content: /*
   * Licensed to the Apache Software Foundation (ASF) under one or more
   * contributor license agreements.  See the NOTICE file distributed with
   * this work for additional information regarding copyright ownership.
   * The ASF licenses this file to You 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 org.apache.activemq.artemis.utils;
  
  import java.lang.reflect.Constructor;
  import java.lang.reflect.Field;
  
  /**
   * Utility that detects various properties specific to the current runtime environment, such as JVM bitness and OS
   * type.
   */
  public final class Env {
  
     private static final int OS_PAGE_SIZE;
  
     static {
        //most common OS page size value
        int osPageSize = 4096;
        sun.misc.Unsafe instance;
        try {
           Field field = sun.misc.Unsafe.class.getDeclaredField("theUnsafe");
           field.setAccessible(true);
           instance = (sun.misc.Unsafe) field.get(null);
        } catch (Throwable t) {
           try {
              Constructor<sun.misc.Unsafe> c = sun.misc.Unsafe.class.getDeclaredConstructor(new Class[0]);
              c.setAccessible(true);
              instance = c.newInstance(new Object[0]);
           } catch (Throwable t1) {
              instance = null;
           }
        }
        if (instance != null) {
           osPageSize = instance.pageSize();
        }
        OS_PAGE_SIZE = osPageSize;
     }
  
     /**
      * The system will change a few logs and semantics to be suitable to run a long testsuite. Like a few log entries
      * that are only valid during a production system. or a few cases we need to know as warn on the testsuite and as log
      * in production.
      */
     private static boolean testEnv = false;
  
     private static final String OS = System.getProperty("os.name").toLowerCase();
     private static final boolean IS_LINUX = OS.startsWith("linux");
     private static final boolean IS_MAC = OS.startsWith("mac");
     private static final boolean IS_WINDOWS = OS.startsWith("windows");
  
     private Env() {
  
     }
  
     /**
      * Return the size in bytes of a OS memory page. This value will always be a power of two.
      */
     public static int osPageSize() {
        return OS_PAGE_SIZE;
     }
  
     public static boolean isTestEnv() {
        return testEnv;
     }
  
     public static void setTestEnv(boolean testEnv) {
        Env.testEnv = testEnv;
     }
  
     public static boolean isLinuxOs() {
        return IS_LINUX == true;
     }
  
     public static boolean isMacOs() {
        return IS_MAC == true;
     }
  
     public static boolean isWindowsOs() {
        return IS_WINDOWS == true;
     }
  }
  