3 files changed, 14 insertions, 9 deletions
diff --git a/vendor/crossbeam-channel/src/flavors/at.rs b/vendor/crossbeam-channel/src/flavors/at.rs
index ca5ee60f5..515c4e33b 100644
--- a/vendor/crossbeam-channel/src/flavors/at.rs
+++ b/vendor/crossbeam-channel/src/flavors/at.rs
@@ -4,7 +4,7 @@
 
 use std::sync::atomic::{AtomicBool, Ordering};
 use std::thread;
-use std::time::{Duration, Instant};
+use std::time::Instant;
 
 use crate::context::Context;
 use crate::err::{RecvTimeoutError, TryRecvError};
@@ -32,11 +32,6 @@ impl Channel {
             received: AtomicBool::new(false),
         }
     }
-    /// Creates a channel that delivers a message after a certain duration of time.
-    #[inline]
-    pub(crate) fn new_timeout(dur: Duration) -> Self {
-        Self::new_deadline(utils::convert_timeout_to_deadline(dur))
-    }
 
     /// Attempts to receive a message without blocking.
     #[inline]
diff --git a/vendor/crossbeam-channel/src/flavors/list.rs b/vendor/crossbeam-channel/src/flavors/list.rs
index 6090b8d47..230edd8d2 100644
--- a/vendor/crossbeam-channel/src/flavors/list.rs
+++ b/vendor/crossbeam-channel/src/flavors/list.rs
@@ -584,6 +584,17 @@ impl<T> Channel<T> {
         let mut head = self.head.index.load(Ordering::Acquire);
         let mut block = self.head.block.load(Ordering::Acquire);
 
+        // If we're going to be dropping messages we need to synchronize with initialization
+        if head >> SHIFT != tail >> SHIFT {
+            // The block can be null here only if a sender is in the process of initializing the
+            // channel while another sender managed to send a message by inserting it into the
+            // semi-initialized channel and advanced the tail.
+            // In that case, just wait until it gets initialized.
+            while block.is_null() {
+                backoff.snooze();
+                block = self.head.block.load(Ordering::Acquire);
+            }
+        }
         unsafe {
             // Drop all messages between head and tail and deallocate the heap-allocated blocks.
             while head >> SHIFT != tail >> SHIFT {
diff --git a/vendor/crossbeam-channel/src/flavors/tick.rs b/vendor/crossbeam-channel/src/flavors/tick.rs
index 4201b6eb0..d38f6a594 100644
--- a/vendor/crossbeam-channel/src/flavors/tick.rs
+++ b/vendor/crossbeam-channel/src/flavors/tick.rs
@@ -10,7 +10,6 @@ use crossbeam_utils::atomic::AtomicCell;
 use crate::context::Context;
 use crate::err::{RecvTimeoutError, TryRecvError};
 use crate::select::{Operation, SelectHandle, Token};
-use crate::utils;
 
 /// Result of a receive operation.
 pub(crate) type TickToken = Option<Instant>;
@@ -27,9 +26,9 @@ pub(crate) struct Channel {
 impl Channel {
     /// Creates a channel that delivers messages periodically.
     #[inline]
-    pub(crate) fn new(dur: Duration) -> Self {
+    pub(crate) fn new(delivery_time: Instant, dur: Duration) -> Self {
         Channel {
-            delivery_time: AtomicCell::new(utils::convert_timeout_to_deadline(dur)),
+            delivery_time: AtomicCell::new(delivery_time),
             duration: dur,
         }
     }