content: /*
   * Copyright (C) 2012 The Android Open Source Project
   *
   * 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.android.server.power;
  
  import android.util.proto.ProtoOutputStream;
  
  /**
   * Low-level suspend blocker mechanism equivalent to holding a partial wake lock.
   *
   * This interface is used internally to avoid introducing internal dependencies
   * on the high-level wake lock mechanism.
   */
  interface SuspendBlocker {
      /**
       * Acquires the suspend blocker.
       * Prevents the CPU from going to sleep.
       *
       * Calls to acquire() nest and must be matched by the same number
       * of calls to release().
       */
      void acquire();
  
      /**
       * Releases the suspend blocker.
       * Allows the CPU to go to sleep if no other suspend blockers are held.
       *
       * It is an error to call release() if the suspend blocker has not been acquired.
       * The system may crash.
       */
      void release();
  
      void writeToProto(ProtoOutputStream proto, long fieldId);
  }
  