ceph/src/boost/libs/sort/example/parallelstring.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/random/mersenne_twister.hpp>
  12 #include <boost/random/uniform_int_distribution.hpp>
  13 #include <boost/sort/spreadsort/spreadsort.hpp>
  14 #include <boost/thread.hpp>
  15 #include <time.h>
  16 #include <stdio.h>
  17 #include <stdlib.h>
  18 #include <algorithm>
  19 #include <vector>
  20 #include <iostream>
  21 #include <fstream>
  22 #include <string>
  23 using std::string;
  24 using namespace boost::sort::spreadsort;
  25
  26 #define DATA_TYPE string
  27
  28 static bool is_sorted(const std::vector<DATA_TYPE> &array) {
  29   for (unsigned u = 0; u + 1 < array.size(); ++u) {
  30     if (array[u] > array[u + 1]) {
  31       return false;
  32     }
  33   }
  34   return true;
  35 }
  36
  37 static void sort_core(std::vector<DATA_TYPE> &array, bool stdSort,
  38                unsigned loopCount) {
  39   if (stdSort)
  40     std::sort(array.begin(), array.end());
  41   else
  42     boost::sort::spreadsort::spreadsort(array.begin(), array.end());
  43   if (!is_sorted(array)) {
  44     fprintf(stderr, "sort failed!\n");
  45     exit(1);
  46   }
  47 }
  48
  49 static void sort_loop(const std::vector<DATA_TYPE> &base_array, bool stdSort,
  50                unsigned loopCount) {
  51   std::vector<DATA_TYPE> array(base_array);
  52   for (unsigned u = 0; u < loopCount; ++u) {
  53     for (unsigned v = 0; v < base_array.size(); ++v) {
  54       array[v] = base_array[v];
  55     }
  56     sort_core(array, stdSort, loopCount);
  57   }
  58 }
  59
  60 //Pass in an argument to test std::sort
  61 int main(int argc, const char ** argv) {
  62   std::ifstream indata;
  63   std::ofstream outfile;
  64   bool stdSort = false;
  65   int constant_to_random_ratio = -1;
  66   int threadCount = -1;
  67   unsigned loopCount = 0;
  68   for (int u = 1; u < argc; ++u) {
  69     if (std::string(argv[u]) == "-std")
  70       stdSort = true;
  71     else if(threadCount < 0)
  72       threadCount = atoi(argv[u]);
  73     else if (!loopCount)
  74       loopCount = atoi(argv[u]);
  75     else
  76       constant_to_random_ratio = atoi(argv[u]);
  77   }
  78   if (!loopCount) {
  79     loopCount = 1;
  80   }
  81   printf("threads: %d loops: %d\n", threadCount, loopCount);
  82
  83   std::vector<DATA_TYPE> base_array;
  84   if (constant_to_random_ratio >= 0) {
  85     //Test for random data with gaps of identical data.
  86     random::mt19937 generator;
  87     random::uniform_int_distribution<int> distribution(0,255);
  88     const int constant_to_random_count = 1000000;
  89     const int string_length = 1000;
  90     for (int i = 0; i < constant_to_random_count; ++i) {
  91       DATA_TYPE temp(string_length, 'x');  // fill with default character.
  92       for (int j = constant_to_random_ratio; j < string_length;) {
  93         int val = distribution(generator);
  94         temp[j] = val;
  95         j += (val * constant_to_random_ratio)/128 + 1;
  96       }
  97       base_array.push_back(temp);
  98     }
  99   } else {
 100     indata.open("input.txt", std::ios_base::in | std::ios_base::binary);
 101     if (indata.bad()) {
 102       printf("input.txt could not be opened\n");
 103       return 1;
 104     }
 105     DATA_TYPE inval;
 106     while (!indata.eof() ) {
 107       indata >> inval;
 108       base_array.push_back(inval);
 109     }
 110   }
 111
 112   // Sort the input
 113   clock_t start, end;
 114   double elapsed;
 115   std::vector<boost::thread *> workers;
 116   start = clock();
 117   if (threadCount == 0) {
 118     if (loopCount > 1) {
 119       sort_loop(base_array, stdSort, loopCount);
 120     } else {
 121       sort_core(base_array, stdSort, loopCount);
 122     }
 123     threadCount = 1;
 124   } else {
 125     for (int i = 0; i < threadCount; ++i) {
 126       workers.push_back(new boost::thread(sort_loop, base_array, stdSort,
 127                                           loopCount));
 128     }
 129     for (int i = 0; i < threadCount; ++i) {
 130       workers[i]->join();
 131       delete workers[i];
 132     }
 133   }
 134   end = clock();
 135   elapsed = static_cast<double>(end - start) ;
 136
 137   printf("for %lu strings\n", base_array.size());
 138   if (stdSort)
 139     printf("std::sort clock time %lf\n", elapsed/CLOCKS_PER_SEC/threadCount);
 140   else
 141     printf("spreadsort clock time %lf\n", elapsed/CLOCKS_PER_SEC/threadCount);
 142   return 0;
 143 }