expectrl
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zhiburt
`interact()` seems consumes too much CPU
Example, following example will cause 100% CPU usage.
fn main() {
let shell = "bash";
let mut sh = expectrl::spawn(shell.to_string()).expect("Error while spawning sh");
println!("Connecting to {}", shell);
sh.interact().unwrap();
}
It seems session.try_read is non_blocking, So infinity loop consume too much CPU. Mybe should spawn new thread to do read & write separately.
Example, following example will cause 100% CPU usage.
Interesting. Good catch.
It seems session.try_read is non_blocking, So infinity loop consume too much CPU. Mybe should spawn new thread to do read & write separately.
Right, because we need to check whether there's something in stdin and in stdout/stderr of a process.
Mybe should spawn new thread to do read & write separately.
It's a good approach. But there might be some different workaround. I have something in mind.
Seems like I've managed it. There's still some todos:
- it doesn't yet work on windows.
- the feature name is not ideal.
- I want to try to add an optional thread spawning as you've suggested.
Do
expectrl = { git = "https://github.com/zhiburt/expectrl/", branch = "reduce_cpu_usage_in_interact", features = ["polling"] }
I want to highlight about your proposal with spawning a thread which will block on read. It works.
But there's no easy way how to stop it. I mean we can't stop it when it's blocked. So the thread will became dangling which brings quite a bit of issues. For example in case of several spawns the threads will compete for the input/output reads.
I guess signals could be used but that's pretty complex. We could terminate it.... but I am not sure about it.
See
a platform invoke call to the Win32 WaitForSingleObject function), neither Thread.Interrupt nor Thread.Abort can take control of the thread until it returns to or calls into managed code
interact feature is too complex. especially you have std & async implements .
Good morning
interact feature is too complex. especially you have std & async implements.
What do you mean?
Just wanted to let you know that I've just published the feature.
You can use 0.6.0 version.
It also brings changes to the interact interface.