Merge pull request #892 from stuartwdouglas/UNDERTOW-1713

UNDERTOW-1713 Don't start async IO too early
undertow-io · Jun 2, 2020 · 89b9000 · 89b9000
2 parents 0892780 + a0e4a90
commit 89b9000
Show file tree

Hide file tree

Showing 2 changed files with 13 additions and 0 deletions.
diff --git a/servlet/src/main/java/io/undertow/servlet/spec/ServletInputStreamImpl.java b/servlet/src/main/java/io/undertow/servlet/spec/ServletInputStreamImpl.java
@@ -67,6 +67,7 @@ public class ServletInputStreamImpl extends ServletInputStream {
     private volatile int state;
     private volatile AsyncContextImpl asyncContext;
     private volatile PooledByteBuffer pooled;
+    private volatile boolean asyncIoStarted;
 
     private static final AtomicIntegerFieldUpdater<ServletInputStreamImpl> stateUpdater = AtomicIntegerFieldUpdater.newUpdater(ServletInputStreamImpl.class, "state");
 
@@ -102,6 +103,10 @@ public boolean isReady() {
                 }
             }
         }
+        if (!asyncIoStarted) {
+            //make sure we don't call resumeReads unless we have started async IO
+            return false;
+        }
         boolean ready = anyAreSet(state, FLAG_READY) && !finished;
         if(!ready && listener != null && !finished) {
             channel.resumeReads();
@@ -135,6 +140,7 @@ public void run() {
                 channel.getIoThread().execute(new Runnable() {
                     @Override
                     public void run() {
+                        asyncIoStarted = true;
                         internalListener.handleEvent(channel);
                     }
                 });

diff --git a/servlet/src/main/java/io/undertow/servlet/spec/ServletOutputStreamImpl.java b/servlet/src/main/java/io/undertow/servlet/spec/ServletOutputStreamImpl.java
@@ -73,6 +73,7 @@ public class ServletOutputStreamImpl extends ServletOutputStream implements Buff
     private StreamSinkChannel channel;
     private long written;
     private volatile int state;
+    private volatile boolean asyncIoStarted;
     private AsyncContextImpl asyncContext;
 
     private WriteListener listener;
@@ -756,6 +757,11 @@ public boolean isReady() {
             //TODO: is this the correct behaviour?
             throw UndertowServletMessages.MESSAGES.streamNotInAsyncMode();
         }
+        if (!asyncIoStarted) {
+            //if we don't add this guard here calls to isReady could start async IO too soon
+            //resulting in a 'resuming + dispatched' message
+            return false;
+        }
         if (!anyAreSet(state, FLAG_READY)) {
             if (channel != null) {
                 channel.resumeWrites();
@@ -790,6 +796,7 @@ public void setWriteListener(final WriteListener writeListener) {
         asyncContext.addAsyncTask(new Runnable() {
             @Override
             public void run() {
+                asyncIoStarted = true;
                 if (channel == null) {
                     servletRequestContext.getExchange().getIoThread().execute(new Runnable() {
                         @Override