Reactor-based alarm implementation (e7d8c660) · Commits · e / os / android_packages_modules_Bluetooth

system/common/Android.bp

+5 −0

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		@@ -11,11 +11,13 @@ cc_library_static {
		],
		srcs: [
		"address_obfuscator.cc",
		"alarm.cc",
		"handler.cc",
		"message_loop_thread.cc",
		"metrics.cc",
		"once_timer.cc",
		"reactor.cc",
		"repeating_alarm.cc",
		"repeating_timer.cc",
		"thread.cc",
		"time_util.cc",
		@@ -42,12 +44,14 @@ cc_test {
		],
		srcs : [
		"address_obfuscator_unittest.cc",
		"alarm_unittest.cc",
		"handler_unittest.cc",
		"leaky_bonded_queue_unittest.cc",
		"message_loop_thread_unittest.cc",
		"metrics_unittest.cc",
		"once_timer_unittest.cc",
		"reactor_unittest.cc",
		"repeating_alarm_unittest.cc",
		"repeating_timer_unittest.cc",
		"state_machine_unittest.cc",
		"thread_unittest.cc",
		@@ -121,6 +125,7 @@ cc_benchmark {
		"liblog",
		"libcrypto",
		"libprotobuf-cpp-lite",
		"libcrypto",
		"libcutils",
		],
		static_libs: [

system/common/alarm.cc

0 → 100644

+76 −0

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		/*
		* Copyright 2019 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.
		*/

		#include "alarm.h"

		#include <sys/timerfd.h>
		#include <cstring>

		#include "base/logging.h"
		#include "utils.h"

		namespace bluetooth {
		namespace common {

		Alarm::Alarm(Thread* thread)
		: thread_(thread),
		fd_(timerfd_create(CLOCK_BOOTTIME_ALARM, 0)) {
		CHECK_NE(fd_, -1) << __func__ << ": cannot create timerfd: " << strerror(errno);

		token_ = thread_->GetReactor()->Register(fd_, [this] { on_fire(); }, nullptr);
		}

		Alarm::~Alarm() {
		thread_->GetReactor()->Unregister(token_);

		int close_status;
		RUN_NO_INTR(close_status = close(fd_));
		CHECK_NE(close_status, -1) << __func__ << ": cannot close timerfd: " << strerror(errno);
		}

		void Alarm::Schedule(Closure task, std::chrono::milliseconds delay) {
		std::lock_guard<std::mutex> lock(mutex_);
		long delay_ms = delay.count();
		itimerspec timer_itimerspec{
		{/* interval for periodic timer */},
		{delay_ms / 1000, delay_ms % 1000 * 1000000}
		};
		int result = timerfd_settime(fd_, 0, &timer_itimerspec, nullptr);
		CHECK_EQ(result, 0) << __func__ << ": failed, error=" << strerror(errno);

		task_ = std::move(task);
		}

		void Alarm::Cancel() {
		std::lock_guard<std::mutex> lock(mutex_);
		itimerspec disarm_itimerspec{/* disarm timer */};
		int result = timerfd_settime(fd_, 0, &disarm_itimerspec, nullptr);
		CHECK_EQ(result, 0) << __func__ << ": failed, error=" << strerror(errno);
		}

		void Alarm::on_fire() {
		std::unique_lock<std::mutex> lock(mutex_);
		auto task = std::move(task_);
		uint64_t times_invoked;
		auto bytes_read = read(fd_, &times_invoked, sizeof(uint64_t));
		lock.unlock();
		task();
		CHECK_EQ(bytes_read, static_cast<ssize_t>(sizeof(uint64_t))) << __func__ << ": failed, error=" << strerror(errno);
		CHECK_EQ(times_invoked, static_cast<uint64_t>(1));
		}

		} // namespace common
		} // namespace bluetooth

system/common/alarm.h

0 → 100644

+59 −0

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		/*
		* Copyright 2019 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 <functional>
		#include <memory>
		#include <mutex>

		#include "common/thread.h"
		#include "common/utils.h"

		namespace bluetooth {
		namespace common {

		// A single-shot alarm for reactor-based thread, implemented by Linux timerfd.
		// When it's constructed, it will register a reactable on the specified thread; when it's destroyed, it will unregister
		// itself from the thread.
		class Alarm {
		public:
		// Create and register a single-shot alarm on given thread
		explicit Alarm(Thread* thread);

		// Unregister this alarm from the thread and release resource
		~Alarm();

		DISALLOW_COPY_AND_ASSIGN(Alarm);

		// Schedule the alarm with given delay
		void Schedule(Closure task, std::chrono::milliseconds delay);

		// Cancel the alarm. No-op if it's not armed.
		void Cancel();

		private:
		Closure task_;
		Thread* thread_;
		int fd_ = 0;
		Reactor::Reactable* token_;
		mutable std::mutex mutex_;
		void on_fire();
		};

		} // namespace common

		} // namespace bluetooth

system/common/alarm_unittest.cc

0 → 100644

+90 −0

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		/*
		* Copyright 2019 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.
		*/

		#include "alarm.h"

		#include <future>

		#include "base/logging.h"
		#include "gtest/gtest.h"

		namespace bluetooth {
		namespace common {
		namespace {

		class AlarmTest : public ::testing::Test {
		protected:
		void SetUp() override {
		thread_ = new Thread("test_thread", Thread::Priority::NORMAL);
		alarm_ = new Alarm(thread_);
		}

		void TearDown() override {
		delete alarm_;
		delete thread_;
		}
		Alarm* alarm_;

		private:
		Thread* thread_;
		};

		TEST_F(AlarmTest, cancel_while_not_armed) {
		alarm_->Cancel();
		}

		TEST_F(AlarmTest, schedule) {
		std::promise<void> promise;
		auto future = promise.get_future();
		auto before = std::chrono::steady_clock::now();
		int delay_ms = 10;
		int delay_error_ms = 3;
		alarm_->Schedule([&promise]() { promise.set_value(); }, std::chrono::milliseconds(delay_ms));
		future.get();
		auto after = std::chrono::steady_clock::now();
		auto duration_ms = std::chrono::duration_cast<std::chrono::milliseconds>(after - before);
		ASSERT_NEAR(duration_ms.count(), delay_ms, delay_error_ms);
		}

		TEST_F(AlarmTest, cancel_alarm) {
		alarm_->Schedule([]() { ASSERT_TRUE(false) << "Should not happen"; }, std::chrono::milliseconds(3));
		alarm_->Cancel();
		std::this_thread::sleep_for(std::chrono::milliseconds(5));
		}

		TEST_F(AlarmTest, cancel_alarm_from_callback) {
		alarm_->Schedule([this]() { this->alarm_->Cancel(); }, std::chrono::milliseconds(1));
		std::this_thread::sleep_for(std::chrono::milliseconds(5));
		}

		TEST_F(AlarmTest, schedule_while_alarm_armed) {
		alarm_->Schedule([]() { ASSERT_TRUE(false) << "Should not happen"; }, std::chrono::milliseconds(1));
		std::promise<void> promise;
		auto future = promise.get_future();
		alarm_->Schedule([&promise]() { promise.set_value(); }, std::chrono::milliseconds(10));
		future.get();
		}

		TEST_F(AlarmTest, delete_while_alarm_armed) {
		alarm_->Schedule([]() { ASSERT_TRUE(false) << "Should not happen"; }, std::chrono::milliseconds(1));
		delete alarm_;
		alarm_ = nullptr;
		std::this_thread::sleep_for(std::chrono::milliseconds(10));
		}

		} // namespace
		} // namespace common
		} // namespace bluetooth

system/common/benchmark/timer_performance_benchmark.cc

+88 −0

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		@@ -20,16 +20,22 @@
		#include <benchmark/benchmark.h>
		#include <future>

		#include "common/alarm.h"
		#include "common/message_loop_thread.h"
		#include "common/once_timer.h"
		#include "common/repeating_alarm.h"
		#include "common/repeating_timer.h"
		#include "common/thread.h"
		#include "common/time_util.h"
		#include "osi/include/alarm.h"

		using ::benchmark::State;
		using bluetooth::common::Alarm;
		using bluetooth::common::MessageLoopThread;
		using bluetooth::common::OnceTimer;
		using bluetooth::common::RepeatingAlarm;
		using bluetooth::common::RepeatingTimer;
		using bluetooth::common::Thread;
		using bluetooth::common::time_get_os_boottime_us;

		// fake get_main_message_loop implementation for alarm
		@@ -268,6 +274,88 @@ BENCHMARK_REGISTER_F(BM_AlarmTaskPeriodicTimer, periodic_accuracy)
		->Iterations(1)
		->UseRealTime();

		class BM_ReactableAlarm : public ::benchmark::Fixture {
		protected:
		void SetUp(State& st) override {
		::benchmark::Fixture::SetUp(st);
		thread_ = std::make_unique<Thread>("timer_benchmark", Thread::Priority::REAL_TIME);
		alarm_ = std::make_unique<Alarm>(thread_.get());
		repeating_alarm_ = std::make_unique<RepeatingAlarm>(thread_.get());
		g_map.clear();
		g_promise = std::make_shared<std::promise<void>>();
		g_scheduled_tasks = 0;
		g_task_length = 0;
		g_task_interval = 0;
		g_task_counter = 0;
		}

		void TearDown(State& st) override {
		g_promise = nullptr;
		alarm_ = nullptr;
		repeating_alarm_ = nullptr;
		thread_->Stop();
		thread_ = nullptr;
		::benchmark::Fixture::TearDown(st);
		}

		std::unique_ptr<Thread> thread_;
		std::unique_ptr<Alarm> alarm_;
		std::unique_ptr<RepeatingAlarm> repeating_alarm_;
		};

		BENCHMARK_DEFINE_F(BM_ReactableAlarm, timer_performance_ms)(State& state) {
		auto milliseconds = static_cast<int>(state.range(0));
		for (auto _ : state) {
		auto start_time_point = time_get_os_boottime_us();
		alarm_->Schedule(std::bind(TimerFire, nullptr), std::chrono::milliseconds(milliseconds));
		g_promise->get_future().get();
		auto end_time_point = time_get_os_boottime_us();
		auto duration = end_time_point - start_time_point;
		state.SetIterationTime(duration * 1e-6);
		alarm_->Cancel();
		}
		};

		BENCHMARK_REGISTER_F(BM_ReactableAlarm, timer_performance_ms)
		->Arg(1)
		->Arg(5)
		->Arg(10)
		->Arg(20)
		->Arg(100)
		->Arg(1000)
		->Arg(2000)
		->Iterations(1)
		->UseRealTime();

		BENCHMARK_DEFINE_F(BM_ReactableAlarm, periodic_accuracy)
		(State& state) {
		for (auto _ : state) {
		g_scheduled_tasks = state.range(0);
		g_task_length = state.range(1);
		g_task_interval = state.range(2);
		g_start_time = time_get_os_boottime_us();
		repeating_alarm_->Schedule([] { AlarmSleepAndCountDelayedTime(nullptr); },
		std::chrono::milliseconds(g_task_interval));
		g_promise->get_future().get();
		repeating_alarm_->Cancel();
		}
		for (const auto& delay : g_map) {
		state.counters[std::to_string(delay.first)] = delay.second;
		}
		};

		BENCHMARK_REGISTER_F(BM_ReactableAlarm, periodic_accuracy)
		->Args({2000, 1, 5})
		->Args({2000, 3, 5})
		->Args({2000, 1, 7})
		->Args({2000, 3, 7})
		->Args({2000, 1, 20})
		->Args({2000, 5, 20})
		->Args({2000, 10, 20})
		->Args({2000, 15, 20})
		->Iterations(1)
		->UseRealTime();

		int main(int argc, char** argv) {
		// Disable LOG() output from libchrome
		logging::LoggingSettings log_settings;