crates/irtt-client/src/client.rs

@@ -60,6 +60,7 @@ struct ClientTestHooks {
     fail_close_send: Cell<bool>,
     close_reported_len: Cell<Option<usize>>,
     close_send_attempts: Cell<usize>,
+    close_sent_at: Cell<Option<ClientTimestamp>>,
     fail_cleanup_send: Cell<bool>,
     recv_buffer_len_override: Cell<Option<usize>>,
     fail_dscp_restore: Cell<bool>,
@@ -199,7 +200,15 @@ impl Client {
                 return Err(ClientError::Socket(err));
             }
         };
-        let event = self.runtime.commit_local_close(prepared.commit);
+        #[cfg(not(test))]
+        let sent_at = ClientTimestamp::now();
+        #[cfg(test)]
+        let sent_at = self
+            .test_hooks
+            .close_sent_at
+            .take()
+            .unwrap_or_else(ClientTimestamp::now);
+        let event = self.runtime.commit_local_close(prepared.commit, sent_at);
         self.schedule = None;
         self.applied_dscp = None;
 

crates/irtt-client/src/client/tests/close.rs

@@ -29,10 +29,19 @@ fn close_sends_one_close_packet_with_negotiated_token() {
     });
     let mut client = Client::connect(default_test_config(server.addr)).unwrap();
     assert_open_started(client.open().unwrap());
+    let sent_at = ClientTimestamp {
+        wall: SystemTime::UNIX_EPOCH + Duration::from_secs(1_234),
+        mono: Instant::now() + Duration::from_secs(5),
+    };
+    client.test_hooks.close_sent_at.set(Some(sent_at));
     let events = client.close().unwrap();
     assert!(matches!(
         events.as_slice(),
-        [ClientEvent::SessionClosed { token: TOKEN, .. }]
+        [ClientEvent::SessionClosed {
+            token: TOKEN,
+            at,
+            ..
+        }] if *at == sent_at
     ));
     assert!(!client.runtime.is_open());
     assert!(client.schedule.is_none());
@@ -127,9 +136,15 @@ fn close_send_failure_leaves_machine_and_schedule_open_for_retry() {
     });
     let mut client = Client::connect(default_test_config(server.addr)).unwrap();
     assert_open_started(client.open().unwrap());
+    let sent_at = ClientTimestamp {
+        wall: SystemTime::UNIX_EPOCH + Duration::from_secs(2_345),
+        mono: Instant::now() + Duration::from_secs(6),
+    };
+    client.test_hooks.close_sent_at.set(Some(sent_at));
     client.test_hooks.fail_close_send.set(true);
 
     assert!(matches!(client.close(), Err(ClientError::Socket(_))));
+    assert_eq!(client.test_hooks.close_sent_at.get(), Some(sent_at));
     assert!(client.runtime.is_open());
     assert!(client.schedule.is_some());
     assert_eq!(client.applied_dscp, Some(0));
@@ -137,8 +152,13 @@ fn close_send_failure_leaves_machine_and_schedule_open_for_retry() {
 
     assert!(matches!(
         client.close().unwrap().as_slice(),
-        [ClientEvent::SessionClosed { token: TOKEN, .. }]
+        [ClientEvent::SessionClosed {
+            token: TOKEN,
+            at,
+            ..
+        }] if *at == sent_at
     ));
+    assert_eq!(client.test_hooks.close_sent_at.get(), None);
     assert_eq!(client.test_hooks.close_send_attempts.get(), 2);
     assert!(matches!(client.close(), Err(ClientError::AlreadyClosed)));
     server.join();
@@ -160,6 +180,11 @@ fn short_successful_close_commits_before_length_mismatch() {
     let mut client = Client::connect(default_test_config(server.addr)).unwrap();
     assert_open_started(client.open().unwrap());
     let expected = client.runtime.prepare_close().unwrap().bytes.len();
+    let sent_at = ClientTimestamp {
+        wall: SystemTime::UNIX_EPOCH + Duration::from_secs(3_456),
+        mono: Instant::now() + Duration::from_secs(7),
+    };
+    client.test_hooks.close_sent_at.set(Some(sent_at));
     client.test_hooks.close_reported_len.set(Some(expected - 1));
 
     assert!(matches!(
@@ -172,6 +197,7 @@ fn short_successful_close_commits_before_length_mismatch() {
     assert!(!client.runtime.is_open());
     assert!(client.schedule.is_none());
     assert_eq!(client.applied_dscp, None);
+    assert_eq!(client.test_hooks.close_sent_at.get(), None);
     assert!(matches!(client.close(), Err(ClientError::AlreadyClosed)));
     server.join();
 }

crates/irtt-client/src/managed/group.rs

@@ -733,6 +733,8 @@ struct TargetState {
     close_send_attempts: usize,
     #[cfg(test)]
     close_event_reserve_error: bool,
+    #[cfg(test)]
+    close_sent_at: Option<ClientTimestamp>,
 }
 
 type ScheduledTarget = (Arc<Mutex<TargetState>>, Instant);
@@ -855,6 +857,8 @@ impl TargetState {
             close_send_attempts: 0,
             #[cfg(test)]
             close_event_reserve_error: false,
+            #[cfg(test)]
+            close_sent_at: None,
         })
     }
 
@@ -1872,7 +1876,14 @@ fn close_locked_target(
                 return;
             }
         };
-        let event = target.runtime.commit_local_close(prepared.commit);
+        #[cfg(not(test))]
+        let sent_at = ClientTimestamp::now();
+        #[cfg(test)]
+        let sent_at = target
+            .close_sent_at
+            .take()
+            .unwrap_or_else(ClientTimestamp::now);
+        let event = target.runtime.commit_local_close(prepared.commit, sent_at);
         target.schedule = None;
         #[cfg(test)]
         let bytes = reported_bytes.unwrap_or(bytes);
@@ -3046,8 +3057,13 @@ mod tests {
         let fixture = active_target_fixture_at(peer.local_addr().unwrap());
         let socket = UdpSocket::bind("127.0.0.1:0").unwrap();
 
+        let sent_at = ClientTimestamp {
+            wall: std::time::SystemTime::UNIX_EPOCH + Duration::from_secs(4_567),
+            mono: Instant::now() + Duration::from_secs(8),
+        };
         {
             let mut target = fixture.target.lock().expect("target mutex poisoned");
+            target.close_sent_at = Some(sent_at);
             close_locked_target(
                 &socket,
                 &fixture.hub,
@@ -3069,19 +3085,20 @@ mod tests {
         assert_eq!(u64::from_le_bytes(packet[4..12].try_into().unwrap()), TOKEN);
         assert_eq!(len, 12);
         let events = drain_available_group_events(&fixture.subscription);
-        assert_eq!(
+        let closes: Vec<_> = events
-            events
+            .iter()
-                .iter()
+            .filter_map(|event| match event {
-                .filter(|event| matches!(
+                ManagedGroupEvent::Client(TargetEvent {
-                    event,
+                    event:
-                    ManagedGroupEvent::Client(TargetEvent {
+                        ClientEvent::SessionClosed {
-                        event: ClientEvent::SessionClosed { token: TOKEN, .. },
+                            token: TOKEN, at, ..
-                        ..
+                        },
-                    })
+                    ..
-                ))
+                }) => Some(*at),
-                .count(),
+                _ => None,
-            1
+            })
-        );
+            .collect();
+        assert_eq!(closes, [sent_at]);
     }
 
     #[test]
@@ -3127,8 +3144,13 @@ mod tests {
         let fixture = active_target_fixture_at(peer.local_addr().unwrap());
         let socket = UdpSocket::bind("127.0.0.1:0").unwrap();
 
+        let sent_at = ClientTimestamp {
+            wall: std::time::SystemTime::UNIX_EPOCH + Duration::from_secs(5_678),
+            mono: Instant::now() + Duration::from_secs(9),
+        };
         {
             let mut target = fixture.target.lock().expect("target mutex poisoned");
+            target.close_sent_at = Some(sent_at);
             target.close_send_error = true;
             close_locked_target(
                 &socket,
@@ -3139,6 +3161,7 @@ mod tests {
             assert!(target.runtime.is_open());
             assert!(target.schedule.is_some());
             assert_eq!(target.close_send_attempts, 1);
+            assert_eq!(target.close_sent_at, Some(sent_at));
             assert!(matches!(
                 target.final_reason,
                 Some(ManagedTargetEndReason::Failed(_))
@@ -3169,9 +3192,14 @@ mod tests {
         let fixture = active_target_fixture_at(peer.local_addr().unwrap());
         let socket = UdpSocket::bind("127.0.0.1:0").unwrap();
 
+        let sent_at = ClientTimestamp {
+            wall: std::time::SystemTime::UNIX_EPOCH + Duration::from_secs(6_789),
+            mono: Instant::now() + Duration::from_secs(10),
+        };
         {
             let mut target = fixture.target.lock().expect("target mutex poisoned");
             let expected = target.runtime.prepare_close().unwrap().bytes.len();
+            target.close_sent_at = Some(sent_at);
             target.close_reported_len = Some(expected - 1);
             close_locked_target(
                 &socket,
@@ -3182,6 +3210,7 @@ mod tests {
             assert!(!target.runtime.is_open());
             assert!(target.schedule.is_none());
             assert_eq!(target.close_send_attempts, 1);
+            assert_eq!(target.close_sent_at, None);
             let failure = target
                 .final_reason
                 .as_ref()

crates/irtt-client/src/session/machine.rs

@@ -115,7 +115,7 @@ pub(crate) struct PreparedClose<'a> {
 #[derive(Debug)]
 pub(crate) struct CloseCommit {
     packets_sent: u64,
-    event: ClientEvent,
+    token: u64,
 }
 
 #[derive(Debug)]
@@ -425,16 +425,16 @@ impl SessionMachine {
             bytes: &session.local_close_packet,
             commit: CloseCommit {
                 packets_sent: session.packets_sent,
-                event: ClientEvent::SessionClosed {
+                token: session.token,
-                    remote: self.remote,
-                    token: session.token,
-                    at: ClientTimestamp::now(),
-                },
             },
         })
     }
 
-    pub(crate) fn commit_local_close(&mut self, commit: CloseCommit) -> ClientEvent {
+    pub(crate) fn commit_local_close(
+        &mut self,
+        commit: CloseCommit,
+        sent_at: ClientTimestamp,
+    ) -> ClientEvent {
         debug_assert!(
             matches!(self.state, MachineState::Open(_)),
             "local close commits only from open state"
@@ -443,7 +443,11 @@ impl SessionMachine {
             source: CloseSource::Local,
             packets_sent: commit.packets_sent,
         };
-        commit.event
+        ClientEvent::SessionClosed {
+            remote: self.remote,
+            token: commit.token,
+            at: sent_at,
+        }
     }
 
     pub(crate) fn pending_is_empty(&self) -> bool {
@@ -1370,9 +1374,8 @@ mod tests {
     }
 
     #[test]
-    fn prepared_close_is_stable_inert_and_commits_preserved_state() {
+    fn prepare_close_is_stable_inert_and_does_not_determine_event_timestamp() {
         let mut machine = open_machine(4, Duration::from_secs(1));
-        let remote = machine.remote;
         active_mut(&mut machine).packets_sent = 7;
 
         let first_bytes = {
@@ -1387,6 +1390,8 @@ mod tests {
                 )
                 .unwrap()
             );
+            assert_eq!(prepared.commit.packets_sent, 7);
+            assert_eq!(prepared.commit.token, 0x0102_0304_0506_0708);
             prepared.bytes.to_vec()
         };
         assert!(machine.is_open());
@@ -1394,15 +1399,31 @@ mod tests {
 
         let prepared = machine.prepare_close().unwrap();
         assert_eq!(prepared.bytes, first_bytes);
-        let event = machine.commit_local_close(prepared.commit);
+        assert_eq!(prepared.commit.packets_sent, 7);
+        assert_eq!(prepared.commit.token, 0x0102_0304_0506_0708);
+        assert!(machine.is_open());
+    }
+
+    #[test]
+    fn local_close_commit_uses_supplied_exact_timestamp() {
+        let mut machine = open_machine(4, Duration::from_secs(1));
+        let remote = machine.remote;
+        active_mut(&mut machine).packets_sent = 7;
+        let prepared = machine.prepare_close().unwrap();
+        let sent_at = ClientTimestamp {
+            wall: UNIX_EPOCH + Duration::from_secs(1_234),
+            mono: Instant::now() + Duration::from_secs(5),
+        };
+        let event = machine.commit_local_close(prepared.commit, sent_at);
 
         assert!(matches!(
             event,
             ClientEvent::SessionClosed {
                 remote: event_remote,
                 token: 0x0102_0304_0506_0708,
-                ..
+                at,
             } if event_remote == remote
+                && at == sent_at
         ));
         assert!(matches!(
             machine.state,