1// 2// Copyright (C) 2016 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#ifndef UPDATE_ENGINE_COMMON_CPU_LIMITER_H_ 18#define UPDATE_ENGINE_COMMON_CPU_LIMITER_H_ 19 20#include <brillo/message_loops/message_loop.h> 21 22namespace chromeos_update_engine { 23 24// Cgroups cpu shares constants. 1024 is the default shares a standard process 25// gets and 2 is the minimum value. We set High as a value that gives the 26// update-engine 2x the cpu share of a standard process. 27enum class CpuShares : int { 28 kHigh = 2048, 29 kNormal = 1024, 30 kLow = 2, 31}; 32 33// Sets the current process shares to |shares|. Returns true on 34// success, false otherwise. 35bool SetCpuShares(CpuShares shares); 36 37class CPULimiter { 38 public: 39 CPULimiter() = default; 40 ~CPULimiter(); 41 42 // Sets the cpu shares to low and sets up timeout events to stop the limiter. 43 void StartLimiter(); 44 45 // Resets the cpu shares to normal and destroys any scheduled timeout sources. 46 void StopLimiter(); 47 48 // Sets the cpu shares to |shares|. This method can be user at any time, but 49 // if the limiter is not running, the shares won't be reset to normal. 50 bool SetCpuShares(CpuShares shares); 51 52 private: 53 // The cpu shares timeout source callback sets the current cpu shares to 54 // normal. 55 void StopLimiterCallback(); 56 57 // Current cpu shares. 58 CpuShares shares_ = CpuShares::kNormal; 59 60 // The cpu shares management timeout task id. 61 brillo::MessageLoop::TaskId manage_shares_id_{ 62 brillo::MessageLoop::kTaskIdNull}; 63}; 64 65} // namespace chromeos_update_engine 66 67#endif // UPDATE_ENGINE_COMMON_CPU_LIMITER_H_ 68