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00011 #include <shogun/lib/config.h>
00012
00013 #ifndef WIN32
00014
00015 #include <stdlib.h>
00016 #include <signal.h>
00017 #include <string.h>
00018
00019 #include <shogun/io/SGIO.h>
00020 #include <shogun/lib/Signal.h>
00021
00022 using namespace shogun;
00023
00024 int CSignal::signals[NUMTRAPPEDSIGS]={SIGINT, SIGURG};
00025 struct sigaction CSignal::oldsigaction[NUMTRAPPEDSIGS];
00026 bool CSignal::active=false;
00027 bool CSignal::cancel_computation=false;
00028 bool CSignal::cancel_immediately=false;
00029
00030 CSignal::CSignal()
00031 : CSGObject()
00032 {
00033 }
00034
00035 CSignal::~CSignal()
00036 {
00037 if (!unset_handler())
00038 SG_PRINT("error uninitalizing signal handler\n");
00039 }
00040
00041 void CSignal::handler(int signal)
00042 {
00043 if (signal == SIGINT)
00044 {
00045 SG_SPRINT("\nImmediately return to prompt / Prematurely finish computations / Do nothing (I/P/D)? ");
00046 char answer=fgetc(stdin);
00047
00048 if (answer == 'I')
00049 {
00050 unset_handler();
00051 set_cancel(true);
00052 if (sg_print_error)
00053 sg_print_error(stdout, "sg stopped by SIGINT\n");
00054 }
00055 else if (answer == 'P')
00056 set_cancel();
00057 else
00058 SG_SPRINT("Continuing...\n");
00059 }
00060 else if (signal == SIGURG)
00061 set_cancel();
00062 else
00063 SG_SPRINT("unknown signal %d received\n", signal);
00064 }
00065
00066 bool CSignal::set_handler()
00067 {
00068 if (!active)
00069 {
00070 struct sigaction act;
00071 sigset_t st;
00072
00073 sigemptyset(&st);
00074 for (int32_t i=0; i<NUMTRAPPEDSIGS; i++)
00075 sigaddset(&st, signals[i]);
00076
00077 #ifndef __INTERIX
00078 act.sa_sigaction=NULL;
00079 #endif
00080 act.sa_handler=CSignal::handler;
00081 act.sa_mask = st;
00082 act.sa_flags = 0;
00083
00084 for (int32_t i=0; i<NUMTRAPPEDSIGS; i++)
00085 {
00086 if (sigaction(signals[i], &act, &oldsigaction[i]))
00087 {
00088 SG_SPRINT("Error trapping signals!\n");
00089 for (int32_t j=i-1; j>=0; j--)
00090 sigaction(signals[i], &oldsigaction[i], NULL);
00091
00092 clear();
00093 return false;
00094 }
00095 }
00096
00097 active=true;
00098 return true;
00099 }
00100 else
00101 return false;
00102 }
00103
00104 bool CSignal::unset_handler()
00105 {
00106 if (active)
00107 {
00108 bool result=true;
00109
00110 for (int32_t i=0; i<NUMTRAPPEDSIGS; i++)
00111 {
00112 if (sigaction(signals[i], &oldsigaction[i], NULL))
00113 {
00114 SG_SPRINT("error uninitalizing signal handler for signal %d\n", signals[i]);
00115 result=false;
00116 }
00117 }
00118
00119 if (result)
00120 clear();
00121
00122 return result;
00123 }
00124 else
00125 return false;
00126 }
00127
00128 void CSignal::clear_cancel()
00129 {
00130 cancel_computation=false;
00131 cancel_immediately=false;
00132 }
00133
00134 void CSignal::set_cancel(bool immediately)
00135 {
00136 cancel_computation=true;
00137
00138 if (immediately)
00139 cancel_immediately=true;
00140 }
00141
00142 void CSignal::clear()
00143 {
00144 clear_cancel();
00145 active=false;
00146 memset(&CSignal::oldsigaction, 0, sizeof(CSignal::oldsigaction));
00147 }
00148 #endif //WIN32