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Improve comments in the blocking threadpool

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Tyler Neely 2019-08-09 12:06:43 +02:00
parent 4cb1faf299
commit ab613a53e5
1 changed files with 8 additions and 4 deletions
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12
src/task/blocking.rs
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@ -50,11 +50,14 @@ lazy_static! {
};
}
// Create up to 10,000 dynamic blocking task worker threads.
// Create up to MAX_THREADS dynamic blocking task worker threads.
// Dynamic threads will terminate themselves if they don't
// receive any work after a timeout that scales down as the
// total number of threads scales up.
fn maybe_create_another_blocking_thread() {
// We use a `Relaxed` atomic operation because
// it's just a heuristic, and would not lose correctness
// even if it's random.
let workers = DYNAMIC_THREAD_COUNT.load(Ordering::Relaxed);
if workers >= MAX_THREADS {
return;
@ -62,9 +65,7 @@ fn maybe_create_another_blocking_thread() {
// We want to give up earlier when we have more threads
// to exert backpressure on the system submitting work
// to do. We use a `Relaxed` atomic operation because
// it's just a heuristic, and would not lose correctness
// even if it's random.
// to do.
let utilization_percent = (workers * 100) / MAX_THREADS;
let relative_wait_limit = (WAIT_SPREAD * utilization_percent) / 100;
@ -93,6 +94,9 @@ fn maybe_create_another_blocking_thread() {
// timeout is dynamic, and when we have more threads we block
// for longer before spinning up another thread for backpressure.
fn schedule(t: async_task::Task<()>) {
// We use a `Relaxed` atomic operation because
// it's just a heuristic, and would not lose correctness
// even if it's random.
let workers = DYNAMIC_THREAD_COUNT.load(Ordering::Relaxed);
// We want to block for longer when we have more threads to