Use tokio 1.10 for safety on windows

Cargo.toml

@@ -18,18 +18,13 @@ exclude = ["/bin", "/.github"]
 [dependencies]
 async-trait = { version = "0.1.50", optional = true }
 
-[target.'cfg(unix)'.dependencies.nix]
-version = "0.22.0"
-
-[target.'cfg(unix)'.dependencies.tokio]
-version = "1.9.0"
+[dependencies.tokio]
+version = "1.10.0"
 features = ["macros", "process", "rt"]
 optional = true
 
-[target.'cfg(windows)'.dependencies.tokio]
-version = "1.9.0"
-features = ["macros", "process", "rt", "sync"]
-optional = true
+[target.'cfg(unix)'.dependencies.nix]
+version = "0.22.0"
 
 [target.'cfg(windows)'.dependencies.winapi]
 version = "0.3.9"
@@ -48,7 +43,7 @@ default = []
 with-tokio = ["async-trait", "tokio"]
 
 [dev-dependencies]
-tokio = { version = "1.9.0", features = ["io-util", "macros", "process", "rt", "rt-multi-thread", "time"] }
+tokio = { version = "1.10.0", features = ["io-util", "macros", "process", "rt", "rt-multi-thread", "time"] }
 
 [package.metadata.docs.rs]
 all-features = true

README.md

@@ -38,7 +38,7 @@ dbg!(status);
 ```toml
 [dependencies]
 command-group = { version = "1.0.4", features = ["with-tokio"] }
-tokio = { version = "1.9.0", features = ["full"] }
+tokio = { version = "1.10.0", features = ["full"] }
 ```
 
 ```rust

src/tokio/child.rs

@@ -324,6 +324,8 @@ impl AsyncGroupChild {
 				err.read_to_end(&mut stderr).await?;
 			}
 			(Some(mut out), Some(mut err)) => {
+				// TODO: replace with futures crate usage
+				// and drop macros feature from tokio
 				tokio::try_join!(out.read_to_end(&mut stdout), err.read_to_end(&mut stderr),)?;
 			}
 		}

src/tokio/windows.rs

@@ -1,14 +1,6 @@
-use std::{
-	io::Result,
-	mem,
-	os::windows::io::AsRawHandle,
-	process::{Child as StdChild, ExitStatus},
-};
-use tokio::{
-	process::{Child, ChildStderr, ChildStdin, ChildStdout, Command},
-	sync::oneshot,
-};
-use winapi::um::{winbase::CREATE_SUSPENDED, winnt::HANDLE};
+use std::io::Result;
+use tokio::process::Command;
+use winapi::um::winbase::CREATE_SUSPENDED;
 
 use crate::{winres::*, AsyncCommandGroup, AsyncGroupChild};
 
@@ -17,64 +9,10 @@ impl AsyncCommandGroup for Command {
 	fn group_spawn(&mut self) -> Result<AsyncGroupChild> {
 		let (job, completion_port) = job_object()?;
 		self.creation_flags(CREATE_SUSPENDED);
-		let child = self.spawn()?;
-
-		// this is incredibly unsafe and also relies on:
-		// - tokio internals staying the same
-		// - rust layout optimiser not fucking us
-		// if https://github.com/tokio-rs/tokio/issues/3987 gets done, use it instead!
 
-		// we could use transmute_copy here, but I want to rely on the compiler telling me if the
-		// types change size to get at least maybe a smidge of a chance to catch internals changing.
-		let uninternal_child: TokioChild = unsafe { mem::transmute(child) };
-		let handle =
-			if let TokioChild {
-				child:
-					FusedChild::Child(ChildDropGuard {
-						inner: TokioImpChild { ref child, .. },
-						..
-					}),
-				..
-			} = uninternal_child
-			{
-				child.as_raw_handle()
-			} else {
-				panic!("child has exited but it has not even started // OR something unsafe is going on");
-			};
-		let child: Child = unsafe { mem::transmute(uninternal_child) };
-
-		assign_child(handle, job)?;
+		let child = self.spawn()?;
+		assign_child(child.raw_handle().expect("child has exited but it has not even started"), job)?;
 
 		Ok(AsyncGroupChild::new(child, job, completion_port))
 	}
 }
-
-struct TokioChild {
-	child: FusedChild,
-	_stdin: Option<ChildStdin>,
-	_stdout: Option<ChildStdout>,
-	_stderr: Option<ChildStderr>,
-}
-
-#[allow(dead_code)]
-enum FusedChild {
-	Child(ChildDropGuard<TokioImpChild>),
-	Done(ExitStatus),
-}
-
-struct ChildDropGuard<T> {
-	inner: T,
-	_kill_on_drop: bool,
-}
-
-struct TokioImpChild {
-	child: StdChild,
-	_waiting: Option<Waiting>,
-}
-
-// the only reason why we need the sync feature:
-struct Waiting {
-	_rx: oneshot::Receiver<()>,
-	_wait_object: HANDLE,
-	_tx: *mut Option<oneshot::Sender<()>>,
-}