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>
22using namespace boost::sort::spreadsort;
23
24#define DATA_TYPE int
25
26bool 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
35void 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(first: array.begin(), last: array.end());
44 else
45 boost::sort::spreadsort::spreadsort(first: array.begin(), last: array.end());
46 if (!is_sorted(array)) {
47 fprintf(stderr, format: "sort failed!\n");
48 exit(status: 1);
49 }
50 }
51}
52
53//Pass in an argument to test std::sort
54int 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(nptr: argv[u]);
64 else
65 loopCount = atoi(nptr: argv[u]);
66 }
67 if (!loopCount) {
68 loopCount = 1;
69 }
70 printf(format: "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(format: "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(new_size: uCount);
84 unsigned v = 0;
85 while (input.good() && v < uCount)
86 input.read(s: reinterpret_cast<char *>(&(base_array[v++])), n: uSize );
87 input.close();
88 if (v < uCount)
89 base_array.resize(new_size: 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(x: 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(format: "std::sort clock time %lf\n", elapsed/CLOCKS_PER_SEC/threadCount);
112 else
113 printf(format: "spreadsort clock time %lf\n", elapsed/CLOCKS_PER_SEC/threadCount);
114 return 0;
115}
116

source code of boost/libs/sort/example/parallelint.cpp