libhoomd/utils/SignalHandler.cc

   1 /*
   2 Highly Optimized Object-oriented Many-particle Dynamics -- Blue Edition
   3 (HOOMD-blue) Open Source Software License Copyright 2009-2014 The Regents of
   4 the University of Michigan All rights reserved.
   5
   6 HOOMD-blue may contain modifications ("Contributions") provided, and to which
   7 copyright is held, by various Contributors who have granted The Regents of the
   8 University of Michigan the right to modify and/or distribute such Contributions.
   9
  10 You may redistribute, use, and create derivate works of HOOMD-blue, in source
  11 and binary forms, provided you abide by the following conditions:
  12
  13 * Redistributions of source code must retain the above copyright notice, this
  14 list of conditions, and the following disclaimer both in the code and
  15 prominently in any materials provided with the distribution.
  16
  17 * Redistributions in binary form must reproduce the above copyright notice, this
  18 list of conditions, and the following disclaimer in the documentation and/or
  19 other materials provided with the distribution.
  20
  21 * All publications and presentations based on HOOMD-blue, including any reports
  22 or published results obtained, in whole or in part, with HOOMD-blue, will
  23 acknowledge its use according to the terms posted at the time of submission on:
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  27 http://codeblue.umich.edu/hoomd-blue/
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  29 * Apart from the above required attributions, neither the name of the copyright
  30 holder nor the names of HOOMD-blue's contributors may be used to endorse or
  31 promote products derived from this software without specific prior written
  32 permission.
  33
  34 Disclaimer
  35
  36 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER AND CONTRIBUTORS ``AS IS'' AND
  37 ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  38 WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, AND/OR ANY
  39 WARRANTIES THAT THIS SOFTWARE IS FREE OF INFRINGEMENT ARE DISCLAIMED.
  40
  41 IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
  42 INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
  43 BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  44 DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  45 LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
  46 OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
  47 ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  48 */
  49
  50 // Maintainer: joaander
  51
  52 #include <signal.h>
  53 #include "SignalHandler.h"
  54 #include <iostream>
  55
  56 using namespace std;
  57
  58 /*! \file SignalHandler.cc
  59     \brief Defines variables and functions related to handling signals
  60 */
  61
  62 //! Tracks the previous signal handler that was set to make a chain
  63 void (*prev_sigint_handler)(int) = NULL;
  64
  65 volatile sig_atomic_t g_sigint_recvd = 0;
  66
  67 //! The actual signal handler
  68 extern "C" void sigint_handler(int sig)
  69     {
  70     // ignore if we didn't get SIGINT
  71     if (sig != SIGINT)
  72         return;
  73
  74     // call the previous signal handler, but only if it is well defined
  75     if (prev_sigint_handler && prev_sigint_handler != SIG_ERR && prev_sigint_handler != SIG_DFL && prev_sigint_handler != SIG_IGN)
  76         prev_sigint_handler(sig);
  77
  78     // set the global
  79     g_sigint_recvd = 1;
  80     }
  81
  82 /*! Call only once at the start of program execution. This method
  83     installs a signal handler for SIGING that will set \c g_sigint_recvd
  84     to 1. It will also call the previously set signal handler.
  85 */
  86 void InstallSIGINTHandler()
  87     {
  88     void (*retval)(int) = NULL;
  89     retval = signal(SIGINT, sigint_handler);
  90
  91     if (retval == SIG_ERR)
  92         {
  93         cerr << "Error setting signal handler" << endl;
  94         return;
  95         }
  96
  97     // set the previous signal handler, but only if it is not the same as the
  98     // one we just set. That would make for a fun infinite loop!
  99     if (retval != sigint_handler)
 100         prev_sigint_handler = retval;
 101     else
 102         prev_sigint_handler = NULL;
 103     }