Remove the semi-secret logging

Rayon has long had some logging functionality, but not well advertised.
The only mention is in the (private) module docs:

> To use in a debug build, set the env var `RAYON_LOG` as
> described below.  In a release build, logs are compiled out by
> default unless Rayon is built with `--cfg rayon_rs_log` (try
> `RUSTFLAGS="--cfg rayon_rs_log"`).
>
> Note that logs are an internally debugging tool and their format
> is considered unstable, as are the details of how to enable them.

I, for one, have not "internally" used this for debugging at all, yet it
comes at some cost to all users, even disabled in release builds. At the
very least it requires `crossbeam-channel` that we're not using anywhere
else except tests. Besides that, this code also bloats the compiled size
of `rayon-core` by about 30%, and similar for its compile time.

**So let's just rip out the logger!**

The remaining uses of `crossbeam-channel` in test cases are easily
avoidable too, since `std::sync::mpsc::Sender` is now `Sync`.

(cherry picked from commit 191ade2)

Author: cuviper

rayon-core/Cargo.toml

@@ -18,7 +18,6 @@ name = "rayon_core"
 
 # Some dependencies may not be their latest version, in order to support older rustc.
 [dependencies]
-crossbeam-channel = "0.5.0"
 crossbeam-deque = "0.8.1"
 crossbeam-utils = "0.8.0"
 

rayon-core/src/broadcast/test.rs

@@ -2,6 +2,7 @@
 
 use crate::ThreadPoolBuilder;
 use std::sync::atomic::{AtomicUsize, Ordering};
+use std::sync::mpsc::channel;
 use std::sync::Arc;
 use std::{thread, time};
 
@@ -14,7 +15,7 @@ fn broadcast_global() {
 #[test]
 #[cfg_attr(any(target_os = "emscripten", target_family = "wasm"), ignore)]
 fn spawn_broadcast_global() {
-    let (tx, rx) = crossbeam_channel::unbounded();
+    let (tx, rx) = channel();
     crate::spawn_broadcast(move |ctx| tx.send(ctx.index()).unwrap());
 
     let mut v: Vec<_> = rx.into_iter().collect();
@@ -33,7 +34,7 @@ fn broadcast_pool() {
 #[test]
 #[cfg_attr(any(target_os = "emscripten", target_family = "wasm"), ignore)]
 fn spawn_broadcast_pool() {
-    let (tx, rx) = crossbeam_channel::unbounded();
+    let (tx, rx) = channel();
     let pool = ThreadPoolBuilder::new().num_threads(7).build().unwrap();
     pool.spawn_broadcast(move |ctx| tx.send(ctx.index()).unwrap());
 
@@ -53,7 +54,7 @@ fn broadcast_self() {
 #[test]
 #[cfg_attr(any(target_os = "emscripten", target_family = "wasm"), ignore)]
 fn spawn_broadcast_self() {
-    let (tx, rx) = crossbeam_channel::unbounded();
+    let (tx, rx) = channel();
     let pool = ThreadPoolBuilder::new().num_threads(7).build().unwrap();
     pool.spawn(|| crate::spawn_broadcast(move |ctx| tx.send(ctx.index()).unwrap()));
 
@@ -81,7 +82,7 @@ fn broadcast_mutual() {
 #[test]
 #[cfg_attr(any(target_os = "emscripten", target_family = "wasm"), ignore)]
 fn spawn_broadcast_mutual() {
-    let (tx, rx) = crossbeam_channel::unbounded();
+    let (tx, rx) = channel();
     let pool1 = Arc::new(ThreadPoolBuilder::new().num_threads(3).build().unwrap());
     let pool2 = ThreadPoolBuilder::new().num_threads(7).build().unwrap();
     pool1.spawn({
@@ -118,7 +119,7 @@ fn broadcast_mutual_sleepy() {
 #[test]
 #[cfg_attr(any(target_os = "emscripten", target_family = "wasm"), ignore)]
 fn spawn_broadcast_mutual_sleepy() {
-    let (tx, rx) = crossbeam_channel::unbounded();
+    let (tx, rx) = channel();
     let pool1 = Arc::new(ThreadPoolBuilder::new().num_threads(3).build().unwrap());
     let pool2 = ThreadPoolBuilder::new().num_threads(7).build().unwrap();
     pool1.spawn({
@@ -158,8 +159,8 @@ fn broadcast_panic_one() {
 #[test]
 #[cfg_attr(not(panic = "unwind"), ignore)]
 fn spawn_broadcast_panic_one() {
-    let (tx, rx) = crossbeam_channel::unbounded();
-    let (panic_tx, panic_rx) = crossbeam_channel::unbounded();
+    let (tx, rx) = channel();
+    let (panic_tx, panic_rx) = channel();
     let pool = ThreadPoolBuilder::new()
         .num_threads(7)
         .panic_handler(move |e| panic_tx.send(e).unwrap())
@@ -196,8 +197,8 @@ fn broadcast_panic_many() {
 #[test]
 #[cfg_attr(not(panic = "unwind"), ignore)]
 fn spawn_broadcast_panic_many() {
-    let (tx, rx) = crossbeam_channel::unbounded();
-    let (panic_tx, panic_rx) = crossbeam_channel::unbounded();
+    let (tx, rx) = channel();
+    let (panic_tx, panic_rx) = channel();
     let pool = ThreadPoolBuilder::new()
         .num_threads(7)
         .panic_handler(move |e| panic_tx.send(e).unwrap())
@@ -231,7 +232,7 @@ fn broadcast_sleep_race() {
 
 #[test]
 fn broadcast_after_spawn_broadcast() {
-    let (tx, rx) = crossbeam_channel::unbounded();
+    let (tx, rx) = channel();
 
     // Queue a non-blocking spawn_broadcast.
     crate::spawn_broadcast(move |ctx| tx.send(ctx.index()).unwrap());
@@ -247,7 +248,7 @@ fn broadcast_after_spawn_broadcast() {
 
 #[test]
 fn broadcast_after_spawn() {
-    let (tx, rx) = crossbeam_channel::bounded(1);
+    let (tx, rx) = channel();
 
     // Queue a regular spawn on a thread-local deque.
     crate::registry::in_worker(move |_, _| {

rayon-core/src/latch.rs

@@ -84,13 +84,6 @@ impl CoreLatch {
         }
     }
 
-    /// Returns the address of this core latch as an integer. Used
-    /// for logging.
-    #[inline]
-    pub(super) fn addr(&self) -> usize {
-        self as *const CoreLatch as usize
-    }
-
     /// Invoked by owning thread as it prepares to sleep. Returns true
     /// if the owning thread may proceed to fall asleep, false if the
     /// latch was set in the meantime.

rayon-core/src/lib.rs

@@ -72,8 +72,6 @@ use std::marker::PhantomData;
 use std::str::FromStr;
 use std::thread;
 
-#[macro_use]
-mod log;
 #[macro_use]
 mod private;