Fix flaky tests

AGENTS.md

@@ -15,6 +15,7 @@ document as your quick reference when submitting pull requests.
 - `tests/` – integration, heavy, and manual tests
 - `arch_docs/` – architectural design documents
 - Contributor guide: `README.md`
+- `target/` - This contains compiled files. You never need to look in here.
 
 ## Repo Specific Utilities
 

core/src/core_tests/workflow_tasks.rs

@@ -2528,7 +2528,7 @@ async fn post_terminal_commands_are_retained_when_not_replaying() {
     ]);
     _do_post_terminal_commands_test(
         commands_sent_by_lang,
-        [ResponseType::ToTaskNum(1), ResponseType::AllHistory],
+        [ResponseType::ToTaskNum(1)],
         expected_command_types_emitted,
         t,
     )
@@ -2602,14 +2602,14 @@ async fn _do_post_terminal_commands_test(
 
     let act = core.poll_workflow_activation().await.unwrap();
 
-    core.initiate_shutdown();
     core.complete_workflow_activation(WorkflowActivationCompletion::from_cmds(
         act.run_id,
         commands_sent_by_lang,
     ))
     .await
     .unwrap();
 
+    core.initiate_shutdown();
     let act = core.poll_workflow_activation().await;
     assert_matches!(act.unwrap_err(), PollError::ShutDown);
     core.shutdown().await;
@@ -2685,10 +2685,6 @@ async fn history_length_with_fail_and_timeout(
     #[values(true, false)] use_cache: bool,
     #[values(1, 2, 3)] history_responses_case: u8,
 ) {
-    if !use_cache && history_responses_case == 3 {
-        /* disabled for now because this keeps flaking*/
-        return;
-    }
     let wfid = "fake_wf_id";
     let mut t = TestHistoryBuilder::default();
     t.add_by_type(EventType::WorkflowExecutionStarted);

core/src/ephemeral_server/mod.rs

@@ -423,7 +423,7 @@ fn get_free_port(bind_ip: &str) -> io::Result<u16> {
     let addr = listen.local_addr()?;
 
     // On Linux and some BSD variants, ephemeral ports are randomized, and may
-    // consequently repeat within a short time frame after the listenning end
+    // consequently repeat within a short time frame after the listening end
     // has been closed. To avoid this, we make a connection to the port, then
     // close that connection from the server's side (this is very important),
     // which puts the connection in TIME_WAIT state for some time (by default,
@@ -622,30 +622,12 @@ fn remove_file_past_ttl(ttl: &Option<Duration>, dest: &PathBuf) -> Result<bool,
 mod tests {
     use super::{get_free_port, remove_file_past_ttl};
     use std::{
-        collections::HashSet,
         env::temp_dir,
         fs::File,
         net::{TcpListener, TcpStream},
         time::{Duration, SystemTime},
     };
 
-    #[test]
-    fn get_free_port_no_double() {
-        let host = "127.0.0.1";
-        let mut port_set = HashSet::new();
-
-        for _ in 0..2000 {
-            let port = get_free_port(host).unwrap();
-            assert!(
-                !port_set.contains(&port),
-                "Port {port} has been assigned more than once"
-            );
-
-            // Add port to the set
-            port_set.insert(port);
-        }
-    }
-
     #[test]
     fn get_free_port_can_bind_immediately() {
         let host = "127.0.0.1";

core/src/test_help/mod.rs

@@ -1068,10 +1068,19 @@ impl WorkerExt for Worker {
                 );
             },
             async {
-                assert_matches!(
-                    self.poll_workflow_activation().await.unwrap_err(),
-                    PollError::ShutDown
-                );
+                loop {
+                    match self.poll_workflow_activation().await {
+                        Err(PollError::ShutDown) => break,
+                        Ok(a) if a.is_only_eviction() => {
+                            self.complete_workflow_activation(WorkflowActivationCompletion::empty(
+                                a.run_id,
+                            ))
+                            .await
+                            .unwrap();
+                        }
+                        o => panic!("Unexpected activation while draining: {o:?}"),
+                    }
+                }
             }
         );
         self.finalize_shutdown().await;

core/src/worker/workflow/mod.rs

@@ -50,7 +50,6 @@ use std::{
     collections::VecDeque,
     fmt::Debug,
     future::Future,
-    mem,
     ops::DerefMut,
     rc::Rc,
     result,
@@ -1100,8 +1099,7 @@ struct BufferedTasks {
     /// current one has been processed).
     query_only_tasks: VecDeque<PermittedWFT>,
     /// These are query-only tasks for the *buffered* wft, if any. They will all be discarded if
-    /// a buffered wft is replaced before being handled. They move to `query_only_tasks` once the
-    /// buffered task is taken.
+    /// a buffered wft is replaced before being handled.
     query_only_tasks_for_buffered: VecDeque<PermittedWFT>,
 }
 
@@ -1136,9 +1134,13 @@ impl BufferedTasks {
         if let Some(q) = self.query_only_tasks.pop_front() {
             return Some(q);
         }
-        if let Some(t) = self.wft.take() {
-            self.query_only_tasks = mem::take(&mut self.query_only_tasks_for_buffered);
-            return Some(t);
+        if self.wft.is_some() {
+            if let Some(q) = self.query_only_tasks_for_buffered.pop_front() {
+                return Some(q);
+            }
+            if let Some(t) = self.wft.take() {
+                return Some(t);
+            }
         }
         None
     }

sdk/src/lib.rs

@@ -109,6 +109,7 @@ use temporal_sdk_core_protos::{
 };
 use tokio::{
     sync::{
+        Notify,
         mpsc::{UnboundedSender, unbounded_channel},
         oneshot,
     },
@@ -151,6 +152,7 @@ struct WorkflowHalf {
     workflows: RefCell<HashMap<String, WorkflowData>>,
     /// Maps workflow type to the function for executing workflow runs with that ID
     workflow_fns: RefCell<HashMap<String, WorkflowFunction>>,
+    workflow_removed_from_map: Notify,
 }
 struct WorkflowData {
     /// Channel used to send the workflow activations
@@ -180,6 +182,7 @@ impl Worker {
             workflow_half: WorkflowHalf {
                 workflows: Default::default(),
                 workflow_fns: Default::default(),
+                workflow_removed_from_map: Default::default(),
             },
             activity_half: ActivityHalf {
                 activity_fns: Default::default(),
@@ -260,6 +263,7 @@ impl Worker {
                             join_handle.await??;
                             debug!(run_id=%run_id, "Removing workflow from cache");
                             wf_half.workflows.borrow_mut().remove(&run_id);
+                            wf_half.workflow_removed_from_map.notify_one();
                             Ok(())
                         }
                     },
@@ -293,12 +297,15 @@ impl Worker {
                     if let Some(ref i) = common.worker_interceptor {
                         i.on_workflow_activation(&activation).await?;
                     }
-                    if let Some(wf_fut) = wf_half.workflow_activation_handler(
-                        common,
-                        shutdown_token.clone(),
-                        activation,
-                        &completions_tx,
-                    )? && wf_future_tx.send(wf_fut).is_err()
+                    if let Some(wf_fut) = wf_half
+                        .workflow_activation_handler(
+                            common,
+                            shutdown_token.clone(),
+                            activation,
+                            &completions_tx,
+                        )
+                        .await?
+                        && wf_future_tx.send(wf_fut).is_err()
                     {
                         panic!("Receive half of completion processor channel cannot be dropped");
                     }
@@ -384,7 +391,7 @@ impl Worker {
 
 impl WorkflowHalf {
     #[allow(clippy::type_complexity)]
-    fn workflow_activation_handler(
+    async fn workflow_activation_handler(
         &self,
         common: &CommonWorker,
         shutdown_token: CancellationToken,
@@ -408,26 +415,29 @@ impl WorkflowHalf {
             _ => None,
         }) {
             let workflow_type = &sw.workflow_type;
-            let wf_fns_borrow = self.workflow_fns.borrow();
-            let Some(wf_function) = wf_fns_borrow.get(workflow_type) else {
-                warn!("Workflow type {workflow_type} not found");
+            let (wff, activations) = {
+                let wf_fns_borrow = self.workflow_fns.borrow();
+
+                let Some(wf_function) = wf_fns_borrow.get(workflow_type) else {
+                    warn!("Workflow type {workflow_type} not found");
+
+                    completions_tx
+                        .send(WorkflowActivationCompletion::fail(
+                            run_id,
+                            format!("Workflow type {workflow_type} not found").into(),
+                            Some(WorkflowTaskFailedCause::WorkflowWorkerUnhandledFailure),
+                        ))
+                        .expect("Completion channel intact");
+                    return Ok(None);
+                };
 
-                completions_tx
-                    .send(WorkflowActivationCompletion::fail(
-                        run_id,
-                        format!("Workflow type {workflow_type} not found").into(),
-                        Some(WorkflowTaskFailedCause::WorkflowWorkerUnhandledFailure),
-                    ))
-                    .expect("Completion channel intact");
-                return Ok(None);
+                wf_function.start_workflow(
+                    common.worker.get_config().namespace.clone(),
+                    common.task_queue.clone(),
+                    std::mem::take(sw),
+                    completions_tx.clone(),
+                )
             };
-
-            let (wff, activations) = wf_function.start_workflow(
-                common.worker.get_config().namespace.clone(),
-                common.task_queue.clone(),
-                std::mem::take(sw),
-                completions_tx.clone(),
-            );
             let jh = tokio::spawn(async move {
                 tokio::select! {
                     r = wff.fuse() => r,
@@ -442,6 +452,17 @@ impl WorkflowHalf {
                 join_handle: jh,
                 run_id: run_id.clone(),
             });
+            loop {
+                // It's possible that we've got a new initialize workflow action before the last
+                // future for this run finished evicting, as a result of how futures might be
+                // interleaved. In that case, just wait until it's not in the map, which should be
+                // a matter of only a few `poll` calls.
+                if self.workflows.borrow_mut().contains_key(&run_id) {
+                    self.workflow_removed_from_map.notified().await;
+                } else {
+                    break;
+                }
+            }
             self.workflows.borrow_mut().insert(
                 run_id.clone(),
                 WorkflowData {
@@ -474,7 +495,8 @@ impl WorkflowHalf {
                 return Ok(None);
             }
 
-            // In all other cases, we want to panic as the runtime could be in an inconsistent state at this point.
+            // In all other cases, we want to error as the runtime could be in an inconsistent state
+            // at this point.
             bail!(
                 "Got activation {:?} for unknown workflow {}",
                 activation,

sdk/src/workflow_future.rs

@@ -177,7 +177,7 @@ impl WorkflowFuture {
         &mut self,
         variant: Option<Variant>,
         outgoing_cmds: &mut Vec<WorkflowCommand>,
-    ) -> Result<bool, Error> {
+    ) -> Result<(), Error> {
         if let Some(v) = variant {
             match v {
                 Variant::InitializeWorkflow(_) => {
@@ -326,17 +326,14 @@ impl WorkflowFuture {
                     ))?
                 }
                 Variant::RemoveFromCache(_) => {
-                    // TODO: Need to abort any user-spawned tasks, etc. See also cancel WF.
-                    //   How best to do this in executor agnostic way? Is that possible?
-                    //  -- tokio JoinSet does this in a nice way.
-                    return Ok(true);
+                    unreachable!("Cache removal should happen higher up");
                 }
             }
         } else {
             bail!("Empty activation job variant");
         }
 
-        Ok(false)
+        Ok(())
     }
 }
 
@@ -370,7 +367,6 @@ impl Future for WorkflowFuture {
                     .map(Into::into);
             }
 
-            let mut die_of_eviction_when_done = false;
             let mut activation_cmds = vec![];
             // Lame hack to avoid hitting "unregistered" update handlers in a situation where
             // the history has no commands until an update is accepted. Will go away w/ SDK redesign
@@ -391,19 +387,6 @@ impl Future for WorkflowFuture {
                 }
             }
 
-            for WorkflowActivationJob { variant } in activation.jobs {
-                match self.handle_job(variant, &mut activation_cmds) {
-                    Ok(true) => {
-                        die_of_eviction_when_done = true;
-                    }
-                    Err(e) => {
-                        self.fail_wft(run_id, e);
-                        continue 'activations;
-                    }
-                    _ => (),
-                }
-            }
-
             if is_only_eviction {
                 // No need to do anything with the workflow code in this case
                 self.outgoing_completions
@@ -412,6 +395,13 @@ impl Future for WorkflowFuture {
                 return Ok(WfExitValue::Evicted).into();
             }
 
+            for WorkflowActivationJob { variant } in activation.jobs {
+                if let Err(e) = self.handle_job(variant, &mut activation_cmds) {
+                    self.fail_wft(run_id, e);
+                    continue 'activations;
+                }
+            }
+
             // Drive update functions
             self.update_futures = std::mem::take(&mut self.update_futures)
                 .into_iter()
@@ -450,10 +440,6 @@ impl Future for WorkflowFuture {
 
             self.send_completion(run_id, activation_cmds);
 
-            if die_of_eviction_when_done {
-                return Ok(WfExitValue::Evicted).into();
-            }
-
             // We don't actually return here, since we could be queried after finishing executing,
             // and it allows us to rely on evictions for death and cache management
         }