1 /* 2 * Copyright (C) 2017 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 specic language governing permissions and 14 * limitations under the License. 15 */ 16 17 #ifndef ANDROID_LIBPERFMGR_NODELOOPERTHREAD_H_ 18 #define ANDROID_LIBPERFMGR_NODELOOPERTHREAD_H_ 19 20 #include <cstddef> 21 #include <string> 22 #include <vector> 23 24 #include <utils/Thread.h> 25 26 #include "perfmgr/Node.h" 27 28 namespace android { 29 namespace perfmgr { 30 31 // The NodeAction specifies the sysfs node, the value to be assigned, and the 32 // timeout for this action: 33 struct NodeAction { NodeActionNodeAction34 NodeAction(std::size_t node_index, std::size_t value_index, 35 std::chrono::milliseconds timeout_ms) 36 : node_index(node_index), 37 value_index(value_index), 38 timeout_ms(timeout_ms) {} 39 std::size_t node_index; 40 std::size_t value_index; 41 std::chrono::milliseconds timeout_ms; // 0ms for forever 42 }; 43 44 // The NodeLooperThread is responsible for managing each of the sysfs nodes 45 // specified in the configuration. At initialization, the NodeLooperThrea holds 46 // a vector containing the nodes defined in the configuration. The NodeManager 47 // gets powerhint requests and cancellations from the HintManager, maintains 48 // state about the current set of powerhint requests on each sysfs node, and 49 // decides how to apply the requests. The NodeLooperThread contains a ThreadLoop 50 // to maintain the sysfs nodes, and that thread is woken up both to handle 51 // powerhint requests and when the timeout expires for an in-progress powerhint. 52 class NodeLooperThread : public ::android::Thread { 53 public: NodeLooperThread(std::vector<std::unique_ptr<Node>> nodes)54 NodeLooperThread(std::vector<std::unique_ptr<Node>> nodes) 55 : Thread(false), nodes_(std::move(nodes)) {} ~NodeLooperThread()56 virtual ~NodeLooperThread() { Stop(); } 57 58 // Need call Stop() as the threadloop will hold a strong pointer 59 // itself and wait for Condition fired or timeout (60s) before 60 // the out looper can call deconstructor to Stop() thread 61 void Stop(); 62 63 // Return true when successfully adds request from actions for the hint_type 64 // in each individual node. Return false if any of the actions has either 65 // invalid node index or value index. 66 bool Request(const std::vector<NodeAction>& actions, 67 const std::string& hint_type); 68 // Return when successfully cancels request from actions for the hint_type 69 // in each individual node. Return false if any of the actions has invalid 70 // node index. 71 bool Cancel(const std::vector<NodeAction>& actions, 72 const std::string& hint_type); 73 74 // Dump all nodes to fd 75 void DumpToFd(int fd); 76 77 private: 78 NodeLooperThread(NodeLooperThread const&) = delete; 79 void operator=(NodeLooperThread const&) = delete; 80 bool threadLoop() override; 81 void onFirstRef() override; 82 83 static constexpr auto kMaxUpdatePeriod = std::chrono::milliseconds::max(); 84 85 std::vector<std::unique_ptr<Node>> nodes_; // parsed from Config 86 87 // conditional variable from C++ standard library can be affected by wall 88 // time change as it is using CLOCK_REAL (b/35756266). The component should 89 // not be impacted by wall time, thus need use Android specific Condition 90 // class for waking up threadloop. 91 ::android::Condition wake_cond_; 92 93 // lock to protect nodes_ 94 ::android::Mutex lock_; 95 }; 96 97 } // namespace perfmgr 98 } // namespace android 99 100 #endif // ANDROID_LIBPERFMGR_NODELOOPERTHREAD_H_ 101