[must squash] use macro for i8 and u8, readd random_number

Author: joboet

library/core/src/random.rs

@@ -29,34 +29,6 @@ impl Random for bool {
     }
 }
 
-impl Random for u8 {
-    /// Generates a random value.
-    ///
-    /// **Warning:** Be careful when manipulating the resulting value! This
-    /// method samples according to a uniform distribution, so a value of 1 is
-    /// just as likely as [`MAX`](Self::MAX). By using modulo operations, some
-    /// values can become more likely than others. Use audited crates when in
-    /// doubt.
-    fn random(source: &mut (impl RandomSource + ?Sized)) -> Self {
-        let mut byte = [0];
-        source.fill_bytes(&mut byte);
-        byte[0]
-    }
-}
-
-impl Random for i8 {
-    /// Generates a random value.
-    ///
-    /// **Warning:** Be careful when manipulating the resulting value! This
-    /// method samples according to a uniform distribution, so a value of 1 is
-    /// just as likely as [`MAX`](Self::MAX). By using modulo operations, some
-    /// values can become more likely than others. Use audited crates when in
-    /// doubt.
-    fn random(source: &mut (impl RandomSource + ?Sized)) -> Self {
-        u8::random(source) as i8
-    }
-}
-
 macro_rules! impl_primitive {
     ($t:ty) => {
         impl Random for $t {
@@ -76,6 +48,8 @@ macro_rules! impl_primitive {
     };
 }
 
+impl_primitive!(u8);
+impl_primitive!(i8);
 impl_primitive!(u16);
 impl_primitive!(i16);
 impl_primitive!(u32);

library/std/src/sys/pal/windows/pipe.rs

@@ -3,6 +3,8 @@ use crate::io::{self, BorrowedCursor, IoSlice, IoSliceMut};
 use crate::os::windows::prelude::*;
 use crate::path::Path;
 use crate::random::{DefaultRandomSource, Random};
+use crate::sync::atomic::AtomicUsize;
+use crate::sync::atomic::Ordering::Relaxed;
 use crate::sys::c;
 use crate::sys::fs::{File, OpenOptions};
 use crate::sys::handle::Handle;
@@ -78,7 +80,7 @@ pub fn anon_pipe(ours_readable: bool, their_handle_inheritable: bool) -> io::Res
             name = format!(
                 r"\\.\pipe\__rust_anonymous_pipe1__.{}.{}",
                 c::GetCurrentProcessId(),
-                usize::random(&mut DefaultRandomSource),
+                random_number(),
             );
             let wide_name = OsStr::new(&name).encode_wide().chain(Some(0)).collect::<Vec<_>>();
             let mut flags = c::FILE_FLAG_FIRST_PIPE_INSTANCE | c::FILE_FLAG_OVERLAPPED;
@@ -206,6 +208,17 @@ pub fn spawn_pipe_relay(
     Ok(theirs)
 }
 
+fn random_number() -> usize {
+    static N: AtomicUsize = AtomicUsize::new(0);
+    loop {
+        if N.load(Relaxed) != 0 {
+            return N.fetch_add(1, Relaxed);
+        }
+
+        N.store(usize::random(&mut DefaultRandomSource), Relaxed);
+    }
+}
+
 impl AnonPipe {
     pub fn handle(&self) -> &Handle {
         &self.inner