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use std::io;
use tokio::runtime;
pub type TaskExecutor = tokio::runtime::Handle;
#[derive(Debug)]
pub enum UninitializedExecutor {
Shared(TaskExecutor),
Unspawned,
}
impl UninitializedExecutor {
pub fn initialize(self) -> io::Result<Executor> {
self.init_with_name("event.loop")
}
pub fn init_with_name<T: Into<String>>(self, name: T) -> io::Result<Executor> {
match self {
UninitializedExecutor::Shared(executor) => Ok(Executor::Shared(executor)),
UninitializedExecutor::Unspawned => RpcEventLoop::with_name(Some(name.into())).map(Executor::Spawned),
}
}
}
#[derive(Debug)]
pub enum Executor {
Shared(TaskExecutor),
Spawned(RpcEventLoop),
}
impl Executor {
pub fn executor(&self) -> TaskExecutor {
match self {
Executor::Shared(ref executor) => executor.clone(),
Executor::Spawned(ref eloop) => eloop.executor(),
}
}
pub fn close(self) {
if let Executor::Spawned(eloop) = self {
eloop.close()
}
}
pub fn wait(self) {
if let Executor::Spawned(eloop) = self {
let _ = eloop.wait();
}
}
}
#[derive(Debug)]
pub struct RpcEventLoop {
executor: TaskExecutor,
close: Option<futures::channel::oneshot::Sender<()>>,
runtime: Option<runtime::Runtime>,
}
impl Drop for RpcEventLoop {
fn drop(&mut self) {
self.close.take().map(|v| v.send(()));
}
}
impl RpcEventLoop {
pub fn spawn() -> io::Result<Self> {
RpcEventLoop::with_name(None)
}
pub fn with_name(name: Option<String>) -> io::Result<Self> {
let (stop, stopped) = futures::channel::oneshot::channel();
let mut tb = runtime::Builder::new_multi_thread();
tb.worker_threads(1);
tb.enable_all();
if let Some(name) = name {
tb.thread_name(name);
}
let runtime = tb.build()?;
let executor = runtime.handle().to_owned();
runtime.spawn(async {
let _ = stopped.await;
});
Ok(RpcEventLoop {
executor,
close: Some(stop),
runtime: Some(runtime),
})
}
pub fn executor(&self) -> runtime::Handle {
self.runtime
.as_ref()
.expect("Runtime is only None if we're being dropped; qed")
.handle()
.clone()
}
pub fn wait(mut self) -> Result<(), ()> {
let runtime = self.runtime.take().ok_or(())?;
drop(runtime);
Ok(())
}
pub fn close(mut self) {
let _ = self
.close
.take()
.expect("Close is always set before self is consumed.")
.send(())
.map_err(|e| {
warn!("Event Loop is already finished. {:?}", e);
});
}
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn make_sure_rpc_event_loop_is_send_and_sync() {
fn is_send_and_sync<T: Send + Sync>() {}
is_send_and_sync::<RpcEventLoop>();
}
}