From 8dddb2294310ad3e8ce0b2af735a702ad72a9a99 Mon Sep 17 00:00:00 2001
From: Ibraheem Ahmed <ibraheem@ibraheem.ca>
Date: Mon, 17 Oct 2022 19:31:15 -0400
Subject: [PATCH] `sync::mpsc`: quadratic backoff

---
 library/std/src/sync/mpmc/utils.rs | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/library/std/src/sync/mpmc/utils.rs b/library/std/src/sync/mpmc/utils.rs
index 3f0cb848cc5ce..85cf5dd244139 100644
--- a/library/std/src/sync/mpmc/utils.rs
+++ b/library/std/src/sync/mpmc/utils.rs
@@ -110,7 +110,8 @@ impl Backoff {
     /// progress.
     #[inline]
     pub fn spin(&self) {
-        for _ in 0..1 << self.step.get().min(SPIN_LIMIT) {
+        let step = self.step.get().min(SPIN_LIMIT);
+        for _ in 0..step.pow(2)  {
             crate::hint::spin_loop();
         }
 
@@ -123,7 +124,7 @@ impl Backoff {
     #[inline]
     pub fn snooze(&self) {
         if self.step.get() <= SPIN_LIMIT {
-            for _ in 0..1 << self.step.get() {
+            for _ in 0..self.step.get().pow(2) {
                 crate::hint::spin_loop()
             }
         } else {