fix: Make event descriptor building and accessing thread safe

platform-sdk/swirlds-platform-core/src/main/java/com/swirlds/platform/event/GossipEvent.java

@@ -142,8 +142,14 @@ public EventDescriptor getDescriptor() {
     /**
      * Build the descriptor of this event. This cannot be done when the event is first instantiated, it needs to be
      * hashed before the descriptor can be built.
+     *
+     * @throws IllegalStateException if the descriptor has already been built
      */
     public void buildDescriptor() {
+        if (descriptor != null) {
+            throw new IllegalStateException("Descriptor has already been built");
+        }
+
         this.descriptor = hashedData.createEventDescriptor();
     }
 

platform-sdk/swirlds-platform-core/src/main/java/com/swirlds/platform/event/creation/tipset/TipsetEventCreator.java

@@ -19,7 +19,6 @@
 import static com.swirlds.logging.legacy.LogMarker.EXCEPTION;
 import static com.swirlds.platform.consensus.GraphGenerations.FIRST_GENERATION;
 import static com.swirlds.platform.event.creation.tipset.TipsetAdvancementWeight.ZERO_ADVANCEMENT_WEIGHT;
-import static com.swirlds.platform.event.creation.tipset.TipsetUtils.buildDescriptor;
 import static com.swirlds.platform.event.creation.tipset.TipsetUtils.getParentDescriptors;
 import static com.swirlds.platform.system.events.EventConstants.CREATOR_ID_UNDEFINED;
 import static com.swirlds.platform.system.events.EventConstants.GENERATION_UNDEFINED;
@@ -168,7 +167,7 @@ public void registerEvent(@NonNull final GossipEvent event) {
             if (lastSelfEvent == null || lastSelfEvent.getGeneration() < event.getGeneration()) {
                 // Normally we will ingest self events before we get to this point, but it's possible
                 // to learn of self events for the first time here if we are loading from a restart or reconnect.
-                lastSelfEvent = buildDescriptor(event);
+                lastSelfEvent = event.getDescriptor();
                 lastSelfEventCreationTime = event.getHashedData().getTimeCreated();
                 lastSelfEventTransactionCount = event.getHashedData().getTransactions() == null
                         ? 0
@@ -181,7 +180,7 @@ public void registerEvent(@NonNull final GossipEvent event) {
             }
         }
 
-        final EventDescriptor descriptor = buildDescriptor(event);
+        final EventDescriptor descriptor = event.getDescriptor();
         final List<EventDescriptor> parentDescriptors = getParentDescriptors(event);
 
         tipsetTracker.addEvent(descriptor, parentDescriptors);
@@ -376,7 +375,7 @@ private GossipEvent buildAndProcessEvent(@Nullable final EventDescriptor otherPa
 
         final GossipEvent event = assembleEventObject(otherParent);
 
-        final EventDescriptor descriptor = buildDescriptor(event);
+        final EventDescriptor descriptor = event.getDescriptor();
         tipsetTracker.addEvent(descriptor, parentDescriptors);
         final TipsetAdvancementWeight advancementWeight =
                 tipsetWeightCalculator.addEventAndGetAdvancementWeight(descriptor);

platform-sdk/swirlds-platform-core/src/main/java/com/swirlds/platform/event/creation/tipset/TipsetUtils.java

@@ -44,17 +44,6 @@ public static EventDescriptor buildDescriptor(@NonNull final EventImpl event) {
         return event.getHashedData().createEventDescriptor();
     }
 
-    /**
-     * Build a descriptor from a GossipEvent.
-     *
-     * @param event the event
-     * @return the descriptor
-     */
-    public static EventDescriptor buildDescriptor(@NonNull final GossipEvent event) {
-        event.buildDescriptor();
-        return event.getDescriptor();
-    }
-
     /**
      * Get the descriptors of an event's parents.
      *

platform-sdk/swirlds-platform-core/src/main/java/com/swirlds/platform/internal/EventImpl.java

@@ -232,9 +232,6 @@ public void awaitPrehandleCompletion() {
      */
     private void setDefaultValues() {
         runningHash = new RunningHash();
-        if (baseEvent.getHashedData().getHash() != null) {
-            baseEvent.buildDescriptor();
-        }
     }
 
     /**

platform-sdk/swirlds-unit-tests/core/swirlds-platform-test/src/test/java/com/swirlds/platform/test/event/intake/OrphanEventsIntakeTest.java

@@ -125,7 +125,10 @@ public void generateAndFeed(final int numEvents) {
                     .limit(numEvents)
                     .collect(Collectors.toList());
             Collections.shuffle(generatedList, r);
-            generatedList.forEach(intake::addUnlinkedEvent);
+            generatedList.forEach(event -> {
+                event.buildDescriptor();
+                intake.addUnlinkedEvent(event);
+            });
         }
 
         public List<EventImpl> getConsensusEvents() {

platform-sdk/swirlds-unit-tests/core/swirlds-platform-test/src/test/java/com/swirlds/platform/test/event/linking/OrphanBufferingLinkerTest.java

@@ -177,6 +177,7 @@ void eventGenerator() {
         final OrphanBufferTester orphanBuffer = new OrphanBufferTester(pf ->
                 new OrphanBufferingLinker(consensusConfig, pf, GENERATIONS_STORED, mock(IntakeEventCounter.class)));
         for (final GossipEvent event : generatedList) {
+            event.buildDescriptor();
             orphanBuffer.linkEvent(event);
             while (orphanBuffer.hasLinkedEvents()) {
                 returnedList.add(orphanBuffer.pollLinkedEvent().getBaseEvent());

platform-sdk/swirlds-unit-tests/core/swirlds-platform-test/src/test/java/com/swirlds/platform/test/event/tipset/TipsetEventCreatorTests.java

@@ -52,6 +52,7 @@
 import com.swirlds.platform.system.address.AddressBook;
 import com.swirlds.platform.system.events.BaseEventHashedData;
 import com.swirlds.platform.system.events.BaseEventUnhashedData;
+import com.swirlds.platform.system.events.ConsensusData;
 import com.swirlds.platform.system.events.EventConstants;
 import com.swirlds.platform.system.events.EventDescriptor;
 import com.swirlds.platform.system.transaction.ConsensusTransactionImpl;
@@ -244,8 +245,7 @@ private EventImpl linkEvent(
         final EventImpl selfParent = events.get(event.getHashedData().getSelfParentHash());
         final EventImpl otherParent = events.get(event.getHashedData().getOtherParentHash());
 
-        final EventImpl eventImpl =
-                new EventImpl(event.getHashedData(), event.getUnhashedData(), selfParent, otherParent);
+        final EventImpl eventImpl = new EventImpl(event, new ConsensusData(), selfParent, otherParent);
         events.put(event.getHashedData().getHash(), eventImpl);
 
         return eventImpl;