[rpc server]: change tokio::Handle::block_in_place to tokio::Handle::block_on

[niklasad1]

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Motivation

paritytech/substrate#13384 (comment)

Request

We should change it to tokio::block_in_place here to tokio::block_on but that requires to fix other code that block in sync code.

If a caller is using block_on in some code that calls start_rpc_servers under the hood it will panic, it would end up with something similar as:

async fn f() -> usize {
    Handle::current().block_on(tokio::time::sleep(Duration::from_millis(10)));
    1
}

#[tokio::main]
async fn main() {
    Handle::current().block_on(f());
}

Solution

Change tokio::Handle::block_in_place to tokio::Handle::block_on but it requires to fix a bunch of tests and related code.

Are you willing to help with this request?

Yes!