fix: ensure hasOngoingSendLoop.exitSafe()

Author: okg-cxf

src/main/java/io/lettuce/core/protocol/DefaultBatchFlushEndpoint.java

@@ -609,7 +609,7 @@ private void scheduleSendJobOnConnected(final ContextualChannel chan) {
         LettuceAssert.assertState(chan.eventLoop().inEventLoop(), "must be called in event loop thread");
 
         // Schedule directly
-        scheduleSendJobInEventLoopIfNeeded(chan);
+        scheduleSendJobInEventLoopIfNeeded(chan, false);
     }
 
     private void scheduleSendJobIfNeeded(final ContextualChannel chan) {
@@ -618,11 +618,6 @@ private void scheduleSendJobIfNeeded(final ContextualChannel chan) {
         }
 
         final EventLoop eventLoop = chan.eventLoop();
-        if (eventLoop.inEventLoop()) {
-            scheduleSendJobInEventLoopIfNeeded(chan);
-            return;
-        }
-
         if (chan.context.batchFlushEndPointContext.hasOngoingSendLoop.tryEnterSafeGetVolatile()) {
             // Benchmark result of using tryEnterSafeGetVolatile() or not (1 thread, async get):
             // 1. uses tryEnterSafeGetVolatile() to avoid unnecessary eventLoop.execute() calls
@@ -631,7 +626,7 @@ private void scheduleSendJobIfNeeded(final ContextualChannel chan) {
             // 2. uses eventLoop.execute() directly
             // Avg latency: 3.2677197021496998s
             // Avg QPS: 476925.0751855796/s
-            eventLoop.execute(() -> scheduleSendJobInEventLoopIfNeeded(chan));
+            eventLoop.execute(() -> scheduleSendJobInEventLoopIfNeeded(chan, true));
         }
 
         // Otherwise:
@@ -642,10 +637,13 @@ private void scheduleSendJobIfNeeded(final ContextualChannel chan) {
         // second loopSend0(), which will call poll()
     }
 
-    private void scheduleSendJobInEventLoopIfNeeded(final ContextualChannel chan) {
+    private void scheduleSendJobInEventLoopIfNeeded(final ContextualChannel chan, boolean enteredSafe) {
         // Guarantee only 1 send loop.
-        if (chan.context.batchFlushEndPointContext.hasOngoingSendLoop.tryEnterUnsafe()) {
+        BatchFlushEndPointContext.HasOngoingSendLoop hasOngoingSendLoop = chan.context.batchFlushEndPointContext.hasOngoingSendLoop;
+        if (hasOngoingSendLoop.tryEnterUnsafe()) {
             loopSend(chan);
+        } else if (enteredSafe) {
+            hasOngoingSendLoop.exitSafe();
         }
     }
 
@@ -691,6 +689,8 @@ private void loopSend0(final BatchFlushEndPointContext batchFlushEndPointContext
             batchFlushEndPointContext.hasOngoingSendLoop.exitSafe();
             // // Guarantee thread-safety: no dangling tasks in the queue.
             loopSend0(batchFlushEndPointContext, chan, remainingSpinnCount, false);
+            // chan.eventLoop().schedule(() -> loopSend0(batchFlushEndPointContext, chan, writeSpinCount, false), 100,
+            // TimeUnit.NANOSECONDS);
         } else {
             // The send loop will be triggered later when a new task is added,
             batchFlushEndPointContext.hasOngoingSendLoop.exitUnsafe();