deadline_timer.cpp

来自「Boost provides free peer-reviewed portab」· C++ 代码 · 共 188 行

//
// deadline_timer.cpp
// ~~~~~~~~~~~~~~~~~~
//
// Copyright (c) 2003-2008 Christopher M. Kohlhoff (chris at kohlhoff dot com)
//
// 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)
//

// Disable autolinking for unit tests.
#if !defined(BOOST_ALL_NO_LIB)
#define BOOST_ALL_NO_LIB 1
#endif // !defined(BOOST_ALL_NO_LIB)

// Test that header file is self-contained.
#include <boost/asio/deadline_timer.hpp>

#include <boost/bind.hpp>
#include <boost/asio.hpp>
#include "unit_test.hpp"

using namespace boost::posix_time;

void increment(int* count)
{
  ++(*count);
}

void decrement_to_zero(boost::asio::deadline_timer* t, int* count)
{
  if (*count > 0)
  {
    --(*count);

    int before_value = *count;

    t->expires_at(t->expires_at() + seconds(1));
    t->async_wait(boost::bind(decrement_to_zero, t, count));

    // Completion cannot nest, so count value should remain unchanged.
    BOOST_CHECK(*count == before_value);
  }
}

void increment_if_not_cancelled(int* count,
    const boost::system::error_code& ec)
{
  if (!ec)
    ++(*count);
}

void cancel_timer(boost::asio::deadline_timer* t)
{
  std::size_t num_cancelled = t->cancel();
  BOOST_CHECK(num_cancelled == 1);
}

ptime now()
{
  return microsec_clock::universal_time();
}

void deadline_timer_test()
{
  boost::asio::io_service ios;
  int count = 0;

  ptime start = now();

  boost::asio::deadline_timer t1(ios, seconds(1));
  t1.wait();

  // The timer must block until after its expiry time.
  ptime end = now();
  ptime expected_end = start + seconds(1);
  BOOST_CHECK(expected_end < end || expected_end == end);

  start = now();

  boost::asio::deadline_timer t2(ios, seconds(1) + microseconds(500000));
  t2.wait();

  // The timer must block until after its expiry time.
  end = now();
  expected_end = start + seconds(1) + microseconds(500000);
  BOOST_CHECK(expected_end < end || expected_end == end);

  t2.expires_at(t2.expires_at() + seconds(1));
  t2.wait();

  // The timer must block until after its expiry time.
  end = now();
  expected_end += seconds(1);
  BOOST_CHECK(expected_end < end || expected_end == end);

  start = now();

  t2.expires_from_now(seconds(1) + microseconds(200000));
  t2.wait();

  // The timer must block until after its expiry time.
  end = now();
  expected_end = start + seconds(1) + microseconds(200000);
  BOOST_CHECK(expected_end < end || expected_end == end);

  start = now();

  boost::asio::deadline_timer t3(ios, seconds(5));
  t3.async_wait(boost::bind(increment, &count));

  // No completions can be delivered until run() is called.
  BOOST_CHECK(count == 0);

  ios.run();

  // The run() call will not return until all operations have finished, and
  // this should not be until after the timer's expiry time.
  BOOST_CHECK(count == 1);
  end = now();
  expected_end = start + seconds(1);
  BOOST_CHECK(expected_end < end || expected_end == end);

  count = 3;
  start = now();

  boost::asio::deadline_timer t4(ios, seconds(1));
  t4.async_wait(boost::bind(decrement_to_zero, &t4, &count));

  // No completions can be delivered until run() is called.
  BOOST_CHECK(count == 3);

  ios.reset();
  ios.run();

  // The run() call will not return until all operations have finished, and
  // this should not be until after the timer's final expiry time.
  BOOST_CHECK(count == 0);
  end = now();
  expected_end = start + seconds(3);
  BOOST_CHECK(expected_end < end || expected_end == end);

  count = 0;
  start = now();

  boost::asio::deadline_timer t5(ios, seconds(10));
  t5.async_wait(boost::bind(increment_if_not_cancelled, &count,
        boost::asio::placeholders::error));
  boost::asio::deadline_timer t6(ios, seconds(1));
  t6.async_wait(boost::bind(cancel_timer, &t5));

  // No completions can be delivered until run() is called.
  BOOST_CHECK(count == 0);

  ios.reset();
  ios.run();

  // The timer should have been cancelled, so count should not have changed.
  // The total run time should not have been much more than 1 second (and
  // certainly far less than 10 seconds).
  BOOST_CHECK(count == 0);
  end = now();
  expected_end = start + seconds(2);
  BOOST_CHECK(end < expected_end);

  // Wait on the timer again without cancelling it. This time the asynchronous
  // wait should run to completion and increment the counter.
  t5.async_wait(boost::bind(increment_if_not_cancelled, &count,
        boost::asio::placeholders::error));

  ios.reset();
  ios.run();

  // The timer should not have been cancelled, so count should have changed.
  // The total time since the timer was created should be more than 10 seconds.
  BOOST_CHECK(count == 1);
  end = now();
  expected_end = start + seconds(10);
  BOOST_CHECK(expected_end < end || expected_end == end);
}

test_suite* init_unit_test_suite(int, char*[])
{
  test_suite* test = BOOST_TEST_SUITE("deadline_timer");
  test->add(BOOST_TEST_CASE(&deadline_timer_test));
  return test;
}