As of the Apr 2021 discussion on low latency general brainstorming chaired by  Staffan TjernstrÃm  , captured in notes here:

This is  a summary of that discussion aiming to elicit more refinement, leading to possible features:
  1. - issues/problems of the domain in C++
    1. need to access hardware features, memory card, I/O controller, DMA, is low latency an  upper bound or determinism
    2. competing with some OS services but not served by all OS 
    3. C++ can offer standard APIs to query for facility
  2. - Features/proposals for C++
    1. thread priorities
    2. cache-control
    3. scheduling periodic thread intervals or by the deadline
    4. CPU pinning like madvise
    5. manage memory-mapped files
    6. Vulkan-like capability model that fits specific hardware
    7. enforce the real-time constraint on a call path or trap at runtime if unable to satisfy
Please feel free to add to this discussion with more issues/proposals, and more details with possible proposals.