Properly test Send and Sync in objc2-foundation

Author: madsmtm

objc2-foundation/src/array.rs

@@ -33,8 +33,6 @@ __inner_extern_class! {
 
 // SAFETY: Same as Id<T, O> (which is what NSArray effectively stores).
 //
-// The `PhantomData` can't get these impls to display in the docs.
-//
 // TODO: Properly verify this
 unsafe impl<T: Sync + Send> Sync for NSArray<T, Shared> {}
 unsafe impl<T: Sync + Send> Send for NSArray<T, Shared> {}
@@ -218,7 +216,7 @@ mod tests {
     use objc2::rc::autoreleasepool;
 
     use super::*;
-    use crate::{NSString, NSValue};
+    use crate::NSValue;
 
     fn sample_array(len: usize) -> Id<NSArray<NSObject, Owned>, Owned> {
         let mut vec = Vec::with_capacity(len);
@@ -350,14 +348,4 @@ mod tests {
         let vec = NSArray::into_vec(array);
         assert_eq!(vec.len(), 4);
     }
-
-    #[test]
-    fn test_send_sync() {
-        fn assert_send_sync<T: Send + Sync>() {}
-
-        assert_send_sync::<NSArray<NSString, Shared>>();
-        assert_send_sync::<NSMutableArray<NSString, Shared>>();
-        assert_send_sync::<Id<NSArray<NSString, Shared>, Shared>>();
-        assert_send_sync::<Id<NSMutableArray<NSString, Shared>, Owned>>();
-    }
 }

objc2-foundation/src/attributed_string.rs

@@ -24,7 +24,8 @@ extern_class! {
     unsafe pub struct NSAttributedString: NSObject;
 }
 
-// TODO: SAFETY
+// SAFETY: `NSAttributedString` is immutable and `NSMutableAttributedString`
+// can only be mutated from `&mut` methods.
 unsafe impl Sync for NSAttributedString {}
 unsafe impl Send for NSAttributedString {}
 

objc2-foundation/src/data.rs

@@ -20,7 +20,8 @@ extern_class! {
     unsafe pub struct NSData: NSObject;
 }
 
-// TODO: SAFETY
+// SAFETY: `NSData` is immutable and `NSMutableData` can only be mutated from
+// `&mut` methods.
 unsafe impl Sync for NSData {}
 unsafe impl Send for NSData {}
 

objc2-foundation/src/dictionary.rs

@@ -18,6 +18,7 @@ __inner_extern_class! {
 }
 
 // TODO: SAFETY
+// Approximately same as `NSArray<T, Shared>`
 unsafe impl<K: Sync + Send, V: Sync> Sync for NSDictionary<K, V> {}
 unsafe impl<K: Sync + Send, V: Send> Send for NSDictionary<K, V> {}
 

objc2-foundation/src/lib.rs

@@ -115,3 +115,48 @@ mod thread;
 mod uuid;
 mod value;
 mod zone;
+
+#[cfg(test)]
+mod tests {
+    use objc2::rc::{Id, Owned, Shared};
+
+    use super::*;
+
+    fn assert_send_sync<T: Send + Sync>() {}
+
+    #[test]
+    fn send_sync() {
+        assert_send_sync::<NSArray<NSString, Shared>>();
+        assert_send_sync::<NSArray<NSString, Owned>>();
+        assert_send_sync::<Id<NSArray<NSString, Shared>, Shared>>();
+        assert_send_sync::<Id<NSArray<NSString, Owned>, Shared>>();
+        assert_send_sync::<Id<NSArray<NSString, Shared>, Owned>>();
+        assert_send_sync::<Id<NSArray<NSString, Owned>, Owned>>();
+
+        assert_send_sync::<NSAttributedString>();
+        assert_send_sync::<NSComparisonResult>();
+        assert_send_sync::<NSData>();
+        assert_send_sync::<NSDictionary<NSString, Shared>>();
+        // TODO: Figure out if safe?
+        // assert_send_sync::<NSEnumerator<NSString>>();
+        // assert_send_sync::<NSFastEnumerator<NSArray<NSString, Shared>>>();
+        assert_send_sync::<NSException>();
+        assert_send_sync::<CGFloat>();
+        assert_send_sync::<NSPoint>();
+        assert_send_sync::<NSRect>();
+        assert_send_sync::<NSSize>();
+        assert_send_sync::<NSMutableArray<NSString, Shared>>();
+        assert_send_sync::<NSMutableAttributedString>();
+        assert_send_sync::<NSMutableData>();
+        assert_send_sync::<NSMutableString>();
+        // assert_send_sync::<NSObject>(); // Intentional
+        assert_send_sync::<NSProcessInfo>();
+        assert_send_sync::<NSRange>();
+        assert_send_sync::<NSString>();
+        // assert_send_sync::<MainThreadMarker>(); // Intentional
+        assert_send_sync::<NSThread>();
+        assert_send_sync::<NSUUID>();
+        assert_send_sync::<NSValue<i32>>();
+        assert_send_sync::<NSZone>();
+    }
+}

objc2-foundation/src/mutable_array.rs

@@ -1,6 +1,7 @@
 use alloc::vec::Vec;
 use core::cmp::Ordering;
 use core::ffi::c_void;
+use core::marker::PhantomData;
 use core::ops::{Index, IndexMut};
 
 use objc2::rc::{DefaultId, Id, Owned, Ownership, Shared, SliceId};
@@ -17,9 +18,19 @@ __inner_extern_class! {
     // TODO: Ensure that this deref to NSArray is safe!
     // This "inherits" NSArray, and has the same `Send`/`Sync` impls as that.
     #[derive(Debug, PartialEq, Eq, Hash)]
-    unsafe pub struct NSMutableArray<T, O: Ownership>: NSArray<T, O>, NSObject {}
+    unsafe pub struct NSMutableArray<T, O: Ownership>: NSArray<T, O>, NSObject {
+        p: PhantomData<*mut ()>,
+    }
 }
 
+// SAFETY: Same as NSArray<T, O>
+//
+// Put here because rustdoc doesn't show these otherwise
+unsafe impl<T: Sync + Send> Sync for NSMutableArray<T, Shared> {}
+unsafe impl<T: Sync + Send> Send for NSMutableArray<T, Shared> {}
+unsafe impl<T: Sync> Sync for NSMutableArray<T, Owned> {}
+unsafe impl<T: Send> Send for NSMutableArray<T, Owned> {}
+
 impl<T: Message, O: Ownership> NSMutableArray<T, O> {
     pub fn new() -> Id<Self, Owned> {
         unsafe { msg_send_id![Self::class(), new].unwrap() }

objc2-foundation/src/mutable_attributed_string.rs

@@ -11,10 +11,6 @@ extern_class! {
     unsafe pub struct NSMutableAttributedString: NSAttributedString, NSObject;
 }
 
-// TODO: SAFETY
-unsafe impl Sync for NSMutableAttributedString {}
-unsafe impl Send for NSMutableAttributedString {}
-
 /// Creating mutable attributed strings.
 impl NSMutableAttributedString {
     /// Construct an empty mutable attributed string.

objc2-foundation/src/mutable_string.rs

@@ -16,10 +16,6 @@ extern_class! {
     unsafe pub struct NSMutableString: NSString, NSObject;
 }
 
-// TODO: SAFETY
-unsafe impl Sync for NSMutableString {}
-unsafe impl Send for NSMutableString {}
-
 /// Creating mutable strings.
 impl NSMutableString {
     /// Construct an empty [`NSMutableString`].

objc2-foundation/src/string.rs

@@ -41,7 +41,8 @@ extern_class! {
     // TODO: Check if performance of NSSelectorFromString is worthwhile
 }
 
-// TODO: SAFETY
+// SAFETY: `NSString` is immutable and `NSMutableString` can only be mutated
+// from `&mut` methods.
 unsafe impl Sync for NSString {}
 unsafe impl Send for NSString {}
 

objc2-foundation/src/uuid.rs

@@ -25,7 +25,7 @@ unsafe impl RefEncode for UuidBytes {
     const ENCODING_REF: Encoding<'static> = Encoding::Array(16, &u8::ENCODING);
 }
 
-// TODO: SAFETY
+// SAFETY: `NSUUID` is immutable.
 unsafe impl Sync for NSUUID {}
 unsafe impl Send for NSUUID {}