| /* |
| * Copyright (C) 2018 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. |
| */ |
| |
| #define LOG_TAG "GeneratorHub" |
| |
| #include <log/log.h> |
| |
| #include "GeneratorHub.h" |
| |
| namespace android { |
| namespace hardware { |
| namespace automotive { |
| namespace vehicle { |
| namespace V2_0 { |
| |
| namespace impl { |
| |
| GeneratorHub::GeneratorHub(const OnHalEvent& onHalEvent) : mOnHalEvent(onHalEvent) { |
| mThread = std::thread(&GeneratorHub::run, this); |
| } |
| |
| GeneratorHub::~GeneratorHub() { |
| { |
| // Even if the shared variable is atomic, it must be modified under the |
| // mutex in order to correctly publish the modification to the waiting |
| // thread. |
| std::unique_lock<std::mutex> g(mLock); |
| mShuttingDownFlag.store(true); |
| } |
| mCond.notify_all(); |
| if (mThread.joinable()) { |
| mThread.join(); |
| } |
| } |
| |
| void GeneratorHub::registerGenerator(int32_t cookie, FakeValueGeneratorPtr generator) { |
| { |
| std::lock_guard<std::mutex> g(mLock); |
| // Register only if the generator can produce event |
| if (generator->hasNext()) { |
| // Push the next event if it is a new generator |
| if (mGenerators.find(cookie) == mGenerators.end()) { |
| ALOGI("%s: Registering new generator, cookie: %d", __func__, cookie); |
| mEventQueue.push({cookie, generator->nextEvent()}); |
| } |
| mGenerators[cookie] = std::move(generator); |
| ALOGI("%s: Registered generator, cookie: %d", __func__, cookie); |
| } |
| } |
| mCond.notify_one(); |
| } |
| |
| void GeneratorHub::unregisterGenerator(int32_t cookie) { |
| { |
| std::lock_guard<std::mutex> g(mLock); |
| mGenerators.erase(cookie); |
| } |
| mCond.notify_one(); |
| ALOGI("%s: Unregistered generator, cookie: %d", __func__, cookie); |
| } |
| |
| void GeneratorHub::run() { |
| while (!mShuttingDownFlag.load()) { |
| std::unique_lock<std::mutex> g(mLock); |
| // Pop events whose generator does not exist (may be already unregistered) |
| while (!mEventQueue.empty() |
| && mGenerators.find(mEventQueue.top().cookie) == mGenerators.end()) { |
| mEventQueue.pop(); |
| } |
| // Wait until event queue is not empty or shutting down flag is set |
| mCond.wait(g, [this] { return !mEventQueue.empty() || mShuttingDownFlag.load(); }); |
| if (mShuttingDownFlag.load()) { |
| break; |
| } |
| |
| const VhalEvent& curEvent = mEventQueue.top(); |
| |
| TimePoint eventTime(Nanos(curEvent.val.timestamp)); |
| // Wait until the soonest event happen |
| if (mCond.wait_until(g, eventTime) != std::cv_status::timeout) { |
| // It is possible that a new generator is registered and produced a sooner event, or current |
| // generator is unregistered, in this case the thread will re-evaluate the soonest event |
| ALOGI("Something happened while waiting"); |
| continue; |
| } |
| // Now it's time to handle current event. |
| mOnHalEvent(curEvent.val); |
| // Update queue by popping current event and producing next event from the same generator |
| int32_t cookie = curEvent.cookie; |
| mEventQueue.pop(); |
| if (hasNext(cookie)) { |
| mEventQueue.push({cookie, mGenerators[cookie]->nextEvent()}); |
| } else { |
| ALOGI("%s: Generator ended, unregister it, cookie: %d", __func__, cookie); |
| mGenerators.erase(cookie); |
| } |
| } |
| } |
| |
| bool GeneratorHub::hasNext(int32_t cookie) { |
| return mGenerators.find(cookie) != mGenerators.end() && mGenerators[cookie]->hasNext(); |
| } |
| |
| } // namespace impl |
| |
| } // namespace V2_0 |
| } // namespace vehicle |
| } // namespace automotive |
| } // namespace hardware |
| } // namespace android |