Hang in PreClose method during dup2 system call

During fcntl, dup2 system calls if read/write happens then PreClose method gets hang. This issue is not seen if we Signal/Kill the thread first and then call the preClose method.

Signed-off-by: Shruthi.Shruthi1 <[email protected]>

Author: shruacha1234

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

@@ -23,6 +23,12 @@
  * questions.
  */
 
+/*
+ * ===========================================================================
+ * (c) Copyright IBM Corp. 2023, 2023 All Rights Reserved
+ * ===========================================================================
+ */
+
 package sun.nio.ch;
 
 import java.io.FileDescriptor;
@@ -1165,13 +1171,13 @@ protected void implCloseSelectableChannel() throws IOException {
                 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);
+
                     // wait for blocking I/O operations to end
                     while (readerThread != 0 || writerThread != 0) {
                         try {

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

@@ -23,6 +23,12 @@
  * questions.
  */
 
+/*
+ * ===========================================================================
+ * (c) Copyright IBM Corp. 2023, 2023 All Rights Reserved
+ * ===========================================================================
+ */
+
 package sun.nio.ch;
 
 import java.io.FileDescriptor;
@@ -361,9 +367,10 @@ protected void implCloseSelectableChannel() throws IOException {
                 assert state == ST_CLOSING;
                 long th = thread;
                 if (th != 0) {
-                    nd.preClose(fd);
                     NativeThread.signal(th);
 
+                    nd.preClose(fd);
+
                     // wait for accept operation to end
                     while (thread != 0) {
                         try {

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

@@ -23,6 +23,12 @@
  * questions.
  */
 
+/*
+ * ===========================================================================
+ * (c) Copyright IBM Corp. 2023, 2023 All Rights Reserved
+ * ===========================================================================
+ */
+
 package sun.nio.ch;
 
 import java.io.FileDescriptor;
@@ -835,14 +841,15 @@ protected void implCloseSelectableChannel() throws IOException {
                 long reader = readerThread;
                 long writer = writerThread;
                 if (reader != 0 || writer != 0) {
-                    nd.preClose(fd);
-                    connected = false; // fd is no longer connected socket
 
                     if (reader != 0)
                         NativeThread.signal(reader);
                     if (writer != 0)
                         NativeThread.signal(writer);
 
+                    nd.preClose(fd);
+                    connected = false; // fd is no longer connected socket
+
                     // wait for blocking I/O operations to end
                     while (readerThread != 0 || writerThread != 0) {
                         try {

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

@@ -23,6 +23,12 @@
  * questions.
  */
 
+/*
+ * ===========================================================================
+ * (c) Copyright IBM Corp. 2023, 2023 All Rights Reserved
+ * ===========================================================================
+*/
+
 package sun.nio.ch;
 
 import java.io.FileDescriptor;
@@ -107,8 +113,8 @@ protected void implCloseSelectableChannel() throws IOException {
                 assert state == ST_CLOSING;
                 long th = thread;
                 if (th != 0) {
-                    nd.preClose(fd);
                     NativeThread.signal(th);
+                    nd.preClose(fd);
 
                     // wait for write operation to end
                     while (thread != 0) {

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

@@ -23,6 +23,11 @@
  * questions.
  */
 
+/*
+ * ===========================================================================
+ * (c) Copyright IBM Corp. 2023, 2023 All Rights Reserved
+ * ===========================================================================
+ */
 package sun.nio.ch;
 
 import java.io.FileDescriptor;
@@ -107,8 +112,8 @@ protected void implCloseSelectableChannel() throws IOException {
                 assert state == ST_CLOSING;
                 long th = thread;
                 if (th != 0) {
-                    nd.preClose(fd);
                     NativeThread.signal(th);
+                    nd.preClose(fd);
 
                     // wait for read operation to end
                     while (thread != 0) {

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

@@ -22,6 +22,13 @@
  * or visit www.oracle.com if you need additional information or have any
  * questions.
  */
+
+/*
+ * ===========================================================================
+ * (c) Copyright IBM Corp. 2023, 2023 All Rights Reserved
+ * ===========================================================================
+*/
+
 package sun.nio.ch.sctp;
 
 import java.net.InetAddress;
@@ -561,7 +568,6 @@ protected void implConfigureBlocking(boolean block) throws IOException {
     @Override
     public void implCloseSelectableChannel() throws IOException {
         synchronized (stateLock) {
-            SctpNet.preClose(fdVal);
 
             if (receiverThread != 0)
                 NativeThread.signal(receiverThread);
@@ -571,6 +577,8 @@ public void implCloseSelectableChannel() throws IOException {
 
             if (!isRegistered())
                 kill();
+
+            SctpNet.preClose(fdVal);
         }
     }
 

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

@@ -22,6 +22,13 @@
  * or visit www.oracle.com if you need additional information or have any
  * questions.
  */
+
+/*
+ * ===========================================================================
+ * (c) Copyright IBM Corp. 2023, 2023 All Rights Reserved
+ * ===========================================================================
+*/
+
 package sun.nio.ch.sctp;
 
 import java.net.InetAddress;
@@ -288,8 +295,6 @@ protected void implConfigureBlocking(boolean block) throws IOException {
     @Override
     public void implCloseSelectableChannel() throws IOException {
         synchronized (stateLock) {
-            SctpNet.preClose(fdVal);
-
             if (receiverThread != 0)
                 NativeThread.signal(receiverThread);
 
@@ -298,6 +303,8 @@ public void implCloseSelectableChannel() throws IOException {
 
             if (!isRegistered())
                 kill();
+
+            SctpNet.preClose(fdVal);
         }
     }
 

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

@@ -22,6 +22,13 @@
  * or visit www.oracle.com if you need additional information or have any
  * questions.
  */
+
+/*
+ * ===========================================================================
+ * (c) Copyright IBM Corp. 2023, 2023 All Rights Reserved
+ * ===========================================================================
+*/
+
 package sun.nio.ch.sctp;
 
 import java.net.SocketAddress;
@@ -265,11 +272,11 @@ protected void implConfigureBlocking(boolean block) throws IOException {
     @Override
     public void implCloseSelectableChannel() throws IOException {
         synchronized (stateLock) {
-            SctpNet.preClose(fdVal);
             if (thread != 0)
                 NativeThread.signal(thread);
             if (!isRegistered())
                 kill();
+            SctpNet.preClose(fdVal);
         }
     }