From 606a01df708fa7b5cfc86ffcd2ce9aa805c825f9 Mon Sep 17 00:00:00 2001
From: "zhaozhao.zz" <zhaozhao.zz@alibaba-inc.com>
Date: Sun, 15 Mar 2020 21:49:10 +0800
Subject: [PATCH] Threaded IO: bugfix #6988 process events while blocked

---
 src/networking.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/networking.c b/src/networking.c
index 4c394af70..261c9b24a 100644
--- a/src/networking.c
+++ b/src/networking.c
@@ -36,6 +36,7 @@
 
 static void setProtocolError(const char *errstr, client *c);
 int postponeClientRead(client *c);
+int process_while_blocked;
 
 /* Return the size consumed from the allocator, for the specified SDS string,
  * including internal fragmentation. This function is used in order to compute
@@ -2738,6 +2739,7 @@ int clientsArePaused(void) {
 int processEventsWhileBlocked(void) {
     int iterations = 4; /* See the function top-comment. */
     int count = 0;
+    process_while_blocked = 1;
     while (iterations--) {
         int events = 0;
         events += aeProcessEvents(server.el, AE_FILE_EVENTS|AE_DONT_WAIT);
@@ -2745,6 +2747,7 @@ int processEventsWhileBlocked(void) {
         if (!events) break;
         count += events;
     }
+    process_while_blocked = 0;
     return count;
 }
 
@@ -2816,6 +2819,7 @@ void *IOThreadMain(void *myid) {
 /* Initialize the data structures needed for threaded I/O. */
 void initThreadedIO(void) {
     io_threads_active = 0; /* We start with threads not active. */
+    process_while_blocked = 0; 
 
     /* Don't spawn any thread if the user selected a single thread:
      * we'll handle I/O directly from the main thread. */
@@ -2970,6 +2974,7 @@ int handleClientsWithPendingWritesUsingThreads(void) {
 int postponeClientRead(client *c) {
     if (io_threads_active &&
         server.io_threads_do_reads &&
+        !process_while_blocked &&
         !(c->flags & (CLIENT_MASTER|CLIENT_SLAVE|CLIENT_PENDING_READ)))
     {
         c->flags |= CLIENT_PENDING_READ;