export nongreedymultilock, spinlock, get_time_tracker

@resumable function nongreedymultilock(env::Environment, resources)
    while true
        if all(!islocked(r)::Bool for r in resources) # type assert to help with inference
            @yield mapreduce(request, &, resources)
            break
        else
            for r in resources
                if islocked(r)
                    @yield request(r)
                    release(r)
                    break
                end
            end
        end
    end
end

@resumable function spinlock(env::Environment, resources, period; randomize=true)
    while true
        if all(x->!islocked(x), resources)
            @yield mapreduce(request, &, resources)
            break
        else
            if randomize
                @yield timeout(env, rand()*period)
            else
                @yield timeout(env, period)
            end
        end
    end
end

##

function get_time_tracker(rn::RegisterNet)
    # TODO assert they are all the same
    return get_time_tracker(rn.registers[1])
end
function get_time_tracker(r::Register)
    # TODO assert all locks and tag_waiters and similar have the same env
    r.locks[1].env::Simulation
end
function get_time_tracker(r::RegRef)
    get_time_tracker(r.reg)
end
function get_time_tracker(mb::MessageBuffer)
    mb.sim
end

##

Base.islocked(r::RegRef) = islocked(r.reg.locks[r.idx])
ConcurrentSim.request(r::RegRef) = request(r.reg.locks[r.idx])
Base.unlock(r::RegRef) = unlock(r.reg.locks[r.idx])
