I yield to the kernel to allow other threads that do some kind of background work to run. Do I want my application's async tasks to yield every 10ms? I assume that is what is being meant here.
Configurability: We absolutely plan to make the 10ms yield interval configurable (or opt-out) in the runtime settings. It is currently a default safety rail to prevent async starvation, not a hard constraint.
Concurrency Options: It is important to note that LOGOS has three distinct execution primitives, and this yield logic doesn't apply to all of them:
Simultaneously: (Parallel CPU): This compiles to rayon::join or dedicated std::threads. It does not use the cooperative yield check, allowing full blocking CPU usage on separate cores.
Attempt all: (Async Join) & Launch a task: (Green Threads): These compile to tokio async tasks. The cooperative yield is specifically here to prevent a single heavy async task from blocking the shared reactor loop.
So if you need raw, uninterrupted CPU cycles, you would use Simultaneously, and you wouldn't be forced to yield.
with cooperative scheduling, yes. This is indeed something missing from the Rust async ecosystem, tasks are meant to be IO-bound and if they become CPU-bound accidentally they will starve other tasks (async-std tried to fix this, but had some backlash due to overhead IIRC). Go actually puts a yield on every loop body (or used to), to prevent starvation. A 10ms thing will have negligible impact
Also: yielding to the kernel is very costly. Yielding to another task in your own thread is practically free in comparison
I yield to the kernel to allow other threads that do some kind of background work to run. Do I want my application's async tasks to yield every 10ms? I assume that is what is being meant here.
That is a valid concern! To clarify:
Configurability: We absolutely plan to make the 10ms yield interval configurable (or opt-out) in the runtime settings. It is currently a default safety rail to prevent async starvation, not a hard constraint.
Concurrency Options: It is important to note that LOGOS has three distinct execution primitives, and this yield logic doesn't apply to all of them:
Simultaneously: (Parallel CPU): This compiles to rayon::join or dedicated std::threads. It does not use the cooperative yield check, allowing full blocking CPU usage on separate cores.
Attempt all: (Async Join) & Launch a task: (Green Threads): These compile to tokio async tasks. The cooperative yield is specifically here to prevent a single heavy async task from blocking the shared reactor loop.
So if you need raw, uninterrupted CPU cycles, you would use Simultaneously, and you wouldn't be forced to yield.
with cooperative scheduling, yes. This is indeed something missing from the Rust async ecosystem, tasks are meant to be IO-bound and if they become CPU-bound accidentally they will starve other tasks (async-std tried to fix this, but had some backlash due to overhead IIRC). Go actually puts a yield on every loop body (or used to), to prevent starvation. A 10ms thing will have negligible impact
Also: yielding to the kernel is very costly. Yielding to another task in your own thread is practically free in comparison