use generic Atomic type where possible

in core/alloc/std only for now, and ignoring test files

library/alloc/src/lib.rs

@@ -125,6 +125,7 @@
 #![feature(extend_one_unchecked)]
 #![feature(fmt_internals)]
 #![feature(fn_traits)]
+#![feature(generic_atomic)]
 #![feature(hasher_prefixfree_extras)]
 #![feature(inplace_iteration)]
 #![feature(iter_advance_by)]

library/alloc/src/sync.rs

@@ -24,8 +24,8 @@ use core::pin::{Pin, PinCoerceUnsized};
 use core::ptr::{self, NonNull};
 #[cfg(not(no_global_oom_handling))]
 use core::slice::from_raw_parts_mut;
-use core::sync::atomic;
 use core::sync::atomic::Ordering::{Acquire, Relaxed, Release};
+use core::sync::atomic::{self, Atomic};
 use core::{borrow, fmt, hint};
 
 #[cfg(not(no_global_oom_handling))]
@@ -346,12 +346,12 @@ impl<T: ?Sized, A: Allocator> fmt::Debug for Weak<T, A> {
 // inner types.
 #[repr(C)]
 struct ArcInner<T: ?Sized> {
-    strong: atomic::AtomicUsize,
+    strong: Atomic<usize>,
 
     // the value usize::MAX acts as a sentinel for temporarily "locking" the
     // ability to upgrade weak pointers or downgrade strong ones; this is used
     // to avoid races in `make_mut` and `get_mut`.
-    weak: atomic::AtomicUsize,
+    weak: Atomic<usize>,
 
     data: T,
 }
@@ -2706,8 +2706,8 @@ impl<T, A: Allocator> Weak<T, A> {
 /// Helper type to allow accessing the reference counts without
 /// making any assertions about the data field.
 struct WeakInner<'a> {
-    weak: &'a atomic::AtomicUsize,
-    strong: &'a atomic::AtomicUsize,
+    weak: &'a Atomic<usize>,
+    strong: &'a Atomic<usize>,
 }
 
 impl<T: ?Sized> Weak<T> {

library/core/src/sync/atomic.rs

@@ -482,7 +482,7 @@ pub enum Ordering {
     note = "the `new` function is now preferred",
     suggestion = "AtomicBool::new(false)"
 )]
-pub const ATOMIC_BOOL_INIT: AtomicBool = AtomicBool::new(false);
+pub const ATOMIC_BOOL_INIT: Atomic<bool> = AtomicBool::new(false);
 
 #[cfg(target_has_atomic_load_store = "8")]
 impl AtomicBool {
@@ -3347,7 +3347,7 @@ macro_rules! atomic_int_ptr_sized {
             note = "the `new` function is now preferred",
             suggestion = "AtomicIsize::new(0)",
         )]
-        pub const ATOMIC_ISIZE_INIT: AtomicIsize = AtomicIsize::new(0);
+        pub const ATOMIC_ISIZE_INIT: Atomic<isize> = AtomicIsize::new(0);
 
         /// An [`AtomicUsize`] initialized to `0`.
         #[cfg(target_pointer_width = $target_pointer_width)]
@@ -3357,7 +3357,7 @@ macro_rules! atomic_int_ptr_sized {
             note = "the `new` function is now preferred",
             suggestion = "AtomicUsize::new(0)",
         )]
-        pub const ATOMIC_USIZE_INIT: AtomicUsize = AtomicUsize::new(0);
+        pub const ATOMIC_USIZE_INIT: Atomic<usize> = AtomicUsize::new(0);
     )* };
 }
 

library/std/src/alloc.rs

@@ -57,7 +57,7 @@
 #![stable(feature = "alloc_module", since = "1.28.0")]
 
 use core::ptr::NonNull;
-use core::sync::atomic::{AtomicPtr, Ordering};
+use core::sync::atomic::{Atomic, AtomicPtr, Ordering};
 use core::{hint, mem, ptr};
 
 #[stable(feature = "alloc_module", since = "1.28.0")]
@@ -287,7 +287,7 @@ unsafe impl Allocator for System {
     }
 }
 
-static HOOK: AtomicPtr<()> = AtomicPtr::new(ptr::null_mut());
+static HOOK: Atomic<*mut ()> = AtomicPtr::new(ptr::null_mut());
 
 /// Registers a custom allocation error hook, replacing any that was previously registered.
 ///

library/std/src/backtrace.rs

@@ -91,8 +91,8 @@ mod tests;
 use crate::backtrace_rs::{self, BytesOrWideString};
 use crate::ffi::c_void;
 use crate::panic::UnwindSafe;
-use crate::sync::atomic::AtomicU8;
 use crate::sync::atomic::Ordering::Relaxed;
+use crate::sync::atomic::{Atomic, AtomicU8};
 use crate::sync::LazyLock;
 use crate::sys::backtrace::{lock, output_filename, set_image_base};
 use crate::{env, fmt};
@@ -254,7 +254,7 @@ impl Backtrace {
         // Cache the result of reading the environment variables to make
         // backtrace captures speedy, because otherwise reading environment
         // variables every time can be somewhat slow.
-        static ENABLED: AtomicU8 = AtomicU8::new(0);
+        static ENABLED: Atomic<u8> = AtomicU8::new(0);
         match ENABLED.load(Relaxed) {
             0 => {}
             1 => return false,

library/std/src/io/stdio.rs

@@ -11,7 +11,7 @@ use crate::io::{
     self, BorrowedCursor, BufReader, IoSlice, IoSliceMut, LineWriter, Lines, SpecReadByte,
 };
 use crate::panic::{RefUnwindSafe, UnwindSafe};
-use crate::sync::atomic::{AtomicBool, Ordering};
+use crate::sync::atomic::{Atomic, AtomicBool, Ordering};
 use crate::sync::{Arc, Mutex, MutexGuard, OnceLock, ReentrantLock, ReentrantLockGuard};
 use crate::sys::stdio;
 use crate::thread::AccessError;
@@ -37,7 +37,7 @@ thread_local! {
 /// have a consistent order between set_output_capture and print_to *within
 /// the same thread*. Within the same thread, things always have a perfectly
 /// consistent order. So Ordering::Relaxed is fine.
-static OUTPUT_CAPTURE_USED: AtomicBool = AtomicBool::new(false);
+static OUTPUT_CAPTURE_USED: Atomic<bool> = AtomicBool::new(false);
 
 /// A handle to a raw instance of the standard input stream of this process.
 ///

library/std/src/lib.rs

@@ -334,6 +334,7 @@
 #![feature(float_minimum_maximum)]
 #![feature(float_next_up_down)]
 #![feature(fmt_internals)]
+#![feature(generic_atomic)]
 #![feature(hasher_prefixfree_extras)]
 #![feature(hashmap_internals)]
 #![feature(ip)]

library/std/src/os/uefi/env.rs

@@ -4,13 +4,13 @@
 
 use crate::ffi::c_void;
 use crate::ptr::NonNull;
-use crate::sync::atomic::{AtomicBool, AtomicPtr, Ordering};
+use crate::sync::atomic::{Atomic, AtomicBool, AtomicPtr, Ordering};
 
-static SYSTEM_TABLE: AtomicPtr<c_void> = AtomicPtr::new(crate::ptr::null_mut());
-static IMAGE_HANDLE: AtomicPtr<c_void> = AtomicPtr::new(crate::ptr::null_mut());
+static SYSTEM_TABLE: Atomic<*mut c_void> = AtomicPtr::new(crate::ptr::null_mut());
+static IMAGE_HANDLE: Atomic<*mut c_void> = AtomicPtr::new(crate::ptr::null_mut());
 // Flag to check if BootServices are still valid.
 // Start with assuming that they are not available
-static BOOT_SERVICES_FLAG: AtomicBool = AtomicBool::new(false);
+static BOOT_SERVICES_FLAG: Atomic<bool> = AtomicBool::new(false);
 
 /// Initializes the global System Table and Image Handle pointers.
 ///

library/std/src/os/xous/services.rs

@@ -1,4 +1,4 @@
-use core::sync::atomic::{AtomicU32, Ordering};
+use core::sync::atomic::{Atomic, AtomicU32, Ordering};
 
 use crate::os::xous::ffi::Connection;
 
@@ -106,7 +106,7 @@ pub fn try_connect(name: &str) -> Option<Connection> {
     ns::try_connect_with_name(name)
 }
 
-static NAME_SERVER_CONNECTION: AtomicU32 = AtomicU32::new(0);
+static NAME_SERVER_CONNECTION: Atomic<u32> = AtomicU32::new(0);
 
 /// Returns a `Connection` to the name server. If the name server has not been started,
 /// then this call will block until the name server has been started. The `Connection`

library/std/src/os/xous/services/dns.rs

@@ -17,7 +17,7 @@ impl Into<usize> for DnsLendMut {
 /// Returns a `Connection` to the DNS lookup server. This server is used for
 /// querying domain name values.
 pub(crate) fn dns_server() -> Connection {
-    static DNS_CONNECTION: AtomicU32 = AtomicU32::new(0);
+    static DNS_CONNECTION: Atomic<u32> = AtomicU32::new(0);
     let cid = DNS_CONNECTION.load(Ordering::Relaxed);
     if cid != 0 {
         return cid.into();

library/std/src/os/xous/services/log.rs

@@ -1,4 +1,4 @@
-use core::sync::atomic::{AtomicU32, Ordering};
+use core::sync::atomic::{Atomic, AtomicU32, Ordering};
 
 use crate::os::xous::ffi::Connection;
 
@@ -64,7 +64,7 @@ impl Into<usize> for LogLend {
 /// running. It is safe to call this multiple times, because the address is
 /// shared among all threads in a process.
 pub(crate) fn log_server() -> Connection {
-    static LOG_SERVER_CONNECTION: AtomicU32 = AtomicU32::new(0);
+    static LOG_SERVER_CONNECTION: Atomic<u32> = AtomicU32::new(0);
 
     let cid = LOG_SERVER_CONNECTION.load(Ordering::Relaxed);
     if cid != 0 {

library/std/src/os/xous/services/net.rs

@@ -84,7 +84,7 @@ impl<'a> Into<[usize; 5]> for NetBlockingScalar {
 /// Returns a `Connection` to the Network server. This server provides all
 /// OS-level networking functions.
 pub(crate) fn net_server() -> Connection {
-    static NET_CONNECTION: AtomicU32 = AtomicU32::new(0);
+    static NET_CONNECTION: Atomic<u32> = AtomicU32::new(0);
     let cid = NET_CONNECTION.load(Ordering::Relaxed);
     if cid != 0 {
         return cid.into();

library/std/src/os/xous/services/systime.rs

@@ -1,4 +1,4 @@
-use core::sync::atomic::{AtomicU32, Ordering};
+use core::sync::atomic::{Atomic, AtomicU32, Ordering};
 
 use crate::os::xous::ffi::{connect, Connection};
 
@@ -17,7 +17,7 @@ impl Into<[usize; 5]> for SystimeScalar {
 /// Returns a `Connection` to the systime server. This server is used for reporting the
 /// realtime clock.
 pub(crate) fn systime_server() -> Connection {
-    static SYSTIME_SERVER_CONNECTION: AtomicU32 = AtomicU32::new(0);
+    static SYSTIME_SERVER_CONNECTION: Atomic<u32> = AtomicU32::new(0);
     let cid = SYSTIME_SERVER_CONNECTION.load(Ordering::Relaxed);
     if cid != 0 {
         return cid.into();

library/std/src/os/xous/services/ticktimer.rs

@@ -1,4 +1,4 @@
-use core::sync::atomic::{AtomicU32, Ordering};
+use core::sync::atomic::{Atomic, AtomicU32, Ordering};
 
 use crate::os::xous::ffi::Connection;
 
@@ -31,7 +31,7 @@ impl Into<[usize; 5]> for TicktimerScalar {
 /// Returns a `Connection` to the ticktimer server. This server is used for synchronization
 /// primitives such as sleep, Mutex, and Condvar.
 pub(crate) fn ticktimer_server() -> Connection {
-    static TICKTIMER_SERVER_CONNECTION: AtomicU32 = AtomicU32::new(0);
+    static TICKTIMER_SERVER_CONNECTION: Atomic<u32> = AtomicU32::new(0);
     let cid = TICKTIMER_SERVER_CONNECTION.load(Ordering::Relaxed);
     if cid != 0 {
         return cid.into();

library/std/src/panic.rs

@@ -3,7 +3,7 @@
 #![stable(feature = "std_panic", since = "1.9.0")]
 
 use crate::any::Any;
-use crate::sync::atomic::{AtomicU8, Ordering};
+use crate::sync::atomic::{Atomic, AtomicU8, Ordering};
 use crate::sync::{Condvar, Mutex, RwLock};
 use crate::thread::Result;
 use crate::{collections, fmt, panicking};
@@ -456,7 +456,7 @@ impl BacktraceStyle {
 // that backtrace.
 //
 // Internally stores equivalent of an Option<BacktraceStyle>.
-static SHOULD_CAPTURE: AtomicU8 = AtomicU8::new(0);
+static SHOULD_CAPTURE: Atomic<u8> = AtomicU8::new(0);
 
 /// Configures whether the default panic hook will capture and display a
 /// backtrace.

library/std/src/panicking.rs

@@ -21,7 +21,7 @@ use crate::any::Any;
 use crate::io::try_set_output_capture;
 use crate::mem::{self, ManuallyDrop};
 use crate::panic::{BacktraceStyle, PanicHookInfo};
-use crate::sync::atomic::{AtomicBool, Ordering};
+use crate::sync::atomic::{Atomic, AtomicBool, Ordering};
 use crate::sync::{PoisonError, RwLock};
 use crate::sys::stdio::panic_output;
 use crate::sys::{backtrace, dbg};
@@ -257,7 +257,7 @@ fn default_hook(info: &PanicHookInfo<'_>) {
         let mut lock = backtrace::lock();
         let _ = writeln!(err, "thread '{name}' panicked at {location}:\n{msg}");
 
-        static FIRST_PANIC: AtomicBool = AtomicBool::new(true);
+        static FIRST_PANIC: Atomic<bool> = AtomicBool::new(true);
 
         match backtrace {
             // SAFETY: we took out a lock just a second ago.
@@ -342,7 +342,7 @@ pub mod panic_count {
 #[unstable(feature = "update_panic_count", issue = "none")]
 pub mod panic_count {
     use crate::cell::Cell;
-    use crate::sync::atomic::{AtomicUsize, Ordering};
+    use crate::sync::atomic::{Atomic, AtomicUsize, Ordering};
 
     const ALWAYS_ABORT_FLAG: usize = 1 << (usize::BITS - 1);
 
@@ -384,7 +384,7 @@ pub mod panic_count {
     //
     // Stealing a bit is fine because it just amounts to assuming that each
     // panicking thread consumes at least 2 bytes of address space.
-    static GLOBAL_PANIC_COUNT: AtomicUsize = AtomicUsize::new(0);
+    static GLOBAL_PANIC_COUNT: Atomic<usize> = AtomicUsize::new(0);
 
     // Increases the global and local panic count, and returns whether an
     // immediate abort is required.

library/std/src/sync/mpmc/array.rs

@@ -16,13 +16,13 @@ use super::waker::SyncWaker;
 use crate::cell::UnsafeCell;
 use crate::mem::MaybeUninit;
 use crate::ptr;
-use crate::sync::atomic::{self, AtomicUsize, Ordering};
+use crate::sync::atomic::{self, Atomic, AtomicUsize, Ordering};
 use crate::time::Instant;
 
 /// A slot in a channel.
 struct Slot<T> {
     /// The current stamp.
-    stamp: AtomicUsize,
+    stamp: Atomic<usize>,
 
     /// The message in this slot. Either read out in `read` or dropped through
     /// `discard_all_messages`.
@@ -55,7 +55,7 @@ pub(crate) struct Channel<T> {
     /// represent the lap. The mark bit in the head is always zero.
     ///
     /// Messages are popped from the head of the channel.
-    head: CachePadded<AtomicUsize>,
+    head: CachePadded<Atomic<usize>>,
 
     /// The tail of the channel.
     ///
@@ -64,7 +64,7 @@ pub(crate) struct Channel<T> {
     /// represent the lap. The mark bit indicates that the channel is disconnected.
     ///
     /// Messages are pushed into the tail of the channel.
-    tail: CachePadded<AtomicUsize>,
+    tail: CachePadded<Atomic<usize>>,
 
     /// The buffer holding slots.
     buffer: Box<[Slot<T>]>,

library/std/src/sync/mpmc/context.rs

@@ -4,7 +4,7 @@ use super::select::Selected;
 use super::waker::current_thread_id;
 use crate::cell::Cell;
 use crate::ptr;
-use crate::sync::atomic::{AtomicPtr, AtomicUsize, Ordering};
+use crate::sync::atomic::{Atomic, AtomicPtr, AtomicUsize, Ordering};
 use crate::sync::Arc;
 use crate::thread::{self, Thread};
 use crate::time::Instant;
@@ -19,10 +19,10 @@ pub struct Context {
 #[derive(Debug)]
 struct Inner {
     /// Selected operation.
-    select: AtomicUsize,
+    select: Atomic<usize>,
 
     /// A slot into which another thread may store a pointer to its `Packet`.
-    packet: AtomicPtr<()>,
+    packet: Atomic<*mut ()>,
 
     /// Thread handle.
     thread: Thread,

library/std/src/sync/mpmc/counter.rs

@@ -1,16 +1,16 @@
-use crate::sync::atomic::{AtomicBool, AtomicUsize, Ordering};
+use crate::sync::atomic::{Atomic, AtomicBool, AtomicUsize, Ordering};
 use crate::{ops, process};
 
 /// Reference counter internals.
 struct Counter<C> {
     /// The number of senders associated with the channel.
-    senders: AtomicUsize,
+    senders: Atomic<usize>,
 
     /// The number of receivers associated with the channel.
-    receivers: AtomicUsize,
+    receivers: Atomic<usize>,
 
     /// Set to `true` if the last sender or the last receiver reference deallocates the channel.
-    destroy: AtomicBool,
+    destroy: Atomic<bool>,
 
     /// The internal channel.
     chan: C,