From 5c71268bb88a1125e822f5a0a68ff996f6811736 Mon Sep 17 00:00:00 2001
From: kalcutter <kal.conley@dectris.com>
Date: Fri, 27 Mar 2020 22:22:16 +0100
Subject: [PATCH] sync: broadcast, revert "Keep lock until sender notified"
 (#2348)

This reverts commit 826fc21abfd04779cde92e4cc33de2adb42cf327.

The code was intentional. Holding the lock while notifying is
unnecessary. Also change the code to use `drop` so clippy doesn't
confuse people against their will.
---
 tokio/src/sync/broadcast.rs | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/tokio/src/sync/broadcast.rs b/tokio/src/sync/broadcast.rs
index 5394c496e..05a58070e 100644
--- a/tokio/src/sync/broadcast.rs
+++ b/tokio/src/sync/broadcast.rs
@@ -114,6 +114,7 @@ use crate::loom::sync::atomic::{spin_loop_hint, AtomicBool, AtomicPtr, AtomicUsi
 use crate::loom::sync::{Arc, Condvar, Mutex};
 
 use std::fmt;
+use std::mem;
 use std::ptr;
 use std::sync::atomic::Ordering::SeqCst;
 use std::task::{Context, Poll, Waker};
@@ -980,7 +981,7 @@ impl<T> Slot<T> {
         if 1 == self.lock.fetch_sub(2, SeqCst) - 2 {
             // First acquire the lock to make sure our sender is waiting on the
             // condition variable, otherwise the notification could be lost.
-            let _lock = tail.lock().unwrap();
+            mem::drop(tail.lock().unwrap());
             // Wake up senders
             condvar.notify_all();
         }
@@ -1000,8 +1001,6 @@ impl<'a, T> RecvGuard<'a, T> {
     }
 
     fn drop_no_rem_dec(self) {
-        use std::mem;
-
         self.slot.rx_unlock(self.tail, self.condvar, false);
 
         mem::forget(self);