Revert "lshal: use std::async" (2cfbc514) · Commits · e / os / android_frameworks_native

cmds/lshal/Timeout.h

+65 −26

Original line number	Diff line number	Diff line
		@@ -16,44 +16,83 @@

		#pragma once

		#include <condition_variable>
		#include <chrono>
		#include <future>
		#include <functional>
		#include <mutex>
		#include <thread>

		#include <hidl/Status.h>
		#include <utils/Errors.h>

		namespace android {
		namespace lshal {

		// Call function on interfaceObject and wait for result until the given timeout has reached.
		// Callback functions pass to timeoutIPC() may be executed after the this function
		// has returned, especially if deadline has been reached. Hence, care must be taken when passing
		// data between the background thread and the main thread. See b/311143089.
		class BackgroundTaskState {
		public:
		explicit BackgroundTaskState(std::function<void(void)> &&func)
		: mFunc(std::forward<decltype(func)>(func)) {}
		void notify() {
		std::unique_lock<std::mutex> lock(mMutex);
		mFinished = true;
		lock.unlock();
		mCondVar.notify_all();
		}
		template<class C, class D>
		bool wait(std::chrono::time_point<C, D> end) {
		std::unique_lock<std::mutex> lock(mMutex);
		mCondVar.wait_until(lock, end, [this](){ return this->mFinished; });
		return mFinished;
		}
		void operator()() {
		mFunc();
		}
		private:
		std::mutex mMutex;
		std::condition_variable mCondVar;
		bool mFinished = false;
		std::function<void(void)> mFunc;
		};

		void callAndNotify(void data) {
		BackgroundTaskState &state = static_cast<BackgroundTaskState >(data);
		state();
		state.notify();
		return nullptr;
		}

		template<class R, class P>
		bool timeout(std::chrono::duration<R, P> delay, std::function<void(void)> &&func) {
		auto now = std::chrono::system_clock::now();
		BackgroundTaskState state{std::forward<decltype(func)>(func)};
		pthread_t thread;
		if (pthread_create(&thread, nullptr, callAndNotify, &state)) {
		std::cerr << "FATAL: could not create background thread." << std::endl;
		return false;
		}
		bool success = state.wait(now + delay);
		if (!success) {
		pthread_kill(thread, SIGINT);
		}
		pthread_join(thread, nullptr);
		return success;
		}

		template<class R, class P, class Function, class I, class... Args>
		typename std::result_of<Function(I *, Args...)>::type
		timeoutIPC(std::chrono::duration<R, P> wait, const sp<I> &interfaceObject, Function &&func,
		Args &&... args) {
		using ::android::hardware::Status;

		// Execute on a background thread but do not defer execution.
		auto future =
		std::async(std::launch::async, func, interfaceObject, std::forward<Args>(args)...);
		auto status = future.wait_for(wait);
		if (status == std::future_status::ready) {
		return future.get();
		}

		// This future belongs to a background thread that we no longer care about.
		// Putting this in the global list avoids std::future::~future() that may wait for the
		// result to come back.
		// This leaks memory, but lshal is a debugging tool, so this is fine.
		static std::vector<decltype(future)> gDeadPool{};
		gDeadPool.emplace_back(std::move(future));

		if (status == std::future_status::timeout) {
		typename std::result_of<Function(I *, Args...)>::type ret{Status::ok()};
		auto boundFunc = std::bind(std::forward<Function>(func),
		interfaceObject.get(), std::forward<Args>(args)...);
		bool success = timeout(wait, [&ret, &boundFunc] {
		ret = std::move(boundFunc());
		});
		if (!success) {
		return Status::fromStatusT(TIMED_OUT);
		}
		return Status::fromExceptionCode(Status::Exception::EX_ILLEGAL_STATE, "Illegal future_status");
		return ret;
		}

		} // namespace lshal
		} // namespace android

cmds/lshal/main.cpp

+1 −2

Original line number	Diff line number	Diff line
		@@ -18,6 +18,5 @@

		int main(int argc, char **argv) {
		using namespace ::android::lshal;
		// Use _exit() to force terminate background threads in Timeout.h
		_exit(Lshal{}.main(Arg{argc, argv}));
		return Lshal{}.main(Arg{argc, argv});
		}

cmds/lshal/test.cpp

+7 −115

Original line number	Diff line number	Diff line
		@@ -14,10 +14,6 @@
		* limitations under the License.
		*/

		#include <chrono>
		#include <future>
		#include <mutex>
		#include "android/hidl/base/1.0/IBase.h"
		#define LOG_TAG "Lshal"
		#include <android-base/logging.h>

		@@ -40,8 +36,6 @@

		using namespace testing;

		using std::chrono_literals::operator""ms;

		using ::android::hidl::base::V1_0::DebugInfo;
		using ::android::hidl::base::V1_0::IBase;
		using ::android::hidl::manager::V1_0::IServiceManager;
		@@ -940,7 +934,10 @@ TEST_F(ListTest, DumpDebug) {
		return hardware::Void();
		}));
		EXPECT_CALL(*serviceManager, get(_, _))
		.WillRepeatedly(Invoke([&](const hidl_string&, const hidl_string&) -> sp<IBase> {
		.WillRepeatedly(
		Invoke([&](const hidl_string&, const hidl_string& instance) -> sp<IBase> {
		int id = getIdFromInstanceName(instance);
		if (id > inheritanceLevel) return nullptr;
		return sp<IBase>(service);
		}));

		@@ -960,110 +957,6 @@ TEST_F(ListTest, DumpDebug) {
		EXPECT_EQ("", err.str());
		}

		// In SlowService, everything goes slooooooow. Each IPC call will wait for
		// the specified time before calling the callback function or returning.
		class SlowService : public IBase {
		public:
		explicit SlowService(std::chrono::milliseconds wait) : mWait(wait) {}
		android::hardware::Return<void> interfaceDescriptor(interfaceDescriptor_cb cb) override {
		std::this_thread::sleep_for(mWait);
		cb(getInterfaceName(1));
		storeHistory("interfaceDescriptor");
		return hardware::Void();
		}
		android::hardware::Return<void> interfaceChain(interfaceChain_cb cb) override {
		std::this_thread::sleep_for(mWait);
		std::vector<hidl_string> ret;
		ret.push_back(getInterfaceName(1));
		ret.push_back(IBase::descriptor);
		cb(ret);
		storeHistory("interfaceChain");
		return hardware::Void();
		}
		android::hardware::Return<void> getHashChain(getHashChain_cb cb) override {
		std::this_thread::sleep_for(mWait);
		std::vector<hidl_hash> ret;
		ret.push_back(getHashFromId(0));
		ret.push_back(getHashFromId(0xff));
		cb(ret);
		storeHistory("getHashChain");
		return hardware::Void();
		}
		android::hardware::Return<void> debug(const hidl_handle&,
		const hidl_vec<hidl_string>&) override {
		std::this_thread::sleep_for(mWait);
		storeHistory("debug");
		return Void();
		}

		template <class R, class P, class Pred>
		bool waitForHistory(std::chrono::duration<R, P> wait, Pred predicate) {
		std::unique_lock<std::mutex> lock(mLock);
		return mCv.wait_for(lock, wait, [&]() { return predicate(mCallHistory); });
		}

		private:
		void storeHistory(std::string hist) {
		{
		std::lock_guard<std::mutex> lock(mLock);
		mCallHistory.emplace_back(std::move(hist));
		}
		mCv.notify_all();
		}

		const std::chrono::milliseconds mWait;
		std::mutex mLock;
		std::condition_variable mCv;
		// List of functions that have finished being called on this interface.
		std::vector<std::string> mCallHistory;
		};

		class TimeoutTest : public ListTest {
		public:
		void setMockServiceManager(sp<IBase> service) {
		EXPECT_CALL(*serviceManager, list(_))
		.WillRepeatedly(Invoke([&](IServiceManager::list_cb cb) {
		std::vector<hidl_string> ret;
		ret.push_back(getInterfaceName(1) + "/default");
		cb(ret);
		return hardware::Void();
		}));
		EXPECT_CALL(*serviceManager, get(_, _))
		.WillRepeatedly(Invoke([&](const hidl_string&, const hidl_string&) -> sp<IBase> {
		return service;
		}));
		}
		};

		TEST_F(TimeoutTest, BackgroundThreadIsKept) {
		auto lshalIpcTimeout = 100ms;
		auto serviceIpcTimeout = 200ms;
		lshal->setWaitTimeForTest(lshalIpcTimeout, lshalIpcTimeout);
		sp<SlowService> service = new SlowService(serviceIpcTimeout);
		setMockServiceManager(service);

		optind = 1; // mimic Lshal::parseArg()
		EXPECT_NE(0u, mockList->main(createArg({"lshal", "--types=b", "-i", "--neat"})));
		EXPECT_THAT(err.str(), HasSubstr("Skipping \"a.h.foo1@1.0::IFoo/default\""));
		EXPECT_TRUE(service->waitForHistory(serviceIpcTimeout * 5, [](const auto& hist) {
		return hist.size() == 1 && hist[0] == "interfaceChain";
		})) << "The background thread should continue after the main thread moves on, but it is killed";
		}

		TEST_F(TimeoutTest, BackgroundThreadDoesNotBlockMainThread) {
		auto lshalIpcTimeout = 100ms;
		auto serviceIpcTimeout = 2000ms;
		auto start = std::chrono::system_clock::now();
		lshal->setWaitTimeForTest(lshalIpcTimeout, lshalIpcTimeout);
		sp<SlowService> service = new SlowService(serviceIpcTimeout);
		setMockServiceManager(service);

		optind = 1; // mimic Lshal::parseArg()
		EXPECT_NE(0u, mockList->main(createArg({"lshal", "--types=b", "-i", "--neat"})));
		EXPECT_LE(std::chrono::system_clock::now(), start + 5 * lshalIpcTimeout)
		<< "The main thread should not be blocked by the background task";
		}

		class ListVintfTest : public ListTest {
		public:
		virtual void SetUp() override {
		@@ -1186,6 +1079,5 @@ TEST_F(HelpTest, UnknownOptionHelp2) {

		int main(int argc, char **argv) {
		::testing::InitGoogleMock(&argc, argv);
		// Use _exit() to force terminate background threads in Timeout.h
		_exit(RUN_ALL_TESTS());
		return RUN_ALL_TESTS();
		}