windows-services, using the service parameter in the closure passed to run with standard library threads. #3694
Description
Summary
I was experimenting with the latest release (0.25.0) of windows-services, but was struggling on how to use the service parameter passed to the callback. Rust rightfully points out I am leaking that parameter when I store the JoinHandle of the thread running my service code (so I can join it later). I saw the example but now I'm wondering if this is possible using the standard library's threads.
the compile error:
Compiling example-winsvc v0.1.0 (C:\Users\prussian\source\example-winsvc)
error[E0521]: borrowed data escapes outside of closure
--> src\main.rs:10:21
|
5 | let mut thread = None;
| ---------- `thread` declared here, outside of the closure body
...
8 | .run(|svc, comm| match comm {
| --- `svc` is a reference that is only valid in the closure body
9 | windows_services::Command::Start if thread.is_none() => {
10 | thread = Some(s.spawn(|| {
| ^^^^^^ `svc` escapes the closure body here
For more information about this error, try `rustc --explain E0521`.
error: could not compile `example-winsvc` (bin "example-winsvc") due to 1 previous error
Crate manifest
[package]
name = "example-winsvc"
version = "0.1.0"
edition = "2024"
[dependencies]
windows-services = "0.25"Crate code
use windows_services::{Service, State};
fn main() {
std::thread::scope(|s| {
let mut thread = None;
if Service::new()
.can_stop()
.run(|svc, comm| match comm {
windows_services::Command::Start if thread.is_none() => {
thread = Some(s.spawn(|| {
println!("Hello, World!");
svc.set_state(State::Stopped);
}));
}
windows_services::Command::Stop => {
if let Some(jh) = thread.take() {
jh.join();
}
}
_ => (),
})
.is_err()
{
eprintln!("not running as service");
};
});
}