perf: add Tokio runtime monitor (#19415)

This commit adds ability to print metrics of the Tokio
runtime to the console by passing "DENO_TOKIO_METRICS=1"
env var.

Metrics will be printed every second, but this can be changed
by "DENO_TOKIO_METRICS_INTERVAL=500" env var.

.cargo/config.toml

@@ -23,4 +23,6 @@ rustflags = [
   "clippy::missing_safety_doc",
   "-D",
   "clippy::undocumented_unsafe_blocks",
+  "--cfg",
+  "tokio_unstable",
 ]

.github/workflows/ci.generate.ts

@@ -5,7 +5,7 @@ import * as yaml from "https://deno.land/std@0.173.0/encoding/yaml.ts";
 // Bump this number when you want to purge the cache.
 // Note: the tools/release/01_bump_crate_versions.ts script will update this version
 // automatically via regex, so ensure that this line maintains this format.
-const cacheVersion = 37;
+const cacheVersion = 38;
 
 const Runners = (() => {
   const ubuntuRunner = "ubuntu-22.04";
@@ -85,6 +85,7 @@ RUSTFLAGS<<__1
   -C link-arg=-Wl,--allow-shlib-undefined
   -C link-arg=-Wl,--thinlto-cache-dir=$(pwd)/target/release/lto-cache
   -C link-arg=-Wl,--thinlto-cache-policy,cache_size_bytes=700m
+  --cfg tokio_unstable
   \${{ env.RUSTFLAGS }}
 __1
 RUSTDOCFLAGS<<__1

.github/workflows/ci.yml

@@ -260,6 +260,7 @@ jobs:
             -C link-arg=-Wl,--allow-shlib-undefined
             -C link-arg=-Wl,--thinlto-cache-dir=$(pwd)/target/release/lto-cache
             -C link-arg=-Wl,--thinlto-cache-policy,cache_size_bytes=700m
+            --cfg tokio_unstable
             ${{ env.RUSTFLAGS }}
           __1
           RUSTDOCFLAGS<<__1
@@ -298,7 +299,7 @@ jobs:
             ~/.cargo/registry/index
             ~/.cargo/registry/cache
             ~/.cargo/git/db
-          key: '37-cargo-home-${{ matrix.os }}-${{ hashFiles(''Cargo.lock'') }}'
+          key: '38-cargo-home-${{ matrix.os }}-${{ hashFiles(''Cargo.lock'') }}'
         if: '!(github.event_name == ''pull_request'' && matrix.skip_pr)'
       - name: Restore cache build output (PR)
         uses: actions/cache/restore@v3
@@ -310,7 +311,7 @@ jobs:
             !./target/*/*.zip
             !./target/*/*.tar.gz
           key: never_saved
-          restore-keys: '37-cargo-target-${{ matrix.os }}-${{ matrix.profile }}-${{ matrix.job }}-'
+          restore-keys: '38-cargo-target-${{ matrix.os }}-${{ matrix.profile }}-${{ matrix.job }}-'
       - name: Apply and update mtime cache
         if: '!(github.event_name == ''pull_request'' && matrix.skip_pr) && (!startsWith(github.ref, ''refs/tags/''))'
         uses: ./.github/mtime_cache
@@ -600,7 +601,7 @@ jobs:
             !./target/*/gn_out
             !./target/*/*.zip
             !./target/*/*.tar.gz
-          key: '37-cargo-target-${{ matrix.os }}-${{ matrix.profile }}-${{ matrix.job }}-${{ github.sha }}'
+          key: '38-cargo-target-${{ matrix.os }}-${{ matrix.profile }}-${{ matrix.job }}-${{ github.sha }}'
   publish-canary:
     name: publish canary
     runs-on: ubuntu-22.04

Cargo.lock

@@ -1315,6 +1315,7 @@ dependencies = [
  "termcolor",
  "test_util",
  "tokio",
+ "tokio-metrics",
  "uuid",
  "winapi",
  "winres",
@@ -5249,6 +5250,18 @@ dependencies = [
  "syn 2.0.13",
 ]
 
+[[package]]
+name = "tokio-metrics"
+version = "0.2.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b60ac6224d622f71d0b80546558eedf8ff6c2d3817517a9d3ed87ce24fccf6a6"
+dependencies = [
+ "futures-util",
+ "pin-project-lite",
+ "tokio",
+ "tokio-stream",
+]
+
 [[package]]
 name = "tokio-rustls"
 version = "0.24.0"

Cargo.toml

@@ -135,6 +135,7 @@ tar = "=0.4.38"
 tempfile = "3.4.0"
 thiserror = "1.0.40"
 tokio = { version = "1.28.1", features = ["full"] }
+tokio-metrics = { version = "0.2.2", features = ["rt"] }
 tokio-rustls = "0.24.0"
 tokio-util = "0.7.4"
 tower-lsp = { version = "=0.17.0", features = ["proposed"] }

cli/main.rs

@@ -41,7 +41,7 @@ use deno_core::futures::FutureExt;
 use deno_core::task::JoinHandle;
 use deno_runtime::colors;
 use deno_runtime::fmt_errors::format_js_error;
-use deno_runtime::tokio_util::create_and_run_current_thread;
+use deno_runtime::tokio_util::create_and_run_current_thread_with_maybe_metrics;
 use factory::CliFactory;
 use std::env;
 use std::env::current_exe;
@@ -308,7 +308,8 @@ pub fn main() {
     run_subcommand(flags).await
   };
 
-  let exit_code = unwrap_or_exit(create_and_run_current_thread(future));
+  let exit_code =
+    unwrap_or_exit(create_and_run_current_thread_with_maybe_metrics(future));
 
   std::process::exit(exit_code);
 }

runtime/Cargo.toml

@@ -105,6 +105,7 @@ serde.workspace = true
 signal-hook-registry = "1.4.0"
 termcolor = "1.1.3"
 tokio.workspace = true
+tokio-metrics.workspace = true
 uuid.workspace = true
 
 [target.'cfg(windows)'.dependencies]

runtime/tokio_util.rs

@@ -3,6 +3,7 @@ use std::fmt::Debug;
 use std::str::FromStr;
 
 use deno_core::task::MaskFutureAsSend;
+use tokio_metrics::RuntimeMonitor;
 
 /// Default configuration for tokio. In the future, this method may have different defaults
 /// depending on the platform and/or CPU layout.
@@ -47,7 +48,10 @@ pub fn create_basic_runtime() -> tokio::runtime::Runtime {
 }
 
 #[inline(always)]
-pub fn create_and_run_current_thread<F, R>(future: F) -> R
+fn create_and_run_current_thread_inner<F, R>(
+  future: F,
+  metrics_enabled: bool,
+) -> R
 where
   F: std::future::Future<Output = R> + 'static,
   R: Send + 'static,
@@ -66,6 +70,47 @@ where
   // 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);
+  let join_handle = if metrics_enabled {
+    rt.spawn(async move {
+      let metrics_interval: u64 = std::env::var("DENO_TOKIO_METRICS_INTERVAL")
+        .ok()
+        .and_then(|val| val.parse().ok())
+        .unwrap_or(1000);
+      let handle = tokio::runtime::Handle::current();
+      let runtime_monitor = RuntimeMonitor::new(&handle);
+      tokio::spawn(async move {
+        for interval in runtime_monitor.intervals() {
+          println!("{:#?}", interval);
+          // wait 500ms
+          tokio::time::sleep(std::time::Duration::from_millis(
+            metrics_interval,
+          ))
+          .await;
+        }
+      });
+      future.await
+    })
+  } else {
+    rt.spawn(future)
+  };
   rt.block_on(join_handle).unwrap().into_inner()
 }
+
+#[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,
+{
+  create_and_run_current_thread_inner(future, false)
+}
+
+#[inline(always)]
+pub fn create_and_run_current_thread_with_maybe_metrics<F, R>(future: F) -> R
+where
+  F: std::future::Future<Output = R> + 'static,
+  R: Send + 'static,
+{
+  let metrics_enabled = std::env::var("DENO_TOKIO_METRICS").ok().is_some();
+  create_and_run_current_thread_inner(future, metrics_enabled)
+}