Edit File: select.c
/* 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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