fix(test_util): make hyper server single-threaded (#8951)

Use Tokio's single-threaded scheduler. The hyper server is used as a
point of comparison for the (single-threaded!) benchmarks in cli/bench.

We're not comparing apples to apples if we use the default
multi-threaded scheduler.

This drops the requests/sec from 284k to 130k on my 12 core Ryzen 5
system. That still leaves a 50k gap for us to close. Working on it!

1 files changed, 4 insertions, 1 deletions

diff --git a/test_util/src/lib.rs b/test_util/src/lib.rs
index 03b830783..a91416bb5 100644
--- a/test_util/src/lib.rs
+++ b/test_util/src/lib.rs
@@ -722,7 +722,10 @@ async fn wrap_main_https_server() {
   }
 }
 
-#[tokio::main]
+// Use the single-threaded scheduler. The hyper server is used as a point of
+// comparison for the (single-threaded!) benchmarks in cli/bench. We're not
+// comparing apples to apples if we use the default multi-threaded scheduler.
+#[tokio::main(basic_scheduler)]
 pub async fn run_all_servers() {
   if let Some(port) = env::args().nth(1) {
     return hyper_hello(port.parse::<u16>().unwrap()).await;