1 files changed, 0 insertions, 63 deletions
diff --git a/src/libstd/io/lazy.rs b/src/libstd/io/lazy.rs
deleted file mode 100644
index 1968d498bbe..00000000000
--- a/src/libstd/io/lazy.rs
+++ /dev/null
@@ -1,63 +0,0 @@
-use crate::cell::Cell;
-use crate::ptr;
-use crate::sync::Arc;
-use crate::sys_common;
-use crate::sys_common::mutex::Mutex;
-
-pub struct Lazy<T> {
-    // We never call `lock.init()`, so it is UB to attempt to acquire this mutex reentrantly!
-    lock: Mutex,
-    ptr: Cell<*mut Arc<T>>,
-}
-
-#[inline]
-const fn done<T>() -> *mut Arc<T> {
-    1_usize as *mut _
-}
-
-unsafe impl<T> Sync for Lazy<T> {}
-
-impl<T> Lazy<T> {
-    pub const fn new() -> Lazy<T> {
-        Lazy { lock: Mutex::new(), ptr: Cell::new(ptr::null_mut()) }
-    }
-}
-
-impl<T: Send + Sync + 'static> Lazy<T> {
-    /// Safety: `init` must not call `get` on the variable that is being
-    /// initialized.
-    pub unsafe fn get(&'static self, init: fn() -> Arc<T>) -> Option<Arc<T>> {
-        let _guard = self.lock.lock();
-        let ptr = self.ptr.get();
-        if ptr.is_null() {
-            Some(self.init(init))
-        } else if ptr == done() {
-            None
-        } else {
-            Some((*ptr).clone())
-        }
-    }
-
-    // Must only be called with `lock` held
-    unsafe fn init(&'static self, init: fn() -> Arc<T>) -> Arc<T> {
-        // If we successfully register an at exit handler, then we cache the
-        // `Arc` allocation in our own internal box (it will get deallocated by
-        // the at exit handler). Otherwise we just return the freshly allocated
-        // `Arc`.
-        let registered = sys_common::at_exit(move || {
-            let ptr = {
-                let _guard = self.lock.lock();
-                self.ptr.replace(done())
-            };
-            drop(Box::from_raw(ptr))
-        });
-        // This could reentrantly call `init` again, which is a problem
-        // because our `lock` allows reentrancy!
-        // That's why `get` is unsafe and requires the caller to ensure no reentrancy happens.
-        let ret = init();
-        if registered.is_ok() {
-            self.ptr.set(Box::into_raw(Box::new(ret.clone())));
-        }
-        ret
-    }
-}