1 files changed, 143 insertions, 0 deletions
diff --git a/libs/sort/example/parallelstring.cpp b/libs/sort/example/parallelstring.cpp
new file mode 100644
index 000000000..f710802bf
--- /dev/null
+++ b/libs/sort/example/parallelstring.cpp
@@ -0,0 +1,143 @@
+//  Benchmark for integer sorting speed across parallel threads.
+//
+//  Copyright Steven Ross 2014
+//
+// Distributed under the Boost Software License, Version 1.0.
+//    (See accompanying file LICENSE_1_0.txt or copy at
+//          http://www.boost.org/LICENSE_1_0.txt)
+
+//  See http://www.boost.org/libs/sort for library home page.
+
+#include <boost/random/mersenne_twister.hpp>
+#include <boost/random/uniform_int_distribution.hpp>
+#include <boost/sort/spreadsort/spreadsort.hpp>
+#include <boost/thread.hpp>
+#include <time.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <algorithm>
+#include <vector>
+#include <iostream>
+#include <fstream>
+#include <string>
+using std::string;
+using namespace boost::sort::spreadsort;
+
+#define DATA_TYPE string
+
+static bool is_sorted(const std::vector<DATA_TYPE> &array) {
+  for (unsigned u = 0; u + 1 < array.size(); ++u) {
+    if (array[u] > array[u + 1]) {
+      return false;
+    }
+  }
+  return true;
+}
+
+static void sort_core(std::vector<DATA_TYPE> &array, bool stdSort,
+               unsigned loopCount) {
+  if (stdSort)
+    std::sort(array.begin(), array.end());
+  else
+    boost::sort::spreadsort::spreadsort(array.begin(), array.end());
+  if (!is_sorted(array)) {
+    fprintf(stderr, "sort failed!\n");
+    exit(1);
+  }
+}
+
+static void sort_loop(const std::vector<DATA_TYPE> &base_array, bool stdSort,
+               unsigned loopCount) {
+  std::vector<DATA_TYPE> array(base_array);
+  for (unsigned u = 0; u < loopCount; ++u) {
+    for (unsigned v = 0; v < base_array.size(); ++v) {
+      array[v] = base_array[v];
+    }
+    sort_core(array, stdSort, loopCount);
+  }
+}
+
+//Pass in an argument to test std::sort
+int main(int argc, const char ** argv) {
+  std::ifstream indata;
+  std::ofstream outfile;
+  bool stdSort = false;
+  int constant_to_random_ratio = -1;
+  int threadCount = -1;
+  unsigned loopCount = 0;
+  for (int u = 1; u < argc; ++u) {
+    if (std::string(argv[u]) == "-std")
+      stdSort = true;
+    else if(threadCount < 0)
+      threadCount = atoi(argv[u]);
+    else if (!loopCount)
+      loopCount = atoi(argv[u]);
+    else
+      constant_to_random_ratio = atoi(argv[u]);
+  }
+  if (!loopCount) {
+    loopCount = 1;
+  }
+  printf("threads: %d loops: %d\n", threadCount, loopCount);
+
+  std::vector<DATA_TYPE> base_array;
+  if (constant_to_random_ratio >= 0) {
+    //Test for random data with gaps of identical data.
+    random::mt19937 generator;
+    random::uniform_int_distribution<int> distribution(0,255);
+    const int constant_to_random_count = 1000000;
+    const int string_length = 1000;
+    for (int i = 0; i < constant_to_random_count; ++i) {
+      DATA_TYPE temp(string_length, 'x');  // fill with default character.
+      for (int j = constant_to_random_ratio; j < string_length;) {
+        int val = distribution(generator);
+        temp[j] = val;
+        j += (val * constant_to_random_ratio)/128 + 1;
+      }
+      base_array.push_back(temp);
+    }
+  } else {
+    indata.open("input.txt", std::ios_base::in | std::ios_base::binary);
+    if (indata.bad()) {
+      printf("input.txt could not be opened\n");
+      return 1;
+    }
+    DATA_TYPE inval;
+    while (!indata.eof() ) {
+      indata >> inval;
+      base_array.push_back(inval);
+    }
+  }
+
+  // Sort the input
+  clock_t start, end;
+  double elapsed;
+  std::vector<boost::thread *> workers;
+  start = clock();
+  if (threadCount == 0) {
+    if (loopCount > 1) {
+      sort_loop(base_array, stdSort, loopCount);
+    } else {
+      sort_core(base_array, stdSort, loopCount);
+    }
+    threadCount = 1;
+  } else {
+    for (int i = 0; i < threadCount; ++i) {
+      workers.push_back(new boost::thread(sort_loop, base_array, stdSort,
+                                          loopCount));
+    }
+    for (int i = 0; i < threadCount; ++i) {
+      workers[i]->join();
+      delete workers[i];
+    }
+  }
+  end = clock();
+  elapsed = static_cast<double>(end - start) ;
+
+  printf("for %lu strings\n", base_array.size());
+  if (stdSort)
+    printf("std::sort clock time %lf\n", elapsed/CLOCKS_PER_SEC/threadCount);
+  else
+    printf("spreadsort clock time %lf\n", elapsed/CLOCKS_PER_SEC/threadCount);
+  return 0;
+}