8317801: java/net/Socket/asyncClose/Race.java fails intermittently (aix)

src/java.base/share/classes/sun/nio/ch/DatagramChannelImpl.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2001, 2023, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2001, 2026, 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
@@ -1729,15 +1729,7 @@ private void implCloseBlockingMode() throws IOException {
                 registry.invalidateAll();
 
             if (!tryClose()) {
-                long reader = readerThread;
-                long writer = writerThread;
-                if (reader != 0 || writer != 0) {
-                    nd.preClose(fd);
-                    if (reader != 0)
-                        NativeThread.signal(reader);
-                    if (writer != 0)
-                        NativeThread.signal(writer);
-                }
+                nd.preClose(fd, readerThread, writerThread);
             }
         }
     }

src/java.base/share/classes/sun/nio/ch/NativeDispatcher.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2000, 2019, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2000, 2026, 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
@@ -73,7 +73,7 @@ abstract long writev(FileDescriptor fd, long address, int len)
     // that's already closed.  This is necessary on some operating systems
     // (Solaris and Linux) to prevent fd recycling.
     //
-    void preClose(FileDescriptor fd) throws IOException {
+    void preClose(FileDescriptor fd, long reader, long writer) throws IOException {
         // Do nothing by default; this is only needed on Unix
     }
 

src/java.base/share/classes/sun/nio/ch/NioSocketImpl.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2019, 2023, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2019, 2026, 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
@@ -909,13 +909,7 @@ protected void close() throws IOException {
             // then the socket is pre-closed and the thread(s) signalled. The
             // last thread will close the file descriptor.
             if (!tryClose()) {
-                nd.preClose(fd);
-                long reader = readerThread;
-                if (reader != 0)
-                    NativeThread.signal(reader);
-                long writer = writerThread;
-                if (writer != 0)
-                    NativeThread.signal(writer);
+                nd.preClose(fd, readerThread, writerThread);
             }
         }
     }

src/java.base/share/classes/sun/nio/ch/ServerSocketChannelImpl.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2000, 2021, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2000, 2026, 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
@@ -581,11 +581,7 @@ private void implCloseBlockingMode() throws IOException {
             assert state < ST_CLOSING;
             state = ST_CLOSING;
             if (!tryClose()) {
-                long th = thread;
-                if (th != 0) {
-                    nd.preClose(fd);
-                    NativeThread.signal(th);
-                }
+                nd.preClose(fd, thread, 0);
             }
         }
     }

src/java.base/share/classes/sun/nio/ch/SocketChannelImpl.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2000, 2021, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2000, 2026, 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
@@ -1028,15 +1028,7 @@ private void implCloseBlockingMode() throws IOException {
             }
 
             if (!tryClose()) {
-                long reader = readerThread;
-                long writer = writerThread;
-                if (reader != 0 || writer != 0) {
-                    nd.preClose(fd);
-                    if (reader != 0)
-                        NativeThread.signal(reader);
-                    if (writer != 0)
-                        NativeThread.signal(writer);
-                }
+                nd.preClose(fd, readerThread, writerThread);
             }
         }
     }

src/java.base/unix/classes/sun/nio/ch/DatagramDispatcher.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2001, 2019, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2001, 2026, 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
@@ -59,8 +59,9 @@ void close(FileDescriptor fd) throws IOException {
         FileDispatcherImpl.close0(fd);
     }
 
-    void preClose(FileDescriptor fd) throws IOException {
-        FileDispatcherImpl.preClose0(fd);
+    void preClose(FileDescriptor fd, long reader, long writer) throws IOException {
+        FileDispatcherImpl dispatcher = new FileDispatcherImpl();
+        dispatcher.preClose(fd, reader, writer);
     }
 
     void dup(FileDescriptor fd1, FileDescriptor fd2) throws IOException {

src/java.base/unix/classes/sun/nio/ch/FileDispatcherImpl.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2000, 2021, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2000, 2026, 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
@@ -32,6 +32,7 @@
 import jdk.internal.access.SharedSecrets;
 
 class FileDispatcherImpl extends FileDispatcher {
+    private static final boolean SUPPORTS_PENDING_SIGNALS = NativeThread.supportPendingSignals();
 
     static {
         IOUtil.load();
@@ -104,8 +105,33 @@ void close(FileDescriptor fd) throws IOException {
         fdAccess.close(fd);
     }
 
-    void preClose(FileDescriptor fd) throws IOException {
+    /**
+     * Prepare the given file descriptor for closing. If a virtual thread is blocked
+     * on the file descriptor then it is unparked so that it stops polling. On Unix systems,
+     * if a platform thread is blocked on the file descriptor then the file descriptor is
+     * dup'ed to a special fd and the thread signalled so that the syscall fails with EINTR.
+     */
+    final void preClose(FileDescriptor fd, long reader, long writer) throws IOException {
+        if (reader != 0 || writer != 0) {
+            implPreClose(fd, reader, writer);
+        }
+    }
+
+    private void signalThreads(long reader, long writer) {
+        if (reader != 0)
+            NativeThread.signal(reader);
+        if (writer != 0)
+            NativeThread.signal(writer);
+    }
+
+    void implPreClose(FileDescriptor fd, long reader, long writer) throws IOException {
+        if (SUPPORTS_PENDING_SIGNALS) {
+            signalThreads(reader, writer);
+        }
         preClose0(fd);
+        if (!SUPPORTS_PENDING_SIGNALS) {
+            signalThreads(reader, writer);
+        }
     }
 
     void dup(FileDescriptor fd1, FileDescriptor fd2) throws IOException {

src/java.base/unix/classes/sun/nio/ch/NativeThread.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2002, 2013, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2002, 2026, 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
@@ -39,6 +39,17 @@
 
 public class NativeThread {
 
+    /**
+     * Return true if the operating system supports pending signals. If a signal is sent
+     * to a thread but cannot be delivered immediately then it will be delivered when the
+     * thread is in the appropriate state.
+     */
+    static boolean supportPendingSignals() {
+        return supportPendingSignals0();
+    }
+
+    private static native boolean supportPendingSignals0();
+
     // Returns an opaque token representing the native thread underlying the
     // invoking Java thread.  On systems that do not require signalling, this
     // method always returns -1.

src/java.base/unix/classes/sun/nio/ch/SinkChannelImpl.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2000, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2000, 2026, 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
@@ -121,11 +121,7 @@ private void implCloseBlockingMode() throws IOException {
             assert state < ST_CLOSING;
             state = ST_CLOSING;
             if (!tryClose()) {
-                long th = thread;
-                if (th != 0) {
-                    nd.preClose(fd);
-                    NativeThread.signal(th);
-                }
+                nd.preClose(fd, thread, 0);
             }
         }
     }

src/java.base/unix/classes/sun/nio/ch/SocketDispatcher.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2000, 2019, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2000, 2026, 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
@@ -70,8 +70,9 @@ void close(FileDescriptor fd) throws IOException {
         FileDispatcherImpl.close0(fd);
     }
 
-    void preClose(FileDescriptor fd) throws IOException {
-        FileDispatcherImpl.preClose0(fd);
+    void preClose(FileDescriptor fd, long reader, long writer) throws IOException {
+        FileDispatcherImpl dispatcher = new FileDispatcherImpl();
+        dispatcher.preClose(fd, reader, writer);
     }
 
     // -- Native methods --

src/java.base/unix/classes/sun/nio/ch/SourceChannelImpl.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2000, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2000, 2026, 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
@@ -121,11 +121,7 @@ private void implCloseBlockingMode() throws IOException {
             assert state < ST_CLOSING;
             state = ST_CLOSING;
             if (!tryClose()) {
-                long th = thread;
-                if (th != 0) {
-                    nd.preClose(fd);
-                    NativeThread.signal(th);
-                }
+                nd.preClose(fd, thread, 0);
             }
         }
     }

src/java.base/unix/native/libnio/ch/NativeThread.c

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2002, 2020, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2002, 2026, 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
@@ -89,3 +89,12 @@ Java_sun_nio_ch_NativeThread_signal(JNIEnv *env, jclass cl, jlong thread)
 #endif
         JNU_ThrowIOExceptionWithLastError(env, "Thread signal failed");
 }
+
+JNIEXPORT jboolean JNICALL
+Java_sun_nio_ch_NativeThread_supportPendingSignals0(JNIEnv *env, jclass cl) {
+#if defined(_AIX)
+    return JNI_TRUE;
+#else
+    return JNI_FALSE;
+#endif
+}