BOOT_ASSERT failure on Visual Studio Debug build (<boost>/lib/fiber/src/scheduler.cpp:406).

[yystju]

Hi,

I have been using boost::fiber in my code for several weeks now. Before today it works very well. But this morning, I run into an BOOT_ASSERT failure which occurred at /lib/fiber/src/scheduler.cpp:406. For now, I think I've tried all what I can do ... from building boosts again to comment all the content of the coroutine functions... At last, I found the official example "work_stealing.cpp" cannot work as well... I am guessing it's related to the updating of my windows10 this morning... But I have no direct evidence. Please take a look, if there're other guys who also run into the situation...

Thank you.

-Quan

The boost code is like below:

// <boost>/lib/fiber/src/scheduler.cpp
...
void
scheduler::detach_worker_context( context * ctx) noexcept {
    BOOST_ASSERT( nullptr != ctx);
    BOOST_ASSERT( ! ctx->ready_is_linked() );
#if ! defined(BOOST_FIBERS_NO_ATOMICS)
    BOOST_ASSERT( ! ctx->remote_ready_is_linked() );
#endif
    BOOST_ASSERT( ! ctx->sleep_is_linked() );
    BOOST_ASSERT( ! ctx->terminated_is_linked() );
    BOOST_ASSERT( ! ctx->wait_is_linked() ); // <-- [THE ERROR RAISED FROM HERE!]
    BOOST_ASSERT( ctx->worker_is_linked() );
    BOOST_ASSERT( ! ctx->is_context( type::pinned_context) );
    ctx->worker_unlink();
    BOOST_ASSERT( ! ctx->worker_is_linked() );
    ctx->scheduler_ = nullptr;
    // a detached context must not belong to any queue
}
...

My code is like (I removed the not-related parts, but it's based on the "work_stealing.cpp"):

//coroutine.h
class CoroutineManager {
  ...

  typedef std::unique_lock<boost::fibers::mutex> lock_type;
  typedef boost::fibers::algo::work_stealing scheduler_algorithm;
  typedef boost::fibers::default_stack stack_type;
  
  ...
  void wait() {
    lock_type shutdown_lock(shutdown_mutex);
    shutdown_condition.wait(shutdown_lock);
  }

  void shutdown(bool wait = true) {
    lock_type shutdown_lock(shutdown_mutex);

    shutdown_lock.unlock();

    this->shutdown_condition.notify_all();

    if (wait) {
      for (std::thread& t : threads) {
        if (t.joinable()) {
          t.join();
        }
      }
    }
  }
  
  ...

  template <class TaskType>
  void submit(const TaskType& task) {
    boost::fibers::fiber(boost::fibers::launch::dispatch, std::allocator_arg, stack_type(this->stack_size), task).detach();
  }
  
  ...
  
  void init() {
    if (verbose) spdlog::info("INIT THREAD({0}) STARTED.", std::this_thread::get_id());

    for (int i = 0; i < (this->thread_count - 1); ++i) {
      threads.push_back(std::thread(&CoroutineManager::thread, this));
    }

    boost::fibers::use_scheduling_algorithm<scheduler_algorithm>(this->thread_count);

    this->start_barrier.wait();
  }

  void dispose() {
    if (verbose) spdlog::info("INIT THREAD({0}) DISPOSED.", std::this_thread::get_id());
  }

  void thread() {
    if(verbose) spdlog::info("WORKER THREAD({0}) STARTED.", std::this_thread::get_id());

    boost::fibers::use_scheduling_algorithm<scheduler_algorithm>(this->thread_count);

    this->start_barrier.wait();

    this->wait();

    if (verbose) spdlog::info("WORKER THREAD({0}) DISPOSED.", std::this_thread::get_id());
  }

  ...
};

- - - - - - - - - - - - - - - - - - - - - - -

// coroutine_test.cpp
...

int main(int argc, char* argv[]) {
  init_file_logger("coroutine_test.log");
  time_tracker tracker("[coroutine_test.main]");

  typedef std::thread::id tid_t;
  typedef boost::fibers::fiber::id fid_t;
  typedef boost::fibers::buffered_channel<std::tuple<tid_t, fid_t, int>> channel_t;

  CoroutineManager manager(std::thread::hardware_concurrency(), 1024 * 1024 * 8, true);

  const int N = 1;

  channel_t chan { 8 };

  boost::fibers::barrier done_flag(2);

  manager.submit([&chan, &done_flag]() {
    std::tuple<tid_t, fid_t, int> p;

    while( boost::fibers::channel_op_status::success == chan.pop_wait_for(p, std::chrono::milliseconds(100))) {
      spdlog::info("[thead({0}) : fiber({1}) from {2}]", std::get<0>(p), std::get<1>(p), std::get<2>(p));
    }

    done_flag.wait();
  });

  for (int i = 0; i < N; ++i) {
    manager.submit([&chan, i]() {
      for (int j = 0; j < 1000; ++j) {
        chan.push(std::move(std::make_tuple(std::this_thread::get_id(), boost::this_fiber::get_id(), i)));
        boost::this_fiber::yield();
      }
    });
  }

  done_flag.wait();

  spdlog::info("-START TO SHUTDOWN-");

  manager.shutdown();

  spdlog::info("-END-");

  return 0;
}

Please see the attached snapshot for what happened...

[yystju]

Oh, I forgot to mention:

1. I am using cmake to manage the build. I found on windows Release build, the code can work very well. On WSL(Windows Subsystem Linux) Ubuntu20.04, It can work as well on both Release and Debug build. I haven't tried macOS, but, yestoday, the code can work on it...

2. My code is based on boot 1.73.0

[Dmitry Khominich]

Hello, @yystju !

Can you please check does it work with last fixes in develop branch?

thanks!