Initial import

[samba] / examples / libsmbclient / smbwrapper / select.c

diff --git a/examples/libsmbclient/smbwrapper/select.c b/examples/libsmbclient/smbwrapper/select.c
new file mode 100644 (file)
index 0000000..aa90169
--- /dev/null
+++ b/examples/libsmbclient/smbwrapper/select.c
@@ -0,0 +1,124 @@
+/* 
+   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;
+}