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 22 namespace 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. 27 enum 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. 35 bool SetCpuShares(CpuShares shares); 36 37 class 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
