WIP

Author: panchenko

servlet/src/main/java/io/grpc/servlet/AsyncServletOutputStreamWriter.java

@@ -46,11 +46,10 @@ final class AsyncServletOutputStreamWriter {
 
   private final Lock writeLock = new ReentrantLock();
   /**
-   * New write actions will be buffered into this queue if the servlet output stream is not ready
-   * or the queue is not drained.
+   * New write actions will be buffered into this queue.
    */
   // SPSC queue would do
-  private final Queue<ActionItem> writeChain = new ConcurrentLinkedQueue<>();
+  private final Queue<ActionItem> writeQueue = new ConcurrentLinkedQueue<>();
 
   AsyncServletOutputStreamWriter(
       AsyncContext asyncContext,
@@ -154,7 +153,8 @@ void onWritePossible() throws IOException {
       } finally {
         writeLock.unlock();
       }
-    } while (!writeChain.isEmpty());
+      // retry if runOrBuffer added tasks to the queue, but have not acquired the lock
+    } while (!writeQueue.isEmpty());
     log.finest("onWritePossible: EXIT. Queue drained");
   }
 
@@ -165,7 +165,7 @@ private enum WriteResult {
 
   private WriteResult writeFromQueue() throws IOException {
     while (isReady.getAsBoolean()) {
-      ActionItem actionItem = writeChain.poll();
+      ActionItem actionItem = writeQueue.poll();
       if (actionItem == null) {
         return WriteResult.QUEUE_DRAINED;
       }
@@ -181,7 +181,7 @@ private WriteResult writeFromQueue() throws IOException {
    * <p>Called from application thread.
    */
   private void runOrBuffer(ActionItem actionItem) throws IOException {
-    writeChain.offer(actionItem);
+    writeQueue.offer(actionItem);
     if (writeLock.tryLock()) { // write to the outputStream directly
       try {
         writeFromQueue();