ceph/src/boost/libs/lockfree/examples/queue.cpp

   1 //  Copyright (C) 2009 Tim Blechmann
   2 //
   3 //  Distributed under the Boost Software License, Version 1.0. (See
   4 //  accompanying file LICENSE_1_0.txt or copy at
   5 //  http://www.boost.org/LICENSE_1_0.txt)
   6
   7 //[queue_example
   8 #include <boost/thread/thread.hpp>
   9 #include <boost/lockfree/queue.hpp>
  10 #include <iostream>
  11
  12 #include <boost/atomic.hpp>
  13
  14 boost::atomic_int producer_count(0);
  15 boost::atomic_int consumer_count(0);
  16
  17 boost::lockfree::queue<int> queue(128);
  18
  19 const int iterations = 10000000;
  20 const int producer_thread_count = 4;
  21 const int consumer_thread_count = 4;
  22
  23 void producer(void)
  24 {
  25     for (int i = 0; i != iterations; ++i) {
  26         int value = ++producer_count;
  27         while (!queue.push(value))
  28             ;
  29     }
  30 }
  31
  32 boost::atomic<bool> done (false);
  33 void consumer(void)
  34 {
  35     int value;
  36     while (!done) {
  37         while (queue.pop(value))
  38             ++consumer_count;
  39     }
  40
  41     while (queue.pop(value))
  42         ++consumer_count;
  43 }
  44
  45 int main(int argc, char* argv[])
  46 {
  47     using namespace std;
  48     cout << "boost::lockfree::queue is ";
  49     if (!queue.is_lock_free())
  50         cout << "not ";
  51     cout << "lockfree" << endl;
  52
  53     boost::thread_group producer_threads, consumer_threads;
  54
  55     for (int i = 0; i != producer_thread_count; ++i)
  56         producer_threads.create_thread(producer);
  57
  58     for (int i = 0; i != consumer_thread_count; ++i)
  59         consumer_threads.create_thread(consumer);
  60
  61     producer_threads.join_all();
  62     done = true;
  63
  64     consumer_threads.join_all();
  65
  66     cout << "produced " << producer_count << " objects." << endl;
  67     cout << "consumed " << consumer_count << " objects." << endl;
  68 }
  69 //]