fix(gateway): improve shutdown flow

Cargo.lock

@@ -1222,7 +1222,6 @@ dependencies = [
  "serde",
  "serde_json",
  "serde_variant",
- "signal-hook",
  "tokio",
  "tracing",
  "twilight-cache-inmemory",
@@ -3634,16 +3633,6 @@ version = "1.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0fda2ff0d084019ba4d7c6f371c95d8fd75ce3524c3cb8fb653a3023f6323e64"
 
-[[package]]
-name = "signal-hook"
-version = "0.3.17"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8621587d4798caf8eb44879d42e56b9a93ea5dcd315a6487c357130095b62801"
-dependencies = [
- "libc",
- "signal-hook-registry",
-]
-
 [[package]]
 name = "signal-hook-registry"
 version = "1.4.2"

Cargo.toml

@@ -18,7 +18,6 @@ reqwest = { version = "0.12.7" , default-features = false, features = ["rustls-t
 sentry = { version = "0.36.0", default-features = false, features =  ["backtrace", "contexts", "panic", "debug-images", "reqwest", "rustls"] } # replace native-tls with rustls
 serde = { version = "1.0.196", features = ["derive"] }
 serde_json = "1.0.117"
-signal-hook = "0.3.17"
 sqlx = { version = "0.8.2", features = ["runtime-tokio", "postgres", "time", "macros", "uuid"] }
 tokio = { version = "1.36.0", features = ["full"] }
 tracing = "0.1"

crates/gateway/Cargo.toml

@@ -16,7 +16,6 @@ metrics = { workspace = true }
 reqwest = { workspace = true }
 serde = { workspace = true }
 serde_json = { workspace = true }
-signal-hook = { workspace = true }
 tokio = { workspace = true }
 tracing = { workspace = true }
 

crates/gateway/src/main.rs

@@ -8,12 +8,12 @@ use event_awaiter::EventAwaiter;
 use fred::{clients::RedisPool, interfaces::*};
 use libpk::runtime_config::RuntimeConfig;
 use reqwest::{ClientBuilder, StatusCode};
-use signal_hook::{
-    consts::{SIGINT, SIGTERM},
-    iterator::Signals,
-};
 use std::{sync::Arc, time::Duration, vec::Vec};
-use tokio::{sync::mpsc::channel, task::JoinSet};
+use tokio::{
+    signal::unix::{signal, SignalKind},
+    sync::mpsc::channel,
+    task::JoinSet,
+};
 use tracing::{error, info, warn};
 use twilight_gateway::{MessageSender, ShardId};
 use twilight_model::gateway::payload::outgoing::UpdatePresence;
@@ -27,9 +27,6 @@ const RUNTIME_CONFIG_KEY_EVENT_TARGET: &'static str = "event_target";
 
 libpk::main!("gateway");
 async fn real_main() -> anyhow::Result<()> {
-    let (shutdown_tx, mut shutdown_rx) = channel::<()>(1);
-    let shutdown_tx = Arc::new(shutdown_tx);
-
     let redis = libpk::db::init_redis().await?;
 
     let runtime_config = Arc::new(
@@ -68,7 +65,8 @@ async fn real_main() -> anyhow::Result<()> {
     let shards = discord::gateway::create_shards(redis.clone())?;
 
     // arbitrary
-    let (event_tx, mut event_rx) = channel(1000);
+    // todo: make sure this doesn't fill up
+    let (event_tx, mut event_rx) = channel::<(ShardId, twilight_gateway::Event, String)>(1000);
 
     let mut senders = Vec::new();
     let mut signal_senders = Vec::new();
@@ -145,43 +143,39 @@ async fn real_main() -> anyhow::Result<()> {
         async move { scheduled_task(redis, senders).await },
     ));
 
-    // todo: probably don't do it this way
-    let api_shutdown_tx = shutdown_tx.clone();
     set.spawn(tokio::spawn(async move {
         match cache_api::run_server(cache, runtime_config, awaiter.clone()).await {
             Err(error) => {
-                tracing::error!(?error, "failed to serve cache api");
-                let _ = api_shutdown_tx.send(());
+                error!(?error, "failed to serve cache api");
             }
             _ => unreachable!(),
         }
     }));
 
-    let mut signals = Signals::new(&[SIGINT, SIGTERM])?;
-
     set.spawn(tokio::spawn(async move {
-        for sig in signals.forever() {
-            info!("received signal {:?}", sig);
-
-            let presence = UpdatePresence {
-                op: twilight_model::gateway::OpCode::PresenceUpdate,
-                d: discord::gateway::presence("Restarting... (please wait)", true),
-            };
-
-            for sender in signal_senders.iter() {
-                let presence = presence.clone();
-                let _ = sender.command(&presence);
-            }
-
-            let _ = shutdown_tx.send(()).await;
-            break;
-        }
+        signal(SignalKind::interrupt()).unwrap().recv().await;
+        info!("got SIGINT");
     }));
 
-    let _ = shutdown_rx.recv().await;
+    set.spawn(tokio::spawn(async move {
+        signal(SignalKind::terminate()).unwrap().recv().await;
+        info!("got SIGTERM");
+    }));
+
+    set.join_next().await;
 
     info!("gateway exiting, have a nice day!");
 
+    let presence = UpdatePresence {
+        op: twilight_model::gateway::OpCode::PresenceUpdate,
+        d: discord::gateway::presence("Restarting... (please wait)", true),
+    };
+
+    for sender in signal_senders.iter() {
+        let presence = presence.clone();
+        let _ = sender.command(&presence);
+    }
+
     set.abort_all();
 
     // sleep 500ms to allow everything to clean up properly