7 files changed, 115 insertions, 10 deletions
diff --git a/third_party/rust/oneshot-uniffi/.cargo-checksum.json b/third_party/rust/oneshot-uniffi/.cargo-checksum.json
index 6b252c6773..985beded51 100644
--- a/third_party/rust/oneshot-uniffi/.cargo-checksum.json
+++ b/third_party/rust/oneshot-uniffi/.cargo-checksum.json
@@ -1 +1 @@
-{"files":{"CHANGELOG.md":"e1165d97c283b915d87e22f209494be39933723a0b544e725f69cfa5cef3876c","Cargo.lock":"7625529900ca1e3626b90e74ef268b31e06da85e8334a885711fdfd80821ddda","Cargo.toml":"81dde8ad3180c7b97325a6a67bfbefb145590606de9008d881c4e04808865f0a","README.md":"811ea1c958d5a65583d0223b7ab09bb282e7a51ed60f9a2cb90ef6d555325a68","benches/benches.rs":"67dcc916d0b7e28e396c28dac0499726366e1cb10e9991948d1c881a5abf5faa","check_mem_leaks.sh":"c1ab6ef27997c7f971352ab1c86a184004843c499bc24925da953aefcf1c624c","examples/recv_before_send.rs":"9a3cabcc2878990b61787d0048061b382555a8cd1a08b1ddec63a6e8a4a31e56","examples/recv_before_send_then_drop_sender.rs":"14706c6b4308a690662ceaa47f1699588bd833b3ec020eb9f42f220f3ffc7ae7","examples/recv_ref_before_send.rs":"43699f4720c46b5f138c260b866eb708ddf616e2b442ffa74a97373f4f48d4d0","examples/recv_ref_before_send_then_drop_sender.rs":"a190ed220cb4288d4965485365c9afaed30535cbfad5f8cb7389071b82d67cac","examples/recv_timeout_before_send.rs":"2262aa6531afce7816d43182ad9cbec2c04f3dc129064e11e89452278ce8b163","examples/recv_timeout_before_send_then_drop_sender.rs":"4cc8eade4c211f52f5b9be0f72a5906689b894490f4cb5255525e44106e7a4a8","examples/recv_with_dropped_sender.rs":"7906685053ce1c53ff6c26ce11d3221d4bf5ca3429d1d4d2c28de9237cb151c6","examples/send_before_recv.rs":"5555bd61ad52273b663007794128d8f012fc54272bd3225259b5546221bcd591","examples/send_then_drop_receiver.rs":"c3612de207309098404b057468687a2d2311d07f354b7e046398e35e93c4cdcf","examples/send_with_dropped_receiver.rs":"f5a7762b231a24a0db4397c5139437cba155d09b9dbb59872d662c7923080706","src/errors.rs":"df6a1db663fdb1c54d6941d737f6591bfe0dc6f01bd627ba0a94d67ed50b27a9","src/lib.rs":"86893f56e8e762b41ee079b42f4248608e9efb68bd76aa9550fce61e7466bbb0","src/loombox.rs":"fc85d1c2d3fda432be60f0c4d1d528e5998ec2b738a5b395a242285051b94d65","tests/assert_mem.rs":"b1e5190af01af22e55c7c1cd1ff2711807591f788e4eb8b6c6d89123e146105e","tests/async.rs":"6fd2826e589b94677d4eeed1080deda8bcc429aa05a20d843d1442a3a48ea757","tests/future.rs":"0e71f0293cd5a8c44210e8882aca20cfbf1e3771ecd4e4f6b59b924c0d01dd97","tests/helpers/mod.rs":"19161ed33e0ba8862746f04678d0606dee90205896083f85d8c1dcd4d211ccb0","tests/helpers/waker.rs":"77494d49f62d0d320df3830643c306e06e6e20751d210cf6fa58b238bd96c3f9","tests/loom.rs":"ea350fa424a95581e1871bc0037badecc5a090f28fd10532917abbaf561218ab","tests/sync.rs":"1186fa6cdb5a180944fa7d793ccb8be412c4a4e88bb504daa70bc097ee081b06"},"package":"9ae4988774e7a7e6a0783d119bdc683ea8c1d01a24d4fff9b4bdc280e07bd99e"}
-\ No newline at end of file
+{"files":{"CHANGELOG.md":"4ad03d95d5532e8f2551e3e53877e6347c04c32f479c4edf517244ecd5921ac7","Cargo.lock":"5d85bcfda2ee559d243099fb26f3724ae239777d891e780a924804e30f6733ad","Cargo.toml":"07a73ff74274df3a7439fccc8acfe306fae0f51ad79a80edbc54b51a730314c0","README.md":"811ea1c958d5a65583d0223b7ab09bb282e7a51ed60f9a2cb90ef6d555325a68","benches/benches.rs":"67dcc916d0b7e28e396c28dac0499726366e1cb10e9991948d1c881a5abf5faa","check_mem_leaks.sh":"c1ab6ef27997c7f971352ab1c86a184004843c499bc24925da953aefcf1c624c","examples/recv_before_send.rs":"9a3cabcc2878990b61787d0048061b382555a8cd1a08b1ddec63a6e8a4a31e56","examples/recv_before_send_then_drop_sender.rs":"14706c6b4308a690662ceaa47f1699588bd833b3ec020eb9f42f220f3ffc7ae7","examples/recv_ref_before_send.rs":"43699f4720c46b5f138c260b866eb708ddf616e2b442ffa74a97373f4f48d4d0","examples/recv_ref_before_send_then_drop_sender.rs":"a190ed220cb4288d4965485365c9afaed30535cbfad5f8cb7389071b82d67cac","examples/recv_timeout_before_send.rs":"2262aa6531afce7816d43182ad9cbec2c04f3dc129064e11e89452278ce8b163","examples/recv_timeout_before_send_then_drop_sender.rs":"4cc8eade4c211f52f5b9be0f72a5906689b894490f4cb5255525e44106e7a4a8","examples/recv_with_dropped_sender.rs":"7906685053ce1c53ff6c26ce11d3221d4bf5ca3429d1d4d2c28de9237cb151c6","examples/send_before_recv.rs":"5555bd61ad52273b663007794128d8f012fc54272bd3225259b5546221bcd591","examples/send_then_drop_receiver.rs":"c3612de207309098404b057468687a2d2311d07f354b7e046398e35e93c4cdcf","examples/send_with_dropped_receiver.rs":"f5a7762b231a24a0db4397c5139437cba155d09b9dbb59872d662c7923080706","src/errors.rs":"a5aa56bc497dccdbdbe15b9070360f50835c762f11be4ee96e0d25b150168ac9","src/lib.rs":"4bef3602ff4f5d2b42ce963d722a48c9ff07275e75ef6bed7b523e8f45e459fe","src/loombox.rs":"fc85d1c2d3fda432be60f0c4d1d528e5998ec2b738a5b395a242285051b94d65","tests/assert_mem.rs":"b1e5190af01af22e55c7c1cd1ff2711807591f788e4eb8b6c6d89123e146105e","tests/async.rs":"6fd2826e589b94677d4eeed1080deda8bcc429aa05a20d843d1442a3a48ea757","tests/future.rs":"0e71f0293cd5a8c44210e8882aca20cfbf1e3771ecd4e4f6b59b924c0d01dd97","tests/helpers/mod.rs":"19161ed33e0ba8862746f04678d0606dee90205896083f85d8c1dcd4d211ccb0","tests/helpers/waker.rs":"77494d49f62d0d320df3830643c306e06e6e20751d210cf6fa58b238bd96c3f9","tests/loom.rs":"ea350fa424a95581e1871bc0037badecc5a090f28fd10532917abbaf561218ab","tests/raw.rs":"5564615fea811b0061d8ad801356e60e0018ec4e3fb99cc739287ed5b96cb7cf","tests/sync.rs":"1186fa6cdb5a180944fa7d793ccb8be412c4a4e88bb504daa70bc097ee081b06"},"package":"6c548d5c78976f6955d72d0ced18c48ca07030f7a1d4024529fedd7c1c01b29c"}
+\ No newline at end of file
diff --git a/third_party/rust/oneshot-uniffi/CHANGELOG.md b/third_party/rust/oneshot-uniffi/CHANGELOG.md
index e12f6cc979..c4c928386b 100644
--- a/third_party/rust/oneshot-uniffi/CHANGELOG.md
+++ b/third_party/rust/oneshot-uniffi/CHANGELOG.md
@@ -16,6 +16,13 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 
 ## [Unreleased]
 
+
+## [0.1.6] - 2023-09-14
+### Added
+* Add `into_raw` and `from_raw` methods on both `Sender` and `Receiver`. Allows passing `oneshot`
+  channels over FFI without an extra layer of heap allocation.
+
+
 ## [0.1.5] - 2022-09-01
 ### Fixed
 - Handle the UNPARKING state correctly in all recv methods. `try_recv` will now not panic
diff --git a/third_party/rust/oneshot-uniffi/Cargo.lock b/third_party/rust/oneshot-uniffi/Cargo.lock
index 1b75d43675..b71644917f 100644
--- a/third_party/rust/oneshot-uniffi/Cargo.lock
+++ b/third_party/rust/oneshot-uniffi/Cargo.lock
@@ -601,7 +601,7 @@ checksum = "dd8b5dd2ae5ed71462c540258bedcb51965123ad7e7ccf4b9a8cafaa4a63576d"
 
 [[package]]
 name = "oneshot-uniffi"
-version = "0.1.5"
+version = "0.1.6"
 dependencies = [
  "async-std",
  "criterion",
diff --git a/third_party/rust/oneshot-uniffi/Cargo.toml b/third_party/rust/oneshot-uniffi/Cargo.toml
index 078a477fb2..cba7266915 100644
--- a/third_party/rust/oneshot-uniffi/Cargo.toml
+++ b/third_party/rust/oneshot-uniffi/Cargo.toml
@@ -13,7 +13,7 @@
 edition = "2021"
 rust-version = "1.60.0"
 name = "oneshot-uniffi"
-version = "0.1.5"
+version = "0.1.6"
 authors = ["Linus Färnstrand <faern@faern.net>"]
 description = """
 Patched version of oneshot specifically for the UniFFI project.
diff --git a/third_party/rust/oneshot-uniffi/src/errors.rs b/third_party/rust/oneshot-uniffi/src/errors.rs
index afc48acd03..1fd0de1eed 100644
--- a/third_party/rust/oneshot-uniffi/src/errors.rs
+++ b/third_party/rust/oneshot-uniffi/src/errors.rs
@@ -4,7 +4,8 @@ use core::mem;
 use core::ptr::NonNull;
 
 /// An error returned when trying to send on a closed channel. Returned from
-/// [`Sender::send`] if the corresponding [`Receiver`] has already been dropped.
+/// [`Sender::send`](crate::Sender::send) if the corresponding [`Receiver`](crate::Receiver)
+/// has already been dropped.
 ///
 /// The message that could not be sent can be retreived again with [`SendError::into_inner`].
 pub struct SendError<T> {
@@ -79,10 +80,10 @@ impl<T> fmt::Debug for SendError<T> {
 #[cfg(feature = "std")]
 impl<T> std::error::Error for SendError<T> {}
 
-/// An error returned from the indefinitely blocking recv functions on a [`Receiver`].
+/// An error returned from the blocking [`Receiver::recv`](crate::Receiver::recv) method.
 ///
-/// The recv operation can only fail if the corresponding [`Sender`] was dropped before sending
-/// any message. Or if a message has already been sent and received on the channel.
+/// The receive operation can only fail if the corresponding [`Sender`](crate::Sender) was dropped
+/// before sending any message, or if a message has already been sent and received on the channel.
 #[derive(Debug, Copy, Clone, Eq, PartialEq, Hash)]
 pub struct RecvError;
 
@@ -95,7 +96,8 @@ impl fmt::Display for RecvError {
 #[cfg(feature = "std")]
 impl std::error::Error for RecvError {}
 
-/// An error returned when trying a non blocking receive on a [`Receiver`].
+/// An error returned when failing to receive a message in the non-blocking
+/// [`Receiver::try_recv`](crate::Receiver::try_recv).
 #[derive(Debug, Copy, Clone, Eq, PartialEq, Hash)]
 pub enum TryRecvError {
     /// The channel is still open, but there was no message present in it.
@@ -119,7 +121,8 @@ impl fmt::Display for TryRecvError {
 #[cfg(feature = "std")]
 impl std::error::Error for TryRecvError {}
 
-/// An error returned when trying a time limited blocking receive on a [`Receiver`].
+/// An error returned when failing to receive a message in
+/// [`Receiver::recv_timeout`](crate::Receiver::recv_timeout).
 #[derive(Debug, Copy, Clone, Eq, PartialEq, Hash)]
 pub enum RecvTimeoutError {
     /// No message arrived on the channel before the timeout was reached. The channel is still open.
diff --git a/third_party/rust/oneshot-uniffi/src/lib.rs b/third_party/rust/oneshot-uniffi/src/lib.rs
index 94bb35d12a..8da012b8c0 100644
--- a/third_party/rust/oneshot-uniffi/src/lib.rs
+++ b/third_party/rust/oneshot-uniffi/src/lib.rs
@@ -314,6 +314,31 @@ impl<T> Sender<T> {
             _ => unreachable!(),
         }
     }
+
+    /// Consumes the Sender, returning a raw pointer to the channel on the heap.
+    ///
+    /// This is intended to simplify using oneshot channels with some FFI code. The only safe thing
+    /// to do with the returned pointer is to later reconstruct the Sender with [Sender::from_raw].
+    /// Memory will leak if the Sender is never reconstructed.
+    pub fn into_raw(self) -> *mut () {
+        let raw = self.channel_ptr.as_ptr() as *mut ();
+        mem::forget(self);
+        raw
+    }
+
+    /// Consumes a raw pointer from [Sender::into_raw], recreating the Sender.
+    ///
+    /// # Safety
+    ///
+    /// This pointer must have come from [`Sender<T>::into_raw`] with the same message type, `T`.
+    /// At most one Sender must exist for a channel at any point in time.
+    /// Constructing multiple Senders from the same raw pointer leads to undefined behavior.
+    pub unsafe fn from_raw(raw: *mut ()) -> Self {
+        Self {
+            channel_ptr: NonNull::new_unchecked(raw as *mut Channel<T>),
+            _invariant: PhantomData,
+        }
+    }
 }
 
 impl<T> Drop for Sender<T> {
@@ -816,6 +841,30 @@ impl<T> Receiver<T> {
             _ => unreachable!(),
         }
     }
+
+    /// Consumes the Receiver, returning a raw pointer to the channel on the heap.
+    ///
+    /// This is intended to simplify using oneshot channels with some FFI code. The only safe thing
+    /// to do with the returned pointer is to later reconstruct the Receiver with
+    /// [Receiver::from_raw]. Memory will leak if the Receiver is never reconstructed.
+    pub fn into_raw(self) -> *mut () {
+        let raw = self.channel_ptr.as_ptr() as *mut ();
+        mem::forget(self);
+        raw
+    }
+
+    /// Consumes a raw pointer from [Receiver::into_raw], recreating the Receiver.
+    ///
+    /// # Safety
+    ///
+    /// This pointer must have come from [`Receiver<T>::into_raw`] with the same message type, `T`.
+    /// At most one Receiver must exist for a channel at any point in time.
+    /// Constructing multiple Receivers from the same raw pointer leads to undefined behavior.
+    pub unsafe fn from_raw(raw: *mut ()) -> Self {
+        Self {
+            channel_ptr: NonNull::new_unchecked(raw as *mut Channel<T>),
+        }
+    }
 }
 
 #[cfg(feature = "async")]
@@ -1178,7 +1227,7 @@ fn receiver_waker_size() {
         (false, false) => 0,
         (false, true) => 16,
         (true, false) => 8,
-        (true, true) => 24,
+        (true, true) => 16,
     };
     assert_eq!(mem::size_of::<ReceiverWaker>(), expected);
 }
diff --git a/third_party/rust/oneshot-uniffi/tests/raw.rs b/third_party/rust/oneshot-uniffi/tests/raw.rs
new file mode 100644
index 0000000000..e38dc45c48
--- /dev/null
+++ b/third_party/rust/oneshot-uniffi/tests/raw.rs
@@ -0,0 +1,46 @@
+#![cfg(not(loom))]
+
+use oneshot::{channel, Receiver, Sender};
+
+#[test]
+fn test_raw_sender() {
+    let (sender, receiver) = channel::<u32>();
+    let raw = sender.into_raw();
+    let recreated = unsafe { Sender::<u32>::from_raw(raw) };
+    recreated
+        .send(100)
+        .unwrap_or_else(|e| panic!("error sending after into_raw/from_raw roundtrip: {e}"));
+    assert_eq!(receiver.try_recv(), Ok(100))
+}
+
+#[test]
+fn test_raw_receiver() {
+    let (sender, receiver) = channel::<u32>();
+    let raw = receiver.into_raw();
+    sender.send(100).unwrap();
+    let recreated = unsafe { Receiver::<u32>::from_raw(raw) };
+    assert_eq!(
+        recreated
+            .try_recv()
+            .unwrap_or_else(|e| panic!("error receiving after into_raw/from_raw roundtrip: {e}")),
+        100
+    )
+}
+
+#[test]
+fn test_raw_sender_and_receiver() {
+    let (sender, receiver) = channel::<u32>();
+    let raw_receiver = receiver.into_raw();
+    let raw_sender = sender.into_raw();
+
+    let recreated_sender = unsafe { Sender::<u32>::from_raw(raw_sender) };
+    recreated_sender.send(100).unwrap();
+
+    let recreated_receiver = unsafe { Receiver::<u32>::from_raw(raw_receiver) };
+    assert_eq!(
+        recreated_receiver
+            .try_recv()
+            .unwrap_or_else(|e| panic!("error receiving after into_raw/from_raw roundtrip: {e}")),
+        100
+    )
+}