Merge #480

480: Make the `queue` module available on no_std + alloc r=jeehoonkang a=phil-opp

The crossbeam_queue crate is no_std compatible since #455.

Co-authored-by: Philipp Oppermann <[email protected]>

Author: bors[bot]

Cargo.toml

@@ -21,15 +21,15 @@ travis-ci = { repository = "crossbeam-rs/crossbeam" }
 
 [features]
 default = ["std"]
-nightly = ["crossbeam-epoch/nightly", "crossbeam-utils/nightly"]
+nightly = ["crossbeam-epoch/nightly", "crossbeam-utils/nightly", "crossbeam-queue/nightly"]
 std = [
   "crossbeam-channel",
   "crossbeam-deque",
   "crossbeam-epoch/std",
-  "crossbeam-queue",
+  "crossbeam-queue/std",
   "crossbeam-utils/std",
 ]
-alloc = ["crossbeam-epoch/alloc", "crossbeam-utils/alloc"]
+alloc = ["crossbeam-epoch/alloc", "crossbeam-utils/alloc", "crossbeam-queue/alloc"]
 
 [dependencies]
 cfg-if = "0.1.2"
@@ -52,6 +52,7 @@ default-features = false
 [dependencies.crossbeam-queue]
 version = "0.2"
 path = "./crossbeam-queue"
+default-features = false
 optional = true
 
 [dependencies.crossbeam-utils]

crossbeam-queue/Cargo.toml

@@ -19,6 +19,7 @@ categories = ["concurrency", "data-structures"]
 default = ["std"]
 std = ["crossbeam-utils/std"]
 alloc = ["crossbeam-utils/alloc"]
+nightly = []
 
 [dependencies]
 cfg-if = "0.1.2"

crossbeam-queue/src/lib.rs

@@ -11,6 +11,7 @@
 #![warn(missing_docs)]
 #![warn(missing_debug_implementations)]
 #![cfg_attr(not(feature = "std"), no_std)]
+#![cfg_attr(feature = "nightly", feature(cfg_target_has_atomic))]
 
 #[macro_use]
 extern crate cfg_if;
@@ -29,6 +30,7 @@ cfg_if! {
 
 extern crate crossbeam_utils;
 
+#[cfg_attr(feature = "nightly", cfg(target_has_atomic = "ptr"))]
 cfg_if! {
     if #[cfg(any(feature = "alloc", feature = "std"))] {
         mod array_queue;

src/lib.rs

@@ -77,6 +77,16 @@ pub mod utils {
     pub use crossbeam_utils::CachePadded;
 }
 
+cfg_if! {
+    if #[cfg(any(feature = "std", feature = "alloc"))] {
+        mod _queue {
+            pub extern crate crossbeam_queue;
+        }
+        #[doc(inline)]
+        pub use _queue::crossbeam_queue as queue;
+    }
+}
+
 cfg_if! {
     if #[cfg(feature = "std")] {
         mod _deque {
@@ -96,12 +106,6 @@ cfg_if! {
         #[doc(hidden)]
         pub use _channel::*;
 
-        mod _queue {
-            pub extern crate crossbeam_queue;
-        }
-        #[doc(inline)]
-        pub use _queue::crossbeam_queue as queue;
-
         pub use crossbeam_utils::sync;
         pub use crossbeam_utils::thread;
         pub use crossbeam_utils::thread::scope;