From fbaad4df93b163d047859b510338ce53360ce9f1 Mon Sep 17 00:00:00 2001
From: Alexey Gerasev <alexey.gerasev@gmail.com>
Date: Fri, 27 Sep 2024 17:50:16 +0700
Subject: [PATCH] Add portable-atomic feature

---
 Cargo.toml       | 4 ++--
 README.md        | 2 +-
 scripts/test.sh  | 1 +
 src/rb/shared.rs | 3 +++
 4 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/Cargo.toml b/Cargo.toml
index ddab21b..9fc5aeb 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -26,14 +26,14 @@ license.workspace = true
 
 [features]
 default = ["std"]
-std = ["alloc", "portable-atomic/std"]
+std = ["alloc", "portable-atomic?/std"]
 alloc = []
 bench = []
 test_local = []
 
 [dependencies]
 crossbeam-utils = { version = "0.8", default-features = false }
-portable-atomic  = "1"
+portable-atomic = { version = "1", default-features = false, optional = true }
 
 [dev-dependencies]
 once_mut = "0.1.0"
diff --git a/README.md b/README.md
index 4f5137e..8b18656 100644
--- a/README.md
+++ b/README.md
@@ -31,7 +31,7 @@ Lock-free SPSC FIFO ring buffer with direct access to inner data.
 + Different types of buffers and underlying storages.
 + Can be used without `std` and even without `alloc` (using only statically-allocated memory).
 + Async and blocking versions (see [this section](#derived-crates)).
-+ Uses the `portable-atomic` crate to allow usage on smaller systems without CAS operations.
++ Can optionally use the [`portable-atomic`](https://crates.io/crates/portable-atomic) crate to allow usage on smaller systems without CAS operations.
 
 # Usage
 
diff --git a/scripts/test.sh b/scripts/test.sh
index 5259ea1..0778e55 100755
--- a/scripts/test.sh
+++ b/scripts/test.sh
@@ -2,6 +2,7 @@
 
 cargo test && \
 cargo test --features test_local && \
+cargo test --features portable-atomic && \
 cargo check --no-default-features --features alloc && \
 cargo check --no-default-features && \
 cd async && \
diff --git a/src/rb/shared.rs b/src/rb/shared.rs
index 0687964..abada88 100644
--- a/src/rb/shared.rs
+++ b/src/rb/shared.rs
@@ -12,12 +12,15 @@ use crate::{
 };
 #[cfg(feature = "alloc")]
 use alloc::{boxed::Box, sync::Arc};
+#[cfg(not(feature = "portable-atomic"))]
+use core::sync::atomic::{AtomicBool, AtomicUsize, Ordering};
 use core::{
     mem::{ManuallyDrop, MaybeUninit},
     num::NonZeroUsize,
     ptr,
 };
 use crossbeam_utils::CachePadded;
+#[cfg(feature = "portable-atomic")]
 use portable_atomic::{AtomicBool, AtomicUsize, Ordering};
 
 /// Ring buffer that can be shared between threads.