8372159: HttpClient SelectorManager thread could be a VirtualThread

src/java.net.http/share/classes/jdk/internal/net/http/HttpClientImpl.java

@@ -98,6 +98,7 @@
 import jdk.internal.net.http.common.OperationTrackers.Tracker;
 import jdk.internal.net.http.common.Utils.SafeExecutor;
 import jdk.internal.net.http.common.Utils.SafeExecutorService;
+import jdk.internal.net.http.common.Utils.UseVTForSelector;
 import jdk.internal.net.http.websocket.BuilderImpl;
 
 import static java.net.http.HttpOption.Http3DiscoveryMode.HTTP_3_URI_ONLY;
@@ -126,6 +127,16 @@ final class HttpClientImpl extends HttpClient implements Trackable {
     static final long IDLE_CONNECTION_TIMEOUT_H2 = getTimeoutProp("jdk.httpclient.keepalive.timeout.h2", KEEP_ALIVE_TIMEOUT);
     static final long IDLE_CONNECTION_TIMEOUT_H3 = getTimeoutProp("jdk.httpclient.keepalive.timeout.h3", IDLE_CONNECTION_TIMEOUT_H2);
 
+    static final UseVTForSelector USE_VT_FOR_SELECTOR =
+        Utils.useVTForSelector("jdk.internal.httpclient.tcp.selector.useVirtualThreads", "default");
+    private static boolean useVtForSelector() {
+        return switch (USE_VT_FOR_SELECTOR) {
+            case ALWAYS -> true;
+            case NEVER -> false;
+            default -> true;
+        };
+    }
+
     // Define the default factory as a static inner class
     // that embeds all the necessary logic to avoid
     // the risk of using a lambda that might keep a reference on the
@@ -293,7 +304,6 @@ static <T> CompletableFuture<T> registerPending(PendingRequest pending, Completa
         if (pending.cf.isDone()) return res;
 
         var client = pending.client;
-        var cf = pending.cf;
         var id = pending.id;
         boolean added = client.pendingRequests.add(pending);
         // this may immediately remove `pending` from the set is the cf is already completed
@@ -342,6 +352,7 @@ static void abortPendingRequests(HttpClientImpl client, Throwable reason) {
     private final boolean isDefaultExecutor;
     private final SSLContext sslContext;
     private final SSLParameters sslParams;
+    private final Thread selmgrThread;
     private final SelectorManager selmgr;
     private final FilterFactory filters;
     private final Http2ClientImpl client2;
@@ -509,7 +520,11 @@ private HttpClientImpl(HttpClientBuilderImpl builder,
             // unlikely
             throw new UncheckedIOException(e);
         }
-        selmgr.setDaemon(true);
+        selmgrThread = useVtForSelector()
+                ? Thread.ofVirtual().name("HttpClient-" + id + "-SelectorManager")
+                .inheritInheritableThreadLocals(false).unstarted(selmgr)
+                : Thread.ofPlatform().name("HttpClient-" + id + "-SelectorManager")
+                .inheritInheritableThreadLocals(false).daemon().unstarted(selmgr);
         filters = new FilterFactory();
         initFilters();
         assert facadeRef.get() != null;
@@ -528,7 +543,7 @@ void onSubmitFailure(Runnable command, Throwable failure) {
 
     private void start() {
         try {
-            selmgr.start();
+            selmgrThread.start();
         } catch (Throwable t) {
             isStarted.set(true);
             throw t;
@@ -635,7 +650,7 @@ public void shutdownNow() {
     @Override
     public boolean awaitTermination(Duration duration) throws InterruptedException {
         // Implicit NPE will be thrown if duration is null
-        return selmgr.join(duration);
+        return selmgrThread.join(duration);
     }
 
     @Override
@@ -927,7 +942,7 @@ void eventUpdated(AsyncEvent event) throws ClosedChannelException {
     }
 
     boolean isSelectorThread() {
-        return Thread.currentThread() == selmgr;
+        return Thread.currentThread() == selmgrThread;
     }
 
     AltServicesRegistry registry() { return registry; }
@@ -1157,7 +1172,7 @@ private static <T> CompletableFuture<HttpResponse<T>> translateSendAsyncExecFail
     }
 
     // Main loop for this client's selector
-    private static final class SelectorManager extends Thread {
+    private static final class SelectorManager implements Runnable {
 
         // For testing purposes we have an internal System property that
         // can control the frequency at which the selector manager will wake
@@ -1196,9 +1211,6 @@ private static final class SelectorManager extends Thread {
         private final ReentrantLock lock = new ReentrantLock();
 
         SelectorManager(HttpClientImpl ref) throws IOException {
-            super(null, null,
-                  "HttpClient-" + ref.id + "-SelectorManager",
-                  0, false);
             owner = ref;
             debug = ref.debug;
             debugtimeout = ref.debugtimeout;
@@ -1221,7 +1233,7 @@ IOException selectorClosedException() {
         }
 
         void eventUpdated(AsyncEvent e) throws ClosedChannelException {
-            if (Thread.currentThread() == this) {
+            if (owner.isSelectorThread()) {
                 SelectionKey key = e.channel().keyFor(selector);
                 if (key != null && key.isValid()) {
                     SelectorAttachment sa = (SelectorAttachment) key.attachment();
@@ -1315,6 +1327,10 @@ void abort(Throwable t) {
             if (!inSelectorThread) selector.wakeup();
         }
 
+        String getName() {
+            return owner.selmgrThread.getName();
+        }
+
         // Only called by the selector manager thread
         private void shutdown() {
             try {

src/java.net.http/share/classes/jdk/internal/net/http/common/Utils.java

@@ -242,6 +242,15 @@ private static Set<String> getDisallowedRedirectHeaders() {
                 return true;
             };
 
+    public enum UseVTForSelector { ALWAYS, NEVER, DEFAULT }
+
+    public static UseVTForSelector useVTForSelector(String property, String defval) {
+        String useVtForSelector = System.getProperty(property, defval);
+        return Stream.of(UseVTForSelector.values())
+                .filter((v) -> v.name().equalsIgnoreCase(useVtForSelector))
+                .findFirst().orElse(UseVTForSelector.DEFAULT);
+    }
+
     public static <T extends Throwable> T addSuppressed(T x, Throwable suppressed) {
         if (x != suppressed && suppressed != null) {
             var sup = x.getSuppressed();

src/java.net.http/share/classes/jdk/internal/net/http/quic/ConnectionTerminatorImpl.java

@@ -143,8 +143,9 @@ void incomingStatelessReset() {
             Log.logError("{0}: stateless reset from peer ({1})", connection.logTag(),
                     (peerIsServer ? "server" : "client"));
         }
+        var label = "quic:" + connection.uniqueId();
         final SilentTermination st = forSilentTermination("stateless reset from peer ("
-                + (peerIsServer ? "server" : "client") + ")");
+                + (peerIsServer ? "server" : "client") + ") on " + label);
         terminate(st);
     }
 

src/java.net.http/share/classes/jdk/internal/net/http/quic/IdleTimeoutManager.java

@@ -346,8 +346,10 @@ private void idleTimedOut() {
             }
         }
         // silently close the connection and discard all its state
-        final TerminationCause cause = forSilentTermination("connection idle timed out ("
-                + timeoutMillis + " milli seconds)");
+        var type = connection.isClientConnection() ? "client" : "server";
+        var label = "quic:" + connection.uniqueId();
+        final TerminationCause cause = forSilentTermination(type + " connection idle timed out ("
+                + timeoutMillis + " milli seconds) on " + label);
         connection.terminator.terminate(cause);
     }
 

src/java.net.http/share/classes/jdk/internal/net/http/quic/QuicEndpoint.java

@@ -62,6 +62,7 @@
 import jdk.internal.net.http.common.TimeLine;
 import jdk.internal.net.http.common.TimeSource;
 import jdk.internal.net.http.common.Utils;
+import jdk.internal.net.http.common.Utils.UseVTForSelector;
 import jdk.internal.net.http.quic.QuicSelector.QuicNioSelector;
 import jdk.internal.net.http.quic.QuicSelector.QuicVirtualThreadPoller;
 import jdk.internal.net.http.quic.packets.QuicPacket.HeadersType;
@@ -116,7 +117,6 @@ public abstract sealed class QuicEndpoint implements AutoCloseable
     static final boolean DGRAM_SEND_ASYNC;
     static final int MAX_BUFFERED_HIGH;
     static final int MAX_BUFFERED_LOW;
-    enum UseVTForSelector { ALWAYS, NEVER, DEFAULT }
     static final UseVTForSelector USE_VT_FOR_SELECTOR;
     static {
         // This default value is the maximum payload size of
@@ -144,11 +144,8 @@ enum UseVTForSelector { ALWAYS, NEVER, DEFAULT }
         if (maxBufferLow >= maxBufferHigh) maxBufferLow = maxBufferHigh >> 1;
         MAX_BUFFERED_HIGH = maxBufferHigh;
         MAX_BUFFERED_LOW = maxBufferLow;
-        String useVtForSelector =
-                System.getProperty("jdk.internal.httpclient.quic.selector.useVirtualThreads", "default");
-        USE_VT_FOR_SELECTOR = Stream.of(UseVTForSelector.values())
-                .filter((v) -> v.name().equalsIgnoreCase(useVtForSelector))
-                .findFirst().orElse(UseVTForSelector.DEFAULT);
+        var property = "jdk.internal.httpclient.quic.selector.useVirtualThreads";
+        USE_VT_FOR_SELECTOR = Utils.useVTForSelector(property, "default");
     }
 
     /**

src/java.net.http/share/classes/jdk/internal/net/http/quic/QuicSelector.java

@@ -45,9 +45,9 @@
 import jdk.internal.net.http.common.TimeLine;
 import jdk.internal.net.http.common.TimeSource;
 import jdk.internal.net.http.common.Utils;
+import jdk.internal.net.http.common.Utils.UseVTForSelector;
 import jdk.internal.net.http.quic.QuicEndpoint.QuicVirtualThreadedEndpoint;
 import jdk.internal.net.http.quic.QuicEndpoint.QuicSelectableEndpoint;
-import jdk.internal.net.http.quic.QuicEndpoint.UseVTForSelector;
 
 import static jdk.internal.net.http.quic.QuicEndpoint.USE_VT_FOR_SELECTOR;
 

test/jdk/java/net/httpclient/ReferenceTracker.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018, 2023, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2018, 2025, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -390,12 +390,6 @@ private static void checkOutstandingOperations(StringBuilder warning,
         }
     }
 
-    private boolean isSelectorManager(Thread t) {
-        String name = t.getName();
-        if (name == null) return false;
-        return name.contains("SelectorManager");
-    }
-
     // This is a slightly more permissive check than the default checks,
     // it only verifies that all CFs returned by send/sendAsync have been
     // completed, and that all opened channels have been closed, and that