8269481: SctpMultiChannel never releases own file descriptor

Backport-of: d1cecaaa22d551b93074c33209dac7354f4b6932

Author: akashche

src/jdk.sctp/unix/classes/sun/nio/ch/sctp/SctpChannelImpl.java

@@ -640,15 +640,16 @@ public void kill() throws IOException {
                 return;
             if (state == ChannelState.UNINITIALIZED) {
                 state = ChannelState.KILLED;
+                SctpNet.close(fdVal);
                 return;
             }
             assert !isOpen() && !isRegistered();
 
             /* Postpone the kill if there is a waiting reader
              * or writer thread. */
             if (receiverThread == 0 && senderThread == 0) {
-                SctpNet.close(fdVal);
                 state = ChannelState.KILLED;
+                SctpNet.close(fdVal);
             } else {
                 state = ChannelState.KILLPENDING;
             }

src/jdk.sctp/unix/classes/sun/nio/ch/sctp/SctpMultiChannelImpl.java

@@ -374,14 +374,15 @@ public void kill() throws IOException {
                 return;
             if (state == ChannelState.UNINITIALIZED) {
                 state = ChannelState.KILLED;
+                SctpNet.close(fdVal);
                 return;
             }
             assert !isOpen() && !isRegistered();
 
             /* Postpone the kill if there is a thread sending or receiving. */
             if (receiverThread == 0 && senderThread == 0) {
-                SctpNet.close(fdVal);
                 state = ChannelState.KILLED;
+                SctpNet.close(fdVal);
             } else {
                 state = ChannelState.KILLPENDING;
             }

src/jdk.sctp/unix/classes/sun/nio/ch/sctp/SctpServerChannelImpl.java

@@ -282,14 +282,15 @@ public void kill() throws IOException {
                 return;
             if (state == ChannelState.UNINITIALIZED) {
                 state = ChannelState.KILLED;
+                SctpNet.close(fdVal);
                 return;
             }
             assert !isOpen() && !isRegistered();
 
             // Postpone the kill if there is a thread in accept
             if (thread == 0) {
-                SctpNet.close(fdVal);
                 state = ChannelState.KILLED;
+                SctpNet.close(fdVal);
             } else {
                 state = ChannelState.KILLPENDING;
             }

test/jdk/com/sun/nio/sctp/SctpMultiChannel/CloseDescriptors.java

@@ -0,0 +1,136 @@
+/*
+ * Copyright (c) 2021, 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
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/* @test
+ * @bug 8269481
+ * @summary Tests that file descriptors are closed
+ * @requires (os.family == "linux")
+ * @run main/othervm CloseDescriptors
+ */
+
+import java.net.InetSocketAddress;
+import java.net.ServerSocket;
+import java.nio.ByteBuffer;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.List;
+import java.util.Optional;
+import com.sun.nio.sctp.MessageInfo;
+import com.sun.nio.sctp.SctpMultiChannel;
+
+public class CloseDescriptors {
+
+    private static final int NUM      = 5;
+    private static final int SIZE     = 1024;
+    private static final int MAX_DESC = 3;
+
+    public static void main(String[] args) throws Exception {
+        if (!Util.isSCTPSupported()) {
+            System.out.println("SCTP protocol is not supported");
+            System.out.println("Test cannot be run");
+            return;
+        }
+
+        List<String> lsofDirs = List.of("/usr/bin", "/usr/sbin");
+        Optional<Path> lsof = lsofDirs.stream()
+                .map(s -> Path.of(s, "lsof"))
+                .filter(f -> Files.isExecutable(f))
+                .findFirst();
+        if (!lsof.isPresent()) {
+            System.out.println("Cannot locate lsof in " + lsofDirs);
+            System.out.println("Test cannot be run");
+            return;
+        }
+
+        try (ServerSocket ss = new ServerSocket(0)) {
+            int port = ss.getLocalPort();
+
+            Thread server = new Server(port);
+            server.start();
+            Thread.sleep(100); // wait for server to be ready
+
+            System.out.println("begin");
+            for (int i = 0; i < 5; ++i) {
+                System.out.println(i);
+                doIt(port);
+                Thread.sleep(100);
+            }
+            System.out.println("end");
+            server.join();
+        }
+
+        long pid = ProcessHandle.current().pid();
+        ProcessBuilder pb = new ProcessBuilder(
+                lsof.get().toString(), "-U", "-a", "-p", Long.toString(pid));
+        Process p = pb.start();
+        Object[] lines = p.inputReader().lines().toArray();
+        p.waitFor();
+
+        int nfds = lines.length - 1;
+        if (nfds > MAX_DESC) {
+            throw new RuntimeException("Number of open descriptors " +
+                nfds + " > " + MAX_DESC);
+        }
+    }
+
+    static void doIt(int port) throws Exception {
+        InetSocketAddress sa = new InetSocketAddress("localhost", port);
+
+        for (int i = 0; i < NUM; ++i) {
+            System.out.println("  " + i);
+            SctpMultiChannel channel = SctpMultiChannel.open();
+            channel.configureBlocking(true);
+            MessageInfo info = MessageInfo.createOutgoing(sa, 0);
+            ByteBuffer buffer = ByteBuffer.allocateDirect(SIZE);
+            channel.send(buffer, info);
+            channel.close();
+
+            Thread.sleep(200);
+        }
+    }
+
+    static class Server extends Thread {
+        int port;
+
+        Server(int port) {
+            this.port = port;
+        }
+
+        @Override
+        public void run() {
+            for (int i = 0; i < NUM; i++) {
+                try {
+                    SctpMultiChannel sm = SctpMultiChannel.open();
+                    InetSocketAddress sa =
+                        new InetSocketAddress("localhost", port);
+                    sm.bind(sa);
+                    ByteBuffer buffer = ByteBuffer.allocateDirect(SIZE);
+                    MessageInfo info = sm.receive(buffer, null, null);
+                    sm.close();
+                } catch (Exception e) {
+                    e.printStackTrace();
+                }
+            }
+        }
+    }
+}