tokio: upgrade to new nightly for CI (#4193)

.github/workflows/ci.yml

@@ -9,7 +9,7 @@ name: CI
 env:
   RUSTFLAGS: -Dwarnings
   RUST_BACKTRACE: 1
-  nightly: nightly-2021-07-09
+  nightly: nightly-2021-10-25
   minrust: 1.45.2
 
 jobs:

.github/workflows/loom.yml

@@ -10,7 +10,6 @@ name: Loom
 env:
   RUSTFLAGS: -Dwarnings
   RUST_BACKTRACE: 1
-  nightly: nightly-2021-07-09
 
 jobs:
   loom:

tokio/src/lib.rs

@@ -16,6 +16,10 @@
     attr(deny(warnings, rust_2018_idioms), allow(dead_code, unused_variables))
 ))]
 #![cfg_attr(docsrs, feature(doc_cfg))]
+#![cfg_attr(docsrs, feature(doc_cfg_hide))]
+#![cfg_attr(docsrs, doc(cfg_hide(docsrs)))]
+#![cfg_attr(docsrs, doc(cfg_hide(loom)))]
+#![cfg_attr(docsrs, doc(cfg_hide(not(loom))))]
 #![cfg_attr(docsrs, allow(unused_attributes))]
 
 //! A runtime for writing reliable network applications without compromising speed.

tokio/src/macros/cfg.rs

@@ -99,6 +99,7 @@ macro_rules! cfg_io_driver_impl {
                 feature = "process",
                 all(unix, feature = "signal"),
             ))]
+            #[cfg_attr(docsrs, doc(cfg(all())))]
             $item
         )*
     }

tokio/src/runtime/handle.rs

@@ -18,15 +18,25 @@ pub struct Handle {
     pub(super) spawner: Spawner,
 
     /// Handles to the I/O drivers
+    #[cfg_attr(
+        not(any(feature = "net", feature = "process", all(unix, feature = "signal"))),
+        allow(dead_code)
+    )]
     pub(super) io_handle: driver::IoHandle,
 
     /// Handles to the signal drivers
+    #[cfg_attr(
+        not(any(feature = "signal", all(unix, feature = "process"))),
+        allow(dead_code)
+    )]
     pub(super) signal_handle: driver::SignalHandle,
 
     /// Handles to the time drivers
+    #[cfg_attr(not(feature = "time"), allow(dead_code))]
     pub(super) time_handle: driver::TimeHandle,
 
     /// Source of `Instant::now()`
+    #[cfg_attr(not(all(feature = "time", feature = "test-util")), allow(dead_code))]
     pub(super) clock: driver::Clock,
 
     /// Blocking pool spawner