Issue #6728 - QUIC and HTTP/3

- Made HttpChannelOverHTTP3.needContent() to look for content if none is immediately available.
- Improved javadocs.

Signed-off-by: Simone Bordet <simone.bordet@gmail.com>

jetty-http3/http3-server/src/main/java/org/eclipse/jetty/http3/server/internal/HttpChannelOverHTTP3.java

@@ -174,6 +174,14 @@ public class HttpChannelOverHTTP3 extends HttpChannel
 
     public boolean onIdleTimeout(Throwable failure, Consumer<Runnable> consumer)
     {
+        try (AutoLock l = lock.lock())
+        {
+            if (content == null)
+                content = new HttpInput.ErrorContent(failure);
+            else
+                return false;
+        }
+
         boolean delayed = delayedUntilContent;
         delayedUntilContent = false;
 
@@ -185,12 +193,6 @@ public class HttpChannelOverHTTP3 extends HttpChannel
 
         failure.addSuppressed(new Throwable("idle timeout"));
 
-        try (AutoLock l = lock.lock())
-        {
-            if (content == null)
-                content = new HttpInput.ErrorContent(failure);
-        }
-
         boolean needed = getRequest().getHttpInput().onContentProducible();
         if (needed || delayed)
         {
@@ -225,8 +227,28 @@ public class HttpChannelOverHTTP3 extends HttpChannel
         try (AutoLock l = lock.lock())
         {
             if (content != null)
+            {
+                if (LOG.isDebugEnabled())
+                    LOG.debug("need content has immediate content {} on {}", content, this);
                 return true;
             }
+        }
+
+        Stream.Data data = stream.readData();
+        if (data != null)
+        {
+            HttpInput.Content result = newContent(data);
+            try (AutoLock l = lock.lock())
+            {
+                if (LOG.isDebugEnabled())
+                    LOG.debug("need content read content {} on {}", result, this);
+                content = result;
+            }
+            return true;
+        }
+
+        if (LOG.isDebugEnabled())
+            LOG.debug("need content demanding content on {}", this);
         stream.demand();
         return false;
     }
@@ -254,26 +276,7 @@ public class HttpChannelOverHTTP3 extends HttpChannel
         if (data == null)
             return null;
 
-        result = new HttpInput.Content(data.getByteBuffer())
-        {
-            @Override
-            public boolean isEof()
-            {
-                return data.isLast();
-            }
-
-            @Override
-            public void succeeded()
-            {
-                data.complete();
-            }
-
-            @Override
-            public void failed(Throwable x)
-            {
-                data.complete();
-            }
-        };
+        result = newContent(data);
         try (AutoLock l = lock.lock())
         {
             content = result;
@@ -303,6 +306,30 @@ public class HttpChannelOverHTTP3 extends HttpChannel
         return result;
     }
 
+    private HttpInput.Content newContent(Stream.Data data)
+    {
+        return new HttpInput.Content(data.getByteBuffer())
+        {
+            @Override
+            public boolean isEof()
+            {
+                return data.isLast();
+            }
+
+            @Override
+            public void succeeded()
+            {
+                data.complete();
+            }
+
+            @Override
+            public void failed(Throwable x)
+            {
+                data.complete();
+            }
+        };
+    }
+
     @Override
     public boolean failAllContent(Throwable failure)
     {

jetty-server/src/main/java/org/eclipse/jetty/server/BlockingContentProducer.java

@@ -171,6 +171,8 @@ class BlockingContentProducer implements ContentProducer
         boolean unready = _asyncContentProducer.isUnready();
         if (LOG.isDebugEnabled())
             LOG.debug("onContentProducible releasing semaphore {} unready={}", _semaphore, unready);
+        // Do not release the semaphore if we are not unready, as certain protocols may call this method
+        // just after having received the request, not only when they have read all the available content.
         if (unready)
             _semaphore.release();
         return false;

jetty-server/src/main/java/org/eclipse/jetty/server/HttpChannel.java

@@ -140,10 +140,11 @@ public abstract class HttpChannel implements Runnable, HttpOutput.Interceptor
     /**
      * Notify the channel that content is needed. If some content is immediately available, true is returned and
      * {@link #produceContent()} has to be called and will return a non-null object.
-     * If no content is immediately available, {@link HttpInput#onContentProducible()} is called once some content arrives
-     * and {@link #produceContent()} can be called without returning null.
-     * If a failure happens, then {@link HttpInput#onContentProducible()} will be called and an error content will return the
-     * error on the next call to {@link #produceContent()}.
+     * If no content is immediately available, an attempt to produce content must be made; if new content has been
+     * produced, true is returned; otherwise {@link HttpInput#onContentProducible()} is called once some content
+     * arrives and {@link #produceContent()} can be called without returning {@code null}.
+     * If a failure happens, then {@link HttpInput#onContentProducible()} will be called and an error content will
+     * return the error on the next call to {@link #produceContent()}.
      * @return true if content is immediately available.
      */
     public abstract boolean needContent();