From 452723508ba993eeb6aae6b3c8f0f244a3527540 Mon Sep 17 00:00:00 2001
From: godotg <jaysunxiao@gmail.com>
Date: Sun, 11 Aug 2024 12:12:40 +0800
Subject: [PATCH] perf[executor]: use & bits operation to improve performance

---
 .../java/com/zfoo/event/manager/EventBus.java |  8 ++++---
 .../main/java/com/zfoo/net/task/TaskBus.java  | 23 +++++++++++--------
 2 files changed, 18 insertions(+), 13 deletions(-)

diff --git a/event/src/main/java/com/zfoo/event/manager/EventBus.java b/event/src/main/java/com/zfoo/event/manager/EventBus.java
index 60084433e..b4a70a5fa 100644
--- a/event/src/main/java/com/zfoo/event/manager/EventBus.java
+++ b/event/src/main/java/com/zfoo/event/manager/EventBus.java
@@ -22,6 +22,7 @@
 import com.zfoo.protocol.util.StringUtils;
 import com.zfoo.protocol.util.ThreadUtils;
 import io.netty.util.concurrent.FastThreadLocalThread;
+import io.netty.util.internal.MathUtil;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -46,7 +47,8 @@ public abstract class EventBus {
      * EN: The size of the thread pool. Event's thread pool is often used to do time-consuming operations, so set it a little bigger
      * CN: 线程池的大小. event的线程池经常用来做一些耗时的操作，所以要设置大一点
      */
-    private static final int EXECUTORS_SIZE = Math.max(Runtime.getRuntime().availableProcessors(), 4) * 2 + 1;
+    public static final int EXECUTORS_SIZE = MathUtil.safeFindNextPositivePowerOfTwo(Math.max(Runtime.getRuntime().availableProcessors(), 4) * 2);
+    private static final int EXECUTOR_MASK = EXECUTORS_SIZE - 1;
 
     private static final ExecutorService[] executors = new ExecutorService[EXECUTORS_SIZE];
 
@@ -144,8 +146,8 @@ public static void asyncExecute(int hash, Runnable runnable) {
         executorOf(hash).execute(ThreadUtils.safeRunnable(runnable));
     }
 
-    public static ExecutorService executorOf(int hash){
-        return executors[Math.abs(hash % EXECUTORS_SIZE)];
+    public static ExecutorService executorOf(int hash) {
+        return executors[hash & EXECUTOR_MASK];
     }
 
     /**
diff --git a/net/src/main/java/com/zfoo/net/task/TaskBus.java b/net/src/main/java/com/zfoo/net/task/TaskBus.java
index d547b3bd6..e3ec4ebe8 100644
--- a/net/src/main/java/com/zfoo/net/task/TaskBus.java
+++ b/net/src/main/java/com/zfoo/net/task/TaskBus.java
@@ -19,6 +19,7 @@
 import com.zfoo.protocol.util.StringUtils;
 import com.zfoo.protocol.util.ThreadUtils;
 import io.netty.util.concurrent.FastThreadLocalThread;
+import io.netty.util.internal.MathUtil;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -40,8 +41,9 @@ public final class TaskBus {
     private static final Logger logger = LoggerFactory.getLogger(TaskBus.class);
 
     // EN: The size of the thread pool can also be specified through the provider thread configuration
-    // CN: 线程池的大小，也可以通过provider thread配置指定
-    private static final int EXECUTOR_SIZE;
+    // CN: 线程池的大小，也可以通过provider thread配置指定，会通过EXECUTOR_MASK的与操作提高定位到Executor的性能
+    public static final int EXECUTOR_SIZE;
+    private static final int EXECUTOR_MASK;
 
     /**
      * EN: Use different thread pools to achieve isolation between thread pools without affecting each other
@@ -50,11 +52,13 @@ public final class TaskBus {
     private static final ExecutorService[] executors;
 
     static {
-        var localConfig = NetContext.getConfigManager().getLocalConfig();
-        var providerConfig = localConfig.getProvider();
-
-        EXECUTOR_SIZE = (providerConfig == null || StringUtils.isBlank(providerConfig.getThread())) ? (Runtime.getRuntime().availableProcessors() + 1) : Integer.parseInt(providerConfig.getThread());
-
+        var providerConfig = NetContext.getConfigManager().getLocalConfig().getProvider();
+        var expectThreads = (providerConfig == null || StringUtils.isBlank(providerConfig.getThread()))
+                ? Runtime.getRuntime().availableProcessors()
+                : Integer.parseInt(providerConfig.getThread());
+        EXECUTOR_SIZE = MathUtil.safeFindNextPositivePowerOfTwo(expectThreads);
+        // if EXECUTOR_SIZE = 8 then EXECUTOR_MASK = 7 =  0b0111
+        EXECUTOR_MASK = EXECUTOR_SIZE - 1;
         executors = new ExecutorService[EXECUTOR_SIZE];
         for (int i = 0; i < executors.length; i++) {
             var namedThreadFactory = new TaskThreadFactory(i);
@@ -89,8 +93,7 @@ public Thread newThread(Runnable runnable) {
 
 
     private static int calTaskExecutorIndex(int taskExecutorHash) {
-        // Other hash algorithms can be customized to make the distribution more uniform
-        return Math.abs(taskExecutorHash % EXECUTOR_SIZE);
+        return taskExecutorHash & EXECUTOR_MASK;
     }
 
     public static int calTaskExecutorHash(Object argument) {
@@ -113,7 +116,7 @@ public static void execute(Object argument, Runnable runnable) {
         execute(calTaskExecutorHash(argument), runnable);
     }
 
-    public static ExecutorService executorOf(int hash){
+    public static ExecutorService executorOf(int hash) {
         return executors[calTaskExecutorIndex(hash)];
     }