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denoland-deno/runtime/tokio_util.rs

71 lines
2.4 KiB
Rust

// Copyright 2018-2023 the Deno authors. All rights reserved. MIT license.
use std::fmt::Debug;
use std::str::FromStr;
use deno_core::task::MaskFutureAsSend;
/// Default configuration for tokio. In the future, this method may have different defaults
/// depending on the platform and/or CPU layout.
const fn tokio_configuration() -> (u32, u32, usize) {
(61, 31, 1024)
}
fn tokio_env<T: FromStr>(name: &'static str, default: T) -> T
where
<T as FromStr>::Err: Debug,
{
match std::env::var(name) {
Ok(value) => value.parse().unwrap(),
Err(_) => default,
}
}
pub fn create_basic_runtime() -> tokio::runtime::Runtime {
let (event_interval, global_queue_interval, max_io_events_per_tick) =
tokio_configuration();
tokio::runtime::Builder::new_current_thread()
.enable_io()
.enable_time()
.event_interval(tokio_env("DENO_TOKIO_EVENT_INTERVAL", event_interval))
.global_queue_interval(tokio_env(
"DENO_TOKIO_GLOBAL_QUEUE_INTERVAL",
global_queue_interval,
))
.max_io_events_per_tick(tokio_env(
"DENO_TOKIO_MAX_IO_EVENTS_PER_TICK",
max_io_events_per_tick,
))
// This limits the number of threads for blocking operations (like for
// synchronous fs ops) or CPU bound tasks like when we run dprint in
// parallel for deno fmt.
// The default value is 512, which is an unhelpfully large thread pool. We
// don't ever want to have more than a couple dozen threads.
.max_blocking_threads(32)
.build()
.unwrap()
}
#[inline(always)]
pub fn create_and_run_current_thread<F, R>(future: F) -> R
where
F: std::future::Future<Output = R> + 'static,
R: Send + 'static,
{
let rt = create_basic_runtime();
// Since this is the main future, we want to box it in debug mode because it tends to be fairly
// large and the compiler won't optimize repeated copies. We also make this runtime factory
// function #[inline(always)] to avoid holding the unboxed, unused future on the stack.
#[cfg(debug_assertions)]
// SAFETY: this this is guaranteed to be running on a current-thread executor
let future = Box::pin(unsafe { MaskFutureAsSend::new(future) });
#[cfg(not(debug_assertions))]
// SAFETY: this this is guaranteed to be running on a current-thread executor
let future = unsafe { MaskFutureAsSend::new(future) };
let join_handle = rt.spawn(future);
rt.block_on(join_handle).unwrap().into_inner()
}