Fibers and mutexes

[dibyendumajumdar]

Hi, first of all many thanks for creating such a marvelous product.

I am trying to use Tracy in a system that has fibers and fiber mutexes.
I notice that fibers show up in the capture - but not mutexes.
If I disable fibers and use threads, then mutexes show up.

Is there an assumption that mutexes are thread based?

[wolfpld]

Support for mutexes with fibers is probably not implemented now.

[dibyendumajumdar]

Is this a problem in the front-end (i.e. server)?

[Sven-v-Beuningen]

Yes, it's running for several loops, bun then stops with the "zone ended twice" message:

[dibyendumajumdar]

I got similar issue initially but that seems to be caused by incorrect or missing Fiber Enter instrumentation.

p.s. although in your case it may be mismatched Zone start/end?

[dibyendumajumdar]

In our code we have fiber mutexes, that work just like thread mutexes.
So I can switch the code between fiber version and thread version.
The instrumentation for mutex is unchanged and works fine in the thread version - so the issue might be that the Tracy frontend (server) is not associating a mutex lock with the active fiber.

[Sven-v-Beuningen]

Thank you very much, for the reply. I'm pretty sure, I do something with entering and leaving the coroutines wrong, but I don't know how to do it right. The best results I do get with the following code in my thread function:

auto JobSystemWorker::workerFunction() -> void
{
    m_running = true;
    while (m_running)
    {
        auto job = std::move(getJob());

        if (job)
        {
            TracyFiberEnter(m_workerName);     
            (*job)();
            TracyFiberLeave;
        }
    }
}

With "best results" I just mean, that the zones look correct in the server. But it still stops after some loops.
In the thread function I just try to grab a suspended coroutine and resume it. It can happen, that the same coroutine is suspended and resumed multiple times, because the coroutine can have multiple lines with "co_await". It can also happen, that a coroutine is resumed by a different thread, than the one which has suspended it.
If I run my application just with one thread, everything works fine.