From 10585e4b3b09e637ca46a12174051bfcc9c06454 Mon Sep 17 00:00:00 2001
From: John Sully <john@csquare.ca>
Date: Wed, 1 Jul 2020 21:59:38 -0400
Subject: [PATCH] Latency fixes

Former-commit-id: 6857c4c2085d3b0902d7b2ece66b3fe8828dd805
---
 src/connection.cpp | 14 +++++++-------
 src/networking.cpp |  9 ++++++---
 2 files changed, 13 insertions(+), 10 deletions(-)

diff --git a/src/connection.cpp b/src/connection.cpp
index 05f49f689..defd5eb9d 100644
--- a/src/connection.cpp
+++ b/src/connection.cpp
@@ -164,7 +164,7 @@ static int connSocketWrite(connection *conn, const void *data, size_t data_len)
     int ret = write(conn->fd, data, data_len);
     if (ret < 0 && errno != EAGAIN) {
         conn->last_errno = errno;
-        conn->state = CONN_STATE_ERROR;
+        conn->state.store(CONN_STATE_ERROR, std::memory_order_relaxed);
     }
 
     return ret;
@@ -173,10 +173,10 @@ static int connSocketWrite(connection *conn, const void *data, size_t data_len)
 static int connSocketRead(connection *conn, void *buf, size_t buf_len) {
     int ret = read(conn->fd, buf, buf_len);
     if (!ret) {
-        conn->state = CONN_STATE_CLOSED;
+        conn->state.store(CONN_STATE_CLOSED, std::memory_order_release);
     } else if (ret < 0 && errno != EAGAIN) {
         conn->last_errno = errno;
-        conn->state = CONN_STATE_ERROR;
+        conn->state.store(CONN_STATE_ERROR, std::memory_order_release);
     }
 
     return ret;
@@ -253,14 +253,14 @@ static void connSocketEventHandler(struct aeEventLoop *el, int fd, void *clientD
     UNUSED(fd);
     connection *conn = (connection*)clientData;
 
-    if (conn->state == CONN_STATE_CONNECTING &&
+    if (conn->state.load(std::memory_order_relaxed) == CONN_STATE_CONNECTING &&
             (mask & AE_WRITABLE) && conn->conn_handler) {
 
         if (connGetSocketError(conn)) {
             conn->last_errno = errno;
-            conn->state = CONN_STATE_ERROR;
+            conn->state.store(CONN_STATE_ERROR, std::memory_order_release);
         } else {
-            conn->state = CONN_STATE_CONNECTED;
+            conn->state.store(CONN_STATE_CONNECTED, std::memory_order_release);
         }
 
         if (!conn->write_handler) aeDeleteFileEvent(serverTL->el,conn->fd,AE_WRITABLE);
@@ -407,7 +407,7 @@ int connRecvTimeout(connection *conn, long long ms) {
 }
 
 int connGetState(connection *conn) {
-    return conn->state;
+    return conn->state.load(std::memory_order_relaxed);
 }
 
 void connSetThreadAffinity(connection *conn, int cpu) {
diff --git a/src/networking.cpp b/src/networking.cpp
index 619db0786..f54870795 100644
--- a/src/networking.cpp
+++ b/src/networking.cpp
@@ -1928,9 +1928,12 @@ int handleClientsWithPendingWrites(int iel, int aof_state) {
         }
     }
 
-    AeLocker locker;
-    locker.arm(nullptr);
-    ProcessPendingAsyncWrites();
+    if (listLength(serverTL->clients_pending_asyncwrite))
+    {
+        AeLocker locker;
+        locker.arm(nullptr);
+        ProcessPendingAsyncWrites();
+    }
 
     return processed;
 }