diff --git a/Cargo.lock b/Cargo.lock

--- a/Cargo.lock

+++ b/Cargo.lock

@@ -972,13 +972,13 @@

  "cfg-if 1.0.0",

 ]

 [[package]]

 name = "crossbeam-channel"

-version = "0.5.2"

-source = "registry+https://github.com/rust-lang/crates.io-index"

-checksum = "e54ea8bc3fb1ee042f5aace6e3c6e025d3874866da222930f70ce62aceba0bfa"

+version = "0.5.4"

+source = "registry+https://github.com/rust-lang/crates.io-index"

+checksum = "5aaa7bd5fb665c6864b5f963dd9097905c54125909c7aa94c9e18507cdbe6c53"

 dependencies = [

  "cfg-if 1.0.0",

  "crossbeam-utils 0.8.6",

 ]

diff --git a/third_party/rust/crossbeam-channel/.cargo-checksum.json b/third_party/rust/crossbeam-channel/.cargo-checksum.json

--- a/third_party/rust/crossbeam-channel/.cargo-checksum.json

+++ b/third_party/rust/crossbeam-channel/.cargo-checksum.json

@@ -1 +1 @@

-{"files":{"CHANGELOG.md":"e70d1a5fa6697a8b24e193e3934975317df12279c167b90fcb9616291792197c","Cargo.lock":"0f4e59f28bdd52c4781d102fc7d1f16d1ea417aaec0a4846432444a4019b2537","Cargo.toml":"c8334f658b699a1a0e25d997d752a9493a627f9ddcb7aab739c7319ea583882f","LICENSE-APACHE":"a60eea817514531668d7e00765731449fe14d059d3249e0bc93b36de45f759f2","LICENSE-MIT":"5734ed989dfca1f625b40281ee9f4530f91b2411ec01cb748223e7eb87e201ab","LICENSE-THIRD-PARTY":"b16db96b93b1d7cf7bea533f572091ec6bca3234fbe0a83038be772ff391a44c","README.md":"415a71d4978cfd338a6ae1f1b41284652eccd277a815542c304647dc437a8274","benches/crossbeam.rs":"96cb1abd23cac3ef8a7174a802e94609926b555bb02c9658c78723d433f1dd92","examples/fibonacci.rs":"4e88fa40048cdc31e9c7bb60347d46f92543d7ddf39cab3b52bfe44affdb6a02","examples/matching.rs":"63c250e164607a7a9f643d46f107bb5da846d49e89cf9069909562d20e530f71","examples/stopwatch.rs":"d02121258f08d56f1eb7997e19bcb9bacb6836cfa0abbba90a9e59d8a50ae5cf","src/channel.rs":"a9baaad2f414c38cd324a60ac9375ca58462ce6662217683648e9b66cec43a8c","src/context.rs":"ff4d39639ddf16aaab582d4a5f3d10ef2c71afe1abbf4e60f3d9d2ddbd72c230","src/counter.rs":"c49a9f44587888850edeb62f7c8ecd1acecb39c836834254ff3ac934c478440a","src/err.rs":"fdbde7279a1e74973e5c7d3e835a97836229a357fe465c0ba1a37f2a012d1bef","src/flavors/array.rs":"853c2ad068f912cfb49877bcd41e241f34b25026b709bf0629523f19952e3adc","src/flavors/at.rs":"65bf870b3ddb14738256706b0276f2656ad1fe9cd8eb91737489868edd088e92","src/flavors/list.rs":"50dbe59616c39b5aa184470023ce0cfb1cb0dbd92e1577375d299446981527c0","src/flavors/mod.rs":"3d9d43bc38b0adb18c96c995c2bd3421d8e33ab6c30b20c3c467d21d48e485dc","src/flavors/never.rs":"0e7921922d00c711552fb063c63c78192fa6ddc0762fb81c1713b847495ec39a","src/flavors/tick.rs":"38a479b9f4a72a5ccb9c407a1e7b44d36b6ad0f4e214e39266b12b9564c803dc","src/flavors/zero.rs":"012a53f56b86df22ce49866da95e5f457fb99a18a098f0f64779c6d1cdd7092f","src/lib.rs":"3a65706d4124844ffc4c8cb1f8cc779631ec94f449f85cbb68364ad3619404f1","src/select.rs":"66eb10a6cbdf8dd0869f2a7cac9992fdaee36c9e2a01d708d39d7c794572935b","src/select_macro.rs":"96bc9acb9a22588a4e733b0ab0761ad2be9a6b3e03744e8fc9c6de9ae433b696","src/utils.rs":"746fe315d6cfc832e3dda35e5055c0fd5c99907f1303b2ea7eacc4e37c8527e1","src/waker.rs":"591ee70bf62ccad5aa2fac7b92d444183b02790a79c024f016c78de2396d08a3","tests/after.rs":"0154a8e152880db17a20514ecdd49dabc361d3629858d119b9746b5e932c780c","tests/array.rs":"e5f25e8991863a9a86d61a66be646d04feae527f35b1697fd215b97af4383736","tests/golang.rs":"dc85669c9c4e902b1bb263d00f5cb6f9ecb6d42b19fe53425b55ce97c887da49","tests/iter.rs":"25dc02135bbae9d47a30f9047661648e66bdc134e40ba78bc2fbacbb8b3819bc","tests/list.rs":"de865ef097f3bcb35c1c814554e6108fed43b3dbb1533c8bbcf8688cceb6b6ab","tests/mpsc.rs":"401aa3c6923815058881ddce98070df68ebab283913c89c007436bb8af7ca0ea","tests/never.rs":"ee40c4fc4dd5af4983fae8de6927f52b81174d222c162f745b26c4a6c7108e4f","tests/ready.rs":"d349702f123925a0781b48d677e6dcf64fc5d1fc788a7bf1e151a3d57e81871c","tests/same_channel.rs":"2bab761443671e841e1b2476bd8082d75533a2f6be7946f5dbcee67cdc82dccb","tests/select.rs":"d20259a45f387cbce80c2c876ae81ea3883f36ea01c5151c159d58c362f6ba07","tests/select_macro.rs":"d3af2dc98e0dd03dc4ffab464b8ccb2f8b7504e8bb830948a04c015b92f0b296","tests/thread_locals.rs":"a1ce59e2aff69161621c0cb215eb6ea238088c06a31a8507a74cf179fd5a4299","tests/tick.rs":"5f697bd14c48505d932e82065b5302ef668e1cc19cac18e8ac22e0c83c221c1d","tests/zero.rs":"afbd838001d4196daddf17133e60ccea31529cc48ee01e245ac0d6366d1e30b9"},"package":"e54ea8bc3fb1ee042f5aace6e3c6e025d3874866da222930f70ce62aceba0bfa"}

\ No newline at end of file

+{"files":{"CHANGELOG.md":"0f549e63930d1e576f117ee9249c84276eadbe6fb95818680c042c6c0af8a807","Cargo.lock":"834da9468c17c8e1b7fe457764257f4dfdaa24bc98cbdfedf3af4f3d4f5c1e6a","Cargo.toml":"1296a016c4c23d38a35b3d737ee8285fcaaf7d23b7bbb5a3484cefe56b7ca32a","LICENSE-APACHE":"a60eea817514531668d7e00765731449fe14d059d3249e0bc93b36de45f759f2","LICENSE-MIT":"5734ed989dfca1f625b40281ee9f4530f91b2411ec01cb748223e7eb87e201ab","LICENSE-THIRD-PARTY":"b16db96b93b1d7cf7bea533f572091ec6bca3234fbe0a83038be772ff391a44c","README.md":"415a71d4978cfd338a6ae1f1b41284652eccd277a815542c304647dc437a8274","benches/crossbeam.rs":"96cb1abd23cac3ef8a7174a802e94609926b555bb02c9658c78723d433f1dd92","examples/fibonacci.rs":"4e88fa40048cdc31e9c7bb60347d46f92543d7ddf39cab3b52bfe44affdb6a02","examples/matching.rs":"63c250e164607a7a9f643d46f107bb5da846d49e89cf9069909562d20e530f71","examples/stopwatch.rs":"d02121258f08d56f1eb7997e19bcb9bacb6836cfa0abbba90a9e59d8a50ae5cf","src/channel.rs":"3bbf69df6c3f0071a44bab0139a749447604f5ffa5e45acc2998803dee066522","src/context.rs":"ff4d39639ddf16aaab582d4a5f3d10ef2c71afe1abbf4e60f3d9d2ddbd72c230","src/counter.rs":"c49a9f44587888850edeb62f7c8ecd1acecb39c836834254ff3ac934c478440a","src/err.rs":"44cb2024ee6b0cd6fd24996430e53720769f64b4ac35016bc3e05cb9db48681d","src/flavors/array.rs":"0743fb71a8adc8d95143b1cdae996823dddb7ab7fb7139eb6e0cdf733ff231ee","src/flavors/at.rs":"1db64919593b7c14f838c16a22732515f1e716d2d5f6cc639f42631380e545cd","src/flavors/list.rs":"017b66a84ada393d11d1730297426338244b115944a4d631573447641a66bed6","src/flavors/mod.rs":"3d9d43bc38b0adb18c96c995c2bd3421d8e33ab6c30b20c3c467d21d48e485dc","src/flavors/never.rs":"747da857aa1a7601641f23f4930e6ad00ebaf50456d9be5c7aa270e2ecc24dcb","src/flavors/tick.rs":"69b2dfe0186bc8b9fd7a73e32da59d2656d8150da1e00fba92a412e0907568a3","src/flavors/zero.rs":"1edd8e5114daa5b82ec9f4a715c0389a9de02cce64de0f71b4225868dad99a99","src/lib.rs":"3a65706d4124844ffc4c8cb1f8cc779631ec94f449f85cbb68364ad3619404f1","src/select.rs":"63dbfde7098dac1424f1cc884f6b8364f3bf3e06527691dde628ff6c416a7f35","src/select_macro.rs":"582a033cc0a51917fd5197dfb66677e9d7982c013414e75ae78b4a740189a56d","src/utils.rs":"b4d38e39a7d7774729458b1b39253377a55657d377c483d30b32e42a0a0092e3","src/waker.rs":"2114bd84f35b2c654d1914127e0380e17a5c20d8ec1e20449af3d653cad27c64","tests/after.rs":"0154a8e152880db17a20514ecdd49dabc361d3629858d119b9746b5e932c780c","tests/array.rs":"e0f3814328c79727a85df3aee0409701849dabfeaaa2f70721e14396fbaba1cd","tests/golang.rs":"dc85669c9c4e902b1bb263d00f5cb6f9ecb6d42b19fe53425b55ce97c887da49","tests/iter.rs":"25dc02135bbae9d47a30f9047661648e66bdc134e40ba78bc2fbacbb8b3819bc","tests/list.rs":"de865ef097f3bcb35c1c814554e6108fed43b3dbb1533c8bbcf8688cceb6b6ab","tests/mpsc.rs":"401aa3c6923815058881ddce98070df68ebab283913c89c007436bb8af7ca0ea","tests/never.rs":"ee40c4fc4dd5af4983fae8de6927f52b81174d222c162f745b26c4a6c7108e4f","tests/ready.rs":"d349702f123925a0781b48d677e6dcf64fc5d1fc788a7bf1e151a3d57e81871c","tests/same_channel.rs":"2bab761443671e841e1b2476bd8082d75533a2f6be7946f5dbcee67cdc82dccb","tests/select.rs":"d20259a45f387cbce80c2c876ae81ea3883f36ea01c5151c159d58c362f6ba07","tests/select_macro.rs":"948eb21f72a9317c0de98a9bd21f6f8ff2b09b73b45c171c45b04c051a2fd0c4","tests/thread_locals.rs":"a1ce59e2aff69161621c0cb215eb6ea238088c06a31a8507a74cf179fd5a4299","tests/tick.rs":"5f697bd14c48505d932e82065b5302ef668e1cc19cac18e8ac22e0c83c221c1d","tests/zero.rs":"afbd838001d4196daddf17133e60ccea31529cc48ee01e245ac0d6366d1e30b9"},"package":"5aaa7bd5fb665c6864b5f963dd9097905c54125909c7aa94c9e18507cdbe6c53"}

\ No newline at end of file

diff --git a/third_party/rust/crossbeam-channel/CHANGELOG.md b/third_party/rust/crossbeam-channel/CHANGELOG.md

--- a/third_party/rust/crossbeam-channel/CHANGELOG.md

+++ b/third_party/rust/crossbeam-channel/CHANGELOG.md

@@ -1,8 +1,16 @@

+# Version 0.5.4

+

+- Workaround a bug in upstream related to TLS access on AArch64 Linux. (#802)

+

+# Version 0.5.3

+

+- Fix panic on very large timeout. (#798)

+

 # Version 0.5.2

-- Fix stacked borrows violations. (#763, #764)

+- Fix stacked borrows violations when `-Zmiri-tag-raw-pointers` is enabled. (#763, #764)

 # Version 0.5.1

 - Fix memory leak in unbounded channel. (#669)

@@ -19,10 +27,12 @@

 - Fix bug in release (yanking 0.4.3)

 - Fix UB and breaking change introduced in 0.4.3

 # Version 0.4.3

+

+**Note**: This release has been yanked. See [CVE-2020-15254](https://github.com/crossbeam-rs/crossbeam/security/advisories/GHSA-v5m7-53cv-f3hx) for details.

 - Change license to "MIT OR Apache-2.0".

 # Version 0.4.2

diff --git a/third_party/rust/crossbeam-channel/Cargo.lock b/third_party/rust/crossbeam-channel/Cargo.lock

--- a/third_party/rust/crossbeam-channel/Cargo.lock

+++ b/third_party/rust/crossbeam-channel/Cargo.lock

@@ -8,34 +8,34 @@

 source = "registry+https://github.com/rust-lang/crates.io-index"

 checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"

 [[package]]

 name = "crossbeam-channel"

-version = "0.5.2"

+version = "0.5.4"

 dependencies = [

  "cfg-if",

  "crossbeam-utils",

  "num_cpus",

  "rand",

  "signal-hook",

 ]

 [[package]]

 name = "crossbeam-utils"

-version = "0.8.6"

+version = "0.8.8"

 source = "registry+https://github.com/rust-lang/crates.io-index"

-checksum = "cfcae03edb34f947e64acdb1c33ec169824e20657e9ecb61cef6c8c74dcb8120"

+checksum = "0bf124c720b7686e3c2663cf54062ab0f68a88af2fb6a030e87e30bf721fcb38"

 dependencies = [

  "cfg-if",

  "lazy_static",

 ]

 [[package]]

 name = "getrandom"

-version = "0.2.3"

+version = "0.2.5"

 source = "registry+https://github.com/rust-lang/crates.io-index"

-checksum = "7fcd999463524c52659517fe2cea98493cfe485d10565e7b0fb07dbba7ad2753"

+checksum = "d39cd93900197114fa1fcb7ae84ca742095eed9442088988ae74fa744e930e77"

 dependencies = [

  "cfg-if",

  "libc",

  "wasi",

 ]

@@ -55,13 +55,13 @@

 source = "registry+https://github.com/rust-lang/crates.io-index"

 checksum = "e2abad23fbc42b3700f2f279844dc832adb2b2eb069b2df918f455c4e18cc646"

 [[package]]

 name = "libc"

-version = "0.2.112"

+version = "0.2.120"

 source = "registry+https://github.com/rust-lang/crates.io-index"

-checksum = "1b03d17f364a3a042d5e5d46b053bbbf82c92c9430c592dd4c064dc6ee997125"

+checksum = "ad5c14e80759d0939d013e6ca49930e59fc53dd8e5009132f76240c179380c09"

 [[package]]

 name = "num_cpus"

 version = "1.13.1"

 source = "registry+https://github.com/rust-lang/crates.io-index"

@@ -77,18 +77,17 @@

 source = "registry+https://github.com/rust-lang/crates.io-index"

 checksum = "eb9f9e6e233e5c4a35559a617bf40a4ec447db2e84c20b55a6f83167b7e57872"

 [[package]]

 name = "rand"

-version = "0.8.4"

+version = "0.8.5"

 source = "registry+https://github.com/rust-lang/crates.io-index"

-checksum = "2e7573632e6454cf6b99d7aac4ccca54be06da05aca2ef7423d22d27d4d4bcd8"

+checksum = "34af8d1a0e25924bc5b7c43c079c942339d8f0a8b57c39049bef581b46327404"

 dependencies = [

  "libc",

  "rand_chacha",

  "rand_core",

- "rand_hc",

 ]

 [[package]]

 name = "rand_chacha"

 version = "0.3.1"

@@ -104,19 +103,10 @@

 version = "0.6.3"

 source = "registry+https://github.com/rust-lang/crates.io-index"

 checksum = "d34f1408f55294453790c48b2f1ebbb1c5b4b7563eb1f418bcfcfdbb06ebb4e7"

 dependencies = [

  "getrandom",

-]

-

-[[package]]

-name = "rand_hc"

-version = "0.3.1"

-source = "registry+https://github.com/rust-lang/crates.io-index"

-checksum = "d51e9f596de227fda2ea6c84607f5558e196eeaf43c986b724ba4fb8fdf497e7"

-dependencies = [

- "rand_core",

 ]

 [[package]]

 name = "signal-hook"

 version = "0.3.13"

diff --git a/third_party/rust/crossbeam-channel/Cargo.toml b/third_party/rust/crossbeam-channel/Cargo.toml

--- a/third_party/rust/crossbeam-channel/Cargo.toml

+++ b/third_party/rust/crossbeam-channel/Cargo.toml

@@ -11,24 +11,36 @@

 [package]

 edition = "2018"

 rust-version = "1.36"

 name = "crossbeam-channel"

-version = "0.5.2"

+version = "0.5.4"

 description = "Multi-producer multi-consumer channels for message passing"

 homepage = "https://github.com/crossbeam-rs/crossbeam/tree/master/crossbeam-channel"

-keywords = ["channel", "mpmc", "select", "golang", "message"]

-categories = ["algorithms", "concurrency", "data-structures"]

+keywords = [

+    "channel",

+    "mpmc",

+    "select",

+    "golang",

+    "message",

+]

+categories = [

+    "algorithms",

+    "concurrency",

+    "data-structures",

+]

 license = "MIT OR Apache-2.0"

 repository = "https://github.com/crossbeam-rs/crossbeam"

+

 [dependencies.cfg-if]

 version = "1"

 [dependencies.crossbeam-utils]

 version = "0.8"

 optional = true

 default-features = false

+

 [dev-dependencies.num_cpus]

 version = "1.13.0"

 [dev-dependencies.rand]

 version = "0.8"

diff --git a/third_party/rust/crossbeam-channel/src/channel.rs b/third_party/rust/crossbeam-channel/src/channel.rs

--- a/third_party/rust/crossbeam-channel/src/channel.rs

+++ b/third_party/rust/crossbeam-channel/src/channel.rs

@@ -12,10 +12,11 @@

 use crate::err::{

     RecvError, RecvTimeoutError, SendError, SendTimeoutError, TryRecvError, TrySendError,

 };

 use crate::flavors;

 use crate::select::{Operation, SelectHandle, Token};

+use crate::utils;

 /// Creates a channel of unbounded capacity.

 ///

 /// This channel has a growable buffer that can hold any number of messages at a time.

 ///

@@ -469,11 +470,11 @@

     ///     s.send_timeout(3, Duration::from_millis(500)),

     ///     Err(SendTimeoutError::Disconnected(3)),

     /// );

     /// ```

     pub fn send_timeout(&self, msg: T, timeout: Duration) -> Result<(), SendTimeoutError<T>> {

-        self.send_deadline(msg, Instant::now() + timeout)

+        self.send_deadline(msg, utils::convert_timeout_to_deadline(timeout))

     }

     /// Waits for a message to be sent into the channel, but only until a given deadline.

     ///

     /// If the channel is full and not disconnected, this call will block until the send operation

@@ -859,11 +860,11 @@

     ///     r.recv_timeout(Duration::from_secs(1)),

     ///     Err(RecvTimeoutError::Disconnected),

     /// );

     /// ```

     pub fn recv_timeout(&self, timeout: Duration) -> Result<T, RecvTimeoutError> {

-        self.recv_deadline(Instant::now() + timeout)

+        self.recv_deadline(utils::convert_timeout_to_deadline(timeout))

     }

     /// Waits for a message to be received from the channel, but only before a given deadline.

     ///

     /// If the channel is empty and not disconnected, this call will block until the receive

diff --git a/third_party/rust/crossbeam-channel/src/err.rs b/third_party/rust/crossbeam-channel/src/err.rs

--- a/third_party/rust/crossbeam-channel/src/err.rs

+++ b/third_party/rust/crossbeam-channel/src/err.rs

@@ -306,20 +306,18 @@

     }

 }

 impl TryRecvError {

     /// Returns `true` if the receive operation failed because the channel is empty.

-    #[allow(clippy::trivially_copy_pass_by_ref)]

     pub fn is_empty(&self) -> bool {

         match self {

             TryRecvError::Empty => true,

             _ => false,

         }

     }

     /// Returns `true` if the receive operation failed because the channel is disconnected.

-    #[allow(clippy::trivially_copy_pass_by_ref)]

     pub fn is_disconnected(&self) -> bool {

         match self {

             TryRecvError::Disconnected => true,

             _ => false,

         }

@@ -345,20 +343,18 @@

     }

 }

 impl RecvTimeoutError {

     /// Returns `true` if the receive operation timed out.

-    #[allow(clippy::trivially_copy_pass_by_ref)]

     pub fn is_timeout(&self) -> bool {

         match self {

             RecvTimeoutError::Timeout => true,

             _ => false,

         }

     }

     /// Returns `true` if the receive operation failed because the channel is disconnected.

-    #[allow(clippy::trivially_copy_pass_by_ref)]

     pub fn is_disconnected(&self) -> bool {

         match self {

             RecvTimeoutError::Disconnected => true,

             _ => false,

         }

diff --git a/third_party/rust/crossbeam-channel/src/flavors/array.rs b/third_party/rust/crossbeam-channel/src/flavors/array.rs

--- a/third_party/rust/crossbeam-channel/src/flavors/array.rs

+++ b/third_party/rust/crossbeam-channel/src/flavors/array.rs

@@ -7,11 +7,10 @@

 //! Source:

 //!   - <http://www.1024cores.net/home/lock-free-algorithms/queues/bounded-mpmc-queue>

 //!   - <https://docs.google.com/document/d/1yIAYmbvL3JxOKOjuCyon7JhW4cSv1wy5hC0ApeGMV9s/pub>

 use std::cell::UnsafeCell;

-use std::marker::PhantomData;

 use std::mem::MaybeUninit;

 use std::ptr;

 use std::sync::atomic::{self, AtomicUsize, Ordering};

 use std::time::Instant;

@@ -31,11 +30,11 @@

     msg: UnsafeCell<MaybeUninit<T>>,

 }

 /// The token type for the array flavor.

 #[derive(Debug)]

-pub struct ArrayToken {

+pub(crate) struct ArrayToken {

     /// Slot to read from or write to.

     slot: *const u8,

     /// Stamp to store into the slot after reading or writing.

     stamp: usize,

@@ -70,11 +69,11 @@

     ///

     /// Messages are pushed into the tail of the channel.

     tail: CachePadded<AtomicUsize>,

     /// The buffer holding slots.

-    buffer: *mut Slot<T>,

+    buffer: Box<[Slot<T>]>,

     /// The channel capacity.

     cap: usize,

     /// A stamp with the value of `{ lap: 1, mark: 0, index: 0 }`.

@@ -86,13 +85,10 @@

     /// Senders waiting while the channel is full.

     senders: SyncWaker,

     /// Receivers waiting while the channel is empty and not disconnected.

     receivers: SyncWaker,

-

-    /// Indicates that dropping a `Channel<T>` may drop values of type `T`.

-    _marker: PhantomData<T>,

 }

 impl<T> Channel<T> {

     /// Creates a bounded channel of capacity `cap`.

     pub(crate) fn with_capacity(cap: usize) -> Self {

@@ -107,33 +103,29 @@

         // Tail is initialized to `{ lap: 0, mark: 0, index: 0 }`.

         let tail = 0;

         // Allocate a buffer of `cap` slots initialized

         // with stamps.

-        let buffer = {

-            let boxed: Box<[Slot<T>]> = (0..cap)

-                .map(|i| {

-                    // Set the stamp to `{ lap: 0, mark: 0, index: i }`.

-                    Slot {

-                        stamp: AtomicUsize::new(i),

-                        msg: UnsafeCell::new(MaybeUninit::uninit()),

-                    }

-                })

-                .collect();

-            Box::into_raw(boxed) as *mut Slot<T>

-        };

+        let buffer: Box<[Slot<T>]> = (0..cap)

+            .map(|i| {

+                // Set the stamp to `{ lap: 0, mark: 0, index: i }`.

+                Slot {

+                    stamp: AtomicUsize::new(i),

+                    msg: UnsafeCell::new(MaybeUninit::uninit()),

+                }

+            })

+            .collect();

         Channel {

             buffer,

             cap,

             one_lap,

             mark_bit,

             head: CachePadded::new(AtomicUsize::new(head)),

             tail: CachePadded::new(AtomicUsize::new(tail)),

             senders: SyncWaker::new(),

             receivers: SyncWaker::new(),

-            _marker: PhantomData,

         }

     }

     /// Returns a receiver handle to the channel.

     pub(crate) fn receiver(&self) -> Receiver<'_, T> {

@@ -161,11 +153,12 @@

             // Deconstruct the tail.

             let index = tail & (self.mark_bit - 1);

             let lap = tail & !(self.one_lap - 1);

             // Inspect the corresponding slot.

-            let slot = unsafe { &*self.buffer.add(index) };

+            debug_assert!(index < self.buffer.len());

+            let slot = unsafe { self.buffer.get_unchecked(index) };

             let stamp = slot.stamp.load(Ordering::Acquire);

             // If the tail and the stamp match, we may attempt to push.

             if tail == stamp {

                 let new_tail = if index + 1 < self.cap {

@@ -243,11 +236,12 @@

             // Deconstruct the head.

             let index = head & (self.mark_bit - 1);

             let lap = head & !(self.one_lap - 1);

             // Inspect the corresponding slot.

-            let slot = unsafe { &*self.buffer.add(index) };

+            debug_assert!(index < self.buffer.len());

+            let slot = unsafe { self.buffer.get_unchecked(index) };

             let stamp = slot.stamp.load(Ordering::Acquire);

             // If the the stamp is ahead of the head by 1, we may attempt to pop.

             if head + 1 == stamp {

                 let new = if index + 1 < self.cap {

@@ -473,11 +467,10 @@

             }

         }

     }

     /// Returns the capacity of the channel.

-    #[allow(clippy::unnecessary_wraps)] // This is intentional.

     pub(crate) fn capacity(&self) -> Option<usize> {

         Some(self.cap)

     }

     /// Disconnects the channel and wakes up all blocked senders and receivers.

@@ -538,26 +531,15 @@

             } else {

                 hix + i - self.cap

             };

             unsafe {

-                let p = {

-                    let slot = &mut *self.buffer.add(index);

-                    let msg = &mut *slot.msg.get();

-                    msg.as_mut_ptr()

-                };

-                p.drop_in_place();

-            }

-        }

-

-        // Finally, deallocate the buffer, but don't run any destructors.

-        unsafe {

-            // Create a slice from the buffer to make

-            // a fat pointer. Then, use Box::from_raw

-            // to deallocate it.

-            let ptr = std::slice::from_raw_parts_mut(self.buffer, self.cap) as *mut [Slot<T>];

-            Box::from_raw(ptr);

+                debug_assert!(index < self.buffer.len());

+                let slot = self.buffer.get_unchecked_mut(index);

+                let msg = &mut *slot.msg.get();

+                msg.as_mut_ptr().drop_in_place();

+            }

         }

     }

 }

 /// Receiver handle to a channel.

diff --git a/third_party/rust/crossbeam-channel/src/flavors/at.rs b/third_party/rust/crossbeam-channel/src/flavors/at.rs

--- a/third_party/rust/crossbeam-channel/src/flavors/at.rs

+++ b/third_party/rust/crossbeam-channel/src/flavors/at.rs

@@ -33,11 +33,11 @@

         }

     }

     /// 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(Instant::now() + dur)

+        Self::new_deadline(utils::convert_timeout_to_deadline(dur))

     }

     /// Attempts to receive a message without blocking.

     #[inline]

     pub(crate) fn try_recv(&self) -> Result<Instant, TryRecvError> {

@@ -140,11 +140,10 @@

             1

         }

     }

     /// Returns the capacity of the channel.

-    #[allow(clippy::unnecessary_wraps)] // This is intentional.

     #[inline]

     pub(crate) fn capacity(&self) -> Option<usize> {

         Some(1)

     }

 }

diff --git a/third_party/rust/crossbeam-channel/src/flavors/list.rs b/third_party/rust/crossbeam-channel/src/flavors/list.rs

--- a/third_party/rust/crossbeam-channel/src/flavors/list.rs

+++ b/third_party/rust/crossbeam-channel/src/flavors/list.rs

@@ -124,11 +124,11 @@

     block: AtomicPtr<Block<T>>,

 }

 /// The token type for the list flavor.

 #[derive(Debug)]

-pub struct ListToken {

+pub(crate) struct ListToken {

     /// The block of slots.

     block: *const u8,

     /// The offset into the block.

     offset: usize,

diff --git a/third_party/rust/crossbeam-channel/src/flavors/never.rs b/third_party/rust/crossbeam-channel/src/flavors/never.rs

--- a/third_party/rust/crossbeam-channel/src/flavors/never.rs

+++ b/third_party/rust/crossbeam-channel/src/flavors/never.rs

@@ -63,11 +63,10 @@

     pub(crate) fn len(&self) -> usize {

         0

     }

     /// Returns the capacity of the channel.

-    #[allow(clippy::unnecessary_wraps)] // This is intentional.

     #[inline]

     pub(crate) fn capacity(&self) -> Option<usize> {

         Some(0)

     }

 }

diff --git a/third_party/rust/crossbeam-channel/src/flavors/tick.rs b/third_party/rust/crossbeam-channel/src/flavors/tick.rs

--- a/third_party/rust/crossbeam-channel/src/flavors/tick.rs

+++ b/third_party/rust/crossbeam-channel/src/flavors/tick.rs

@@ -8,10 +8,11 @@

 use crossbeam_utils::atomic::AtomicCell;

 use crate::context::Context;

 use crate::err::{RecvTimeoutError, TryRecvError};

 use crate::select::{Operation, SelectHandle, Token};