performance: netty: simplify date header service

Author: jknack

modules/jooby-netty/src/main/java/io/jooby/internal/netty/NettyDateService.java

@@ -8,44 +8,27 @@
 import java.time.ZoneOffset;
 import java.time.ZonedDateTime;
 import java.time.format.DateTimeFormatter;
-import java.util.concurrent.RejectedExecutionException;
 import java.util.concurrent.ScheduledExecutorService;
 import java.util.concurrent.TimeUnit;
-import java.util.concurrent.atomic.AtomicReference;
 
-import io.jooby.SneakyThrows;
+import io.netty.util.AsciiString;
 
-public class NettyDateService {
-  private static final AtomicReference<String> cachedDateString = new AtomicReference<>();
-  private static final Runnable INVALIDATE_TASK = () -> cachedDateString.set(null);
+public class NettyDateService implements Runnable {
   private static final int DATE_INTERVAL = 1000;
-  private final ScheduledExecutorService scheduler;
+  private AsciiString date;
 
   public NettyDateService(ScheduledExecutorService scheduler) {
-    this.scheduler = scheduler;
+    scheduler.scheduleAtFixedRate(this, 0, DATE_INTERVAL, TimeUnit.MILLISECONDS);
   }
 
-  public String date() {
-    var dateString = cachedDateString.get();
-    if (dateString == null) {
-      // set the time and register a timer to invalidate it
-      // note that this is racey, it does not matter if multiple threads do this
-      // the perf cost of synchronizing would be more than the perf cost of multiple threads running
-      // it
-      long realTime = System.currentTimeMillis();
-      long mod = realTime % DATE_INTERVAL;
-      long toGo = DATE_INTERVAL - mod;
-      dateString = DateTimeFormatter.RFC_1123_DATE_TIME.format(ZonedDateTime.now(ZoneOffset.UTC));
-      if (cachedDateString.compareAndSet(null, dateString)) {
-        try {
-          scheduler.schedule(INVALIDATE_TASK, toGo, TimeUnit.MILLISECONDS);
-        } catch (RejectedExecutionException rejected) {
-          if (!scheduler.isShutdown()) {
-            throw SneakyThrows.propagate(rejected);
-          }
-        }
-      }
-    }
-    return dateString;
+  public AsciiString date() {
+    return this.date;
+  }
+
+  @Override
+  public void run() {
+    this.date =
+        new AsciiString(
+            DateTimeFormatter.RFC_1123_DATE_TIME.format(ZonedDateTime.now(ZoneOffset.UTC)));
   }
 }

modules/jooby-netty/src/main/java/io/jooby/netty/NettyServer.java

@@ -139,7 +139,7 @@ public Server start(@NonNull Jooby application) {
       var transport = NettyTransport.transport(application.getClassLoader());
 
       /* Acceptor event-loop */
-      this.acceptorloop = transport.createEventLoop(1, "acceptor", _100);
+      this.acceptorloop = transport.createEventLoop(1, "acceptor", _50);
 
       /* Event loop: processing connections, parsing messages and doing engine's internal work */
       this.eventloop = transport.createEventLoop(options.getIoThreads(), "eventloop", _100);