ServiceManagement -> HidlServiceManagement

To make logs more clear.

Bug: N/A
Test: N/A
Change-Id: Ib91b6eaad4f2958127c9a0aa7097736f35fbc1a3
diff --git a/transport/HidlServiceManagement.cpp b/transport/HidlServiceManagement.cpp
new file mode 100644
index 0000000..357bb30
--- /dev/null
+++ b/transport/HidlServiceManagement.cpp
@@ -0,0 +1,865 @@
+/*
+ * 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.
+ */
+
+#define LOG_TAG "HidlServiceManagement"
+
+#include <android/dlext.h>
+#include <condition_variable>
+#include <dlfcn.h>
+#include <dirent.h>
+#include <fstream>
+#include <pthread.h>
+#include <unistd.h>
+
+#include <mutex>
+#include <regex>
+#include <set>
+
+#include <hidl/HidlBinderSupport.h>
+#include <hidl/HidlInternal.h>
+#include <hidl/HidlTransportUtils.h>
+#include <hidl/ServiceManagement.h>
+#include <hidl/Status.h>
+#include <utils/SystemClock.h>
+
+#include <android-base/file.h>
+#include <android-base/logging.h>
+#include <android-base/parseint.h>
+#include <android-base/properties.h>
+#include <android-base/stringprintf.h>
+#include <android-base/strings.h>
+#include <hwbinder/IPCThreadState.h>
+#include <hwbinder/Parcel.h>
+#if !defined(__ANDROID_RECOVERY__)
+#include <vndksupport/linker.h>
+#endif
+
+#include <android/hidl/manager/1.2/BnHwServiceManager.h>
+#include <android/hidl/manager/1.2/BpHwServiceManager.h>
+#include <android/hidl/manager/1.2/IServiceManager.h>
+
+#define RE_COMPONENT    "[a-zA-Z_][a-zA-Z_0-9]*"
+#define RE_PATH         RE_COMPONENT "(?:[.]" RE_COMPONENT ")*"
+static const std::regex gLibraryFileNamePattern("(" RE_PATH "@[0-9]+[.][0-9]+)-impl(.*?).so");
+
+using android::base::WaitForProperty;
+
+using ::android::hidl::base::V1_0::IBase;
+using IServiceManager1_0 = android::hidl::manager::V1_0::IServiceManager;
+using IServiceManager1_1 = android::hidl::manager::V1_1::IServiceManager;
+using IServiceManager1_2 = android::hidl::manager::V1_2::IServiceManager;
+using ::android::hidl::manager::V1_0::IServiceNotification;
+
+namespace android {
+namespace hardware {
+
+static const char* kHwServicemanagerReadyProperty = "hwservicemanager.ready";
+
+#if defined(__ANDROID_RECOVERY__)
+static constexpr bool kIsRecovery = true;
+#else
+static constexpr bool kIsRecovery = false;
+#endif
+
+static void waitForHwServiceManager() {
+    using std::literals::chrono_literals::operator""s;
+
+    while (!WaitForProperty(kHwServicemanagerReadyProperty, "true", 1s)) {
+        LOG(WARNING) << "Waited for hwservicemanager.ready for a second, waiting another...";
+    }
+}
+
+static std::string binaryName() {
+    std::ifstream ifs("/proc/self/cmdline");
+    std::string cmdline;
+    if (!ifs.is_open()) {
+        return "";
+    }
+    ifs >> cmdline;
+
+    size_t idx = cmdline.rfind('/');
+    if (idx != std::string::npos) {
+        cmdline = cmdline.substr(idx + 1);
+    }
+
+    return cmdline;
+}
+
+static std::string packageWithoutVersion(const std::string& packageAndVersion) {
+    size_t at = packageAndVersion.find('@');
+    if (at == std::string::npos) return packageAndVersion;
+    return packageAndVersion.substr(0, at);
+}
+
+static void tryShortenProcessName(const std::string& descriptor) {
+    const static std::string kTasks = "/proc/self/task/";
+
+    // make sure that this binary name is in the same package
+    std::string processName = binaryName();
+
+    // e.x. android.hardware.foo is this package
+    if (!base::StartsWith(packageWithoutVersion(processName), packageWithoutVersion(descriptor))) {
+        return;
+    }
+
+    // e.x. android.hardware.module.foo@1.2::IFoo -> foo@1.2
+    size_t lastDot = descriptor.rfind('.');
+    if (lastDot == std::string::npos) return;
+    size_t secondDot = descriptor.rfind('.', lastDot - 1);
+    if (secondDot == std::string::npos) return;
+
+    std::string newName = processName.substr(secondDot + 1, std::string::npos);
+    ALOGI("Removing namespace from process name %s to %s.", processName.c_str(), newName.c_str());
+
+    std::unique_ptr<DIR, decltype(&closedir)> dir(opendir(kTasks.c_str()), closedir);
+    if (dir == nullptr) return;
+
+    dirent* dp;
+    while ((dp = readdir(dir.get())) != nullptr) {
+        if (dp->d_type != DT_DIR) continue;
+        if (dp->d_name[0] == '.') continue;
+
+        std::fstream fs(kTasks + dp->d_name + "/comm");
+        if (!fs.is_open()) {
+            ALOGI("Could not rename process, failed read comm for %s.", dp->d_name);
+            continue;
+        }
+
+        std::string oldComm;
+        fs >> oldComm;
+
+        // don't rename if it already has an explicit name
+        if (base::StartsWith(descriptor, oldComm)) {
+            fs.seekg(0, fs.beg);
+            fs << newName;
+        }
+    }
+}
+
+namespace details {
+
+/*
+ * Returns the age of the current process by reading /proc/self/stat and comparing starttime to the
+ * current time. This is useful for measuring how long it took a HAL to register itself.
+ */
+static long getProcessAgeMs() {
+    constexpr const int PROCFS_STAT_STARTTIME_INDEX = 21;
+    std::string content;
+    android::base::ReadFileToString("/proc/self/stat", &content, false);
+    auto stats = android::base::Split(content, " ");
+    if (stats.size() <= PROCFS_STAT_STARTTIME_INDEX) {
+        LOG(INFO) << "Could not read starttime from /proc/self/stat";
+        return -1;
+    }
+    const std::string& startTimeString = stats[PROCFS_STAT_STARTTIME_INDEX];
+    static const int64_t ticksPerSecond = sysconf(_SC_CLK_TCK);
+    const int64_t uptime = android::uptimeMillis();
+
+    unsigned long long startTimeInClockTicks = 0;
+    if (android::base::ParseUint(startTimeString, &startTimeInClockTicks)) {
+        long startTimeMs = 1000ULL * startTimeInClockTicks / ticksPerSecond;
+        return uptime - startTimeMs;
+    }
+    return -1;
+}
+
+static void onRegistrationImpl(const std::string& descriptor, const std::string& instanceName) {
+    long halStartDelay = getProcessAgeMs();
+    if (halStartDelay >= 0) {
+        // The "start delay" printed here is an estimate of how long it took the HAL to go from
+        // process creation to registering itself as a HAL.  Actual start time could be longer
+        // because the process might not have joined the threadpool yet, so it might not be ready to
+        // process transactions.
+        LOG(INFO) << "Registered " << descriptor << "/" << instanceName << " (start delay of "
+                  << halStartDelay << "ms)";
+    }
+
+    tryShortenProcessName(descriptor);
+}
+
+void onRegistration(const std::string& packageName, const std::string& interfaceName,
+                    const std::string& instanceName) {
+    return onRegistrationImpl(packageName + "::" + interfaceName, instanceName);
+}
+
+}  // details
+
+sp<IServiceManager1_0> defaultServiceManager() {
+    return defaultServiceManager1_2();
+}
+sp<IServiceManager1_1> defaultServiceManager1_1() {
+    return defaultServiceManager1_2();
+}
+sp<IServiceManager1_2> defaultServiceManager1_2() {
+    using android::hidl::manager::V1_2::BnHwServiceManager;
+    using android::hidl::manager::V1_2::BpHwServiceManager;
+
+    static std::mutex gDefaultServiceManagerLock;
+    static sp<IServiceManager1_2> gDefaultServiceManager;
+
+    {
+        std::lock_guard<std::mutex> _l(gDefaultServiceManagerLock);
+        if (gDefaultServiceManager != nullptr) {
+            return gDefaultServiceManager;
+        }
+
+        if (access("/dev/hwbinder", F_OK|R_OK|W_OK) != 0) {
+            // HwBinder not available on this device or not accessible to
+            // this process.
+            return nullptr;
+        }
+
+        waitForHwServiceManager();
+
+        while (gDefaultServiceManager == nullptr) {
+            gDefaultServiceManager =
+                fromBinder<IServiceManager1_2, BpHwServiceManager, BnHwServiceManager>(
+                    ProcessState::self()->getContextObject(nullptr));
+            if (gDefaultServiceManager == nullptr) {
+                LOG(ERROR) << "Waited for hwservicemanager, but got nullptr.";
+                sleep(1);
+            }
+        }
+    }
+
+    return gDefaultServiceManager;
+}
+
+static std::vector<std::string> findFiles(const std::string& path, const std::string& prefix,
+                                          const std::string& suffix) {
+    std::unique_ptr<DIR, decltype(&closedir)> dir(opendir(path.c_str()), closedir);
+    if (!dir) return {};
+
+    std::vector<std::string> results{};
+
+    dirent* dp;
+    while ((dp = readdir(dir.get())) != nullptr) {
+        std::string name = dp->d_name;
+
+        if (base::StartsWith(name, prefix) && base::EndsWith(name, suffix)) {
+            results.push_back(name);
+        }
+    }
+
+    return results;
+}
+
+bool matchPackageName(const std::string& lib, std::string* matchedName, std::string* implName) {
+    std::smatch match;
+    if (std::regex_match(lib, match, gLibraryFileNamePattern)) {
+        *matchedName = match.str(1) + "::I*";
+        *implName = match.str(2);
+        return true;
+    }
+    return false;
+}
+
+static void registerReference(const hidl_string &interfaceName, const hidl_string &instanceName) {
+    if (kIsRecovery) {
+        // No hwservicemanager in recovery.
+        return;
+    }
+
+    sp<IServiceManager1_0> binderizedManager = defaultServiceManager();
+    if (binderizedManager == nullptr) {
+        LOG(WARNING) << "Could not registerReference for "
+                     << interfaceName << "/" << instanceName
+                     << ": null binderized manager.";
+        return;
+    }
+    auto ret = binderizedManager->registerPassthroughClient(interfaceName, instanceName);
+    if (!ret.isOk()) {
+        LOG(WARNING) << "Could not registerReference for "
+                     << interfaceName << "/" << instanceName
+                     << ": " << ret.description();
+        return;
+    }
+    LOG(VERBOSE) << "Successfully registerReference for "
+                 << interfaceName << "/" << instanceName;
+}
+
+using InstanceDebugInfo = hidl::manager::V1_0::IServiceManager::InstanceDebugInfo;
+static inline void fetchPidsForPassthroughLibraries(
+    std::map<std::string, InstanceDebugInfo>* infos) {
+    static const std::string proc = "/proc/";
+
+    std::map<std::string, std::set<pid_t>> pids;
+    std::unique_ptr<DIR, decltype(&closedir)> dir(opendir(proc.c_str()), closedir);
+    if (!dir) return;
+    dirent* dp;
+    while ((dp = readdir(dir.get())) != nullptr) {
+        pid_t pid = strtoll(dp->d_name, nullptr, 0);
+        if (pid == 0) continue;
+        std::string mapsPath = proc + dp->d_name + "/maps";
+        std::ifstream ifs{mapsPath};
+        if (!ifs.is_open()) continue;
+
+        for (std::string line; std::getline(ifs, line);) {
+            // The last token of line should look like
+            // vendor/lib64/hw/android.hardware.foo@1.0-impl-extra.so
+            // Use some simple filters to ignore bad lines before extracting libFileName
+            // and checking the key in info to make parsing faster.
+            if (line.back() != 'o') continue;
+            if (line.rfind('@') == std::string::npos) continue;
+
+            auto spacePos = line.rfind(' ');
+            if (spacePos == std::string::npos) continue;
+            auto libFileName = line.substr(spacePos + 1);
+            auto it = infos->find(libFileName);
+            if (it == infos->end()) continue;
+            pids[libFileName].insert(pid);
+        }
+    }
+    for (auto& pair : *infos) {
+        pair.second.clientPids =
+            std::vector<pid_t>{pids[pair.first].begin(), pids[pair.first].end()};
+    }
+}
+
+struct PassthroughServiceManager : IServiceManager1_1 {
+    static void openLibs(
+        const std::string& fqName,
+        const std::function<bool /* continue */ (void* /* handle */, const std::string& /* lib */,
+                                                 const std::string& /* sym */)>& eachLib) {
+        //fqName looks like android.hardware.foo@1.0::IFoo
+        size_t idx = fqName.find("::");
+
+        if (idx == std::string::npos ||
+                idx + strlen("::") + 1 >= fqName.size()) {
+            LOG(ERROR) << "Invalid interface name passthrough lookup: " << fqName;
+            return;
+        }
+
+        std::string packageAndVersion = fqName.substr(0, idx);
+        std::string ifaceName = fqName.substr(idx + strlen("::"));
+
+        const std::string prefix = packageAndVersion + "-impl";
+        const std::string sym = "HIDL_FETCH_" + ifaceName;
+
+        constexpr int dlMode = RTLD_LAZY;
+        void* handle = nullptr;
+
+        dlerror(); // clear
+
+        static std::string halLibPathVndkSp = android::base::StringPrintf(
+            HAL_LIBRARY_PATH_VNDK_SP_FOR_VERSION, details::getVndkVersionStr().c_str());
+        std::vector<std::string> paths = {
+            HAL_LIBRARY_PATH_ODM, HAL_LIBRARY_PATH_VENDOR, halLibPathVndkSp,
+#ifndef __ANDROID_VNDK__
+            HAL_LIBRARY_PATH_SYSTEM,
+#endif
+        };
+
+#ifdef LIBHIDL_TARGET_DEBUGGABLE
+        const char* env = std::getenv("TREBLE_TESTING_OVERRIDE");
+        const bool trebleTestingOverride = env && !strcmp(env, "true");
+        if (trebleTestingOverride) {
+            // Load HAL implementations that are statically linked
+            handle = dlopen(nullptr, dlMode);
+            if (handle == nullptr) {
+                const char* error = dlerror();
+                LOG(ERROR) << "Failed to dlopen self: "
+                           << (error == nullptr ? "unknown error" : error);
+            } else if (!eachLib(handle, "SELF", sym)) {
+                return;
+            }
+
+            const char* vtsRootPath = std::getenv("VTS_ROOT_PATH");
+            if (vtsRootPath && strlen(vtsRootPath) > 0) {
+                const std::string halLibraryPathVtsOverride =
+                    std::string(vtsRootPath) + HAL_LIBRARY_PATH_SYSTEM;
+                paths.insert(paths.begin(), halLibraryPathVtsOverride);
+            }
+        }
+#endif
+
+        for (const std::string& path : paths) {
+            std::vector<std::string> libs = findFiles(path, prefix, ".so");
+
+            for (const std::string &lib : libs) {
+                const std::string fullPath = path + lib;
+
+                if (kIsRecovery || path == HAL_LIBRARY_PATH_SYSTEM) {
+                    handle = dlopen(fullPath.c_str(), dlMode);
+                } else {
+#if !defined(__ANDROID_RECOVERY__)
+                    handle = android_load_sphal_library(fullPath.c_str(), dlMode);
+#endif
+                }
+
+                if (handle == nullptr) {
+                    const char* error = dlerror();
+                    LOG(ERROR) << "Failed to dlopen " << lib << ": "
+                               << (error == nullptr ? "unknown error" : error);
+                    continue;
+                }
+
+                if (!eachLib(handle, lib, sym)) {
+                    return;
+                }
+            }
+        }
+    }
+
+    Return<sp<IBase>> get(const hidl_string& fqName,
+                          const hidl_string& name) override {
+        sp<IBase> ret = nullptr;
+
+        openLibs(fqName, [&](void* handle, const std::string &lib, const std::string &sym) {
+            IBase* (*generator)(const char* name);
+            *(void **)(&generator) = dlsym(handle, sym.c_str());
+            if(!generator) {
+                const char* error = dlerror();
+                LOG(ERROR) << "Passthrough lookup opened " << lib
+                           << " but could not find symbol " << sym << ": "
+                           << (error == nullptr ? "unknown error" : error);
+                dlclose(handle);
+                return true;
+            }
+
+            ret = (*generator)(name.c_str());
+
+            if (ret == nullptr) {
+                dlclose(handle);
+                return true; // this module doesn't provide this instance name
+            }
+
+            // Actual fqname might be a subclass.
+            // This assumption is tested in vts_treble_vintf_test
+            using ::android::hardware::details::getDescriptor;
+            std::string actualFqName = getDescriptor(ret.get());
+            CHECK(actualFqName.size() > 0);
+            registerReference(actualFqName, name);
+            return false;
+        });
+
+        return ret;
+    }
+
+    Return<bool> add(const hidl_string& /* name */,
+                     const sp<IBase>& /* service */) override {
+        LOG(FATAL) << "Cannot register services with passthrough service manager.";
+        return false;
+    }
+
+    Return<Transport> getTransport(const hidl_string& /* fqName */,
+                                   const hidl_string& /* name */) {
+        LOG(FATAL) << "Cannot getTransport with passthrough service manager.";
+        return Transport::EMPTY;
+    }
+
+    Return<void> list(list_cb /* _hidl_cb */) override {
+        LOG(FATAL) << "Cannot list services with passthrough service manager.";
+        return Void();
+    }
+    Return<void> listByInterface(const hidl_string& /* fqInstanceName */,
+                                 listByInterface_cb /* _hidl_cb */) override {
+        // TODO: add this functionality
+        LOG(FATAL) << "Cannot list services with passthrough service manager.";
+        return Void();
+    }
+
+    Return<bool> registerForNotifications(const hidl_string& /* fqName */,
+                                          const hidl_string& /* name */,
+                                          const sp<IServiceNotification>& /* callback */) override {
+        // This makes no sense.
+        LOG(FATAL) << "Cannot register for notifications with passthrough service manager.";
+        return false;
+    }
+
+    Return<void> debugDump(debugDump_cb _hidl_cb) override {
+        using Arch = ::android::hidl::base::V1_0::DebugInfo::Architecture;
+        using std::literals::string_literals::operator""s;
+        static std::string halLibPathVndkSp64 = android::base::StringPrintf(
+            HAL_LIBRARY_PATH_VNDK_SP_64BIT_FOR_VERSION, details::getVndkVersionStr().c_str());
+        static std::string halLibPathVndkSp32 = android::base::StringPrintf(
+            HAL_LIBRARY_PATH_VNDK_SP_32BIT_FOR_VERSION, details::getVndkVersionStr().c_str());
+        static std::vector<std::pair<Arch, std::vector<const char*>>> sAllPaths{
+            {Arch::IS_64BIT,
+             {
+                 HAL_LIBRARY_PATH_ODM_64BIT, HAL_LIBRARY_PATH_VENDOR_64BIT,
+                 halLibPathVndkSp64.c_str(),
+#ifndef __ANDROID_VNDK__
+                 HAL_LIBRARY_PATH_SYSTEM_64BIT,
+#endif
+             }},
+            {Arch::IS_32BIT,
+             {
+                 HAL_LIBRARY_PATH_ODM_32BIT, HAL_LIBRARY_PATH_VENDOR_32BIT,
+                 halLibPathVndkSp32.c_str(),
+#ifndef __ANDROID_VNDK__
+                 HAL_LIBRARY_PATH_SYSTEM_32BIT,
+#endif
+             }}};
+        std::map<std::string, InstanceDebugInfo> map;
+        for (const auto &pair : sAllPaths) {
+            Arch arch = pair.first;
+            for (const auto &path : pair.second) {
+                std::vector<std::string> libs = findFiles(path, "", ".so");
+                for (const std::string &lib : libs) {
+                    std::string matchedName;
+                    std::string implName;
+                    if (matchPackageName(lib, &matchedName, &implName)) {
+                        std::string instanceName{"* ("s + path + ")"s};
+                        if (!implName.empty()) instanceName += " ("s + implName + ")"s;
+                        map.emplace(path + lib, InstanceDebugInfo{.interfaceName = matchedName,
+                                                                  .instanceName = instanceName,
+                                                                  .clientPids = {},
+                                                                  .arch = arch});
+                    }
+                }
+            }
+        }
+        fetchPidsForPassthroughLibraries(&map);
+        hidl_vec<InstanceDebugInfo> vec;
+        vec.resize(map.size());
+        size_t idx = 0;
+        for (auto&& pair : map) {
+            vec[idx++] = std::move(pair.second);
+        }
+        _hidl_cb(vec);
+        return Void();
+    }
+
+    Return<void> registerPassthroughClient(const hidl_string &, const hidl_string &) override {
+        // This makes no sense.
+        LOG(FATAL) << "Cannot call registerPassthroughClient on passthrough service manager. "
+                   << "Call it on defaultServiceManager() instead.";
+        return Void();
+    }
+
+    Return<bool> unregisterForNotifications(const hidl_string& /* fqName */,
+                                            const hidl_string& /* name */,
+                                            const sp<IServiceNotification>& /* callback */) override {
+        // This makes no sense.
+        LOG(FATAL) << "Cannot unregister for notifications with passthrough service manager.";
+        return false;
+    }
+
+};
+
+sp<IServiceManager1_0> getPassthroughServiceManager() {
+    return getPassthroughServiceManager1_1();
+}
+sp<IServiceManager1_1> getPassthroughServiceManager1_1() {
+    static sp<PassthroughServiceManager> manager(new PassthroughServiceManager());
+    return manager;
+}
+
+namespace details {
+
+void preloadPassthroughService(const std::string &descriptor) {
+    PassthroughServiceManager::openLibs(descriptor,
+        [&](void* /* handle */, const std::string& /* lib */, const std::string& /* sym */) {
+            // do nothing
+            return true; // open all libs
+        });
+}
+
+struct Waiter : IServiceNotification {
+    Waiter(const std::string& interface, const std::string& instanceName,
+           const sp<IServiceManager1_1>& sm) : mInterfaceName(interface),
+                                               mInstanceName(instanceName), mSm(sm) {
+    }
+
+    void onFirstRef() override {
+        // If this process only has one binder thread, and we're calling wait() from
+        // that thread, it will block forever because we hung up the one and only
+        // binder thread on a condition variable that can only be notified by an
+        // incoming binder call.
+        if (IPCThreadState::self()->isOnlyBinderThread()) {
+            LOG(WARNING) << "Can't efficiently wait for " << mInterfaceName << "/"
+                         << mInstanceName << ", because we are called from "
+                         << "the only binder thread in this process.";
+            return;
+        }
+
+        Return<bool> ret = mSm->registerForNotifications(mInterfaceName, mInstanceName, this);
+
+        if (!ret.isOk()) {
+            LOG(ERROR) << "Transport error, " << ret.description()
+                       << ", during notification registration for " << mInterfaceName << "/"
+                       << mInstanceName << ".";
+            return;
+        }
+
+        if (!ret) {
+            LOG(ERROR) << "Could not register for notifications for " << mInterfaceName << "/"
+                       << mInstanceName << ".";
+            return;
+        }
+
+        mRegisteredForNotifications = true;
+    }
+
+    ~Waiter() {
+        if (!mDoneCalled) {
+            LOG(FATAL)
+                << "Waiter still registered for notifications, call done() before dropping ref!";
+        }
+    }
+
+    Return<void> onRegistration(const hidl_string& /* fqName */,
+                                const hidl_string& /* name */,
+                                bool /* preexisting */) override {
+        std::unique_lock<std::mutex> lock(mMutex);
+        if (mRegistered) {
+            return Void();
+        }
+        mRegistered = true;
+        lock.unlock();
+
+        mCondition.notify_one();
+        return Void();
+    }
+
+    void wait(bool timeout) {
+        using std::literals::chrono_literals::operator""s;
+
+        if (!mRegisteredForNotifications) {
+            // As an alternative, just sleep for a second and return
+            LOG(WARNING) << "Waiting one second for " << mInterfaceName << "/" << mInstanceName;
+            sleep(1);
+            return;
+        }
+
+        std::unique_lock<std::mutex> lock(mMutex);
+        do {
+            mCondition.wait_for(lock, 1s, [this]{
+                return mRegistered;
+            });
+
+            if (mRegistered) {
+                break;
+            }
+
+            LOG(WARNING) << "Waited one second for " << mInterfaceName << "/" << mInstanceName;
+        } while (!timeout);
+    }
+
+    // Be careful when using this; after calling reset(), you must always try to retrieve
+    // the corresponding service before blocking on the waiter; otherwise, you might run
+    // into a race-condition where the service has just (re-)registered, you clear the state
+    // here, and subsequently calling waiter->wait() will block forever.
+    void reset() {
+        std::unique_lock<std::mutex> lock(mMutex);
+        mRegistered = false;
+    }
+
+    // done() must be called before dropping the last strong ref to the Waiter, to make
+    // sure we can properly unregister with hwservicemanager.
+    void done() {
+        if (mRegisteredForNotifications) {
+            if (!mSm->unregisterForNotifications(mInterfaceName, mInstanceName, this)
+                     .withDefault(false)) {
+                LOG(ERROR) << "Could not unregister service notification for " << mInterfaceName
+                           << "/" << mInstanceName << ".";
+            } else {
+                mRegisteredForNotifications = false;
+            }
+        }
+        mDoneCalled = true;
+    }
+
+   private:
+    const std::string mInterfaceName;
+    const std::string mInstanceName;
+    sp<IServiceManager1_1> mSm;
+    std::mutex mMutex;
+    std::condition_variable mCondition;
+    bool mRegistered = false;
+    bool mRegisteredForNotifications = false;
+    bool mDoneCalled = false;
+};
+
+void waitForHwService(
+        const std::string &interface, const std::string &instanceName) {
+    sp<Waiter> waiter = new Waiter(interface, instanceName, defaultServiceManager1_1());
+    waiter->wait(false /* timeout */);
+    waiter->done();
+}
+
+// Prints relevant error/warning messages for error return values from
+// details::canCastInterface(), both transaction errors (!castReturn.isOk())
+// as well as actual cast failures (castReturn.isOk() && castReturn = false).
+// Returns 'true' if the error is non-fatal and it's useful to retry
+bool handleCastError(const Return<bool>& castReturn, const std::string& descriptor,
+                     const std::string& instance) {
+    if (castReturn.isOk()) {
+        if (castReturn) {
+            details::logAlwaysFatal("Successful cast value passed into handleCastError.");
+        }
+        // This should never happen, and there's not really a point in retrying.
+        ALOGE("getService: received incompatible service (bug in hwservicemanager?) for "
+            "%s/%s.", descriptor.c_str(), instance.c_str());
+        return false;
+    }
+    if (castReturn.isDeadObject()) {
+        ALOGW("getService: found dead hwbinder service for %s/%s.", descriptor.c_str(),
+              instance.c_str());
+        return true;
+    }
+    // This can happen due to:
+    // 1) No SELinux permissions
+    // 2) Other transaction failure (no buffer space, kernel error)
+    // The first isn't recoverable, but the second is.
+    // Since we can't yet differentiate between the two, and clients depend
+    // on us not blocking in case 1), treat this as a fatal error for now.
+    ALOGW("getService: unable to call into hwbinder service for %s/%s.",
+          descriptor.c_str(), instance.c_str());
+    return false;
+}
+
+sp<::android::hidl::base::V1_0::IBase> getRawServiceInternal(const std::string& descriptor,
+                                                             const std::string& instance,
+                                                             bool retry, bool getStub) {
+    using Transport = ::android::hidl::manager::V1_0::IServiceManager::Transport;
+    using ::android::hidl::manager::V1_0::IServiceManager;
+    sp<Waiter> waiter;
+
+    sp<IServiceManager1_1> sm;
+    Transport transport = Transport::EMPTY;
+    if (kIsRecovery) {
+        transport = Transport::PASSTHROUGH;
+    } else {
+        sm = defaultServiceManager1_1();
+        if (sm == nullptr) {
+            ALOGE("getService: defaultServiceManager() is null");
+            return nullptr;
+        }
+
+        Return<Transport> transportRet = sm->getTransport(descriptor, instance);
+
+        if (!transportRet.isOk()) {
+            ALOGE("getService: defaultServiceManager()->getTransport returns %s",
+                  transportRet.description().c_str());
+            return nullptr;
+        }
+        transport = transportRet;
+    }
+
+    const bool vintfHwbinder = (transport == Transport::HWBINDER);
+    const bool vintfPassthru = (transport == Transport::PASSTHROUGH);
+
+#ifdef ENFORCE_VINTF_MANIFEST
+
+#ifdef LIBHIDL_TARGET_DEBUGGABLE
+    const char* env = std::getenv("TREBLE_TESTING_OVERRIDE");
+    const bool trebleTestingOverride = env && !strcmp(env, "true");
+    const bool vintfLegacy = (transport == Transport::EMPTY) && trebleTestingOverride;
+#else   // ENFORCE_VINTF_MANIFEST but not LIBHIDL_TARGET_DEBUGGABLE
+    const bool trebleTestingOverride = false;
+    const bool vintfLegacy = false;
+#endif  // LIBHIDL_TARGET_DEBUGGABLE
+
+#else   // not ENFORCE_VINTF_MANIFEST
+    const char* env = std::getenv("TREBLE_TESTING_OVERRIDE");
+    const bool trebleTestingOverride = env && !strcmp(env, "true");
+    const bool vintfLegacy = (transport == Transport::EMPTY);
+
+    ALOGE("getService: Potential race detected. The VINTF manifest is not being enforced. If a HAL "
+          "server has a delay in starting and it is not in the manifest, it will not be retrieved. "
+          "Please make sure all HALs on this device are in the VINTF manifest and enable "
+          "PRODUCT_ENFORCE_VINTF_MANIFEST on this device (this is also enabled by "
+          "PRODUCT_FULL_TREBLE). PRODUCT_ENFORCE_VINTF_MANIFEST will ensure that no race condition "
+          "is possible here.");
+#endif  // ENFORCE_VINTF_MANIFEST
+
+    for (int tries = 0; !getStub && (vintfHwbinder || vintfLegacy); tries++) {
+        if (waiter == nullptr && tries > 0) {
+            waiter = new Waiter(descriptor, instance, sm);
+        }
+        if (waiter != nullptr) {
+            waiter->reset();  // don't reorder this -- see comments on reset()
+        }
+        Return<sp<IBase>> ret = sm->get(descriptor, instance);
+        if (!ret.isOk()) {
+            ALOGE("getService: defaultServiceManager()->get returns %s for %s/%s.",
+                  ret.description().c_str(), descriptor.c_str(), instance.c_str());
+            break;
+        }
+        sp<IBase> base = ret;
+        if (base != nullptr) {
+            Return<bool> canCastRet =
+                details::canCastInterface(base.get(), descriptor.c_str(), true /* emitError */);
+
+            if (canCastRet.isOk() && canCastRet) {
+                if (waiter != nullptr) {
+                    waiter->done();
+                }
+                return base; // still needs to be wrapped by Bp class.
+            }
+
+            if (!handleCastError(canCastRet, descriptor, instance)) break;
+        }
+
+        // In case of legacy or we were not asked to retry, don't.
+        if (vintfLegacy || !retry) break;
+
+        if (waiter != nullptr) {
+            ALOGI("getService: Trying again for %s/%s...", descriptor.c_str(), instance.c_str());
+            waiter->wait(true /* timeout */);
+        }
+    }
+
+    if (waiter != nullptr) {
+        waiter->done();
+    }
+
+    if (getStub || vintfPassthru || vintfLegacy) {
+        const sp<IServiceManager> pm = getPassthroughServiceManager();
+        if (pm != nullptr) {
+            sp<IBase> base = pm->get(descriptor, instance).withDefault(nullptr);
+            if (!getStub || trebleTestingOverride) {
+                base = wrapPassthrough(base);
+            }
+            return base;
+        }
+    }
+
+    return nullptr;
+}
+
+status_t registerAsServiceInternal(const sp<IBase>& service, const std::string& name) {
+    if (service == nullptr) {
+        return UNEXPECTED_NULL;
+    }
+
+    sp<IServiceManager1_2> sm = defaultServiceManager1_2();
+    if (sm == nullptr) {
+        return INVALID_OPERATION;
+    }
+
+    bool registered = false;
+    Return<void> ret = service->interfaceChain([&](const auto& chain) {
+        registered = sm->addWithChain(name.c_str(), service, chain).withDefault(false);
+    });
+
+    if (!ret.isOk()) {
+        LOG(ERROR) << "Could not retrieve interface chain: " << ret.description();
+    }
+
+    if (registered) {
+        onRegistrationImpl(getDescriptor(service.get()), name);
+    }
+
+    return registered ? OK : UNKNOWN_ERROR;
+}
+
+} // namespace details
+
+} // namespace hardware
+} // namespace android