tokio/examples/dump.rs

//! This example demonstrates tokio's experimental taskdumping functionality.

#[cfg(all(
    tokio_unstable,
    tokio_taskdump,
    target_os = "linux",
    any(target_arch = "aarch64", target_arch = "x86", target_arch = "x86_64")
))]
#[tokio::main]
async fn main() {
    use std::hint::black_box;

    #[inline(never)]
    async fn a() {
        black_box(b()).await
    }

    #[inline(never)]
    async fn b() {
        black_box(c()).await
    }

    #[inline(never)]
    async fn c() {
        loop {
            tokio::task::yield_now().await;
        }
    }

    async fn dump() {
        let handle = tokio::runtime::Handle::current();
        let dump = handle.dump().await;

        for (i, task) in dump.tasks().iter().enumerate() {
            let trace = task.trace();
            println!("task {i} trace:");
            println!("{trace}\n");
        }
    }

    tokio::select!(
        biased;
        _ = tokio::spawn(a()) => {},
        _ = tokio::spawn(b()) => {},
        _ = tokio::spawn(c()) => {},
        _ = dump() => {},
    );
}

#[cfg(not(all(
    tokio_unstable,
    tokio_taskdump,
    target_os = "linux",
    any(target_arch = "aarch64", target_arch = "x86", target_arch = "x86_64")
)))]
fn main() {
    println!("task dumps are not available")
}