[ISSUE alibaba#7992] Support ThreadUtils preset processors count by p…

…roperty or env.

common/src/main/java/com/alibaba/nacos/common/utils/PropertyUtils.java

@@ -0,0 +1,67 @@
+/*
+ * Copyright 1999-2022 Alibaba Group Holding Ltd.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.alibaba.nacos.common.utils;
+
+/**
+ * A convenient tool to get property or env value.
+ *
+ * @author Pixy Yuan on 2022/3/24
+ */
+public class PropertyUtils {
+
+    private static final String PROCESSORS_ENV_NAME = "NACOS_COMMON_PROCESSORS";
+
+    private static final String PROCESSORS_PROP_NAME = "nacos.common.processors";
+
+    /**
+     * Get system env or property value.
+     *
+     * <p>If {@link System#getenv()} has no value for {@code envName},
+     * return {@link System#getProperty(String)}.
+     */
+    public static String getProperty(String propertyName, String envName) {
+        return System.getenv().getOrDefault(envName, System.getProperty(propertyName));
+    }
+
+    /**
+     * Get system env or property value.
+     *
+     * <p>If {@link System#getenv()} has no value for {@code envName},
+     * return {@link System#getProperty(String, String)} or {@code defaultValue}.
+     */
+    public static String getProperty(String propertyName, String envName, String defaultValue) {
+        return System.getenv().getOrDefault(envName, System.getProperty(propertyName, defaultValue));
+    }
+
+    /**
+     * Get processors count maybe preset by env or property.
+     */
+    public static int getProcessorsCount() {
+        int processorsCount = 0;
+        String processorsCountPreSet = getProperty(PROCESSORS_PROP_NAME, PROCESSORS_ENV_NAME);
+        if (processorsCountPreSet != null) {
+            try {
+                processorsCount = Integer.parseInt(processorsCountPreSet);
+            } catch (NumberFormatException ignored) {
+            }
+        }
+        if (processorsCount <= 0) {
+            processorsCount = Runtime.getRuntime().availableProcessors();
+        }
+        return processorsCount;
+    }
+}

common/src/main/java/com/alibaba/nacos/common/utils/ThreadUtils.java

@@ -107,7 +107,7 @@ public static int getSuitableThreadCount() {
      * @return thread count
      */
     public static int getSuitableThreadCount(int threadMultiple) {
-        final int coreCount = Runtime.getRuntime().availableProcessors();
+        final int coreCount = PropertyUtils.getProcessorsCount();
         int workerCount = 1;
         while (workerCount < coreCount * threadMultiple) {
             workerCount <<= 1;