5 ms·

Lthread - A coroutine lib with multicore support

5 points by halayli 15y ago

dkersten 15y ago
Just the other day I started sketching out plans for something similar to run on top of Intel's Threading Building Blocks' task scheduler for a personal project I'm working on. What I'm basically looking for is low overhead lightweight threads that can be run in parallel in a pool of real heavy-weight threads. Coroutines with multicore, as this library does, should do exactly what I want and I can avoid the "lthreads cannot block or other lthreads in that pthread will not run" rule since in my codebase I can replace blockiing calls with ones which would yield so useful work can continue. The only feature that I would also like but don't know if lthread has is being able to move lthreads between schedulers (something like TBB's work stealing would be ideal).
- halayli 15y ago
  Unfortunately, as of now you cannot move an lthread from one scheduler to another but it can be implemented. May I ask why you want to do that? I am working on lthread_compute for compute intensive tasks which will offload the work to a worker pool and resume the function once it's done.
  - dkersten 15y ago
    Well, what I basically want is a TBB-like task scheduler, but with the ability to pause and resume tasks without running them to completion (to allow tasks to "block" - the condition variables in lthread are perfect for this). To do this in plain TBB, I would have to split the task into multiple smaller tasks, since there is no way to suspend a task but have the scheduler still process other tasks and then later resume the task mid-function. I want to be able to move tasks to other threads so that if a thread runs out of work early it can steal work from a busy thread. Unfortunately I just realised that for the project I have in mind I won't be able to use lthread as I won't be able to release it under the GPL, but I really like what I see so far and I also really like the sound of lthread_compute, so I am definitely keeping an eye on the project and will likely make use of it in the future.
    - halayli 15y ago
      Ah, that's unfortunate. I'll be implementing lthread_compute during the holidays. Keep an eye on that. :)

5 points by halayli 15y ago

Just the other day I started sketching out plans for something similar to run on top of Intel's Threading Building Blocks' task scheduler for a personal project I'm working on. What I'm basically looking for is low overhead lightweight threads that can be run in parallel in a pool of real heavy-weight threads. Coroutines with multicore, as this library does, should do exactly what I want and I can avoid the "lthreads cannot block or other lthreads in that pthread will not run" rule since in my codebase I can replace blockiing calls with ones which would yield so useful work can continue. The only feature that I would also like but don't know if lthread has is being able to move lthreads between schedulers (something like TBB's work stealing would be ideal).

halayli 15y ago
Unfortunately, as of now you cannot move an lthread from one scheduler to another but it can be implemented. May I ask why you want to do that? I am working on lthread_compute for compute intensive tasks which will offload the work to a worker pool and resume the function once it's done.
- dkersten 15y ago
  Well, what I basically want is a TBB-like task scheduler, but with the ability to pause and resume tasks without running them to completion (to allow tasks to "block" - the condition variables in lthread are perfect for this). To do this in plain TBB, I would have to split the task into multiple smaller tasks, since there is no way to suspend a task but have the scheduler still process other tasks and then later resume the task mid-function. I want to be able to move tasks to other threads so that if a thread runs out of work early it can steal work from a busy thread. Unfortunately I just realised that for the project I have in mind I won't be able to use lthread as I won't be able to release it under the GPL, but I really like what I see so far and I also really like the sound of lthread_compute, so I am definitely keeping an eye on the project and will likely make use of it in the future.
  - halayli 15y ago
    Ah, that's unfortunate. I'll be implementing lthread_compute during the holidays. Keep an eye on that. :)