Rust #325: describe parents with several open children

.github/workflows/server-parity.yml

@@ -64,6 +64,7 @@ on:
       - tests/Unit/ServerParityLargeCommandBatchesContractTest.mjs
       - tests/Unit/ServerParityManyUpdatesContractTest.mjs
       - tests/Unit/ServerParityWorkerErrorBodiesContractTest.mjs
+      - tests/Unit/ServerParityChildDescriptionsContractTest.mjs
       - tests/Unit/ServerParityStartSearchAttributesContractTest.mjs
       - tests/Unit/ServerParityQueryArgumentsContractTest.mjs
       - tests/Unit/ServerParityQueryContractArgumentsContractTest.mjs
@@ -1990,7 +1991,7 @@ jobs:
           bash scripts/ci/run-composer.sh --rm -v "$PWD:/source" -w /source -- \
             install --working-dir=scripts/conformance/server-parity --no-interaction --no-progress
           docker run --rm --user=1000:1000 --entrypoint node -v "$PWD:/source:ro" -w /source \
-            "$image" --test tests/Unit/ServerParityRunnerTest.mjs tests/Unit/ServerParityRunnerBlockedExcerptTest.mjs tests/Unit/ServerParityProbeNotesTest.mjs tests/Unit/ServerParitySdkDirectionLanesTest.mjs tests/Unit/ServerParityCodecDeadlineCellsTest.mjs tests/Unit/ServerParityCooperativeContractTest.mjs tests/Unit/ServerParityChildCancellationContractTest.mjs tests/Unit/ServerParityScheduleContractTest.mjs tests/Unit/ServerParityVisibilityContractTest.mjs tests/Unit/ServerParityAdmissionContractTest.mjs tests/Unit/ServerParityRoleTokenContractTest.mjs tests/Unit/ServerParityWorkerDeregistrationContractTest.mjs tests/Unit/ServerParitySearchAttributeContractTest.mjs tests/Unit/ServerParityWorkerListingContractTest.mjs tests/Unit/ServerParityWorkerReplacementContractTest.mjs tests/Unit/ServerParityPatchDeploymentContractTest.mjs tests/Unit/ServerParityWaitingHistoryContractTest.mjs tests/Unit/ServerParityTaskRetryContractTest.mjs tests/Unit/ServerParityPublishedPatchContractTest.mjs tests/Unit/ServerParityPublishedPatchTransportTest.mjs tests/Unit/ServerParityRecordFileTest.mjs tests/Unit/ServerParityFailureLocationTest.mjs tests/Unit/ServerParityFailureExcerptTest.mjs tests/Unit/ServerParityLateWorkflowCompletionContractTest.mjs tests/Unit/ServerParityStorageTestContractTest.mjs tests/Unit/ServerParitySchedulePoliciesContractTest.mjs tests/Unit/ServerParitySignalsBeforeWorkerContractTest.mjs tests/Unit/ServerParityScheduleCatalogContractTest.mjs tests/Unit/ServerParityOperatorMetricsContractTest.mjs tests/Unit/ServerParityActivityLeaseRenewalContractTest.mjs tests/Unit/ServerParityConcurrentWaitsContractTest.mjs tests/Unit/ServerParityContinueTransfersContractTest.mjs tests/Unit/ServerParityWorkerErrorBodiesContractTest.mjs tests/Unit/ServerParityLargeCommandBatchesContractTest.mjs tests/Unit/ServerParityManyUpdatesContractTest.mjs tests/Unit/ServerParityStartSearchAttributesContractTest.mjs tests/Unit/ServerParityQueryArgumentsContractTest.mjs tests/Unit/ServerParityQueryContractArgumentsContractTest.mjs tests/Unit/ServerParityParentCloseCancellationContractTest.mjs tests/Unit/ServerParityRecordLocalActivityContractTest.mjs tests/Unit/ServerParityActivityCancellationAckContractTest.mjs tests/Unit/ServerParityServiceCatalogContractTest.mjs tests/Unit/ServerParityServiceEndpointsContractTest.mjs tests/Unit/ServerParityServiceCallsContractTest.mjs tests/Unit/ServerParityWorkflowImportContractTest.mjs tests/Unit/ServerParityWaterlineImportContractTest.mjs tests/Unit/ServerParitySystemMetricsContractTest.mjs tests/Unit/ServerParityOperatorDashboardTypesContractTest.mjs tests/Unit/ServerParityPrometheusMetricsContractTest.mjs tests/Unit/ServerParityPayloadCleanupContractTest.mjs tests/Unit/ServerParityRepairPassContractTest.mjs tests/Unit/ServerParityClusterInfoContractTest.mjs tests/Unit/ServerParityNamespaceDeleteContractTest.mjs tests/Unit/ServerParityMessageStreamsContractTest.mjs tests/Unit/ServerParityCancellationScopesContractTest.mjs tests/Unit/ServerParityWorkflowPollRequestContractTest.mjs tests/Unit/ServerParityUpdateValidationContractTest.mjs tests/Unit/ServerParityFixtureSelectionTest.mjs tests/Unit/ServerParityUpdateValidationRetryTest.mjs tests/Unit/ServerParityKilledAuthorPollTest.mjs tests/Unit/ServerParityImagePullTest.mjs tests/Unit/ServerParityAdapterCacheTest.mjs tests/Unit/ServerParityWorkerSessionsContractTest.mjs tests/Unit/ServerParityWorkerSessionActivitiesContractTest.mjs tests/Unit/ServerParityNexusOperationsContractTest.mjs tests/Unit/ServerParityBridgeAdaptersContractTest.mjs tests/Unit/ServerParityWorkflowStreamWritesContractTest.mjs > parity-evidence/comparator-tests.txt
+            "$image" --test tests/Unit/ServerParityRunnerTest.mjs tests/Unit/ServerParityRunnerBlockedExcerptTest.mjs tests/Unit/ServerParityProbeNotesTest.mjs tests/Unit/ServerParitySdkDirectionLanesTest.mjs tests/Unit/ServerParityCodecDeadlineCellsTest.mjs tests/Unit/ServerParityCooperativeContractTest.mjs tests/Unit/ServerParityChildCancellationContractTest.mjs tests/Unit/ServerParityScheduleContractTest.mjs tests/Unit/ServerParityVisibilityContractTest.mjs tests/Unit/ServerParityAdmissionContractTest.mjs tests/Unit/ServerParityRoleTokenContractTest.mjs tests/Unit/ServerParityWorkerDeregistrationContractTest.mjs tests/Unit/ServerParitySearchAttributeContractTest.mjs tests/Unit/ServerParityWorkerListingContractTest.mjs tests/Unit/ServerParityWorkerReplacementContractTest.mjs tests/Unit/ServerParityPatchDeploymentContractTest.mjs tests/Unit/ServerParityWaitingHistoryContractTest.mjs tests/Unit/ServerParityTaskRetryContractTest.mjs tests/Unit/ServerParityPublishedPatchContractTest.mjs tests/Unit/ServerParityPublishedPatchTransportTest.mjs tests/Unit/ServerParityRecordFileTest.mjs tests/Unit/ServerParityFailureLocationTest.mjs tests/Unit/ServerParityFailureExcerptTest.mjs tests/Unit/ServerParityLateWorkflowCompletionContractTest.mjs tests/Unit/ServerParityStorageTestContractTest.mjs tests/Unit/ServerParitySchedulePoliciesContractTest.mjs tests/Unit/ServerParitySignalsBeforeWorkerContractTest.mjs tests/Unit/ServerParityScheduleCatalogContractTest.mjs tests/Unit/ServerParityOperatorMetricsContractTest.mjs tests/Unit/ServerParityActivityLeaseRenewalContractTest.mjs tests/Unit/ServerParityConcurrentWaitsContractTest.mjs tests/Unit/ServerParityContinueTransfersContractTest.mjs tests/Unit/ServerParityChildDescriptionsContractTest.mjs tests/Unit/ServerParityWorkerErrorBodiesContractTest.mjs tests/Unit/ServerParityLargeCommandBatchesContractTest.mjs tests/Unit/ServerParityManyUpdatesContractTest.mjs tests/Unit/ServerParityStartSearchAttributesContractTest.mjs tests/Unit/ServerParityQueryArgumentsContractTest.mjs tests/Unit/ServerParityQueryContractArgumentsContractTest.mjs tests/Unit/ServerParityParentCloseCancellationContractTest.mjs tests/Unit/ServerParityRecordLocalActivityContractTest.mjs tests/Unit/ServerParityActivityCancellationAckContractTest.mjs tests/Unit/ServerParityServiceCatalogContractTest.mjs tests/Unit/ServerParityServiceEndpointsContractTest.mjs tests/Unit/ServerParityServiceCallsContractTest.mjs tests/Unit/ServerParityWorkflowImportContractTest.mjs tests/Unit/ServerParityWaterlineImportContractTest.mjs tests/Unit/ServerParitySystemMetricsContractTest.mjs tests/Unit/ServerParityOperatorDashboardTypesContractTest.mjs tests/Unit/ServerParityPrometheusMetricsContractTest.mjs tests/Unit/ServerParityPayloadCleanupContractTest.mjs tests/Unit/ServerParityRepairPassContractTest.mjs tests/Unit/ServerParityClusterInfoContractTest.mjs tests/Unit/ServerParityNamespaceDeleteContractTest.mjs tests/Unit/ServerParityMessageStreamsContractTest.mjs tests/Unit/ServerParityCancellationScopesContractTest.mjs tests/Unit/ServerParityWorkflowPollRequestContractTest.mjs tests/Unit/ServerParityUpdateValidationContractTest.mjs tests/Unit/ServerParityFixtureSelectionTest.mjs tests/Unit/ServerParityUpdateValidationRetryTest.mjs tests/Unit/ServerParityKilledAuthorPollTest.mjs tests/Unit/ServerParityImagePullTest.mjs tests/Unit/ServerParityAdapterCacheTest.mjs tests/Unit/ServerParityWorkerSessionsContractTest.mjs tests/Unit/ServerParityWorkerSessionActivitiesContractTest.mjs tests/Unit/ServerParityNexusOperationsContractTest.mjs tests/Unit/ServerParityBridgeAdaptersContractTest.mjs tests/Unit/ServerParityWorkflowStreamWritesContractTest.mjs > parity-evidence/comparator-tests.txt
           docker run --rm --user=1000:1000 --cpus=1 --memory=256m --memory-swap=256m \
             --network=none --entrypoint node -v "$PWD:/source:ro" -w /source \
             "$image" --test tests/Unit/ServerParityCodecDeadlineLoadTest.mjs > parity-evidence/codec-load-tests.txt

docs/rust-server-port-checkpoints/2026-10-29-child-descriptions.md

@@ -0,0 +1,30 @@
+# October 29, descriptions with several open children
+
+- **Before.** Native's child summary (`child_summary.rs`), which describes a
+  parent waiting on children, gave up when:
+  - a second child was open while another was still waiting;
+  - a child's `parent_close_policy` was not `abandon`;
+  - more than 100 children had been started over the run's life;
+  - a timer wait was also open.
+
+  The parent was then described with no wait (`wait_kind` null).
+- **Contract** (published 2.11.5; `WorkflowController::show`, Workflow
+  2.15.1 `RunWaitView`): a parent is described by its open waits. With
+  several open children it waits for the first. An open timer is described
+  ahead of open children, whichever was scheduled first. The parent-close
+  policy does not change the description.
+- **Fixture.** `child-descriptions`, raw worker HTTP on protocol 1.20 in a
+  fresh namespace. Each case completes the parent's first workflow task with
+  its commands and records the answer and the description: one child, two
+  children, a child then a timer, a timer then a child, and a child under
+  `parent_close_policy: terminate`.
+- **Native.**
+  - The summary keeps any number of open children, with no lifetime cap.
+  - Any parent-close policy is allowed.
+  - When a timer wait is already chosen and every child is still open, the
+    timer stays the run's wait.
+- **Not covered here.** A child with a cancellation policy other than
+  `abandon` or with a retry or timeout policy, and a child beside an open
+  activity, are still described without their wait, pending evidence.
+- **Tests.** `child_descriptions.rs`. On the previous source, two children
+  and a child beside a timer were described with a null wait.

docs/rust-server-port.md

@@ -586,8 +586,18 @@ contract fixture before its correction.
   `many-updates` fixture records a run waiting for a signal through 65
   completed updates, then a 66th left accepted, against published 2.11.5
   ([checkpoint](rust-server-port-checkpoints/2026-10-29-many-updates.md)).
-  The child summary still stops at 100 children over a run's life; that
-  needs its own fixture.
+- **Descriptions with several open children** (October 29, closed).
+  Published PHP describes a parent by its open waits however many children
+  it holds: the first open child, or an open timer ahead of open children,
+  under any parent-close policy. Native's child summary allowed one waiting
+  child at a time, only the `abandon` parent-close policy, at most 100
+  children over a run's life, and no timer beside a child. Such a parent
+  was described with no wait. The `child-descriptions` fixture records five
+  cases against published 2.11.5
+  ([checkpoint](rust-server-port-checkpoints/2026-10-29-child-descriptions.md)).
+  A child with a cancellation policy other than `abandon`, a retry or
+  timeout policy, or beside an open activity is still described without
+  its wait, pending its own evidence.
 - **Trace context (Core 2.10, published in Server 2.11.1).** Core adds
   nullable `observability_context` columns on runs, commands and tasks.
   Native has no carrier: it accepts and ignores a top-level carrier on

rust/src/runtime/child_summary.rs

@@ -1,4 +1,5 @@
-//! Sequential child liveness requires original typed identity and retained waits.
+//! Child liveness requires original typed identity and retained waits. A run
+//! may hold any number of open children, each under any parent-close policy.
 use super::{
     Result,
     active_summary::{ActiveSummary, SummaryWait},
@@ -33,13 +34,10 @@ impl ChildSummaryHistory {
             return false;
         };
         if event == "ChildWorkflowScheduled" {
-            if self.calls.len() >= 100
-                || self.calls.contains_key(&sequence)
-                || self
-                    .calls
-                    .values()
-                    .any(|child| child.status == "waiting" || child.id == identity.id)
-                || payload["parent_close_policy"] != "abandon"
+            // Any number of children may be open at once, and the parent-close
+            // policy only decides what happens when the parent closes.
+            if self.calls.contains_key(&sequence)
+                || self.calls.values().any(|child| child.id == identity.id)
                 || payload["cancellation_policy"] != "abandon"
                 || !payload["retry_policy"].is_null()
                 || !payload["timeout_policy"].is_null()
@@ -152,9 +150,9 @@ where
         history: &ChildSummaryHistory,
         summary: &mut ActiveSummary,
     ) -> Result<bool> {
-        let rows = Self::query("SELECT w.*,c.status AS call_status,c.resolved_child_run_id,c.resolved_child_instance_id,c.child_workflow_type,c.metadata AS call_metadata,l.id AS link_id,l.child_workflow_run_id AS link_run,l.child_workflow_instance_id AS link_instance FROM workflow_run_waits w LEFT JOIN workflow_child_calls c ON c.parent_workflow_run_id=w.workflow_run_id AND c.sequence=w.sequence LEFT JOIN workflow_links l ON l.parent_workflow_run_id=w.workflow_run_id AND l.sequence=w.sequence AND l.link_type='child_workflow' WHERE w.workflow_run_id=$1 AND w.kind='child' ORDER BY w.sequence LIMIT 101")
+        let rows = Self::query("SELECT w.*,c.status AS call_status,c.resolved_child_run_id,c.resolved_child_instance_id,c.child_workflow_type,c.metadata AS call_metadata,l.id AS link_id,l.child_workflow_run_id AS link_run,l.child_workflow_instance_id AS link_instance FROM workflow_run_waits w LEFT JOIN workflow_child_calls c ON c.parent_workflow_run_id=w.workflow_run_id AND c.sequence=w.sequence LEFT JOIN workflow_links l ON l.parent_workflow_run_id=w.workflow_run_id AND l.sequence=w.sequence AND l.link_type='child_workflow' WHERE w.workflow_run_id=$1 AND w.kind='child' ORDER BY w.sequence")
             .bind(run_id).fetch_all(&mut **tx).await?;
-        if rows.len() != history.calls.len() || rows.len() > 100 {
+        if rows.len() != history.calls.len() {
             return Ok(false);
         }
         for row in &rows {
@@ -171,7 +169,16 @@ where
         if rows.is_empty() {
             return Ok(true);
         }
-        // Other wait families retain their separately qualified precedence.
+        // An open timer wait describes the run ahead of open children, as
+        // PHP's run description does. Other wait families, and a resolved
+        // child beside a timer, retain their separately qualified precedence.
+        let all_open = rows.iter().all(|row| DB::string(row, "status").is_ok_and(|status| status == "open"));
+        if summary.wait.as_ref().is_some_and(|wait| wait.kind == "timer")
+            && all_open
+            && summary.task_type.as_deref().is_none_or(|kind| kind == "timer")
+        {
+            return Ok(true);
+        }
         if summary
             .wait
             .as_ref()

rust/tests/execution.rs

@@ -352,6 +352,8 @@ mod close_inventory;
 mod start_search_attributes;
 #[path = "execution/worker_error_bodies.rs"]
 mod worker_error_bodies;
+#[path = "execution/child_descriptions.rs"]
+mod child_descriptions;
 
 enum TestDatabase {
     Sqlite(tempfile::TempDir),

rust/tests/execution/child_descriptions.rs

@@ -0,0 +1,42 @@
+use super::*;
+
+// Published Server 2.11.5 describes a parent by its open waits however many
+// children it holds: the first open child, or an open timer ahead of open
+// children, under any parent-close policy. The child-descriptions fixture
+// records the same cases.
+
+fn child(policy: Option<&str>) -> Value {
+    let mut command = json!({"type":"start_child_workflow","workflow_type":"echo","arguments":envelope(Payload::Array(vec![]))});
+    if let Some(policy) = policy {
+        command["parent_close_policy"] = json!(policy);
+    }
+    command
+}
+
+#[tokio::test]
+async fn a_parent_is_described_by_its_waits_with_several_children() {
+    let timer = json!({"type":"start_timer","delay_seconds":3600});
+    let child_wait = (json!("child"), json!("Waiting for child workflow echo"));
+    let timer_wait = (json!("timer"), json!("Waiting for timer"));
+    for (id, commands, expected) in [
+        ("one-child", json!([child(None)]), child_wait.clone()),
+        ("two-children", json!([child(None), child(None)]), child_wait.clone()),
+        ("child-then-timer", json!([child(None), timer.clone()]), timer_wait.clone()),
+        ("timer-then-child", json!([timer.clone(), child(None)]), timer_wait.clone()),
+        ("terminating-child", json!([child(Some("terminate"))]), child_wait.clone()),
+    ] {
+        let database = TestDatabase::new().await;
+        let runtime = database.open().await.unwrap();
+        let app = router(runtime.clone());
+        register(&app, "worker", json!(["echo"]), json!([])).await;
+        start(&app, id).await;
+        let task = poll(&app, "worker", "workflow").await;
+        let (status, body) = finish_task(&app, &task, commands).await;
+        assert_eq!(status, StatusCode::OK, "{id}: {body}");
+        let (_, described) = request(&app, "GET", &format!("/api/workflows/{id}"), Value::Null).await;
+        assert_eq!(described["status"], "waiting", "{id}: {described}");
+        assert_eq!((described["wait_kind"].clone(), described["wait_reason"].clone()), expected, "{id}: {described}");
+        runtime.close().await;
+        database.remove().await;
+    }
+}

scripts/conformance/server-parity/child-descriptions-contract.mjs

@@ -0,0 +1,23 @@
+import assert from 'node:assert/strict';
+
+// Reviewed parent descriptions while children are open
+// (child-descriptions-probe.php), recorded against published Server 2.11.5.
+// The fixture's `expected` holds the whole observation.
+export function checkChildDescriptions(fixture, observation) {
+  const definition = fixture.child_descriptions;
+  const state = observation.child_descriptions;
+  const projection = {scope: 'child_descriptions', cases: Object.keys(definition.cases).length};
+  assert.ok(state && typeof state === 'object', 'actual child descriptions observation');
+  if (observation.mode === 'embedded') {
+    assert.deepStrictEqual(state, {applicable: false, reason: 'embedded_has_no_worker_protocol'},
+      'embedded child descriptions explicitly inapplicable');
+    return projection;
+  }
+  assert.equal(state.applicable, true, 'HTTP targets record child descriptions');
+  for (const [run, expected] of Object.entries(definition.expected)) {
+    assert.deepStrictEqual(state[run], expected, `child descriptions ${run}`);
+  }
+  assert.deepStrictEqual(Object.keys(state).sort(), ['applicable', ...Object.keys(definition.expected)].sort(),
+    'child descriptions cases');
+  return projection;
+}