Assertion "! ctx->ready_is_linked()" when using condition_variable::wait_for

[m0xf]

When i use condition_variable::wait_for in multipliy fibers program crashes with assertion:
"Assertion failed: ! ctx->ready_is_linked(), file libs\fiber\src\scheduler.cpp, line 192".

Minimal sample:

#include <boost/fiber/all.hpp>
#include <mutex>
#include <thread>
#include <chrono>

int main()
{
    boost::fibers::condition_variable condvar;
    boost::fibers::mutex mutex;

    auto do_work = [&]()
    {
        while (true)
        {
            {
                std::unique_lock<boost::fibers::mutex> lock(mutex);
                condvar.wait_for(lock, std::chrono::milliseconds(50));
            }
            //emulate some calculations
            std::this_thread::sleep_for(std::chrono::milliseconds(5));
        }
    };

    boost::fibers::fiber fiber1(do_work);
    boost::fibers::fiber fiber2(do_work);
    boost::fibers::fiber fiber3(do_work);
    boost::fibers::fiber fiber4(do_work);
    boost::fibers::fiber fiber5(do_work);
    boost::fibers::fiber fiber6(do_work);

    boost::fibers::fiber fiber([&]()
    {
        while (true)
        {
            {
                std::lock_guard<boost::fibers::mutex> lock(mutex);
                condvar.notify_one();
            }
            boost::this_fiber::sleep_for(std::chrono::milliseconds(10));
        }
    });
    fiber.join();
    return 0;
}

Compiler msvc-14.0, windows 7.

[olk]

ty - fixed