exceptions.cpp
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00001 
00008 /*****************************************************************************
00009 ** Includes
00010 *****************************************************************************/
00011 #include <iostream>
00012 #include <sstream>
00013 #include <ecl/threads/priority.hpp>
00014 #include <ecl/time/stopwatch.hpp>
00015 #include <ecl/time/timestamp.hpp>
00016 #include <ecl/exceptions/standard_exception.hpp>
00017 
00018 /*****************************************************************************
00019 ** Using
00020 *****************************************************************************/
00021 
00022 using std::string;
00023 using ecl::StopWatch;
00024 using ecl::TimeStamp;
00025 using ecl::ConfigurationError;
00026 using ecl::StandardException;
00027 
00028 /*****************************************************************************
00029 ** Globals
00030 *****************************************************************************/
00031 
00032 void f1() {
00033         int i = 0;
00034         if ( i == 1 ) {}
00035 }
00036 
00037 void f2() throw(StandardException) {
00038         int i = 0;
00039         if ( i == 1 ) {}
00040 }
00041 
00042 void f3() throw(StandardException) {
00043         int i = 0;
00044         if ( i == 1 ) {
00045                 throw StandardException(LOC,ConfigurationError);
00046         }
00047 }
00048 
00049 void f4() throw(StandardException) {
00050         int i = 0;
00051         if ( i == 1 ) {
00052                 throw StandardException(LOC,ConfigurationError, "Standard exception with an extra string message.");
00053         }
00054 }
00055 
00056 void f5() throw(StandardException) {
00057         throw StandardException(LOC,ConfigurationError);
00058 }
00059 
00060 void f6() throw(StandardException) {
00061         throw StandardException(LOC,ConfigurationError, "Standard exception with an extra string message.");
00062 }
00063 
00064 void g1() throw(StandardException) {
00065         double dude[5];
00066         for ( unsigned int j = 0; j < 5; ++j ) {
00067                 dude[j] = 3.15*543/230.235;
00068         }
00069 }
00070 
00071 void g2() throw(StandardException) {
00072         int i = 0;
00073         double dude[5];
00074         for ( unsigned int j = 0; j < 5; ++j ) {
00075                 dude[j] = 3.15*543/230.235;
00076         }
00077         if ( i == 1 ) {
00078                 throw StandardException(LOC,ConfigurationError, "Standard exception with an extra string message.");
00079         }
00080 }
00081 
00082 /*****************************************************************************
00083 ** Main
00084 *****************************************************************************/
00085 
00086 int main()
00087 {
00088         try {
00089                 ecl::set_priority(ecl::RealTimePriority4);
00090         } catch ( StandardException &e ) {
00091                 // dont worry about it.
00092         }
00093     StopWatch stopwatch;
00094     TimeStamp times[9];
00095 
00096     stopwatch.restart();
00097     f1();
00098     times[0] = stopwatch.split();
00099     f2();
00100     times[1] = stopwatch.split();
00101     f3();
00102     times[2] = stopwatch.split();
00103     f4();
00104     times[3] = stopwatch.split();
00105     g1();
00106     times[4] = stopwatch.split();
00107     g2();
00108     times[5] = stopwatch.split();
00109     try {
00110         f2();
00111     } catch ( StandardException &e ) {
00112     }
00113     times[6] = stopwatch.split();
00114     try {
00115         f5();
00116     } catch ( StandardException &e ) {}
00117     times[7] = stopwatch.split();
00118     try {
00119         f6();
00120     } catch ( StandardException &e ) {}
00121     times[8] = stopwatch.split();
00122 
00123     // Try and negate the effects of caching on early instructions (i.e. get right into cache).
00124     stopwatch.restart();
00125     f1();
00126     times[0] = stopwatch.split();
00127     f2();
00128     times[1] = stopwatch.split();
00129     f3();
00130     times[2] = stopwatch.split();
00131     f4();
00132     times[3] = stopwatch.split();
00133     g1();
00134     times[4] = stopwatch.split();
00135     g2();
00136     times[5] = stopwatch.split();
00137 
00138     try {
00139         f2();
00140     } catch ( StandardException &e ) {
00141     }
00142     times[6] = stopwatch.split();
00143     try {
00144         f5();
00145     } catch ( StandardException &e ) {}
00146     times[7] = stopwatch.split();
00147     try {
00148         f6();
00149     } catch ( StandardException &e ) {}
00150     times[8] = stopwatch.split();
00151 
00152     std::cout << std::endl;
00153     std::cout << "***********************************************************" << std::endl;
00154     std::cout << "         Performance comparison ecl exceptions" << std::endl;
00155     std::cout << "***********************************************************" << std::endl;
00156     std::cout << std::endl;
00157 
00158     std::cout << "Simple Candidate Function      " << " Time: " << times[0] <<  std::endl;
00159     std::cout << "  Undeclared exception         " << " Time: " << times[1] <<  std::endl;
00160     std::cout << "  Unused exception             " << " Time: " << times[2] <<  std::endl;
00161     std::cout << "  Unused exception w/ string   " << " Time: " << times[3] <<  std::endl;
00162     std::cout << std::endl;
00163     std::cout << "Complex Candidate Function     " << " Time: " << times[4] <<  std::endl;
00164     std::cout << "  Unused exception w/ string   " << " Time: " << times[5] <<  std::endl;
00165     std::cout << std::endl;
00166     std::cout << "Try Catch Blocks  " << std::endl;
00167     std::cout << "  Uncaught exceptions          " << " Time: " << times[6] <<  std::endl;
00168     std::cout << "  Caught exception             " << " Time: " << times[7] <<  std::endl;
00169     std::cout << "  Caught exception w/string    " << " Time: " << times[8] <<  std::endl;
00170 
00171     std::cout << std::endl;
00172     std::cout << "***********************************************************" << std::endl;
00173     std::cout << "                      Conclusions" << std::endl;
00174     std::cout << "***********************************************************" << std::endl;
00175     std::cout << std::endl;
00176 
00177     std::cout << "The following conclusions are after testing on a dual core." << std::endl;
00178     std::cout << std::endl;
00179     std::cout << " - In simple functions, unused ecl exceptions < 50ns." << std::endl;
00180     std::cout << " - String messages don't effect the cost of unused ecl exceptions." << std::endl;
00181     std::cout << " - Try-catch blocks have negligible cost." << std::endl;
00182     std::cout << " - String messages do impact caught messages ~1us." << std::endl;
00183     std::cout << std::endl;
00184     return 0;
00185 }
00186 
00187 


ecl_core_apps
Author(s): Daniel Stonier
autogenerated on Wed Aug 26 2015 11:27:59