Change to async

Author: timja

src/main/java/io/jenkins/plugins/pipelinegraphview/livestate/LiveGraphPopulator.java

@@ -13,13 +13,14 @@
  * feeds it to the corresponding {@link LiveGraphState}. The downstream {@code PipelineGraphApi}
  * path reads a snapshot of that state instead of walking the whole execution each time.
  *
- * <p>This is the {@link GraphListener.Synchronous} variant because we need to observe each
- * node before the HTTP layer can query for it. The listener runs on the CPS VM thread and
- * must not block — all work here is non-blocking and every code path is guarded against
- * exceptions (a thrown exception would kill the build).
+ * <p>We use the async {@link GraphListener} rather than {@code GraphListener.Synchronous}:
+ * HTTP readers poll every few seconds, so we only need eventual consistency, and keeping
+ * the listener off the CPS VM thread avoids any risk of blocking execution. Every code path
+ * is still wrapped in try/catch and poisons the state on failure so a bug here can never
+ * disrupt a build.
  */
 @Extension
-public class LiveGraphPopulator implements GraphListener.Synchronous {
+public class LiveGraphPopulator implements GraphListener {
 
     private static final Logger logger = LoggerFactory.getLogger(LiveGraphPopulator.class);