Remove lazy_static dependancy

Author: josephlr

Cargo.toml

@@ -23,14 +23,9 @@ log = { version = "0.4", optional = true }
 [target.'cfg(any(unix, target_os = "wasi"))'.dependencies]
 libc = "0.2.54"
 
-# For holding file descriptors
-[target.'cfg(any(unix, target_os = "redox"))'.dependencies]
-lazy_static = "1.3.0"
-
 [target.wasm32-unknown-unknown.dependencies]
 wasm-bindgen = { version = "0.2.29", optional = true }
 stdweb = { version = "0.4.9", optional = true }
-lazy_static = "1.3.0"
 
 [features]
 std = []

src/use_file.rs

@@ -11,8 +11,7 @@ extern crate std;
 
 use crate::Error;
 use core::num::NonZeroU32;
-use lazy_static::lazy_static;
-use std::{fs::File, io::Read};
+use std::{fs::File, io::Read, sync::Once};
 
 #[cfg(target_os = "redox")]
 const FILE_PATH: &str = "rand:";
@@ -29,10 +28,12 @@ const FILE_PATH: &str = "/dev/urandom";
 const FILE_PATH: &str = "/dev/random";
 
 pub fn getrandom_inner(dest: &mut [u8]) -> Result<(), Error> {
-    lazy_static! {
-        static ref FILE: Result<File, Error> = init_file();
-    }
-    let mut f = FILE.as_ref()?;
+    static ONCE: Once = Once::new();
+    static mut FILE: Option<Result<File, Error>> = None;
+
+    // SAFETY: FILE is only written once, before being read.
+    ONCE.call_once(|| unsafe { FILE = Some(init_file()); });
+    let mut f = unsafe { FILE.as_ref() }.unwrap().as_ref()?;
 
     if cfg!(target_os = "emscripten") {
         // `Crypto.getRandomValues` documents `dest` should be at most 65536 bytes.

src/wasm32_stdweb.rs

@@ -15,7 +15,7 @@ use stdweb::web::error::Error as WebError;
 use stdweb::{_js_impl, js};
 
 use crate::Error;
-use lazy_static::lazy_static;
+use std::sync::Once;
 
 #[derive(Clone, Copy, Debug)]
 enum RngSource {
@@ -25,11 +25,12 @@ enum RngSource {
 
 pub fn getrandom_inner(dest: &mut [u8]) -> Result<(), Error> {
     assert_eq!(mem::size_of::<usize>(), 4);
+    static ONCE: Once = Once::new();
+    static mut RNG_SOURCE: Result<RngSource, Error> = Err(Error::UNAVAILABLE);
 
-    lazy_static! {
-        static ref RNG_SOURCE: Result<RngSource, Error> = getrandom_init();
-    }
-    getrandom_fill((*RNG_SOURCE)?, dest)
+    // SAFETY: RNG_SOURCE is only written once, before being read.
+    ONCE.call_once(|| unsafe { RNG_SOURCE = getrandom_init(); });
+    getrandom_fill(unsafe { RNG_SOURCE }?, dest)
 }
 
 fn getrandom_init() -> Result<RngSource, Error> {