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Diffstat (limited to 'examples/libsmbclient/smbwrapper/select.c')
| -rw-r--r-- | examples/libsmbclient/smbwrapper/select.c | 122 |
1 files changed, 122 insertions, 0 deletions
diff --git a/examples/libsmbclient/smbwrapper/select.c b/examples/libsmbclient/smbwrapper/select.c new file mode 100644 index 0000000000..bb7a25f13e --- /dev/null +++ b/examples/libsmbclient/smbwrapper/select.c @@ -0,0 +1,122 @@ +/* + 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; +} |