| /* |
| * Copyright 2023 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. |
| */ |
| |
| #pragma once |
| |
| #include <chrono> |
| #include <condition_variable> |
| #include <functional> |
| #include <mutex> |
| #include <queue> |
| #include <shared_mutex> |
| #include <string> |
| #include <thread> |
| #include <unordered_map> |
| |
| #include "AdpfTypes.h" |
| |
| namespace aidl { |
| namespace google { |
| namespace hardware { |
| namespace power { |
| namespace impl { |
| namespace pixel { |
| |
| // Background thread processing from priority queue based on time deadline |
| // This class isn't meant to be used directly, use TemplatePriorityQueueWorker below |
| class PriorityQueueWorkerPool { |
| public: |
| // CTOR |
| // thread count is number of threads to create in thread pool |
| // thread name prefix is use for naming threads to help with debugging |
| PriorityQueueWorkerPool(size_t threadCount, const std::string &threadNamePrefix); |
| // DTOR |
| ~PriorityQueueWorkerPool(); |
| // Map callback id to callback function |
| void addCallback(int64_t templateQueueWorkerId, std::function<void(int64_t)> callback); |
| // Unmap callback id with callback function |
| void removeCallback(int64_t templateQueueWorkerId); |
| // Schedule work for specific worker id with package id to be run at time deadline |
| void schedule(int64_t templateQueueWorkerId, int64_t packageId, |
| std::chrono::steady_clock::time_point deadline); |
| |
| private: |
| // Thread coordination |
| std::mutex mMutex; |
| bool mRunning; |
| std::condition_variable mCv; |
| std::vector<std::thread> mThreadPool; |
| void loop(); |
| |
| // Work package with worker id to find correct callback in |
| struct Package { |
| Package() {} |
| Package(std::chrono::steady_clock::time_point pDeadline, int64_t pTemplateQueueWorkerId, |
| int64_t pPackageId) |
| : deadline(pDeadline), |
| templateQueueWorkerId(pTemplateQueueWorkerId), |
| packageId(pPackageId) {} |
| std::chrono::steady_clock::time_point deadline; |
| int64_t templateQueueWorkerId{0}; |
| int64_t packageId{0}; |
| // Sort time earliest first |
| bool operator<(const Package &p) const { return deadline > p.deadline; } |
| }; |
| std::priority_queue<Package> mPackageQueue; |
| |
| // Callback management |
| std::shared_mutex mSharedMutex; |
| std::unordered_map<int64_t, std::function<void(int64_t)>> mCallbackMap; |
| }; |
| |
| // Generic templated worker for registering a single std::function callback one time |
| // and reusing it to reduce memory allocations. Many TemplatePriorityQueueWorkers |
| // can make use of the same PriorityQueue worker which enables sharing a thread pool |
| // across callbacks of different types. This class is a template to allow for different |
| // types of work packages while not requiring virtual calls. |
| template <typename PACKAGE> |
| class TemplatePriorityQueueWorker { |
| public: |
| // CTOR, callback to run when added work is run, worker to use for adding work to |
| TemplatePriorityQueueWorker(std::function<void(const PACKAGE &)> cb, |
| std::shared_ptr<PriorityQueueWorkerPool> worker) |
| : mCallbackId(reinterpret_cast<std::intptr_t>(this)), mCallback(cb), mWorker(worker) { |
| if (!mCallback) { |
| mCallback = [](const auto &) {}; |
| } |
| mWorker->addCallback(mCallbackId, [&](int64_t packageId) { process(packageId); }); |
| } |
| |
| // DTOR |
| ~TemplatePriorityQueueWorker() { mWorker->removeCallback(mCallbackId); } |
| |
| void schedule(const PACKAGE &package, |
| std::chrono::steady_clock::time_point t = std::chrono::steady_clock::now()) { |
| { |
| std::lock_guard<std::mutex> lock(mMutex); |
| ++mPackageIdCounter; |
| mPackages.emplace(mPackageIdCounter, package); |
| } |
| mWorker->schedule(mCallbackId, mPackageIdCounter, t); |
| } |
| |
| private: |
| int64_t mCallbackId{0}; |
| std::function<void(const PACKAGE &)> mCallback; |
| // Must ensure PriorityQueueWorker does not go out of scope before this class does |
| std::shared_ptr<PriorityQueueWorkerPool> mWorker; |
| mutable std::mutex mMutex; |
| // Counter is used as a unique identifier for work packages |
| int64_t mPackageIdCounter{0}; |
| // Want a container that is: |
| // fast to add, fast random find find, fast random removal, |
| // and with reasonable space efficiency |
| std::unordered_map<int64_t, PACKAGE> mPackages; |
| |
| void process(int64_t packageId) { |
| PACKAGE package; |
| { |
| std::lock_guard<std::mutex> lock(mMutex); |
| auto itr = mPackages.find(packageId); |
| if (itr == mPackages.end()) { |
| // Work id does not have matching entry, drop it |
| return; |
| } |
| |
| package = itr->second; |
| mPackages.erase(itr); |
| } |
| mCallback(package); |
| } |
| }; |
| |
| } // namespace pixel |
| } // namespace impl |
| } // namespace power |
| } // namespace hardware |
| } // namespace google |
| } // namespace aidl |