Drop lazy_static in favour of std::sync::OnceLock (#609)

.clippy.toml

@@ -1 +1 @@
-msrv = "1.56.1"
+msrv = "1.70"

CHANGELOG.md

@@ -14,6 +14,9 @@ versions.
 ### Fixed
 ### Changed
 
+- Drop usage of `lazy_static` in favour of `std::sync::OnceLock`. This change
+  raises the minimal supported Rust version to 1.70.
+
 ### Removed
 
 - The old macros `rustler_export_nifs!`, `rustler::rustler_atoms!` and

rustler/Cargo.toml

@@ -7,6 +7,7 @@ authors = ["Hansihe <[email protected]>"]
 license = "MIT/Apache-2.0"
 readme = "../README.md"
 edition = "2021"
+rust-version = "1.70"
 
 [features]
 big_integer = ["dep:num-bigint"]
@@ -20,7 +21,6 @@ nif_version_2_17 = ["nif_version_2_16", "rustler_sys/nif_version_2_17"]
 serde = ["dep:serde"]
 
 [dependencies]
-lazy_static = "1.4"
 rustler_codegen = { path = "../rustler_codegen", version = "0.32.1", optional = true}
 rustler_sys = { path = "../rustler_sys", version = "~2.4.0" }
 num-bigint = { version = "0.4", optional = true }

rustler/src/lib.rs

@@ -29,8 +29,6 @@ pub mod wrapper;
 #[doc(hidden)]
 pub mod codegen_runtime;
 
-pub use lazy_static;
-
 #[macro_use]
 pub mod types;
 

rustler/src/serde/atoms.rs

@@ -3,12 +3,8 @@
 use crate::serde::Error;
 use crate::{types::atom::Atom, Encoder, Env, Term};
 
-use lazy_static::lazy_static;
-
-lazy_static! {
-    pub static ref OK: String = String::from("Ok");
-    pub static ref ERROR: String = String::from("Err");
-}
+pub static OK: &str = "Ok";
+pub static ERROR: &str = "Err";
 
 atoms! {
     nil,

rustler/src/types/atom.rs

@@ -201,17 +201,23 @@ macro_rules! atoms {
         struct RustlerAtoms {
             $( $name : $crate::types::atom::Atom ),*
         }
-        $crate::lazy_static::lazy_static! {
-            static ref RUSTLER_ATOMS: RustlerAtoms = $crate::env::OwnedEnv::new().run(|env| {
-                RustlerAtoms {
-                    $( $name: $crate::atoms!(@internal_make_atom(env, $name $( = $str)? )) ),*
-                }
-            });
+        impl RustlerAtoms {
+            fn get() -> &'static Self {
+                use std::sync::OnceLock;
+                static RUSTLER_ATOMS: OnceLock<RustlerAtoms> = OnceLock::new();
+                RUSTLER_ATOMS.get_or_init(||
+                    $crate::env::OwnedEnv::new().run(|env| {
+                        RustlerAtoms {
+                            $( $name: $crate::atoms!(@internal_make_atom(env, $name $( = $str)? )) ),*
+                        }
+                    })
+                )
+            }
         }
         $(
             $( #[$attr] )*
             pub fn $name() -> $crate::types::atom::Atom {
-                RUSTLER_ATOMS.$name
+                RustlerAtoms::get().$name
             }
         )*
     };

rustler_tests/native/rustler_compile_tests/Cargo.toml

@@ -10,5 +10,4 @@ path = "src/lib.rs"
 crate-type = ["cdylib"]
 
 [dependencies]
-lazy_static = "1.4"
 rustler = { path = "../../../rustler" }

rustler_tests/native/rustler_serde_test/Cargo.toml

@@ -10,7 +10,6 @@ name = "rustler_serde_test"
 crate-type = ["cdylib"]
 
 [dependencies]
-lazy_static = "1"
 rustler = {path = "../../../rustler", features = ["serde"]}
 serde = { version = "1.0", features = ["derive"] }
 serde_bytes = "0.11"

rustler_tests/native/rustler_test/Cargo.toml

@@ -20,5 +20,4 @@ nif_version_2_16 = ["nif_version_2_15", "rustler/nif_version_2_16"]
 nif_version_2_17 = ["nif_version_2_16", "rustler/nif_version_2_17"]
 
 [dependencies]
-lazy_static = "1.4"
 rustler = { path = "../../../rustler" }

rustler_tests/native/rustler_test/src/test_resource.rs

@@ -1,5 +1,5 @@
 use rustler::{Binary, Env, ResourceArc};
-use std::sync::RwLock;
+use std::sync::{OnceLock, RwLock};
 
 pub struct TestResource {
     test_field: RwLock<i32>,
@@ -46,14 +46,19 @@ pub fn resource_get_integer_field(resource: ResourceArc<TestResource>) -> i32 {
 
 use std::sync::atomic::{AtomicUsize, Ordering};
 
-lazy_static::lazy_static! {
-    static ref COUNT: AtomicUsize = AtomicUsize::new(0);
-    static ref STATIC_BIN: [u8; 10] = [0,1,2,3,4,5,6,7,8,9];
+fn get_count() -> &'static AtomicUsize {
+    static COUNT: OnceLock<AtomicUsize> = OnceLock::new();
+    COUNT.get_or_init(|| AtomicUsize::new(0))
+}
+
+fn get_static_bin() -> &'static [u8; 10] {
+    static STATIC_BIN: OnceLock<[u8; 10]> = OnceLock::new();
+    STATIC_BIN.get_or_init(|| [0, 1, 2, 3, 4, 5, 6, 7, 8, 9])
 }
 
 impl ImmutableResource {
     fn new(u: u32) -> ImmutableResource {
-        COUNT.fetch_add(1, Ordering::SeqCst);
+        get_count().fetch_add(1, Ordering::SeqCst);
         ImmutableResource { a: u, b: !u }
     }
 }
@@ -62,7 +67,7 @@ impl Drop for ImmutableResource {
     fn drop(&mut self) {
         assert_eq!(self.a, !self.b);
         self.b = self.a;
-        COUNT.fetch_sub(1, Ordering::SeqCst);
+        get_count().fetch_sub(1, Ordering::SeqCst);
     }
 }
 
@@ -74,7 +79,7 @@ pub fn resource_make_immutable(u: u32) -> ResourceArc<ImmutableResource> {
 // Count how many instances of `ImmutableResource` are currently alive globally.
 #[rustler::nif]
 pub fn resource_immutable_count() -> u32 {
-    COUNT.load(Ordering::SeqCst) as u32
+    get_count().load(Ordering::SeqCst) as u32
 }
 
 #[rustler::nif]
@@ -100,7 +105,7 @@ pub fn resource_make_binaries(
         // From vec (on the heap)
         resource.make_binary(env, |w| &w.b),
         // From static
-        resource.make_binary(env, |_| &*STATIC_BIN),
+        resource.make_binary(env, |_| get_static_bin()),
     )
 }