feat(core): handling CTRL-C signal with graceful shutdown

mm2src/mm2_bin_lib/src/lib.rs

@@ -99,5 +99,5 @@ fn prepare_for_mm2_stop() -> PrepareForStopResult {
 
 async fn finalize_mm2_stop(ctx: MmArc) {
     dispatch_lp_event(ctx.clone(), StopCtxEvent.into()).await;
-    let _ = ctx.stop();
+    let _ = ctx.stop().await;
 }

mm2src/mm2_core/src/mm_ctx.rs

@@ -500,7 +500,10 @@ lazy_static! {
 impl MmArc {
     pub fn new(ctx: MmCtx) -> MmArc { MmArc(SharedRc::new(ctx)) }
 
-    pub fn stop(&self) -> Result<(), String> {
+    pub async fn stop(&self) -> Result<(), String> {
+        #[cfg(not(target_arch = "wasm32"))]
+        try_s!(self.close_async_connection().await);
+
         try_s!(self.stop.pin(true));
 
         // Notify shutdown listeners.
@@ -514,6 +517,16 @@ impl MmArc {
         Ok(())
     }
 
+    #[cfg(not(target_arch = "wasm32"))]
+    async fn close_async_connection(&self) -> Result<(), db_common::async_sql_conn::AsyncConnError> {
+        if let Some(async_conn) = self.async_sqlite_connection.as_option() {
+            let mut conn = async_conn.lock().await;
+            conn.close().await?;
+        }
+
+        Ok(())
+    }
+
     #[cfg(feature = "track-ctx-pointer")]
     fn track_ctx_pointer(&self) {
         let ctx_weak = self.weak();

mm2src/mm2_main/Cargo.toml

@@ -116,7 +116,7 @@ hyper = { version = "0.14.26", features = ["client", "http2", "server", "tcp"] }
 rcgen = "0.10"
 rustls = { version = "0.21", default-features = false }
 rustls-pemfile = "1.0.2"
-tokio = { version = "1.20", features = ["io-util", "rt-multi-thread", "net"] }
+tokio = { version = "1.20", features = ["io-util", "rt-multi-thread", "net", "signal"] }
 
 [target.'cfg(windows)'.dependencies]
 winapi = "0.3"

mm2src/mm2_main/src/mm2.rs

@@ -43,6 +43,8 @@
 #[cfg(not(target_arch = "wasm32"))] use common::block_on;
 use common::crash_reports::init_crash_reports;
 use common::double_panic_crash;
+use common::executor::SpawnFuture;
+use common::log;
 use common::log::LogLevel;
 use common::password_policy::password_policy;
 use mm2_core::mm_ctx::MmCtxBuilder;
@@ -54,7 +56,6 @@ use lp_swap::PAYMENT_LOCKTIME;
 use std::sync::atomic::Ordering;
 
 use gstuff::slurp;
-
 use serde::ser::Serialize;
 use serde_json::{self as json, Value as Json};
 
@@ -64,7 +65,6 @@ use std::process::exit;
 use std::ptr::null;
 use std::str;
 
-mod lp_native_dex;
 pub use self::lp_native_dex::init_hw;
 pub use self::lp_native_dex::lp_init;
 use coins::update_coins_config;
@@ -75,6 +75,7 @@ use mm2_err_handle::prelude::*;
 pub mod heartbeat_event;
 pub mod lp_dispatcher;
 pub mod lp_message_service;
+mod lp_native_dex;
 pub mod lp_network;
 pub mod lp_ordermatch;
 pub mod lp_stats;
@@ -160,10 +161,30 @@ pub async fn lp_main(
         .with_datetime(datetime.clone())
         .into_mm_arc();
     ctx_cb(try_s!(ctx.ffi_handle()));
+
+    #[cfg(not(target_arch = "wasm32"))]
+    spawn_ctrl_c_handler(ctx.clone());
+
     try_s!(lp_init(ctx, version, datetime).await);
     Ok(())
 }
 
+/// Handles CTRL-C signals and shutdowns the KDF runtime gracefully.
+///
+/// It's important to spawn this task as soon as `Ctx` is in the correct state.
+#[cfg(not(target_arch = "wasm32"))]
+fn spawn_ctrl_c_handler(ctx: mm2_core::mm_ctx::MmArc) {
+    ctx.spawner().spawn(async move {
+        tokio::signal::ctrl_c()
+            .await
+            .expect("Couldn't listen for the CTRL-C signal.");
+
+        log::info!("Wrapping things up and shutting down...");
+
+        ctx.stop().await.expect("Couldn't stop the KDF runtime.");
+    });
+}
+
 fn help() {
     const HELP_MSG: &str = r#"Command-line options.
 The first command-line argument is special and designates the mode.

mm2src/mm2_main/src/rpc/lp_commands/lp_commands_legacy.rs

@@ -21,7 +21,6 @@
 
 use coins::{lp_coinfind, lp_coinfind_any, lp_coininit, CoinsContext, MmCoinEnum};
 use common::executor::Timer;
-use common::log::error;
 use common::{rpc_err_response, rpc_response, HyRes};
 use futures::compat::Future01CompatExt;
 use http::Response;
@@ -242,29 +241,13 @@ pub async fn my_balance(ctx: MmArc, req: Json) -> Result<Response<Vec<u8>>, Stri
     Ok(try_s!(Response::builder().body(res)))
 }
 
-#[cfg(not(target_arch = "wasm32"))]
-async fn close_async_connection(ctx: &MmArc) {
-    if let Some(async_conn) = ctx.async_sqlite_connection.as_option() {
-        let mut conn = async_conn.lock().await;
-        if let Err(e) = conn.close().await {
-            error!("Error stopping AsyncConnection: {}", e);
-        }
-    }
-}
-
 pub async fn stop(ctx: MmArc) -> Result<Response<Vec<u8>>, String> {
     dispatch_lp_event(ctx.clone(), StopCtxEvent.into()).await;
     // Should delay the shutdown a bit in order not to trip the "stop" RPC call in unit tests.
     // Stopping immediately leads to the "stop" RPC call failing with the "errno 10054" sometimes.
     let fut = async move {
         Timer::sleep(0.05).await;
-
-        #[cfg(not(target_arch = "wasm32"))]
-        close_async_connection(&ctx).await;
-
-        if let Err(e) = ctx.stop() {
-            error!("Error stopping MmCtx: {}", e);
-        }
+        ctx.stop().await.expect("Couldn't stop the KDF runtime.");
     };
 
     // Please note we shouldn't use `MmCtx::spawner` to spawn this future,