mirror of
https://gitlab.com/etherlab.org/ethercat.git
synced 2026-08-18 09:07:24 +08:00
Per Noergaard Christensen
38038f6a48
This flag specifies that the file descriptor should be closed when an exec function is invoked. When a file descriptor is allocated (as with open or dup), O_CLOEXEC bit is initially cleared on the new file descriptor, meaning that descriptor will survive into the new program after exec. Setting O_CLOEXEC avoid this survival of the desciptor in the new program. And setting it at open() time is the only race-free way to avoid accidentally leaking the fd via other threads that concurrently do fork()+exec() (or similar, e.g. posix_spawn).
------------------------------------------------------------------------------ This is the README file of the IgH EtherCAT Master. $Id$ vim: spelllang=en spell tw=78 ------------------------------------------------------------------------------ Contents: 1) General Information 2) Requirements 3) Building and installing 4) Realtime & Tuning 5) License 6) Coding Style ------------------------------------------------------------------------------ 1) General Information ====================== This is an open-source EtherCAT master implementation for Linux 2.6. See the FEATURES file for a list of features. For more information, see http://etherlab.org/en/ethercat. or contact Dipl.-Ing. (FH) Florian Pose <fp@igh-essen.com> Ingenieurgemeinschaft IgH Heinz-Baecker-Str. 34 D-45356 Essen http://igh-essen.com ------------------------------------------------------------------------------ 2) Requirements =============== 1) Software requirements Configured sources for the Linux 2.6 kernel are required to build the EtherCAT master. 2) Hardware requirements A table of supported hardware can be found at http://etherlab.org/en/ethercat/hardware.php. ------------------------------------------------------------------------------ 3) Building and installing ========================== See the INSTALL file. ------------------------------------------------------------------------------ 4) Realtime & Tuning ==================== Realtime patches for the Linux kernel are supported, but not required. The realtime processing has to be done by the calling module (see API documentation). The EtherCAT master code itself is passive (except for the idle mode and EoE). To avoid frame timeouts, deactivating DMA access for hard drives is recommended (hdparm -d0 <DEV>). ------------------------------------------------------------------------------ 5) License ========== Copyright (C) 2006-2009 Florian Pose, Ingenieurgemeinschaft IgH This file is part of the IgH EtherCAT Master. The IgH EtherCAT Master is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License version 2, as published by the Free Software Foundation. The IgH EtherCAT Master 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 the IgH EtherCAT Master; if not, write to the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA --- The license mentioned above concerns the source code only. Using the EtherCAT technology and brand is only permitted in compliance with the industrial property and similar rights of Beckhoff Automation GmbH. ------------------------------------------------------------------------------ 6) Coding Style =============== Developers shall use the coding style rules in the CodingStyle.txt file. ------------------------------------------------------------------------------