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.kafka.common.utils;
  
  /**
   * Internal class that should be used instead of `System.exit()` and `Runtime.getRuntime().halt()` so that tests can
   * easily change the behaviour.
   */
  public class Exit {
  
      @FunctionalInterface
      public interface Procedure {
          void execute(int statusCode, String message);
      }
  
      @FunctionalInterface
      public interface ShutdownHookAdder {
          void addShutdownHook(String name, Runnable runnable);
      }
  
      private static final Procedure DEFAULT_HALT_PROCEDURE = (statusCode, message) -> Runtime.getRuntime().halt(statusCode);
  
      private static final Procedure DEFAULT_EXIT_PROCEDURE = (statusCode, message) -> System.exit(statusCode);
  
      private static final ShutdownHookAdder DEFAULT_SHUTDOWN_HOOK_ADDER = (name, runnable) -> {
          if (name != null)
              Runtime.getRuntime().addShutdownHook(KafkaThread.nonDaemon(name, runnable));
          else
              Runtime.getRuntime().addShutdownHook(new Thread(runnable));
      };
  
      private static final Procedure NOOP_HALT_PROCEDURE = (statusCode, message) -> {
          throw new IllegalStateException("Halt called after resetting procedures; possible race condition present in test");
      };
  
      private static final Procedure NOOP_EXIT_PROCEDURE = (statusCode, message) -> {
          throw new IllegalStateException("Exit called after resetting procedures; possible race condition present in test");
      };
  
      private static volatile Procedure exitProcedure = DEFAULT_EXIT_PROCEDURE;
      private static volatile Procedure haltProcedure = DEFAULT_HALT_PROCEDURE;
      private static volatile ShutdownHookAdder shutdownHookAdder = DEFAULT_SHUTDOWN_HOOK_ADDER;
  
      public static void exit(int statusCode) {
          exit(statusCode, null);
      }
  
      public static void exit(int statusCode, String message) {
          exitProcedure.execute(statusCode, message);
      }
  
      public static void halt(int statusCode) {
          halt(statusCode, null);
      }
  
      public static void halt(int statusCode, String message) {
          haltProcedure.execute(statusCode, message);
      }
  
      public static void addShutdownHook(String name, Runnable runnable) {
          shutdownHookAdder.addShutdownHook(name, runnable);
      }
  
      /**
       * For testing only, do not call in main code.
       */
      public static void setExitProcedure(Procedure procedure) {
          exitProcedure = procedure;
      }
  
      /**
       * For testing only, do not call in main code.
       */
      public static void setHaltProcedure(Procedure procedure) {
          haltProcedure = procedure;
      }
  
      /**
       * For testing only, do not call in main code.
       */
      public static void setShutdownHookAdder(ShutdownHookAdder shutdownHookAdder) {
          Exit.shutdownHookAdder = shutdownHookAdder;
      }
  
      /**
       * For testing only, do not call in main code.
       * <p>Clears the procedure set in {@link #setExitProcedure(Procedure)}, but does not restore system default behavior of exiting the JVM.
       */
      public static void resetExitProcedure() {
          exitProcedure = NOOP_EXIT_PROCEDURE;
      }
  
      /**
       * For testing only, do not call in main code.
       * <p>Clears the procedure set in {@link #setHaltProcedure(Procedure)}, but does not restore system default behavior of exiting the JVM.
       */
      public static void resetHaltProcedure() {
          haltProcedure = NOOP_HALT_PROCEDURE;
      }
  
      /**
       * For testing only, do not call in main code.
       * <p>Restores the system default shutdown hook behavior.
       */
      public static void resetShutdownHookAdder() {
          shutdownHookAdder = DEFAULT_SHUTDOWN_HOOK_ADDER;
      }
  }
  