ceph/src/boost/libs/sort/example/parallelint.cpp

   1 //  Benchmark for integer sorting speed across parallel threads.
   2 //
   3 //  Copyright Steven Ross 2014
   4 //
   5 // Distributed under the Boost Software License, Version 1.0.
   6 //    (See accompanying file LICENSE_1_0.txt or copy at
   7 //          http://www.boost.org/LICENSE_1_0.txt)
   8
   9 //  See http://www.boost.org/libs/sort for library home page.
  10
  11 #include <boost/sort/spreadsort/spreadsort.hpp>
  12 #include <boost/thread.hpp>
  13 #include <time.h>
  14 #include <stdio.h>
  15 #include <stdlib.h>
  16 #include <algorithm>
  17 #include <vector>
  18 #include <string>
  19 #include <fstream>
  20 #include <sstream>
  21 #include <iostream>
  22 using namespace boost::sort::spreadsort;
  23
  24 #define DATA_TYPE int
  25
  26 bool is_sorted(const std::vector<DATA_TYPE> &array) {
  27   for (unsigned u = 0; u + 1 < array.size(); ++u) {
  28     if (array[u] > array[u + 1]) {
  29       return false;
  30     }
  31   }
  32   return true;
  33 }
  34
  35 void sort_loop(const std::vector<DATA_TYPE> &base_array, bool stdSort,
  36                unsigned loopCount) {
  37   std::vector<DATA_TYPE> array(base_array);
  38   for (unsigned u = 0; u < loopCount; ++u) {
  39     for (unsigned v = 0; v < base_array.size(); ++v) {
  40       array[v] = base_array[v];
  41     }
  42     if (stdSort)
  43       std::sort(array.begin(), array.end());
  44     else
  45       boost::sort::spreadsort::spreadsort(array.begin(), array.end());
  46     if (!is_sorted(array)) {
  47       fprintf(stderr, "sort failed!\n");
  48       exit(1);
  49     }
  50   }
  51 }
  52
  53 //Pass in an argument to test std::sort
  54 int main(int argc, const char ** argv) {
  55   size_t uCount,uSize=sizeof(DATA_TYPE);
  56   bool stdSort = false;
  57   int threadCount = -1;
  58   unsigned loopCount = 0;
  59   for (int u = 1; u < argc; ++u) {
  60     if (std::string(argv[u]) == "-std")
  61       stdSort = true;
  62     else if(threadCount < 0)
  63       threadCount = atoi(argv[u]);
  64     else
  65       loopCount = atoi(argv[u]);
  66   }
  67   if (!loopCount) {
  68     loopCount = 1;
  69   }
  70   printf("threads: %d loops: %d\n", threadCount, loopCount);
  71
  72   std::ifstream input("input.txt", std::ios_base::in | std::ios_base::binary);
  73   if (input.fail()) {
  74     printf("input.txt could not be opened\n");
  75     return 1;
  76   }
  77   std::vector<DATA_TYPE> base_array;
  78   input.seekg (0, std::ios_base::end);
  79   size_t length = input.tellg();
  80   uCount = length/uSize;
  81   input.seekg (0, std::ios_base::beg);
  82   //Conversion to a vector
  83   base_array.resize(uCount);
  84   unsigned v = 0;
  85   while (input.good() && v < uCount)
  86     input.read(reinterpret_cast<char *>(&(base_array[v++])), uSize );
  87   input.close();
  88   if (v < uCount)
  89     base_array.resize(v);
  90   //Run multiple loops, if requested
  91   clock_t start, end;
  92   double elapsed;
  93   std::vector<boost::thread *> workers;
  94   start = clock();
  95   if (threadCount == 0) {
  96     sort_loop(base_array, stdSort, loopCount);
  97   } else {
  98     for (int i = 0; i < threadCount; ++i) {
  99       workers.push_back(new boost::thread(sort_loop, base_array, stdSort,
 100                                           loopCount));
 101     }
 102     for (int i = 0; i < threadCount; ++i) {
 103       workers[i]->join();
 104       delete workers[i];
 105     }
 106   }
 107   end = clock();
 108   elapsed = static_cast<double>(end - start) ;
 109
 110   if (stdSort)
 111     printf("std::sort clock time %lf\n", elapsed/CLOCKS_PER_SEC/threadCount);
 112   else
 113     printf("spreadsort clock time %lf\n", elapsed/CLOCKS_PER_SEC/threadCount);
 114   return 0;
 115 }