a task in one spawn will prevent the execution of a task in another spawn

[gengfanbin]

Version
List the versions of all tokio crates you are using. The easiest way to get
this information is using cargo tree subcommand:

cargo tree | grep tokio

tokio v1.40.0

Platform
The output of uname -a (UNIX), or version and 32 or 64-bit (Windows)

Windows

Description
Enter your issue details here.
One way to structure the description:

[short summary of the bug]
a task in one spawn will prevent the execution of a task in another spawn

I tried this code:

[code sample that causes the bug]

#[tokio::main]
async fn main() {
    tokio::spawn(async move {
        let handle = std::thread::current();
        println!("Execute thread::{:?}::{:?}", handle.id(), handle.name());
        let mut i = 0;
        loop {
            if i < 2 {
                i = i + 1;
                println!("spawn {i}");
                tokio::spawn(async move {
                    demo(i).await;
                });
            } else { 
                // Only when this spawn is suspended will the output in the “fn demo” be executed
                // tokio::task::yield_now().await; 
            }
        }
    }).await;
}
async fn demo(i: i32) {
    let handle = std::thread::current();
    println!("Execute thread::{}::{:?}::{:?}", i, handle.id(), handle.name());
}

I expected to see this happen: [explanation]
I thought println in the “fn demo” would execute correctly

like it:
Execute thread::ThreadId(6)::Some("tokio-runtime-worker")
spawn 1
spawn 2
Execute thread::2::ThreadId(6)::Some("tokio-runtime-worker")
Execute thread::1::ThreadId(11)::Some("tokio-runtime-worker")

Instead, this happened: [explanation]
But during execution, it was found that the 'fn demo' would be blocked
Execute thread::ThreadId(8)::Some("tokio-runtime-worker")
spawn 1
spawn 2
Execute thread::1::ThreadId(6)::Some("tokio-runtime-worker")

[Darksonn]

Your code is blocking the thread because the loop runs forever without encountering an .await point.

Closing as duplicate of #4941.