| /* |
| * Copyright (C) 2015 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 "profile_saver.h" |
| |
| #include <sys/types.h> |
| #include <sys/stat.h> |
| #include <fcntl.h> |
| |
| #include "art_method-inl.h" |
| #include "base/systrace.h" |
| #include "scoped_thread_state_change.h" |
| #include "oat_file_manager.h" |
| |
| namespace art { |
| |
| // An arbitrary value to throttle save requests. Set to 2s for now. |
| static constexpr const uint64_t kMilisecondsToNano = 1000000; |
| static constexpr const uint64_t kMinimumTimeBetweenCodeCacheUpdatesNs = 2000 * kMilisecondsToNano; |
| |
| // TODO: read the constants from ProfileOptions, |
| // Add a random delay each time we go to sleep so that we don't hammer the CPU |
| // with all profile savers running at the same time. |
| static constexpr const uint64_t kRandomDelayMaxMs = 20 * 1000; // 20 seconds |
| static constexpr const uint64_t kMaxBackoffMs = 5 * 60 * 1000; // 5 minutes |
| static constexpr const uint64_t kSavePeriodMs = 10 * 1000; // 10 seconds |
| static constexpr const uint64_t kInitialDelayMs = 2 * 1000; // 2 seconds |
| static constexpr const double kBackoffCoef = 1.5; |
| |
| static constexpr const uint32_t kMinimumNrOrMethodsToSave = 10; |
| |
| ProfileSaver* ProfileSaver::instance_ = nullptr; |
| pthread_t ProfileSaver::profiler_pthread_ = 0U; |
| |
| ProfileSaver::ProfileSaver(const std::string& output_filename, |
| jit::JitCodeCache* jit_code_cache, |
| const std::vector<std::string>& code_paths, |
| const std::string& foreign_dex_profile_path, |
| const std::string& app_data_dir) |
| : jit_code_cache_(jit_code_cache), |
| foreign_dex_profile_path_(foreign_dex_profile_path), |
| code_cache_last_update_time_ns_(0), |
| shutting_down_(false), |
| first_profile_(true), |
| wait_lock_("ProfileSaver wait lock"), |
| period_condition_("ProfileSaver period condition", wait_lock_) { |
| AddTrackedLocations(output_filename, code_paths); |
| app_data_dir_ = ""; |
| if (!app_data_dir.empty()) { |
| // The application directory is used to determine which dex files are owned by app. |
| // Since it could be a symlink (e.g. /data/data instead of /data/user/0), and we |
| // don't have control over how the dex files are actually loaded (symlink or canonical path), |
| // store it's canonical form to be sure we use the same base when comparing. |
| UniqueCPtr<const char[]> app_data_dir_real_path(realpath(app_data_dir.c_str(), nullptr)); |
| if (app_data_dir_real_path != nullptr) { |
| app_data_dir_.assign(app_data_dir_real_path.get()); |
| } else { |
| LOG(WARNING) << "Failed to get the real path for app dir: " << app_data_dir_ |
| << ". The app dir will not be used to determine which dex files belong to the app"; |
| } |
| } |
| } |
| |
| void ProfileSaver::Run() { |
| srand(MicroTime() * getpid()); |
| Thread* self = Thread::Current(); |
| |
| uint64_t save_period_ms = kSavePeriodMs; |
| VLOG(profiler) << "Save profiling information every " << save_period_ms << " ms"; |
| |
| bool first_iteration = true; |
| while (!ShuttingDown(self)) { |
| uint64_t sleep_time_ms; |
| if (first_iteration) { |
| // Sleep less long for the first iteration since we want to record loaded classes shortly |
| // after app launch. |
| sleep_time_ms = kInitialDelayMs; |
| } else { |
| const uint64_t random_sleep_delay_ms = rand() % kRandomDelayMaxMs; |
| sleep_time_ms = save_period_ms + random_sleep_delay_ms; |
| } |
| { |
| MutexLock mu(self, wait_lock_); |
| period_condition_.TimedWait(self, sleep_time_ms, 0); |
| } |
| |
| if (ShuttingDown(self)) { |
| break; |
| } |
| |
| if (!ProcessProfilingInfo() && save_period_ms < kMaxBackoffMs) { |
| // If we don't need to save now it is less likely that we will need to do |
| // so in the future. Increase the time between saves according to the |
| // kBackoffCoef, but make it no larger than kMaxBackoffMs. |
| save_period_ms = static_cast<uint64_t>(kBackoffCoef * save_period_ms); |
| } else { |
| // Reset the period to the initial value as it's highly likely to JIT again. |
| save_period_ms = kSavePeriodMs; |
| } |
| first_iteration = false; |
| } |
| } |
| |
| bool ProfileSaver::ProcessProfilingInfo() { |
| ScopedTrace trace(__PRETTY_FUNCTION__); |
| uint64_t last_update_time_ns = jit_code_cache_->GetLastUpdateTimeNs(); |
| if (!first_profile_ && last_update_time_ns - code_cache_last_update_time_ns_ |
| < kMinimumTimeBetweenCodeCacheUpdatesNs) { |
| VLOG(profiler) << "Not enough time has passed since the last code cache update." |
| << "Last update: " << last_update_time_ns |
| << " Last save: " << code_cache_last_update_time_ns_; |
| return false; |
| } |
| |
| uint64_t start = NanoTime(); |
| code_cache_last_update_time_ns_ = last_update_time_ns; |
| SafeMap<std::string, std::set<std::string>> tracked_locations; |
| { |
| // Make a copy so that we don't hold the lock while doing I/O. |
| MutexLock mu(Thread::Current(), *Locks::profiler_lock_); |
| tracked_locations = tracked_dex_base_locations_; |
| } |
| for (const auto& it : tracked_locations) { |
| if (ShuttingDown(Thread::Current())) { |
| return true; |
| } |
| const std::string& filename = it.first; |
| const std::set<std::string>& locations = it.second; |
| std::vector<ArtMethod*> methods; |
| { |
| ScopedObjectAccess soa(Thread::Current()); |
| jit_code_cache_->GetCompiledArtMethods(locations, methods); |
| } |
| // Always save for the first one for loaded classes profile. |
| if (methods.size() < kMinimumNrOrMethodsToSave && !first_profile_) { |
| VLOG(profiler) << "Not enough information to save to: " << filename |
| <<" Nr of methods: " << methods.size(); |
| return false; |
| } |
| |
| std::set<DexCacheResolvedClasses> resolved_classes; |
| if (first_profile_) { |
| ClassLinker* const class_linker = Runtime::Current()->GetClassLinker(); |
| resolved_classes = class_linker->GetResolvedClasses(/*ignore boot classes*/true); |
| } |
| |
| if (!ProfileCompilationInfo::SaveProfilingInfo(filename, methods, resolved_classes)) { |
| LOG(WARNING) << "Could not save profiling info to " << filename; |
| return false; |
| } |
| |
| VLOG(profiler) << "Profile process time: " << PrettyDuration(NanoTime() - start); |
| } |
| first_profile_ = false; |
| return true; |
| } |
| |
| void* ProfileSaver::RunProfileSaverThread(void* arg) { |
| Runtime* runtime = Runtime::Current(); |
| ProfileSaver* profile_saver = reinterpret_cast<ProfileSaver*>(arg); |
| |
| CHECK(runtime->AttachCurrentThread("Profile Saver", |
| /*as_daemon*/true, |
| runtime->GetSystemThreadGroup(), |
| /*create_peer*/true)); |
| profile_saver->Run(); |
| |
| runtime->DetachCurrentThread(); |
| VLOG(profiler) << "Profile saver shutdown"; |
| return nullptr; |
| } |
| |
| void ProfileSaver::Start(const std::string& output_filename, |
| jit::JitCodeCache* jit_code_cache, |
| const std::vector<std::string>& code_paths, |
| const std::string& foreign_dex_profile_path, |
| const std::string& app_data_dir) { |
| DCHECK(Runtime::Current()->UseJit()); |
| DCHECK(!output_filename.empty()); |
| DCHECK(jit_code_cache != nullptr); |
| |
| MutexLock mu(Thread::Current(), *Locks::profiler_lock_); |
| if (instance_ != nullptr) { |
| // If we already have an instance, make sure it uses the same jit_code_cache. |
| // This may be called multiple times via Runtime::registerAppInfo (e.g. for |
| // apps which share the same runtime). |
| DCHECK_EQ(instance_->jit_code_cache_, jit_code_cache); |
| // Add the code_paths to the tracked locations. |
| instance_->AddTrackedLocations(output_filename, code_paths); |
| return; |
| } |
| |
| VLOG(profiler) << "Starting profile saver using output file: " << output_filename |
| << ". Tracking: " << Join(code_paths, ':'); |
| |
| instance_ = new ProfileSaver(output_filename, |
| jit_code_cache, |
| code_paths, |
| foreign_dex_profile_path, |
| app_data_dir); |
| |
| // Create a new thread which does the saving. |
| CHECK_PTHREAD_CALL( |
| pthread_create, |
| (&profiler_pthread_, nullptr, &RunProfileSaverThread, reinterpret_cast<void*>(instance_)), |
| "Profile saver thread"); |
| } |
| |
| void ProfileSaver::Stop() { |
| ProfileSaver* profile_saver = nullptr; |
| pthread_t profiler_pthread = 0U; |
| |
| { |
| MutexLock profiler_mutex(Thread::Current(), *Locks::profiler_lock_); |
| VLOG(profiler) << "Stopping profile saver thread"; |
| profile_saver = instance_; |
| profiler_pthread = profiler_pthread_; |
| if (instance_ == nullptr) { |
| DCHECK(false) << "Tried to stop a profile saver which was not started"; |
| return; |
| } |
| if (instance_->shutting_down_) { |
| DCHECK(false) << "Tried to stop the profile saver twice"; |
| return; |
| } |
| instance_->shutting_down_ = true; |
| } |
| |
| { |
| // Wake up the saver thread if it is sleeping to allow for a clean exit. |
| MutexLock wait_mutex(Thread::Current(), profile_saver->wait_lock_); |
| profile_saver->period_condition_.Signal(Thread::Current()); |
| } |
| |
| // Wait for the saver thread to stop. |
| CHECK_PTHREAD_CALL(pthread_join, (profiler_pthread, nullptr), "profile saver thread shutdown"); |
| |
| { |
| MutexLock profiler_mutex(Thread::Current(), *Locks::profiler_lock_); |
| instance_ = nullptr; |
| profiler_pthread_ = 0U; |
| } |
| delete profile_saver; |
| } |
| |
| bool ProfileSaver::ShuttingDown(Thread* self) { |
| MutexLock mu(self, *Locks::profiler_lock_); |
| return shutting_down_; |
| } |
| |
| bool ProfileSaver::IsStarted() { |
| MutexLock mu(Thread::Current(), *Locks::profiler_lock_); |
| return instance_ != nullptr; |
| } |
| |
| void ProfileSaver::AddTrackedLocations(const std::string& output_filename, |
| const std::vector<std::string>& code_paths) { |
| auto it = tracked_dex_base_locations_.find(output_filename); |
| if (it == tracked_dex_base_locations_.end()) { |
| tracked_dex_base_locations_.Put(output_filename, |
| std::set<std::string>(code_paths.begin(), code_paths.end())); |
| } else { |
| it->second.insert(code_paths.begin(), code_paths.end()); |
| } |
| } |
| |
| void ProfileSaver::NotifyDexUse(const std::string& dex_location) { |
| std::set<std::string> app_code_paths; |
| std::string foreign_dex_profile_path; |
| std::string app_data_dir; |
| { |
| MutexLock mu(Thread::Current(), *Locks::profiler_lock_); |
| DCHECK(instance_ != nullptr); |
| // Make a copy so that we don't hold the lock while doing I/O. |
| for (const auto& it : instance_->tracked_dex_base_locations_) { |
| app_code_paths.insert(it.second.begin(), it.second.end()); |
| } |
| foreign_dex_profile_path = instance_->foreign_dex_profile_path_; |
| app_data_dir = instance_->app_data_dir_; |
| } |
| |
| MaybeRecordDexUseInternal(dex_location, |
| app_code_paths, |
| foreign_dex_profile_path, |
| app_data_dir); |
| } |
| |
| void ProfileSaver::MaybeRecordDexUseInternal( |
| const std::string& dex_location, |
| const std::set<std::string>& app_code_paths, |
| const std::string& foreign_dex_profile_path, |
| const std::string& app_data_dir) { |
| if (dex_location.empty()) { |
| LOG(WARNING) << "Asked to record foreign dex use with an empty dex location."; |
| return; |
| } |
| if (foreign_dex_profile_path.empty()) { |
| LOG(WARNING) << "Asked to record foreign dex use without a valid profile path "; |
| return; |
| } |
| |
| UniqueCPtr<const char[]> dex_location_real_path(realpath(dex_location.c_str(), nullptr)); |
| if (dex_location_real_path == nullptr) { |
| PLOG(WARNING) << "Could not get realpath for " << dex_location; |
| } |
| std::string dex_location_real_path_str((dex_location_real_path == nullptr) |
| ? dex_location.c_str() |
| : dex_location_real_path.get()); |
| |
| if (dex_location_real_path_str.compare(0, app_data_dir.length(), app_data_dir) == 0) { |
| // The dex location is under the application folder. Nothing to record. |
| return; |
| } |
| |
| if (app_code_paths.find(dex_location) != app_code_paths.end()) { |
| // The dex location belongs to the application code paths. Nothing to record. |
| return; |
| } |
| // Do another round of checks with the real paths. |
| // Note that we could cache all the real locations in the saver (since it's an expensive |
| // operation). However we expect that app_code_paths is small (usually 1 element), and |
| // NotifyDexUse is called just a few times in the app lifetime. So we make the compromise |
| // to save some bytes of memory usage. |
| for (const auto& app_code_location : app_code_paths) { |
| UniqueCPtr<const char[]> real_app_code_location(realpath(app_code_location.c_str(), nullptr)); |
| if (real_app_code_location == nullptr) { |
| PLOG(WARNING) << "Could not get realpath for " << app_code_location; |
| } |
| std::string real_app_code_location_str((real_app_code_location == nullptr) |
| ? app_code_location.c_str() |
| : real_app_code_location.get()); |
| if (real_app_code_location_str == dex_location_real_path_str) { |
| // The dex location belongs to the application code paths. Nothing to record. |
| return; |
| } |
| } |
| |
| // For foreign dex files we record a flag on disk. PackageManager will (potentially) take this |
| // into account when deciding how to optimize the loaded dex file. |
| // The expected flag name is the canonical path of the apk where '/' is substituted to '@'. |
| // (it needs to be kept in sync with |
| // frameworks/base/services/core/java/com/android/server/pm/PackageDexOptimizer.java) |
| std::replace(dex_location_real_path_str.begin(), dex_location_real_path_str.end(), '/', '@'); |
| std::string flag_path = foreign_dex_profile_path + "/" + dex_location_real_path_str; |
| // No need to give any sort of access to flag_path. The system has enough permissions |
| // to test for its existence. |
| int fd = TEMP_FAILURE_RETRY(open(flag_path.c_str(), O_CREAT | O_EXCL, 0)); |
| if (fd != -1) { |
| if (close(fd) != 0) { |
| PLOG(WARNING) << "Could not close file after flagging foreign dex use " << flag_path; |
| } |
| } else { |
| if (errno != EEXIST) { |
| // Another app could have already created the file. |
| PLOG(WARNING) << "Could not create foreign dex use mark " << flag_path; |
| } |
| } |
| } |
| |
| } // namespace art |