Replace lazy_statics with std::sync::LazyLocks (#314)

* Remove needless lazy_static

Mutex::new() is available in const contexts since Rust 1.63, so
no lazy_static is needed.

* Replace lazy_statics with std::sync::LazyLock

Cargo.toml

@@ -35,7 +35,6 @@ sm-raw-window-handle-06 = ["dep:rwh_06"]
 bitflags = "2.6"
 euclid = "0.22"
 fnv = { version = "1.0", optional = true }
-lazy_static = "1"
 libc = "0.2"
 log = "0.4"
 sparkle = { version = "0.1", optional = true }

src/context.rs

@@ -19,10 +19,8 @@ use std::sync::Mutex;
 #[derive(Clone, Copy, Debug, Eq, Hash, PartialEq)]
 pub struct ContextID(pub u64);
 
-lazy_static! {
-    #[doc(hidden)]
-    pub static ref CREATE_CONTEXT_MUTEX: Mutex<ContextID> = Mutex::new(ContextID(0));
-}
+#[doc(hidden)]
+pub static CREATE_CONTEXT_MUTEX: Mutex<ContextID> = Mutex::new(ContextID(0));
 
 bitflags! {
     /// Various flags that control attributes of the context and/or surfaces created from that

src/lib.rs

@@ -12,8 +12,6 @@
 
 #[macro_use]
 extern crate bitflags;
-#[macro_use]
-extern crate lazy_static;
 #[allow(unused_imports)]
 #[macro_use]
 extern crate log;

src/platform/generic/egl/device.rs

@@ -4,12 +4,12 @@
 
 use crate::egl::Egl;
 
+#[cfg(not(target_os = "windows"))]
+use libc::{dlopen, dlsym, RTLD_LAZY};
 use std::ffi::{CStr, CString};
 use std::mem;
 use std::os::raw::c_void;
-
-#[cfg(not(target_os = "windows"))]
-use libc::{dlopen, dlsym, RTLD_LAZY};
+use std::sync::LazyLock;
 #[cfg(target_os = "windows")]
 use winapi::shared::minwindef::HMODULE;
 #[cfg(target_os = "windows")]
@@ -20,29 +20,23 @@ thread_local! {
 }
 
 #[cfg(target_os = "windows")]
-lazy_static! {
-    static ref EGL_LIBRARY: EGLLibraryWrapper = {
-        unsafe {
-            let module = libloaderapi::LoadLibraryA(c"libEGL.dll".as_ptr());
-            EGLLibraryWrapper(module)
-        }
-    };
-}
+static EGL_LIBRARY: LazyLock<EGLLibraryWrapper> = LazyLock::new(|| unsafe {
+    let module = libloaderapi::LoadLibraryA(c"libEGL.dll".as_ptr());
+    EGLLibraryWrapper(module)
+});
 
 #[cfg(not(any(target_os = "windows", target_os = "macos")))]
-lazy_static! {
-    static ref EGL_LIBRARY: EGLLibraryWrapper = {
-        for soname in [c"libEGL.so.1".as_ptr(), c"libEGL.so".as_ptr()] {
-            unsafe {
-                let handle = dlopen(soname as *const _, RTLD_LAZY);
-                if !handle.is_null() {
-                    return EGLLibraryWrapper(handle);
-                }
+static EGL_LIBRARY: LazyLock<EGLLibraryWrapper> = LazyLock::new(|| {
+    for soname in [c"libEGL.so.1".as_ptr(), c"libEGL.so".as_ptr()] {
+        unsafe {
+            let handle = dlopen(soname as *const _, RTLD_LAZY);
+            if !handle.is_null() {
+                return EGLLibraryWrapper(handle);
             }
         }
-        panic!("Unable to load the libEGL shared object");
-    };
-}
+    }
+    panic!("Unable to load the libEGL shared object");
+});
 
 #[cfg(target_os = "windows")]
 struct EGLLibraryWrapper(HMODULE);

src/platform/generic/egl/ffi.rs

@@ -8,6 +8,7 @@ use crate::egl::types::{EGLAttrib, EGLBoolean, EGLContext, EGLDeviceEXT, EGLDisp
 use crate::egl::types::{EGLenum, EGLint};
 
 use std::os::raw::c_void;
+use std::sync::LazyLock;
 
 pub enum EGLClientBufferOpaque {}
 pub type EGLClientBuffer = *mut EGLClientBufferOpaque;
@@ -76,22 +77,20 @@ pub(crate) struct EGLExtensionFunctions {
     >,
 }
 
-lazy_static! {
-    pub(crate) static ref EGL_EXTENSION_FUNCTIONS: EGLExtensionFunctions = {
-        use crate::platform::generic::egl::device::lookup_egl_extension as get;
-        use std::mem::transmute as cast;
-        unsafe {
-            EGLExtensionFunctions {
-                CreateImageKHR: cast(get(c"eglCreateImageKHR")),
-                DestroyImageKHR: cast(get(c"eglDestroyImageKHR")),
-                ImageTargetTexture2DOES: cast(get(c"glEGLImageTargetTexture2DOES")),
+pub(crate) static EGL_EXTENSION_FUNCTIONS: LazyLock<EGLExtensionFunctions> = LazyLock::new(|| {
+    use crate::platform::generic::egl::device::lookup_egl_extension as get;
+    use std::mem::transmute as cast;
+    unsafe {
+        EGLExtensionFunctions {
+            CreateImageKHR: cast(get(c"eglCreateImageKHR")),
+            DestroyImageKHR: cast(get(c"eglDestroyImageKHR")),
+            ImageTargetTexture2DOES: cast(get(c"glEGLImageTargetTexture2DOES")),
 
-                CreateDeviceANGLE: cast(get(c"eglCreateDeviceANGLE")),
-                GetNativeClientBufferANDROID: cast(get(c"eglGetNativeClientBufferANDROID")),
-                QueryDeviceAttribEXT: cast(get(c"eglQueryDeviceAttribEXT")),
-                QueryDisplayAttribEXT: cast(get(c"eglQueryDisplayAttribEXT")),
-                QuerySurfacePointerANGLE: cast(get(c"eglQuerySurfacePointerANGLE")),
-            }
+            CreateDeviceANGLE: cast(get(c"eglCreateDeviceANGLE")),
+            GetNativeClientBufferANDROID: cast(get(c"eglGetNativeClientBufferANDROID")),
+            QueryDeviceAttribEXT: cast(get(c"eglQueryDeviceAttribEXT")),
+            QueryDisplayAttribEXT: cast(get(c"eglQueryDisplayAttribEXT")),
+            QuerySurfacePointerANGLE: cast(get(c"eglQuerySurfacePointerANGLE")),
         }
-    };
-}
+    }
+});

src/platform/unix/x11/connection.rs

@@ -17,16 +17,10 @@ use euclid::default::Size2D;
 use std::marker::PhantomData;
 use std::os::raw::c_void;
 use std::ptr;
-use std::sync::Arc;
+use std::sync::{Arc, Once};
 use x11::xlib::{Display, XCloseDisplay, XInitThreads, XLockDisplay, XOpenDisplay, XUnlockDisplay};
 
-lazy_static! {
-    static ref X_THREADS_INIT: () = {
-        unsafe {
-            XInitThreads();
-        }
-    };
-}
+static X_THREADS_INIT: Once = Once::new();
 
 /// A connection to the X11 display server.
 #[derive(Clone)]
@@ -72,7 +66,9 @@ impl Connection {
     #[inline]
     pub fn new() -> Result<Connection, Error> {
         unsafe {
-            *X_THREADS_INIT;
+            X_THREADS_INIT.call_once(|| {
+                XInitThreads();
+            });
 
             let x11_display = XOpenDisplay(ptr::null());
             if x11_display.is_null() {
@@ -93,7 +89,9 @@ impl Connection {
 
     /// Wraps an existing X11 `Display` in a `Connection`.
     ///
-    /// Important: Before calling this function, X11 must have be initialized in a thread-safe
+    /// # Safety
+    ///
+    /// Before calling this function, X11 must have be initialized in a thread-safe
     /// manner by using `XInitThreads()`. Otherwise, it will not be safe to use `surfman` from
     /// multiple threads.
     ///

src/platform/windows/wgl/context.rs

@@ -17,6 +17,7 @@ use std::ffi::{CStr, CString};
 use std::mem;
 use std::os::raw::{c_char, c_int, c_void};
 use std::ptr;
+use std::sync::LazyLock;
 use std::thread;
 use winapi::shared::minwindef::{BOOL, FALSE, FLOAT, HMODULE, LPARAM, LPVOID, LRESULT, UINT};
 use winapi::shared::minwindef::{WORD, WPARAM};
@@ -153,10 +154,8 @@ thread_local! {
     };
 }
 
-lazy_static! {
-    pub(crate) static ref WGL_EXTENSION_FUNCTIONS: WGLExtensionFunctions =
-        thread::spawn(extension_loader_thread).join().unwrap();
-}
+pub(crate) static WGL_EXTENSION_FUNCTIONS: LazyLock<WGLExtensionFunctions> =
+    LazyLock::new(|| thread::spawn(extension_loader_thread).join().unwrap());
 
 impl Device {
     /// Creates a context descriptor with the given attributes.