// test_threads.cc
//
//   Copyright (C) 2005-2006, 2009 Daniel Burrows
//
//   This program is free software; you can redistribute it and/or
//   modify it under the terms of the GNU General Public License as
//   published by the Free Software Foundation; either version 2 of
//   the License, or (at your option) any later version.
//
//   This program is distributed in the hope that it will be useful,
//   but WITHOUT ANY WARRANTY; without even the implied warranty of
//   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
//   General Public License for more details.
//
//   You should have received a copy of the GNU General Public License
//   along with this program; see the file COPYING.  If not, write to
//   the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
//   Boston, MA 02111-1307, USA.

// TODO: threads code lives in cwidget now, this test should move
// there.

#include <cppunit/extensions/HelperMacros.h>

#include <cwidget/generic/threads/event_queue.h>
#include <cwidget/generic/threads/threads.h>
#include <cwidget/generic/util/ssprintf.h>

#include <iostream>

#include <sys/time.h>
#include <time.h>

#include <unistd.h>

namespace cw = cwidget;

class TestThreads : public CppUnit::TestFixture
{
  CPPUNIT_TEST_SUITE(TestThreads);

  CPPUNIT_TEST(testBox);
  CPPUNIT_TEST(testTimedTake);
  CPPUNIT_TEST(testEventQueue);
  CPPUNIT_TEST(testAutoDetach);

  CPPUNIT_TEST_SUITE_END();

public:
  // Ye Olde Addition Thread
  struct add_thread
  {
    int n;
    cw::threads::box<int> &count;
  public:
    add_thread(int _n, cw::threads::box<int> &_count)
      :n(_n), count(_count)
    {
    }

    void operator()() const
    {
      for(int i = 0; i < n; ++i)
	count.put(count.take()+1);
    }
  };

  void do_testBox()
  {
    const int thread_count_max = 50;
    const int thread_limit = 1000;

    long real_threads_max = sysconf(_SC_THREAD_THREADS_MAX);
    int thread_count;
    if(real_threads_max == -1)
      thread_count = thread_count_max; // No definite limit.
    else
      thread_count = std::min<int>((int)thread_count_max, (int)real_threads_max);

    cw::threads::box<int> b(100);

    CPPUNIT_ASSERT_EQUAL(100, b.take());

    std::unique_ptr<cw::threads::thread> *writers =
      new std::unique_ptr<cw::threads::thread>[thread_count];

    try
      {
	for(int i = 0; i<thread_count; ++i)
	  writers[i] = std::unique_ptr<cw::threads::thread>(new cw::threads::thread(add_thread(thread_limit, b)));

	int foo;
	CPPUNIT_ASSERT(!b.try_take(foo));

	CPPUNIT_ASSERT(b.try_put(-1));

	for(int i = 0; i < thread_count; ++i)
	  writers[i]->join();

	CPPUNIT_ASSERT_EQUAL(thread_count*thread_limit-1, b.take());
      }
    catch(...)
      {
	delete[] writers;
	throw;
      }

    delete[] writers;
  }

  void testBox()
  {
    try
      {
	do_testBox();
      }
    catch(const cw::util::Exception &e)
      {
	std::cerr << "Caught exception in testBox: " << e.errmsg() << std::endl;
	throw;
      }
  }

  void testTimedTake()
  {
    timeval now;

    cw::threads::box<int> b;

    gettimeofday(&now, NULL);
    timespec timeout;
    timeout.tv_sec = now.tv_sec + 2;
    timeout.tv_nsec = now.tv_usec * 1000;

    int dummy;

    // Test that timing out trying to take values from an empty box works:

    CPPUNIT_ASSERT(!b.timed_take(dummy, timeout));

    timeval now2;
    gettimeofday(&now2, NULL);

    //  pthread_cond_timedwait is allowed to return before the timeout
    //  expires, according to Bastian Blank <waldi@debian.org>, so this
    //  invariant is not an invariant at all.
    //
    //CPPUNIT_ASSERT(now2.tv_sec >= now.tv_sec + 2);
    //CPPUNIT_ASSERT(now2.tv_sec > now.tv_sec + 2 || now2.tv_usec >= now.tv_usec);

    // Test that we can retrieve a value from a full box:

    timeout.tv_sec = now2.tv_sec + 2;
    timeout.tv_nsec = now2.tv_usec * 1000;
    b.put(5);
    CPPUNIT_ASSERT(b.timed_take(dummy, timeout));
    CPPUNIT_ASSERT_EQUAL(5, dummy);
  }

  class event_queue_write_thread
  {
    cw::threads::event_queue<std::pair<int, int> > &eq;

    int id, n;
  public:
    event_queue_write_thread(cw::threads::event_queue<std::pair<int, int> > &_eq,
			     int _id, int _n)
      :eq(_eq), id(_id), n(_n)
    {
    }

    void operator()() const
    {
      for(int i = 0; i < n; ++i)
	eq.put(std::pair<int, int>(id, i));
    }
  };

  void testEventQueue()
  {
    const int thread_count_max = 100;
    const int thread_limit = 1000;

    long real_threads_max = sysconf(_SC_THREAD_THREADS_MAX);
    int thread_count;
    if(real_threads_max == -1)
      thread_count = thread_count_max; // No definite limit.
    else
      thread_count = std::min<int>((int)thread_count_max, (int)real_threads_max);

    cw::threads::event_queue<std::pair<int, int> > eq;

    std::unique_ptr<cw::threads::thread> *writers =
      new std::unique_ptr<cw::threads::thread>[thread_count];
    int *last_thread_msg =
      new int[thread_count];

    try
      {
	for(int i = 0; i < thread_count; ++i)
	  last_thread_msg[i] = -1;

	for(int i = 0; i < thread_count; ++i)
	  writers[i] = std::unique_ptr<cw::threads::thread>(new cw::threads::thread(event_queue_write_thread(eq, i, thread_limit)));

	for(int i = 0; i < thread_count * thread_limit; ++i)
	  {
	    std::pair<int, int> next = eq.get();

	    CPPUNIT_ASSERT_EQUAL(next.second-1, last_thread_msg[next.first]);
	    last_thread_msg[next.first] = next.second;
	  }

	for(int i = 0; i < thread_count; ++i)
	  writers[i]->join();

	CPPUNIT_ASSERT(eq.empty());
      }
    catch(...)
      {
	delete[] writers;
	delete[] last_thread_msg;

	throw;
      }

    delete[] writers;
    delete[] last_thread_msg;
  }

  struct do_nothing
  {
  public:
    void operator()() const
    {
    }
  };

  void testAutoDetach()
  {
    cw::threads::thread t(do_nothing());
  }
};

CPPUNIT_TEST_SUITE_REGISTRATION(TestThreads);