Index: java/org/apache/coyote/http11/InternalInputBuffer.java
===================================================================
--- java/org/apache/coyote/http11/InternalInputBuffer.java	(revision 1711641)
+++ java/org/apache/coyote/http11/InternalInputBuffer.java	(working copy)
@@ -76,7 +76,7 @@
      * tested for == 0 or > 0.
      */
     @Override
-    public int available() {
+    public int available(boolean read) {
         return 1;
     }
 
Index: java/org/apache/coyote/http11/AbstractHttp11Processor.java
===================================================================
--- java/org/apache/coyote/http11/AbstractHttp11Processor.java	(revision 1711641)
+++ java/org/apache/coyote/http11/AbstractHttp11Processor.java	(working copy)
@@ -873,7 +873,7 @@
             break;
         }
         case AVAILABLE: {
-            request.setAvailable(inputBuffer.available());
+            request.setAvailable(inputBuffer.available(param == Boolean.TRUE));
             break;
         }
         case NB_WRITE_INTEREST: {
Index: java/org/apache/catalina/connector/InputBuffer.java
===================================================================
--- java/org/apache/catalina/connector/InputBuffer.java	(revision 1711641)
+++ java/org/apache/catalina/connector/InputBuffer.java	(working copy)
@@ -241,7 +241,7 @@
             available = cb.getLength();
         }
         if (available == 0) {
-            coyoteRequest.action(ActionCode.AVAILABLE, null);
+            coyoteRequest.action(ActionCode.AVAILABLE, Boolean.valueOf(coyoteRequest.getReadListener() != null));
             available = (coyoteRequest.getAvailable() > 0) ? 1 : 0;
         }
         return available;
Index: java/org/apache/tomcat/util/net/Nio2Channel.java
===================================================================
--- java/org/apache/tomcat/util/net/Nio2Channel.java	(revision 1711641)
+++ java/org/apache/tomcat/util/net/Nio2Channel.java	(working copy)
@@ -26,6 +26,8 @@
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.TimeoutException;
 
+import org.apache.juli.logging.Log;
+import org.apache.juli.logging.LogFactory;
 import org.apache.tomcat.util.net.SecureNio2Channel.ApplicationBufferHandler;
 
 /**
@@ -35,6 +37,7 @@
  */
 public class Nio2Channel implements AsynchronousByteChannel {
 
+    private static final Log log = LogFactory.getLog(Nio2Channel.class);
     protected static ByteBuffer emptyBuf = ByteBuffer.allocate(0);
 
     protected AsynchronousSocketChannel sc = null;
@@ -128,9 +131,21 @@
         return super.toString()+":"+this.sc.toString();
     }
 
+    private volatile Exception stack = null;
     @Override
     public Future<Integer> read(ByteBuffer dst) {
-        return sc.read(dst);
+        Exception previous = stack;
+        try {
+            throw new Exception(Thread.currentThread().getName());
+        } catch (Exception e) {
+            stack = e;
+        }
+        try {
+            return sc.read(dst);
+        } catch (java.nio.channels.ReadPendingException e) {
+            log.error("Read pending exception, previous read stack was: ", previous);
+            throw e;
+        }
     }
 
     @Override
@@ -142,6 +157,11 @@
     public <A> void read(ByteBuffer dst,
             long timeout, TimeUnit unit, A attachment,
             CompletionHandler<Integer, ? super A> handler) {
+        try {
+            throw new Exception(Thread.currentThread().getName());
+        } catch (Exception e) {
+            stack = e;
+        }
         sc.read(dst, timeout, unit, attachment, handler);
     }
 
Index: java/org/apache/coyote/http11/AbstractInputBuffer.java
===================================================================
--- java/org/apache/coyote/http11/AbstractInputBuffer.java	(revision 1711641)
+++ java/org/apache/coyote/http11/AbstractInputBuffer.java	(working copy)
@@ -326,7 +326,7 @@
      * Available bytes in the buffers (note that due to encoding, this may not
      * correspond).
      */
-    public int available() {
+    public int available(boolean read) {
         int available = lastValid - pos;
         if ((available == 0) && (lastActiveFilter >= 0)) {
             for (int i = 0; (available == 0) && (i <= lastActiveFilter); i++) {
@@ -337,17 +337,19 @@
             return available;
         }
 
-        try {
-            fill(false);
-            available = lastValid - pos;
-        } catch (IOException ioe) {
-            if (getLog().isDebugEnabled()) {
-                getLog().debug(sm.getString("iib.available.readFail"), ioe);
+        if (read) {
+            try {
+                fill(false);
+                available = lastValid - pos;
+            } catch (IOException ioe) {
+                if (getLog().isDebugEnabled()) {
+                    getLog().debug(sm.getString("iib.available.readFail"), ioe);
+                }
+                // Not ideal. This will indicate that data is available which should
+                // trigger a read which in turn will trigger another IOException and
+                // that one can be thrown.
+                available = 1;
             }
-            // Not ideal. This will indicate that data is available which should
-            // trigger a read which in turn will trigger another IOException and
-            // that one can be thrown.
-            available = 1;
         }
         return available;
     }