Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit e2dadf0c authored by Yifan Hong's avatar Yifan Hong
Browse files

lshal: Add timeout for IPC calls. 

IPC calls into interfaces should be done fault-torelently.
Add a timeout for each IPC call made so that lshal won't be
indefinitely blocked even if the interface don't reply
promptly.

Bug: 35317039

Test: lshal

Change-Id: Icb8157716ad68bddb5b33304b9063aa6f233985d
parent 38d53e03

cmds/lshal/Lshal.cpp

+7 −5
Original line number Diff line number Diff line
@@ -29,6 +29,8 @@ 
#include <android/hidl/manager/1.0/IServiceManager.h>

#include <hidl/ServiceManagement.h>



#include "Timeout.h"



using ::android::hardware::hidl_string;

using ::android::hidl::manager::V1_0::IServiceManager;
@@ -163,7 +165,7 @@ Status Lshal::fetchAllLibraries(const sp<IServiceManager> &manager) { 
    using namespace ::android::hardware;

    using namespace ::android::hidl::manager::V1_0;

    using namespace ::android::hidl::base::V1_0;

    auto ret = manager->list([&] (const auto &fqInstanceNames) {

    auto ret = timeoutIPC(manager, &IServiceManager::list, [&] (const auto &fqInstanceNames) {

        for (const auto &fqInstanceName : fqInstanceNames) {

            putEntry({

                .interfaceName = fqInstanceName,
@@ -186,7 +188,7 @@ Status Lshal::fetchPassthrough(const sp<IServiceManager> &manager) { 
    using namespace ::android::hardware;

    using namespace ::android::hidl::manager::V1_0;

    using namespace ::android::hidl::base::V1_0;

    auto ret = manager->debugDump([&] (const auto &infos) {

    auto ret = timeoutIPC(manager, &IServiceManager::debugDump, [&] (const auto &infos) {

        for (const auto &info : infos) {

            putEntry({

                .interfaceName =
@@ -214,7 +216,7 @@ Status Lshal::fetchBinderized(const sp<IServiceManager> &manager) { 
    using namespace ::android::hidl::base::V1_0;

    const std::string mode = "hwbinder";

    Status status = OK;

    auto listRet = manager->list([&] (const auto &fqInstanceNames) {

    auto listRet = timeoutIPC(manager, &IServiceManager::list, [&] (const auto &fqInstanceNames) {

        // server pid, .ptr value of binder object, child pids

        std::map<std::string, DebugInfo> allDebugInfos;

        std::map<pid_t, std::map<uint64_t, Pids>> allPids;
@@ -222,7 +224,7 @@ Status Lshal::fetchBinderized(const sp<IServiceManager> &manager) { 
            const auto pair = split(fqInstanceName, '/');

            const auto &serviceName = pair.first;

            const auto &instanceName = pair.second;

            auto getRet = manager->get(serviceName, instanceName);

            auto getRet = timeoutIPC(manager, &IServiceManager::get, serviceName, instanceName);

            if (!getRet.isOk()) {

                mErr << "Warning: Skipping \"" << fqInstanceName << "\": "

                     << "cannot be fetched from service manager:"
@@ -237,7 +239,7 @@ Status Lshal::fetchBinderized(const sp<IServiceManager> &manager) { 
                status |= DUMP_BINDERIZED_ERROR;

                continue;

            }

            auto debugRet = service->getDebugInfo([&] (const auto &debugInfo) {

            auto debugRet = timeoutIPC(service, &IBase::getDebugInfo, [&] (const auto &debugInfo) {

                allDebugInfos[fqInstanceName] = debugInfo;

                if (debugInfo.pid >= 0) {

                    allPids[static_cast<pid_t>(debugInfo.pid)].clear();

cmds/lshal/Timeout.h

0 → 100644
+81 −0
Original line number Diff line number Diff line 
/*

 * Copyright (C) 2016 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 <condition_variable>

#include <chrono>

#include <functional>

#include <mutex>

#include <thread>



#include <hidl/Status.h>



namespace android {

namespace lshal {



static constexpr std::chrono::milliseconds IPC_CALL_WAIT{500};



class BackgroundTaskState {

public:

    BackgroundTaskState(){}

    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;

    }

private:

    std::mutex mMutex;

    std::condition_variable mCondVar;

    bool mFinished = false;

};



template<class R, class P>

bool timeout(std::chrono::duration<R, P> delay, const std::function<void(void)> &func) {

    auto now = std::chrono::system_clock::now();

    BackgroundTaskState state{};

    std::thread t([&state, &func] {

        func();

        state.notify();

    });

    t.detach();

    bool success = state.wait(now + delay);

    return success;

}



template<class Function, class I, class... Args>

typename std::result_of<Function(I *, Args...)>::type

timeoutIPC(const sp<I> &interfaceObject, Function &&func, Args &&... args) {

    using ::android::hardware::Status;

    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(IPC_CALL_WAIT, [&ret, &boundFunc] {

        ret = boundFunc();

    });

    if (!success) {

        return Status::fromStatusT(TIMED_OUT);

    }

    return ret;

}



}  // namespace lshal

}  // namespace android