Auto merge of #3848 - tiif:tokiotest, r=RalfJung

Add tokio io test

After #3804 landed, these tests passed.

src/tools/miri/test_dependencies/Cargo.lock

@@ -44,6 +44,12 @@ version = "3.16.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "79296716171880943b8470b5f8d03aa55eb2e645a4874bdbb28adb49162e012c"
 
+[[package]]
+name = "bytes"
+version = "1.7.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8318a53db07bb3f8dca91a600466bdb3f2eaadeedfdbcf02e1accbad9271ba50"
+
 [[package]]
 name = "cc"
 version = "1.1.7"
@@ -304,6 +310,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "daa4fb1bc778bd6f04cbfc4bb2d06a7396a8f299dc33ea1900cedaa316f467b1"
 dependencies = [
  "backtrace",
+ "bytes",
  "libc",
  "mio",
  "pin-project-lite",

src/tools/miri/test_dependencies/Cargo.toml

@@ -20,7 +20,7 @@ tempfile = "3"
 page_size = "0.6"
 # Avoid pulling in all of tokio's dependencies.
 # However, without `net` and `signal`, tokio uses fewer relevant system APIs.
-tokio = { version = "1.24", features = ["macros", "rt-multi-thread", "time", "net", "fs", "sync", "signal"] }
+tokio = { version = "1.24", features = ["macros", "rt-multi-thread", "time", "net", "fs", "sync", "signal", "io-util"] }
 
 [target.'cfg(windows)'.dependencies]
 windows-sys = { version = "0.52", features = [ "Win32_Foundation", "Win32_System_Threading" ] }

src/tools/miri/tests/pass-dep/tokio/file-io.rs

@@ -0,0 +1,41 @@
+//@compile-flags: -Zmiri-disable-isolation
+//@only-target-linux: We only support tokio on Linux
+
+use std::fs::remove_file;
+use tokio::fs::{File, OpenOptions};
+use tokio::io::{self, AsyncReadExt, AsyncWriteExt};
+
+#[path = "../../utils/mod.rs"]
+mod utils;
+
+#[tokio::main]
+async fn main() {
+    test_create_and_write().await.unwrap();
+    test_create_and_read().await.unwrap();
+}
+
+async fn test_create_and_write() -> io::Result<()> {
+    let path = utils::prepare("foo.txt");
+    let mut file = File::create(&path).await?;
+
+    // Write 10 bytes to the file.
+    file.write(b"some bytes").await?;
+    assert_eq!(file.metadata().await.unwrap().len(), 10);
+
+    remove_file(&path).unwrap();
+    Ok(())
+}
+
+async fn test_create_and_read() -> io::Result<()> {
+    let bytes = b"more bytes";
+    let path = utils::prepare_with_content("foo.txt", bytes);
+    let mut file = OpenOptions::new().read(true).open(&path).await.unwrap();
+    let mut buffer = [0u8; 10];
+
+    // Read the whole file.
+    file.read(&mut buffer[..]).await?;
+    assert_eq!(&buffer, b"more bytes");
+
+    remove_file(&path).unwrap();
+    Ok(())
+}

src/tools/miri/tests/pass-dep/tokio/mpsc-await.rs

@@ -0,0 +1,20 @@
+//@only-target-linux: We only support tokio on Linux
+use tokio::sync::mpsc;
+
+#[tokio::main]
+async fn main() {
+    let (tx, mut rx) = mpsc::channel(32);
+    let tx2 = tx.clone();
+
+    tokio::spawn(async move {
+        tx.send("sending from handle").await.unwrap();
+    });
+
+    tokio::spawn(async move {
+        tx2.send("sending from handle").await.unwrap();
+    });
+
+    while let Some(message) = rx.recv().await {
+        println!("GOT = {}", message);
+    }
+}

src/tools/miri/tests/pass-dep/tokio/mpsc-await.stdout

@@ -0,0 +1,2 @@
+GOT = sending from handle
+GOT = sending from handle

src/tools/miri/tests/pass-dep/tokio/sleep.rs

@@ -1,5 +1,4 @@
-//@compile-flags: -Zmiri-permissive-provenance -Zmiri-backtrace=full
-//@only-target-x86_64-unknown-linux: support for tokio only on linux and x86
+//@only-target-linux: We only support tokio on Linux
 
 use tokio::time::{sleep, Duration, Instant};
 

src/tools/miri/tests/pass-dep/tokio/tokio_mvp.rs

@@ -1,6 +0,0 @@
-// Need to disable preemption to stay on the supported MVP codepath in mio.
-//@compile-flags: -Zmiri-permissive-provenance -Zmiri-preemption-rate=0
-//@only-target-x86_64-unknown-linux: support for tokio exists only on linux and x86
-
-#[tokio::main]
-async fn main() {}