNU General Public License   along with this program; if not, write to the Free Software   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.*//* * WHY THIS FILE? * * This file implements the two functions in the select() family, as required * by samba.  The samba native functions, though, implement a pipe to help * alleviate a deadlock problem, but which creates problems of its own (the * timeout stops working correctly).  Those functions also require that all * signal handlers call a function which writes to the pipe -- a task which is * difficult to do in the smbwrapper environment. */#include <sys/select.h>#include <errno.h>#include <stdio.h>int sys_select(int maxfd, fd_set *readfds, fd_set *writefds, fd_set *errorfds, struct timeval *tval){        int ret;	fd_set *readfds2, readfds_buf;	/* If readfds is NULL we need to provide our own set. */	if (readfds) {		readfds2 = readfds;	} else {		readfds2 = &readfds_buf;		FD_ZERO(readfds2);	}	errno = 0;	ret = select(maxfd,readfds2,writefds,errorfds,tval);	if (ret <= 0) {		FD_ZERO(readfds2);		if (writefds)			FD_ZERO(writefds);		if (errorfds)			FD_ZERO(errorfds);	}	return ret;}/******************************************************************* Similar to sys_select() but catch EINTR and continue. This is what sys_select() used to do in Samba.********************************************************************/int sys_select_intr(int maxfd, fd_set *readfds, fd_set *writefds, fd_set *errorfds, struct timeval *tval){	int ret;	fd_set *readfds2, readfds_buf, *writefds2, writefds_buf, *errorfds2, errorfds_buf;	struct timeval tval2, *ptval, end_time, now_time;        extern void GetTimeOfDay(struct timeval *tval);	readfds2 = (readfds ? &readfds_buf : NULL);	writefds2 = (writefds ? &writefds_buf : NULL);	errorfds2 = (errorfds ? &errorfds_buf : NULL);        if (tval) {                GetTimeOfDay(&end_time);                end_time.tv_sec += tval->tv_sec;                end_time.tv_usec += tval->tv_usec;                end_time.tv_sec += end_time.tv_usec / 1000000;                end_time.tv_usec %= 1000000;                ptval = &tval2;        } else {                ptval = NULL;        }	do {		if (readfds)			readfds_buf = *readfds;		if (writefds)			writefds_buf = *writefds;		if (errorfds)			errorfds_buf = *errorfds;		if (tval) {                        GetTimeOfDay(&now_time);                        tval2.tv_sec = end_time.tv_sec - now_time.tv_sec;			tval2.tv_usec = end_time.tv_usec - now_time.tv_usec;                        if ((signed long) tval2.tv_usec < 0) {                                tval2.tv_usec += 1000000;                                tval2.tv_sec--;                        }                        if ((signed long) tval2.tv_sec < 0) {                                ret = 0;                                break;          /* time has already elapsed */                        }                }		ret = sys_select(maxfd, readfds2, writefds2, errorfds2, ptval);	} while (ret == -1 && errno == EINTR);	if (readfds)		*readfds = readfds_buf;	if (writefds)		*writefds = writefds_buf;	if (errorfds)		*errorfds = errorfds_buf;	return ret;}