Set tracing event info before marking request as delivered.

src/workerd/api/hibernatable-web-socket.c++

@@ -184,27 +184,23 @@ HibernatableWebSocketCustomEvent::HibernatableWebSocketCustomEvent(
       params(kj::mv(params)),
       manager(manager) {}
 
-// TODO(cleanup): Try to reduce duplication with consumeParams()
-tracing::EventInfo HibernatableWebSocketCustomEvent::getEventInfo() const {
-  // Try to extract event type from params if available
+// Try to extract event type from params if available
+tracing::HibernatableWebSocketEventInfo::Type HibernatableWebSocketCustomEvent::getEventType()
+    const {
   KJ_SWITCH_ONEOF(params) {
     KJ_CASE_ONEOF(socketParams, HibernatableSocketParams) {
       KJ_SWITCH_ONEOF(socketParams.eventType) {
-        KJ_CASE_ONEOF(text, HibernatableSocketParams::Text) {
-          return tracing::HibernatableWebSocketEventInfo(
-              tracing::HibernatableWebSocketEventInfo::Message());
+        KJ_CASE_ONEOF(_, HibernatableSocketParams::Text) {
+          return tracing::HibernatableWebSocketEventInfo::Message{};
         }
-        KJ_CASE_ONEOF(data, HibernatableSocketParams::Data) {
-          return tracing::HibernatableWebSocketEventInfo(
-              tracing::HibernatableWebSocketEventInfo::Message());
+        KJ_CASE_ONEOF(_, HibernatableSocketParams::Data) {
+          return tracing::HibernatableWebSocketEventInfo::Message{};
         }
         KJ_CASE_ONEOF(close, HibernatableSocketParams::Close) {
-          return tracing::HibernatableWebSocketEventInfo(
-              tracing::HibernatableWebSocketEventInfo::Close{close.code, close.wasClean});
+          return tracing::HibernatableWebSocketEventInfo::Close{close.code, close.wasClean};
         }
-        KJ_CASE_ONEOF(error, HibernatableSocketParams::Error) {
-          return tracing::HibernatableWebSocketEventInfo(
-              tracing::HibernatableWebSocketEventInfo::Error());
+        KJ_CASE_ONEOF(_, HibernatableSocketParams::Error) {
+          return tracing::HibernatableWebSocketEventInfo::Error{};
         }
       }
     }
@@ -214,23 +210,24 @@ tracing::EventInfo HibernatableWebSocketCustomEvent::getEventInfo() const {
       switch (payload.which()) {
         case rpc::HibernatableWebSocketEventMessage::Payload::TEXT:
         case rpc::HibernatableWebSocketEventMessage::Payload::DATA:
-          return tracing::HibernatableWebSocketEventInfo(
-              tracing::HibernatableWebSocketEventInfo::Message());
+          return tracing::HibernatableWebSocketEventInfo::Message{};
         case rpc::HibernatableWebSocketEventMessage::Payload::CLOSE: {
           auto close = payload.getClose();
-          return tracing::HibernatableWebSocketEventInfo(
-              tracing::HibernatableWebSocketEventInfo::Close{close.getCode(), close.getWasClean()});
+          return tracing::HibernatableWebSocketEventInfo::Close{
+            close.getCode(), close.getWasClean()};
         }
         case rpc::HibernatableWebSocketEventMessage::Payload::ERROR:
-          return tracing::HibernatableWebSocketEventInfo(
-              tracing::HibernatableWebSocketEventInfo::Error());
+          return tracing::HibernatableWebSocketEventInfo::Error{};
       }
-      KJ_UNREACHABLE;
     }
   }
   KJ_UNREACHABLE;
 }
 
+tracing::EventInfo HibernatableWebSocketCustomEvent::getEventInfo() const {
+  return tracing::HibernatableWebSocketEventInfo(getEventType());
+}
+
 HibernatableSocketParams HibernatableWebSocketCustomEvent::consumeParams() {
   KJ_IF_SOME(p, params.tryGet<kj::Own<HibernationReader>>()) {
     kj::Maybe<HibernatableSocketParams> eventParameters;

src/workerd/api/hibernatable-web-socket.h

@@ -88,6 +88,9 @@ class HibernatableWebSocketCustomEvent final: public WorkerInterface::CustomEven
   // HibernatableSocketParams first.
   HibernatableSocketParams consumeParams();
 
+  // Peeks at params to extract the event type for tracing, without consuming them.
+  tracing::HibernatableWebSocketEventInfo::Type getEventType() const;
+
   uint16_t typeId;
   kj::OneOf<HibernatableSocketParams, kj::Own<HibernationReader>> params;
   kj::Maybe<uint32_t> timeoutMs;

src/workerd/io/worker-entrypoint.c++

@@ -252,7 +252,6 @@ kj::Promise<void> WorkerEntrypoint::request(kj::HttpMethod method,
   auto incomingRequest =
       kj::mv(KJ_REQUIRE_NONNULL(this->incomingRequest, "request() can only be called once"));
   this->incomingRequest = kj::none;
-  incomingRequest->delivered();
   auto& context = incomingRequest->getContext();
 
   auto wrappedResponse = kj::heap<ResponseSentTracker>(response);
@@ -292,6 +291,8 @@ kj::Promise<void> WorkerEntrypoint::request(kj::HttpMethod method,
     workerTracer = t;
   }
 
+  incomingRequest->delivered();
+
   auto metricsForCatch = kj::addRef(incomingRequest->getMetrics());
   auto metricsForProxyTask = kj::addRef(incomingRequest->getMetrics());
 
@@ -575,7 +576,6 @@ kj::Promise<WorkerInterface::ScheduledResult> WorkerEntrypoint::runScheduled(
   auto incomingRequest =
       kj::mv(KJ_REQUIRE_NONNULL(this->incomingRequest, "runScheduled() can only be called once"));
   this->incomingRequest = kj::none;
-  incomingRequest->delivered();
   auto& context = incomingRequest->getContext();
 
   KJ_ASSERT(context.getActor() == kj::none);
@@ -585,10 +585,12 @@ kj::Promise<WorkerInterface::ScheduledResult> WorkerEntrypoint::runScheduled(
 
   double eventTime = (scheduledTime - kj::UNIX_EPOCH) / kj::MILLISECONDS;
 
-  KJ_IF_SOME(t, context.getWorkerTracer()) {
+  KJ_IF_SOME(t, incomingRequest->getWorkerTracer()) {
     t.setEventInfo(*incomingRequest, tracing::ScheduledEventInfo(eventTime, kj::str(cron)));
   }
 
+  incomingRequest->delivered();
+
   // Scheduled handlers run entirely in waitUntil() tasks.
   context.addWaitUntil(context.run(
       [scheduledTime, cron, entrypointName = entrypointName, props = kj::mv(props), &context,
@@ -642,13 +644,14 @@ kj::Promise<WorkerInterface::AlarmResult> WorkerEntrypoint::runAlarmImpl(
     co_return result;
   }
 
-  // There isn't a pre-existing alarm, we can call `delivered()` (and emit metrics events).
-  incomingRequest->delivered();
-
+  // There isn't a pre-existing alarm, we can set event info and call `delivered()` (which emits
+  // metrics events).
   KJ_IF_SOME(t, incomingRequest->getWorkerTracer()) {
     t.setEventInfo(*incomingRequest, tracing::AlarmEventInfo(scheduledTime));
   }
 
+  incomingRequest->delivered();
+
   auto scheduleAlarmResult = co_await actor.scheduleAlarm(scheduledTime);
   KJ_SWITCH_ONEOF(scheduleAlarmResult) {
     KJ_CASE_ONEOF(af, WorkerInterface::AlarmFulfiller) {
@@ -736,13 +739,13 @@ kj::Promise<bool> WorkerEntrypoint::test() {
   auto incomingRequest =
       kj::mv(KJ_REQUIRE_NONNULL(this->incomingRequest, "test() can only be called once"));
   this->incomingRequest = kj::none;
-  incomingRequest->delivered();
-
   auto& context = incomingRequest->getContext();
-  KJ_IF_SOME(t, context.getWorkerTracer()) {
+  KJ_IF_SOME(t, incomingRequest->getWorkerTracer()) {
     t.setEventInfo(*incomingRequest, tracing::CustomEventInfo());
   }
 
+  incomingRequest->delivered();
+
   context.addWaitUntil(context.run([entrypointName = entrypointName, props = kj::mv(props),
                                        &context, &metrics = incomingRequest->getMetrics()](
                                        Worker::Lock& lock) mutable -> kj::Promise<void> {

src/workerd/io/worker-interface.h

@@ -132,7 +132,6 @@ class WorkerInterface: public kj::HttpService {
     virtual uint16_t getType() = 0;
 
     // Get event info for tracing.
-    // Return none if this event type doesn't need tracing.
     virtual tracing::EventInfo getEventInfo() const = 0;
 
     // If the CustomEvent fails before any of the other methods are called, this may be invoked