1 /* 2 * Copyright (C) 2012 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package com.android.server.power; 18 19 import android.util.proto.ProtoOutputStream; 20 21 /** 22 * Low-level suspend blocker mechanism equivalent to holding a partial wake lock. 23 * 24 * This interface is used internally to avoid introducing internal dependencies 25 * on the high-level wake lock mechanism. 26 */ 27 interface SuspendBlocker { 28 /** 29 * Acquires the suspend blocker. 30 * Prevents the CPU from going to sleep. 31 * 32 * Calls to acquire() nest and must be matched by the same number 33 * of calls to release(). 34 */ acquire()35 void acquire(); 36 37 /** 38 * Releases the suspend blocker. 39 * Allows the CPU to go to sleep if no other suspend blockers are held. 40 * 41 * It is an error to call release() if the suspend blocker has not been acquired. 42 * The system may crash. 43 */ release()44 void release(); 45 writeToProto(ProtoOutputStream proto, long fieldId)46 void writeToProto(ProtoOutputStream proto, long fieldId); 47 } 48