NIFI-4461: When reading from socket channel use blocking mode instead of sleeping; when writing, use a far smaller sleep duration

This closes #2193.

Signed-off-by: Bryan Bende <bbende@apache.org>

nifi-commons/nifi-security-utils/src/main/java/org/apache/nifi/remote/io/socket/ssl/SSLSocketChannel.java

@@ -48,7 +48,7 @@ public class SSLSocketChannel implements Closeable {
     public static final int MAX_WRITE_SIZE = 65536;
 
     private static final Logger logger = LoggerFactory.getLogger(SSLSocketChannel.class);
-    private static final long BUFFER_FULL_EMPTY_WAIT_NANOS = TimeUnit.NANOSECONDS.convert(10, TimeUnit.MILLISECONDS);
+    private static final long BUFFER_FULL_EMPTY_WAIT_NANOS = TimeUnit.NANOSECONDS.convert(1, TimeUnit.MILLISECONDS);
 
     private final String hostname;
     private final int port;
@@ -307,18 +307,21 @@ public class SSLSocketChannel implements Closeable {
 
             final int readCount = channel.read(dest);
 
+            long sleepNanos = 1L;
             if (readCount == 0) {
                 if (System.currentTimeMillis() > startTime + timeoutMillis) {
                     throw new SocketTimeoutException("Timed out reading from socket connected to " + hostname + ":" + port);
                 }
                 try {
-                    TimeUnit.NANOSECONDS.sleep(BUFFER_FULL_EMPTY_WAIT_NANOS);
+                    TimeUnit.NANOSECONDS.sleep(sleepNanos);
                 } catch (InterruptedException e) {
                     close();
                     Thread.currentThread().interrupt(); // set the interrupt status
                     throw new ClosedByInterruptException();
                 }
 
+                sleepNanos = Math.min(sleepNanos * 2, BUFFER_FULL_EMPTY_WAIT_NANOS);
+
                 continue;
             }
 
@@ -360,6 +363,8 @@ public class SSLSocketChannel implements Closeable {
             final int written = channel.write(src);
             bytesWritten += written;
             final long now = System.currentTimeMillis();
+            long sleepNanos = 1L;
+
             if (written > 0) {
                 lastByteWrittenTime = now;
             } else {
@@ -367,12 +372,14 @@ public class SSLSocketChannel implements Closeable {
                     throw new SocketTimeoutException("Timed out writing to socket connected to " + hostname + ":" + port);
                 }
                 try {
-                    TimeUnit.NANOSECONDS.sleep(BUFFER_FULL_EMPTY_WAIT_NANOS);
+                    TimeUnit.NANOSECONDS.sleep(sleepNanos);
                 } catch (final InterruptedException e) {
                     close();
                     Thread.currentThread().interrupt(); // set the interrupt status
                     throw new ClosedByInterruptException();
                 }
+
+                sleepNanos = Math.min(sleepNanos * 2, BUFFER_FULL_EMPTY_WAIT_NANOS);
             }
         }
 

nifi-commons/nifi-utils/src/main/java/org/apache/nifi/remote/io/socket/SocketChannelInputStream.java

@@ -21,7 +21,6 @@ import java.io.IOException;
 import java.io.InputStream;
 import java.net.SocketTimeoutException;
 import java.nio.ByteBuffer;
-import java.nio.channels.ClosedByInterruptException;
 import java.nio.channels.SocketChannel;
 import java.util.concurrent.TimeUnit;
 
@@ -68,28 +67,33 @@ public class SocketChannelInputStream extends InputStream {
         oneByteBuffer.clear();
 
         final long maxTime = System.currentTimeMillis() + timeoutMillis;
-        int bytesRead;
-        do {
-            bytesRead = channel.read(oneByteBuffer);
-            if (bytesRead == 0) {
-                if (System.currentTimeMillis() > maxTime) {
-                    throw new SocketTimeoutException("Timed out reading from socket");
-                }
-                try {
-                    TimeUnit.NANOSECONDS.sleep(CHANNEL_EMPTY_WAIT_NANOS);
-                } catch (InterruptedException e) {
-                    close();
-                    Thread.currentThread().interrupt(); // set the interrupt status
-                    throw new ClosedByInterruptException(); // simulate an interrupted blocked read operation
-                }
-            }
-        } while (bytesRead == 0);
 
-        if (bytesRead == -1) {
+        final boolean blocking = channel.isBlocking();
-            return -1;
+
+        try {
+            channel.configureBlocking(true);
+
+            int bytesRead;
+            do {
+                bytesRead = channel.read(oneByteBuffer);
+                if (bytesRead == 0) {
+                    if (System.currentTimeMillis() > maxTime) {
+                        throw new SocketTimeoutException("Timed out reading from socket");
+                    }
+                }
+            } while (bytesRead == 0);
+
+            if (bytesRead == -1) {
+                return -1;
+            }
+
+            oneByteBuffer.flip();
+            return oneByteBuffer.get() & 0xFF;
+        } finally {
+            if (!blocking) {
+                channel.configureBlocking(false);
+            }
         }
-        oneByteBuffer.flip();
-        return oneByteBuffer.get() & 0xFF;
     }
 
     @Override
@@ -108,25 +112,27 @@ public class SocketChannelInputStream extends InputStream {
 
         final ByteBuffer buffer = ByteBuffer.wrap(b, off, len);
 
-        final long maxTime = System.currentTimeMillis() + timeoutMillis;
+        final boolean blocking = channel.isBlocking();
-        int bytesRead;
+        try {
-        do {
+            channel.configureBlocking(true);
-            bytesRead = channel.read(buffer);
-            if (bytesRead == 0) {
-                if (System.currentTimeMillis() > maxTime) {
-                    throw new SocketTimeoutException("Timed out reading from socket");
-                }
-                try {
-                    TimeUnit.NANOSECONDS.sleep(CHANNEL_EMPTY_WAIT_NANOS);
-                } catch (InterruptedException e) {
-                    close();
-                    Thread.currentThread().interrupt(); // set the interrupt status
-                    throw new ClosedByInterruptException(); // simulate an interrupted blocked read operation
-                }
-            }
-        } while (bytesRead == 0);
 
-        return bytesRead;
+            final long maxTime = System.currentTimeMillis() + timeoutMillis;
+            int bytesRead;
+            do {
+                bytesRead = channel.read(buffer);
+                if (bytesRead == 0) {
+                    if (System.currentTimeMillis() > maxTime) {
+                        throw new SocketTimeoutException("Timed out reading from socket");
+                    }
+                }
+            } while (bytesRead == 0);
+
+            return bytesRead;
+        } finally {
+            if (!blocking) {
+                channel.configureBlocking(false);
+            }
+        }
     }
 
     @Override

nifi-commons/nifi-utils/src/main/java/org/apache/nifi/remote/io/socket/SocketChannelOutputStream.java

@@ -26,7 +26,7 @@ import java.util.concurrent.TimeUnit;
 
 public class SocketChannelOutputStream extends OutputStream {
 
-    private static final long CHANNEL_FULL_WAIT_NANOS = TimeUnit.NANOSECONDS.convert(10, TimeUnit.MILLISECONDS);
+    private static final long CHANNEL_FULL_WAIT_NANOS = TimeUnit.NANOSECONDS.convert(1, TimeUnit.MILLISECONDS);
     private final SocketChannel channel;
     private volatile int timeout = 30000;
 
@@ -52,19 +52,24 @@ public class SocketChannelOutputStream extends OutputStream {
         final int timeoutMillis = this.timeout;
         long maxTime = System.currentTimeMillis() + timeoutMillis;
         int bytesWritten;
+
+        long sleepNanos = 1L;
         while (oneByteBuffer.hasRemaining()) {
             bytesWritten = channel.write(oneByteBuffer);
             if (bytesWritten == 0) {
                 if (System.currentTimeMillis() > maxTime) {
                     throw new SocketTimeoutException("Timed out writing to socket");
                 }
+
                 try {
-                    TimeUnit.NANOSECONDS.sleep(CHANNEL_FULL_WAIT_NANOS);
+                    TimeUnit.NANOSECONDS.sleep(sleepNanos);
                 } catch (InterruptedException e) {
                     close();
                     Thread.currentThread().interrupt(); // set the interrupt status
                     throw new ClosedByInterruptException(); // simulate an interrupted blocked write operation
                 }
+
+                sleepNanos = Math.min(sleepNanos * 2, CHANNEL_FULL_WAIT_NANOS);
             } else {
                 return;
             }
@@ -83,19 +88,24 @@ public class SocketChannelOutputStream extends OutputStream {
         final int timeoutMillis = this.timeout;
         long maxTime = System.currentTimeMillis() + timeoutMillis;
         int bytesWritten;
+
+        long sleepNanos = 1L;
         while (buffer.hasRemaining()) {
             bytesWritten = channel.write(buffer);
             if (bytesWritten == 0) {
                 if (System.currentTimeMillis() > maxTime) {
                     throw new SocketTimeoutException("Timed out writing to socket");
                 }
+
                 try {
-                    TimeUnit.NANOSECONDS.sleep(CHANNEL_FULL_WAIT_NANOS);
+                    TimeUnit.NANOSECONDS.sleep(sleepNanos);
                 } catch (InterruptedException e) {
                     close();
                     Thread.currentThread().interrupt(); // set the interrupt status
                     throw new ClosedByInterruptException(); // simulate an interrupted blocked write operation
                 }
+
+                sleepNanos = Math.min(sleepNanos * 2, CHANNEL_FULL_WAIT_NANOS);
             } else {
                 maxTime = System.currentTimeMillis() + timeoutMillis;
             }