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/*
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 3 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, see <http://www.gnu.org/licenses/>.
*/
/*
* 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;
readfds2 = (readfds ? &readfds_buf : NULL);
writefds2 = (writefds ? &writefds_buf : NULL);
errorfds2 = (errorfds ? &errorfds_buf : NULL);
if (tval) {
gettimeofday(&end_time, NULL);
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, NULL);
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;
}
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