refactored TCP server

satrs-example/src/tcp.rs

@@ -5,7 +5,7 @@ use std::{
 
 use log::{info, warn};
 use satrs::{
-    hal::std::tcp_server::{ServerConfig, TcpSpacepacketsServer},
+    hal::std::tcp_server::{HandledConnectionHandler, ServerConfig, TcpSpacepacketsServer},
     pus::ReceivesEcssPusTc,
     spacepackets::PacketId,
     tmtc::{CcsdsDistributor, CcsdsError, ReceivesCcsdsTc, TmPacketSourceCore},
@@ -13,6 +13,18 @@ use satrs::{
 
 use crate::ccsds::CcsdsReceiver;
 
+#[derive(Default)]
+pub struct ConnectionFinishedHandler {}
+
+impl HandledConnectionHandler for ConnectionFinishedHandler {
+    fn handled_connection(&mut self, info: satrs::hal::std::tcp_server::HandledConnectionInfo) {
+        info!(
+            "Served {} TMs and {} TCs for client {:?}",
+            info.num_sent_tms, info.num_received_tcs, info.addr
+        );
+    }
+}
+
 #[derive(Default, Clone)]
 pub struct SyncTcpTmSource {
     tm_queue: Arc<Mutex<VecDeque<Vec<u8>>>>,
@@ -70,11 +82,12 @@ impl TmPacketSourceCore for SyncTcpTmSource {
 }
 
 pub type TcpServerType<TcSource, MpscErrorType> = TcpSpacepacketsServer<
-    (),
-    CcsdsError<MpscErrorType>,
     SyncTcpTmSource,
     CcsdsDistributor<CcsdsReceiver<TcSource, MpscErrorType>, MpscErrorType>,
     HashSet<PacketId>,
+    ConnectionFinishedHandler,
+    (),
+    CcsdsError<MpscErrorType>,
 >;
 
 pub struct TcpTask<
@@ -109,6 +122,7 @@ impl<
                 tm_source,
                 tc_receiver,
                 packet_id_lookup,
+                ConnectionFinishedHandler::default(),
                 None,
             )?,
         })
@@ -116,14 +130,9 @@ impl<
 
     pub fn periodic_operation(&mut self) {
         loop {
-            let result = self.server.handle_next_connection();
+            let result = self.server.handle_next_connection(None);
             match result {
-                Ok(conn_result) => {
+                Ok(_conn_result) => (),
-                    info!(
-                        "Served {} TMs and {} TCs for client {:?}",
-                        conn_result.num_sent_tms, conn_result.num_received_tcs, conn_result.addr
-                    );
-                }
                 Err(e) => {
                     warn!("TCP server error: {e:?}");
                 }

satrs/CHANGELOG.md

@@ -22,9 +22,13 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
   parameter type. This message also contains the sender ID which can be useful for debugging
   or application layer / FDIR logic.
 - Stop signal handling for the TCP servers.
+- TCP server now uses `mio` crate to allow non-blocking operation. The server can now handle
+  multiple connections at once, and the context information about handled transfers is
+  passed via a callback which is inserted as a generic as well.
 
 ## Changed
 
+- TCP server generics order. The error generics come last now.
 - `encoding::ccsds::PacketIdValidator` renamed to `ValidatorU16Id`, which lives in the crate root.
   It can be used for both CCSDS packet ID and CCSDS APID validation.
 - `EventManager::try_event_handling` not expects a mutable error handling closure instead of

satrs/src/hal/std/tcp_cobs_server.rs

@@ -2,11 +2,11 @@ use alloc::sync::Arc;
 use alloc::vec;
 use cobs::encode;
 use core::sync::atomic::AtomicBool;
+use core::time::Duration;
 use delegate::delegate;
+use mio::net::{TcpListener, TcpStream};
 use std::io::Write;
 use std::net::SocketAddr;
-use std::net::TcpListener;
-use std::net::TcpStream;
 use std::vec::Vec;
 
 use crate::encoding::parse_buffer_for_cobs_encoded_packets;
@@ -17,6 +17,9 @@ use crate::hal::std::tcp_server::{
     ConnectionResult, ServerConfig, TcpTcParser, TcpTmSender, TcpTmtcError, TcpTmtcGenericServer,
 };
 
+use super::tcp_server::HandledConnectionHandler;
+use super::tcp_server::HandledConnectionInfo;
+
 /// Concrete [TcpTcParser] implementation for the [TcpTmtcInCobsServer].
 #[derive(Default)]
 pub struct CobsTcParser {}
@@ -26,7 +29,7 @@ impl<TmError, TcError: 'static> TcpTcParser<TmError, TcError> for CobsTcParser {
         &mut self,
         tc_buffer: &mut [u8],
         tc_receiver: &mut (impl ReceivesTc<Error = TcError> + ?Sized),
-        conn_result: &mut ConnectionResult,
+        conn_result: &mut HandledConnectionInfo,
         current_write_idx: usize,
         next_write_idx: &mut usize,
     ) -> Result<(), TcpTmtcError<TmError, TcError>> {
@@ -60,7 +63,7 @@ impl<TmError, TcError> TcpTmSender<TmError, TcError> for CobsTmSender {
         &mut self,
         tm_buffer: &mut [u8],
         tm_source: &mut (impl TmPacketSource<Error = TmError> + ?Sized),
-        conn_result: &mut ConnectionResult,
+        conn_result: &mut HandledConnectionInfo,
         stream: &mut TcpStream,
     ) -> Result<bool, TcpTmtcError<TmError, TcError>> {
         let mut tm_was_sent = false;
@@ -112,21 +115,30 @@ impl<TmError, TcError> TcpTmSender<TmError, TcError> for CobsTmSender {
 /// The [TCP integration tests](https://egit.irs.uni-stuttgart.de/rust/sat-rs/src/branch/main/satrs/tests/tcp_servers.rs)
 /// test also serves as the example application for this module.
 pub struct TcpTmtcInCobsServer<
-    TmError,
-    TcError: 'static,
     TmSource: TmPacketSource<Error = TmError>,
     TcReceiver: ReceivesTc<Error = TcError>,
+    HandledConnection: HandledConnectionHandler,
+    TmError,
+    TcError: 'static,
 > {
-    generic_server:
+    pub generic_server: TcpTmtcGenericServer<
-        TcpTmtcGenericServer<TmError, TcError, TmSource, TcReceiver, CobsTmSender, CobsTcParser>,
+        TmSource,
+        TcReceiver,
+        CobsTmSender,
+        CobsTcParser,
+        HandledConnection,
+        TmError,
+        TcError,
+    >,
 }
 
 impl<
-        TmError: 'static,
-        TcError: 'static,
         TmSource: TmPacketSource<Error = TmError>,
         TcReceiver: ReceivesTc<Error = TcError>,
-    > TcpTmtcInCobsServer<TmError, TcError, TmSource, TcReceiver>
+        HandledConnection: HandledConnectionHandler,
+        TmError: 'static,
+        TcError: 'static,
+    > TcpTmtcInCobsServer<TmSource, TcReceiver, HandledConnection, TmError, TcError>
 {
     /// Create a new TCP TMTC server which exchanges TMTC packets encoded with
     /// [COBS protocol](https://en.wikipedia.org/wiki/Consistent_Overhead_Byte_Stuffing).
@@ -142,6 +154,7 @@ impl<
         cfg: ServerConfig,
         tm_source: TmSource,
         tc_receiver: TcReceiver,
+        handled_connection: HandledConnection,
         stop_signal: Option<Arc<AtomicBool>>,
     ) -> Result<Self, std::io::Error> {
         Ok(Self {
@@ -151,6 +164,7 @@ impl<
                 CobsTmSender::new(cfg.tm_buffer_size),
                 tm_source,
                 tc_receiver,
+                handled_connection,
                 stop_signal,
             )?,
         })
@@ -167,6 +181,7 @@ impl<
             /// Delegation to the [TcpTmtcGenericServer::handle_next_connection] call.
             pub fn handle_next_connection(
                 &mut self,
+                poll_duration: Option<Duration>,
             ) -> Result<ConnectionResult, TcpTmtcError<TmError, TcError>>;
         }
     }
@@ -181,15 +196,15 @@ mod tests {
     use std::{
         io::{Read, Write},
         net::{IpAddr, Ipv4Addr, SocketAddr, TcpStream},
-        panic, println, thread,
+        panic, thread,
         time::Instant,
     };
 
     use crate::{
         encoding::tests::{INVERTED_PACKET, SIMPLE_PACKET},
         hal::std::tcp_server::{
-            tests::{SyncTcCacher, SyncTmSource},
+            tests::{ConnectionFinishedHandler, SyncTcCacher, SyncTmSource},
-            ServerConfig,
+            ConnectionResult, ServerConfig,
         },
     };
     use alloc::sync::Arc;
@@ -218,11 +233,12 @@ mod tests {
         tc_receiver: SyncTcCacher,
         tm_source: SyncTmSource,
         stop_signal: Option<Arc<AtomicBool>>,
-    ) -> TcpTmtcInCobsServer<(), (), SyncTmSource, SyncTcCacher> {
+    ) -> TcpTmtcInCobsServer<SyncTmSource, SyncTcCacher, ConnectionFinishedHandler, (), ()> {
         TcpTmtcInCobsServer::new(
             ServerConfig::new(*addr, Duration::from_millis(2), 1024, 1024),
             tm_source,
             tc_receiver,
+            ConnectionFinishedHandler::default(),
             stop_signal,
         )
         .expect("TCP server generation failed")
@@ -242,13 +258,20 @@ mod tests {
         let set_if_done = conn_handled.clone();
         // Call the connection handler in separate thread, does block.
         thread::spawn(move || {
-            let result = tcp_server.handle_next_connection();
+            let result = tcp_server.handle_next_connection(Some(Duration::from_millis(100)));
             if result.is_err() {
                 panic!("handling connection failed: {:?}", result.unwrap_err());
             }
-            let conn_result = result.unwrap();
+            let result = result.unwrap();
-            assert_eq!(conn_result.num_received_tcs, 1);
+            assert_eq!(result, ConnectionResult::HandledConnections(1));
-            assert_eq!(conn_result.num_sent_tms, 0);
+            tcp_server
+                .generic_server
+                .finished_handler
+                .check_last_connection(0, 1);
+            tcp_server
+                .generic_server
+                .finished_handler
+                .check_no_connections_left();
             set_if_done.store(true, Ordering::Relaxed);
         });
         // Send TC to server now.
@@ -299,13 +322,20 @@ mod tests {
         let set_if_done = conn_handled.clone();
         // Call the connection handler in separate thread, does block.
         thread::spawn(move || {
-            let result = tcp_server.handle_next_connection();
+            let result = tcp_server.handle_next_connection(Some(Duration::from_millis(100)));
             if result.is_err() {
                 panic!("handling connection failed: {:?}", result.unwrap_err());
             }
-            let conn_result = result.unwrap();
+            let result = result.unwrap();
-            assert_eq!(conn_result.num_received_tcs, 2, "Not enough TCs received");
+            assert_eq!(result, ConnectionResult::HandledConnections(1));
-            assert_eq!(conn_result.num_sent_tms, 2, "Not enough TMs received");
+            tcp_server
+                .generic_server
+                .finished_handler
+                .check_last_connection(2, 2);
+            tcp_server
+                .generic_server
+                .finished_handler
+                .check_no_connections_left();
             set_if_done.store(true, Ordering::Relaxed);
         });
         // Send TC to server now.
@@ -389,6 +419,31 @@ mod tests {
         drop(tc_queue);
     }
 
+    #[test]
+    fn test_server_accept_timeout() {
+        let auto_port_addr = SocketAddr::new(IpAddr::V4(Ipv4Addr::new(127, 0, 0, 1)), 0);
+        let tc_receiver = SyncTcCacher::default();
+        let tm_source = SyncTmSource::default();
+        let mut tcp_server =
+            generic_tmtc_server(&auto_port_addr, tc_receiver.clone(), tm_source, None);
+        let start = Instant::now();
+        // Call the connection handler in separate thread, does block.
+        let thread_jh = thread::spawn(move || loop {
+            let result = tcp_server.handle_next_connection(Some(Duration::from_millis(20)));
+            if result.is_err() {
+                panic!("handling connection failed: {:?}", result.unwrap_err());
+            }
+            let result = result.unwrap();
+            if result == ConnectionResult::AcceptTimeout {
+                break;
+            }
+            if Instant::now() - start > Duration::from_millis(100) {
+                panic!("regular stop signal handling failed");
+            }
+        });
+        thread_jh.join().expect("thread join failed");
+    }
+
     #[test]
     fn test_server_stop_signal() {
         let auto_port_addr = SocketAddr::new(IpAddr::V4(Ipv4Addr::new(127, 0, 0, 1)), 0);
@@ -401,26 +456,32 @@ mod tests {
             tm_source,
             Some(stop_signal.clone()),
         );
+        let dest_addr = tcp_server
+            .local_addr()
+            .expect("retrieving dest addr failed");
+        let stop_signal_copy = stop_signal.clone();
         let start = Instant::now();
         // Call the connection handler in separate thread, does block.
         let thread_jh = thread::spawn(move || loop {
-            println!("hello wtf!!!!");
+            let result = tcp_server.handle_next_connection(Some(Duration::from_millis(20)));
-            let result = tcp_server.handle_next_connection();
             if result.is_err() {
                 panic!("handling connection failed: {:?}", result.unwrap_err());
             }
-            println!("helluuuu");
             let result = result.unwrap();
-            if result.stopped_by_signal {
+            if result == ConnectionResult::AcceptTimeout {
+                panic!("unexpected accept timeout");
+            }
+            if stop_signal_copy.load(Ordering::Relaxed) {
                 break;
             }
-            if Instant::now() - start > Duration::from_millis(50) {
+            if Instant::now() - start > Duration::from_millis(100) {
                 panic!("regular stop signal handling failed");
             }
         });
+        // We connect but do not do anything.
+        let _stream = TcpStream::connect(dest_addr).expect("connecting to TCP server failed");
         stop_signal.store(true, Ordering::Relaxed);
-        thread::sleep(Duration::from_millis(100));
+        // No need to drop the connection, the stop signal should take take of everything.
-        panic!("shit")
+        thread_jh.join().expect("thread join failed");
-        //thread_jh.join().expect("thread join failed");
     }
 }

satrs/src/hal/std/tcp_server.rs

@@ -7,7 +7,7 @@ use core::time::Duration;
 use mio::net::{TcpListener, TcpStream};
 use mio::{Events, Interest, Poll, Token};
 use socket2::{Domain, Socket, Type};
-use std::io::Read;
+use std::io::{self, Read};
 use std::net::SocketAddr;
 // use std::net::TcpListener;
 // use std::net::{SocketAddr, TcpStream};
@@ -84,21 +84,15 @@ pub enum TcpTmtcError<TmError, TcError> {
 
 /// Result of one connection attempt. Contains the client address if a connection was established,
 /// in addition to the number of telecommands and telemetry packets exchanged.
-#[derive(Debug)]
+#[derive(Debug, PartialEq, Eq)]
 pub enum ConnectionResult {
     AcceptTimeout,
-    HandledConnection(HandledConnectionInfo),
+    HandledConnections(u32),
 }
 
-impl From<HandledConnectionInfo> for ConnectionResult {
+#[derive(Debug)]
-    fn from(info: HandledConnectionInfo) -> Self {
-        ConnectionResult::HandledConnection(info)
-    }
-}
-
-#[derive(Debug, Default)]
 pub struct HandledConnectionInfo {
-    pub addr: Option<SocketAddr>,
+    pub addr: SocketAddr,
     pub num_received_tcs: u32,
     pub num_sent_tms: u32,
     /// The generic TCP server can be stopped using an external signal. If this happened, this
@@ -106,6 +100,17 @@ pub struct HandledConnectionInfo {
     pub stopped_by_signal: bool,
 }
 
+impl HandledConnectionInfo {
+    pub fn new(addr: SocketAddr) -> Self {
+        Self {
+            addr,
+            num_received_tcs: 0,
+            num_sent_tms: 0,
+            stopped_by_signal: false,
+        }
+    }
+}
+
 pub trait HandledConnectionHandler {
     fn handled_connection(&mut self, info: HandledConnectionInfo);
 }
@@ -156,14 +161,15 @@ pub trait TcpTmSender<TmError, TcError> {
 ///
 /// 1. [TcpTmtcInCobsServer] to exchange TMTC wrapped inside the COBS framing protocol.
 pub struct TcpTmtcGenericServer<
-    TmError,
-    TcError,
     TmSource: TmPacketSource<Error = TmError>,
     TcReceiver: ReceivesTc<Error = TcError>,
     TmSender: TcpTmSender<TmError, TcError>,
     TcParser: TcpTcParser<TmError, TcError>,
-    //HandledConnection: HandledConnectionHandler
+    HandledConnection: HandledConnectionHandler,
+    TmError,
+    TcError,
 > {
+    pub finished_handler: HandledConnection,
     pub(crate) listener: TcpListener,
     pub(crate) inner_loop_delay: Duration,
     pub(crate) tm_source: TmSource,
@@ -172,19 +178,29 @@ pub struct TcpTmtcGenericServer<
     pub(crate) tc_buffer: Vec<u8>,
     poll: Poll,
     events: Events,
-    stop_signal: Option<Arc<AtomicBool>>,
     tc_handler: TcParser,
     tm_handler: TmSender,
+    stop_signal: Option<Arc<AtomicBool>>,
 }
 
 impl<
-        TmError: 'static,
-        TcError: 'static,
         TmSource: TmPacketSource<Error = TmError>,
         TcReceiver: ReceivesTc<Error = TcError>,
         TmSender: TcpTmSender<TmError, TcError>,
         TcParser: TcpTcParser<TmError, TcError>,
-    > TcpTmtcGenericServer<TmError, TcError, TmSource, TcReceiver, TmSender, TcParser>
+        HandledConnection: HandledConnectionHandler,
+        TmError: 'static,
+        TcError: 'static,
+    >
+    TcpTmtcGenericServer<
+        TmSource,
+        TcReceiver,
+        TmSender,
+        TcParser,
+        HandledConnection,
+        TmError,
+        TcError,
+    >
 {
     /// Create a new generic TMTC server instance.
     ///
@@ -198,12 +214,14 @@ impl<
     ///     then sent back to the client.
     /// * `tc_receiver` - Any received telecommand which was decoded successfully will be forwarded
     ///     to this TC receiver.
+    /// * `stop_signal` - Can be used to stop the server even if a connection is ongoing.
     pub fn new(
         cfg: ServerConfig,
         tc_parser: TcParser,
         tm_sender: TmSender,
         tm_source: TmSource,
         tc_receiver: TcReceiver,
+        finished_handler: HandledConnection,
         stop_signal: Option<Arc<AtomicBool>>,
     ) -> Result<Self, std::io::Error> {
         // Create a TCP listener bound to two addresses.
@@ -212,14 +230,16 @@ impl<
         socket.set_reuse_address(cfg.reuse_addr)?;
         #[cfg(unix)]
         socket.set_reuse_port(cfg.reuse_port)?;
+        // MIO does not do this for us. We want the accept calls to be non-blocking.
+        socket.set_nonblocking(true)?;
         let addr = (cfg.addr).into();
         socket.bind(&addr)?;
         socket.listen(128)?;
 
         // Create a poll instance.
-        let mut poll = Poll::new()?;
+        let poll = Poll::new()?;
         // Create storage for events.
-        let mut events = Events::with_capacity(10);
+        let events = Events::with_capacity(10);
         let listener: std::net::TcpListener = socket.into();
         let mut mio_listener = TcpListener::from_std(listener);
 
@@ -239,6 +259,7 @@ impl<
             tc_receiver,
             tc_buffer: vec![0; cfg.tc_buffer_size],
             stop_signal,
+            finished_handler,
         })
     }
 
@@ -268,19 +289,38 @@ impl<
     /// client does not send any telecommands and no telemetry needs to be sent back to the client.
     pub fn handle_next_connection(
         &mut self,
+        poll_timeout: Option<Duration>,
     ) -> Result<ConnectionResult, TcpTmtcError<TmError, TcError>> {
-        // Poll Mio for events, blocking until we get an event.
+        let mut handled_connections = 0;
-        self.poll
+        // Poll Mio for events.
-            .poll(&mut self.events, Some(Duration::from_millis(400)))?;
+        self.poll.poll(&mut self.events, poll_timeout)?;
+        let mut acceptable_connection = false;
         // Process each event.
-        if let Some(event) = self.events.iter().next() {
+        for event in self.events.iter() {
             if event.token() == Token(0) {
-                let connection = self.listener.accept()?;
+                acceptable_connection = true;
-                return self
+            } else {
-                    .handle_accepted_connection(connection.0, connection.1)
+                // Should never happen..
-                    .map(|v| v.into());
+                panic!("unexpected TCP event token");
             }
-            panic!("unexpected TCP event token");
+        }
+        // I'd love to do this in the loop above, but there are issues with multiple borrows.
+        if acceptable_connection {
+            // There might be mutliple connections available. Accept until all of them have
+            // been handled.
+            loop {
+                match self.listener.accept() {
+                    Ok((stream, addr)) => {
+                        self.handle_accepted_connection(stream, addr)?;
+                        handled_connections += 1;
+                    }
+                    Err(ref err) if err.kind() == io::ErrorKind::WouldBlock => break,
+                    Err(err) => return Err(TcpTmtcError::Io(err)),
+                }
+            }
+        }
+        if handled_connections > 0 {
+            return Ok(ConnectionResult::HandledConnections(handled_connections));
         }
         Ok(ConnectionResult::AcceptTimeout)
     }
@@ -289,13 +329,10 @@ impl<
         &mut self,
         mut stream: TcpStream,
         addr: SocketAddr,
-    ) -> Result<HandledConnectionInfo, TcpTmtcError<TmError, TcError>> {
+    ) -> Result<(), TcpTmtcError<TmError, TcError>> {
         let mut current_write_idx;
         let mut next_write_idx = 0;
-        let mut connection_result = HandledConnectionInfo::default();
+        let mut connection_result = HandledConnectionInfo::new(addr);
-        // stream.set_nonblocking(true)?;
-        connection_result.addr = Some(addr);
-        connection_result.stopped_by_signal = false;
         current_write_idx = next_write_idx;
         loop {
             let read_result = stream.read(&mut self.tc_buffer[current_write_idx..]);
@@ -359,7 +396,8 @@ impl<
                                     .load(std::sync::atomic::Ordering::Relaxed)
                             {
                                 connection_result.stopped_by_signal = true;
-                                return Ok(connection_result);
+                                self.finished_handler.handled_connection(connection_result);
+                                return Ok(());
                             }
                         }
                     }
@@ -375,7 +413,8 @@ impl<
             &mut connection_result,
             &mut stream,
         )?;
-        Ok(connection_result)
+        self.finished_handler.handled_connection(connection_result);
+        Ok(())
     }
 }
 
@@ -387,6 +426,8 @@ pub(crate) mod tests {
 
     use crate::tmtc::{ReceivesTcCore, TmPacketSourceCore};
 
+    use super::*;
+
     #[derive(Default, Clone)]
     pub(crate) struct SyncTcCacher {
         pub(crate) tc_queue: Arc<Mutex<VecDeque<Vec<u8>>>>,
@@ -433,4 +474,30 @@ pub(crate) mod tests {
             Ok(0)
         }
     }
+
+    #[derive(Default)]
+    pub struct ConnectionFinishedHandler {
+        connection_info: VecDeque<HandledConnectionInfo>,
+    }
+
+    impl HandledConnectionHandler for ConnectionFinishedHandler {
+        fn handled_connection(&mut self, info: HandledConnectionInfo) {
+            self.connection_info.push_back(info);
+        }
+    }
+
+    impl ConnectionFinishedHandler {
+        pub fn check_last_connection(&mut self, num_tms: u32, num_tcs: u32) {
+            let last_conn_result = self
+                .connection_info
+                .pop_back()
+                .expect("no connection info available");
+            assert_eq!(last_conn_result.num_received_tcs, num_tcs);
+            assert_eq!(last_conn_result.num_sent_tms, num_tms);
+        }
+
+        pub fn check_no_connections_left(&self) {
+            assert!(self.connection_info.is_empty());
+        }
+    }
 }

satrs/src/hal/std/tcp_spacepackets_server.rs

@@ -1,10 +1,8 @@
 use alloc::sync::Arc;
-use core::sync::atomic::AtomicBool;
+use core::{sync::atomic::AtomicBool, time::Duration};
 use delegate::delegate;
-use std::{
+use mio::net::{TcpListener, TcpStream};
-    io::Write,
+use std::{io::Write, net::SocketAddr};
-    net::{SocketAddr, TcpListener, TcpStream},
-};
 
 use crate::{
     encoding::parse_buffer_for_ccsds_space_packets,
@@ -13,7 +11,8 @@ use crate::{
 };
 
 use super::tcp_server::{
-    ConnectionResult, ServerConfig, TcpTcParser, TcpTmSender, TcpTmtcError, TcpTmtcGenericServer,
+    ConnectionResult, HandledConnectionHandler, HandledConnectionInfo, ServerConfig, TcpTcParser,
+    TcpTmSender, TcpTmtcError, TcpTmtcGenericServer,
 };
 
 /// Concrete [TcpTcParser] implementation for the [TcpSpacepacketsServer].
@@ -27,14 +26,14 @@ impl<PacketIdChecker: ValidatorU16Id> SpacepacketsTcParser<PacketIdChecker> {
     }
 }
 
-impl<TmError, TcError: 'static, PacketIdChecker: ValidatorU16Id> TcpTcParser<TmError, TcError>
+impl<PacketIdChecker: ValidatorU16Id, TmError, TcError: 'static> TcpTcParser<TmError, TcError>
     for SpacepacketsTcParser<PacketIdChecker>
 {
     fn handle_tc_parsing(
         &mut self,
         tc_buffer: &mut [u8],
         tc_receiver: &mut (impl ReceivesTc<Error = TcError> + ?Sized),
-        conn_result: &mut ConnectionResult,
+        conn_result: &mut HandledConnectionInfo,
         current_write_idx: usize,
         next_write_idx: &mut usize,
     ) -> Result<(), TcpTmtcError<TmError, TcError>> {
@@ -59,7 +58,7 @@ impl<TmError, TcError> TcpTmSender<TmError, TcError> for SpacepacketsTmSender {
         &mut self,
         tm_buffer: &mut [u8],
         tm_source: &mut (impl TmPacketSource<Error = TmError> + ?Sized),
-        conn_result: &mut ConnectionResult,
+        conn_result: &mut HandledConnectionInfo,
         stream: &mut TcpStream,
     ) -> Result<bool, TcpTmtcError<TmError, TcError>> {
         let mut tm_was_sent = false;
@@ -94,29 +93,40 @@ impl<TmError, TcError> TcpTmSender<TmError, TcError> for SpacepacketsTmSender {
 /// The [TCP server integration tests](https://egit.irs.uni-stuttgart.de/rust/sat-rs/src/branch/main/satrs/tests/tcp_servers.rs)
 /// also serves as the example application for this module.
 pub struct TcpSpacepacketsServer<
-    TmError,
-    TcError: 'static,
     TmSource: TmPacketSource<Error = TmError>,
     TcReceiver: ReceivesTc<Error = TcError>,
     PacketIdChecker: ValidatorU16Id,
+    HandledConnection: HandledConnectionHandler,
+    TmError,
+    TcError: 'static,
 > {
-    generic_server: TcpTmtcGenericServer<
+    pub generic_server: TcpTmtcGenericServer<
-        TmError,
-        TcError,
         TmSource,
         TcReceiver,
         SpacepacketsTmSender,
         SpacepacketsTcParser<PacketIdChecker>,
+        HandledConnection,
+        TmError,
+        TcError,
     >,
 }
 
 impl<
-        TmError: 'static,
-        TcError: 'static,
         TmSource: TmPacketSource<Error = TmError>,
         TcReceiver: ReceivesTc<Error = TcError>,
         PacketIdChecker: ValidatorU16Id,
-    > TcpSpacepacketsServer<TmError, TcError, TmSource, TcReceiver, PacketIdChecker>
+        HandledConnection: HandledConnectionHandler,
+        TmError: 'static,
+        TcError: 'static,
+    >
+    TcpSpacepacketsServer<
+        TmSource,
+        TcReceiver,
+        PacketIdChecker,
+        HandledConnection,
+        TmError,
+        TcError,
+    >
 {
     ///
     /// ## Parameter
@@ -133,6 +143,7 @@ impl<
         tm_source: TmSource,
         tc_receiver: TcReceiver,
         packet_id_checker: PacketIdChecker,
+        handled_connection: HandledConnection,
         stop_signal: Option<Arc<AtomicBool>>,
     ) -> Result<Self, std::io::Error> {
         Ok(Self {
@@ -142,6 +153,7 @@ impl<
                 SpacepacketsTmSender::default(),
                 tm_source,
                 tc_receiver,
+                handled_connection,
                 stop_signal,
             )?,
         })
@@ -158,6 +170,7 @@ impl<
             /// Delegation to the [TcpTmtcGenericServer::handle_next_connection] call.
             pub fn handle_next_connection(
                 &mut self,
+                poll_timeout: Option<Duration>
             ) -> Result<ConnectionResult, TcpTmtcError<TmError, TcError>>;
         }
     }
@@ -185,8 +198,8 @@ mod tests {
     };
 
     use crate::hal::std::tcp_server::{
-        tests::{SyncTcCacher, SyncTmSource},
+        tests::{ConnectionFinishedHandler, SyncTcCacher, SyncTmSource},
-        ServerConfig,
+        ConnectionResult, ServerConfig,
     };
 
     use super::TcpSpacepacketsServer;
@@ -202,12 +215,20 @@ mod tests {
         tm_source: SyncTmSource,
         packet_id_lookup: HashSet<PacketId>,
         stop_signal: Option<Arc<AtomicBool>>,
-    ) -> TcpSpacepacketsServer<(), (), SyncTmSource, SyncTcCacher, HashSet<PacketId>> {
+    ) -> TcpSpacepacketsServer<
+        SyncTmSource,
+        SyncTcCacher,
+        HashSet<PacketId>,
+        ConnectionFinishedHandler,
+        (),
+        (),
+    > {
         TcpSpacepacketsServer::new(
             ServerConfig::new(*addr, Duration::from_millis(2), 1024, 1024),
             tm_source,
             tc_receiver,
             packet_id_lookup,
+            ConnectionFinishedHandler::default(),
             stop_signal,
         )
         .expect("TCP server generation failed")
@@ -234,13 +255,20 @@ mod tests {
         let set_if_done = conn_handled.clone();
         // Call the connection handler in separate thread, does block.
         thread::spawn(move || {
-            let result = tcp_server.handle_next_connection();
+            let result = tcp_server.handle_next_connection(Some(Duration::from_millis(100)));
             if result.is_err() {
                 panic!("handling connection failed: {:?}", result.unwrap_err());
             }
             let conn_result = result.unwrap();
-            assert_eq!(conn_result.num_received_tcs, 1);
+            matches!(conn_result, ConnectionResult::HandledConnections(1));
-            assert_eq!(conn_result.num_sent_tms, 0);
+            tcp_server
+                .generic_server
+                .finished_handler
+                .check_last_connection(0, 1);
+            tcp_server
+                .generic_server
+                .finished_handler
+                .check_no_connections_left();
             set_if_done.store(true, Ordering::Relaxed);
         });
         let ping_tc =
@@ -305,16 +333,20 @@ mod tests {
 
         // Call the connection handler in separate thread, does block.
         thread::spawn(move || {
-            let result = tcp_server.handle_next_connection();
+            let result = tcp_server.handle_next_connection(Some(Duration::from_millis(100)));
             if result.is_err() {
                 panic!("handling connection failed: {:?}", result.unwrap_err());
             }
             let conn_result = result.unwrap();
-            assert_eq!(
+            matches!(conn_result, ConnectionResult::HandledConnections(1));
-                conn_result.num_received_tcs, 2,
+            tcp_server
-                "wrong number of received TCs"
+                .generic_server
-            );
+                .finished_handler
-            assert_eq!(conn_result.num_sent_tms, 2, "wrong number of sent TMs");
+                .check_last_connection(2, 2);
+            tcp_server
+                .generic_server
+                .finished_handler
+                .check_no_connections_left();
             set_if_done.store(true, Ordering::Relaxed);
         });
         let mut stream = TcpStream::connect(dest_addr).expect("connecting to TCP server failed");

satrs/tests/tcp_servers.rs

@@ -24,7 +24,10 @@ use std::{
 use hashbrown::HashSet;
 use satrs::{
     encoding::cobs::encode_packet_with_cobs,
-    hal::std::tcp_server::{ServerConfig, TcpSpacepacketsServer, TcpTmtcInCobsServer},
+    hal::std::tcp_server::{
+        ConnectionResult, HandledConnectionHandler, HandledConnectionInfo, ServerConfig,
+        TcpSpacepacketsServer, TcpTmtcInCobsServer,
+    },
     tmtc::{ReceivesTcCore, TmPacketSourceCore},
 };
 use spacepackets::{
@@ -33,10 +36,36 @@ use spacepackets::{
 };
 use std::{collections::VecDeque, sync::Arc, vec::Vec};
 
+#[derive(Default)]
+pub struct ConnectionFinishedHandler {
+    connection_info: VecDeque<HandledConnectionInfo>,
+}
+
+impl HandledConnectionHandler for ConnectionFinishedHandler {
+    fn handled_connection(&mut self, info: HandledConnectionInfo) {
+        self.connection_info.push_back(info);
+    }
+}
+
+impl ConnectionFinishedHandler {
+    pub fn check_last_connection(&mut self, num_tms: u32, num_tcs: u32) {
+        let last_conn_result = self
+            .connection_info
+            .pop_back()
+            .expect("no connection info available");
+        assert_eq!(last_conn_result.num_received_tcs, num_tcs);
+        assert_eq!(last_conn_result.num_sent_tms, num_tms);
+    }
+
+    pub fn check_no_connections_left(&self) {
+        assert!(self.connection_info.is_empty());
+    }
+}
 #[derive(Default, Clone)]
 struct SyncTcCacher {
     tc_queue: Arc<Mutex<VecDeque<Vec<u8>>>>,
 }
+
 impl ReceivesTcCore for SyncTcCacher {
     type Error = ();
 
@@ -96,6 +125,7 @@ fn test_cobs_server() {
         ServerConfig::new(AUTO_PORT_ADDR, Duration::from_millis(2), 1024, 1024),
         tm_source,
         tc_receiver.clone(),
+        ConnectionFinishedHandler::default(),
         None,
     )
     .expect("TCP server generation failed");
@@ -107,13 +137,20 @@ fn test_cobs_server() {
 
     // Call the connection handler in separate thread, does block.
     thread::spawn(move || {
-        let result = tcp_server.handle_next_connection();
+        let result = tcp_server.handle_next_connection(Some(Duration::from_millis(400)));
         if result.is_err() {
             panic!("handling connection failed: {:?}", result.unwrap_err());
         }
         let conn_result = result.unwrap();
-        assert_eq!(conn_result.num_received_tcs, 1, "No TC received");
+        assert_eq!(conn_result, ConnectionResult::HandledConnections(1));
-        assert_eq!(conn_result.num_sent_tms, 1, "No TM received");
+        tcp_server
+            .generic_server
+            .finished_handler
+            .check_last_connection(1, 1);
+        tcp_server
+            .generic_server
+            .finished_handler
+            .check_no_connections_left();
         // Signal the main thread we are done.
         set_if_done.store(true, Ordering::Relaxed);
     });
@@ -180,6 +217,7 @@ fn test_ccsds_server() {
         tm_source,
         tc_receiver.clone(),
         packet_id_lookup,
+        ConnectionFinishedHandler::default(),
         None,
     )
     .expect("TCP server generation failed");
@@ -190,13 +228,20 @@ fn test_ccsds_server() {
     let set_if_done = conn_handled.clone();
     // Call the connection handler in separate thread, does block.
     thread::spawn(move || {
-        let result = tcp_server.handle_next_connection();
+        let result = tcp_server.handle_next_connection(Some(Duration::from_millis(500)));
         if result.is_err() {
             panic!("handling connection failed: {:?}", result.unwrap_err());
         }
         let conn_result = result.unwrap();
-        assert_eq!(conn_result.num_received_tcs, 1);
+        assert_eq!(conn_result, ConnectionResult::HandledConnections(1));
-        assert_eq!(conn_result.num_sent_tms, 1);
+        tcp_server
+            .generic_server
+            .finished_handler
+            .check_last_connection(1, 1);
+        tcp_server
+            .generic_server
+            .finished_handler
+            .check_no_connections_left();
         set_if_done.store(true, Ordering::Relaxed);
     });
     let mut stream = TcpStream::connect(dest_addr).expect("connecting to TCP server failed");