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      1 /*
      2  * Copyright (C) 2015 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 #include "profile_saver.h"
     18 
     19 #include <sys/resource.h>
     20 #include <sys/types.h>
     21 #include <sys/stat.h>
     22 #include <fcntl.h>
     23 
     24 #include "android-base/strings.h"
     25 
     26 #include "art_method-inl.h"
     27 #include "base/enums.h"
     28 #include "base/systrace.h"
     29 #include "base/time_utils.h"
     30 #include "compiler_filter.h"
     31 #include "gc/collector_type.h"
     32 #include "gc/gc_cause.h"
     33 #include "gc/scoped_gc_critical_section.h"
     34 #include "oat_file_manager.h"
     35 #include "scoped_thread_state_change-inl.h"
     36 
     37 namespace art {
     38 
     39 ProfileSaver* ProfileSaver::instance_ = nullptr;
     40 pthread_t ProfileSaver::profiler_pthread_ = 0U;
     41 
     42 ProfileSaver::ProfileSaver(const ProfileSaverOptions& options,
     43                            const std::string& output_filename,
     44                            jit::JitCodeCache* jit_code_cache,
     45                            const std::vector<std::string>& code_paths)
     46     : jit_code_cache_(jit_code_cache),
     47       shutting_down_(false),
     48       last_time_ns_saver_woke_up_(0),
     49       jit_activity_notifications_(0),
     50       wait_lock_("ProfileSaver wait lock"),
     51       period_condition_("ProfileSaver period condition", wait_lock_),
     52       total_bytes_written_(0),
     53       total_number_of_writes_(0),
     54       total_number_of_code_cache_queries_(0),
     55       total_number_of_skipped_writes_(0),
     56       total_number_of_failed_writes_(0),
     57       total_ms_of_sleep_(0),
     58       total_ns_of_work_(0),
     59       max_number_of_profile_entries_cached_(0),
     60       total_number_of_hot_spikes_(0),
     61       total_number_of_wake_ups_(0),
     62       options_(options) {
     63   DCHECK(options_.IsEnabled());
     64   AddTrackedLocations(output_filename, code_paths);
     65 }
     66 
     67 ProfileSaver::~ProfileSaver() {
     68   for (auto& it : profile_cache_) {
     69     delete it.second;
     70   }
     71 }
     72 
     73 void ProfileSaver::Run() {
     74   Thread* self = Thread::Current();
     75 
     76   // Fetch the resolved classes for the app images after sleeping for
     77   // options_.GetSaveResolvedClassesDelayMs().
     78   // TODO(calin) This only considers the case of the primary profile file.
     79   // Anything that gets loaded in the same VM will not have their resolved
     80   // classes save (unless they started before the initial saving was done).
     81   {
     82     MutexLock mu(self, wait_lock_);
     83     const uint64_t end_time = NanoTime() + MsToNs(options_.GetSaveResolvedClassesDelayMs());
     84     while (true) {
     85       const uint64_t current_time = NanoTime();
     86       if (current_time >= end_time) {
     87         break;
     88       }
     89       period_condition_.TimedWait(self, NsToMs(end_time - current_time), 0);
     90     }
     91     total_ms_of_sleep_ += options_.GetSaveResolvedClassesDelayMs();
     92   }
     93   FetchAndCacheResolvedClassesAndMethods();
     94 
     95   // Loop for the profiled methods.
     96   while (!ShuttingDown(self)) {
     97     uint64_t sleep_start = NanoTime();
     98     {
     99       uint64_t sleep_time = 0;
    100       {
    101         MutexLock mu(self, wait_lock_);
    102         period_condition_.Wait(self);
    103         sleep_time = NanoTime() - sleep_start;
    104       }
    105       // Check if the thread was woken up for shutdown.
    106       if (ShuttingDown(self)) {
    107         break;
    108       }
    109       total_number_of_wake_ups_++;
    110       // We might have been woken up by a huge number of notifications to guarantee saving.
    111       // If we didn't meet the minimum saving period go back to sleep (only if missed by
    112       // a reasonable margin).
    113       uint64_t min_save_period_ns = MsToNs(options_.GetMinSavePeriodMs());
    114       while (min_save_period_ns * 0.9 > sleep_time) {
    115         {
    116           MutexLock mu(self, wait_lock_);
    117           period_condition_.TimedWait(self, NsToMs(min_save_period_ns - sleep_time), 0);
    118           sleep_time = NanoTime() - sleep_start;
    119         }
    120         // Check if the thread was woken up for shutdown.
    121         if (ShuttingDown(self)) {
    122           break;
    123         }
    124         total_number_of_wake_ups_++;
    125       }
    126     }
    127     total_ms_of_sleep_ += NsToMs(NanoTime() - sleep_start);
    128 
    129     if (ShuttingDown(self)) {
    130       break;
    131     }
    132 
    133     uint16_t number_of_new_methods = 0;
    134     uint64_t start_work = NanoTime();
    135     bool profile_saved_to_disk = ProcessProfilingInfo(/*force_save*/false, &number_of_new_methods);
    136     // Update the notification counter based on result. Note that there might be contention on this
    137     // but we don't care about to be 100% precise.
    138     if (!profile_saved_to_disk) {
    139       // If we didn't save to disk it may be because we didn't have enough new methods.
    140       // Set the jit activity notifications to number_of_new_methods so we can wake up earlier
    141       // if needed.
    142       jit_activity_notifications_ = number_of_new_methods;
    143     }
    144     total_ns_of_work_ += NanoTime() - start_work;
    145   }
    146 }
    147 
    148 void ProfileSaver::NotifyJitActivity() {
    149   MutexLock mu(Thread::Current(), *Locks::profiler_lock_);
    150   if (instance_ == nullptr || instance_->shutting_down_) {
    151     return;
    152   }
    153   instance_->NotifyJitActivityInternal();
    154 }
    155 
    156 void ProfileSaver::WakeUpSaver() {
    157   jit_activity_notifications_ = 0;
    158   last_time_ns_saver_woke_up_ = NanoTime();
    159   period_condition_.Signal(Thread::Current());
    160 }
    161 
    162 void ProfileSaver::NotifyJitActivityInternal() {
    163   // Unlikely to overflow but if it happens,
    164   // we would have waken up the saver long before that.
    165   jit_activity_notifications_++;
    166   // Note that we are not as precise as we could be here but we don't want to wake the saver
    167   // every time we see a hot method.
    168   if (jit_activity_notifications_ > options_.GetMinNotificationBeforeWake()) {
    169     MutexLock wait_mutex(Thread::Current(), wait_lock_);
    170     if ((NanoTime() - last_time_ns_saver_woke_up_) > MsToNs(options_.GetMinSavePeriodMs())) {
    171       WakeUpSaver();
    172     } else if (jit_activity_notifications_ > options_.GetMaxNotificationBeforeWake()) {
    173       // Make sure to wake up the saver if we see a spike in the number of notifications.
    174       // This is a precaution to avoid losing a big number of methods in case
    175       // this is a spike with no jit after.
    176       total_number_of_hot_spikes_++;
    177       WakeUpSaver();
    178     }
    179   }
    180 }
    181 
    182 // Get resolved methods that have a profile info or more than kStartupMethodSamples samples.
    183 // Excludes native methods and classes in the boot image.
    184 class GetMethodsVisitor : public ClassVisitor {
    185  public:
    186   GetMethodsVisitor(std::vector<MethodReference>* methods, uint32_t startup_method_samples)
    187     : methods_(methods),
    188       startup_method_samples_(startup_method_samples) {}
    189 
    190   virtual bool operator()(ObjPtr<mirror::Class> klass) REQUIRES_SHARED(Locks::mutator_lock_) {
    191     if (Runtime::Current()->GetHeap()->ObjectIsInBootImageSpace(klass) ||
    192         !klass->IsResolved() ||
    193         klass->IsErroneousResolved()) {
    194       return true;
    195     }
    196     for (ArtMethod& method : klass->GetMethods(kRuntimePointerSize)) {
    197       if (!method.IsNative()) {
    198         if (method.GetCounter() >= startup_method_samples_ ||
    199             method.GetProfilingInfo(kRuntimePointerSize) != nullptr) {
    200           // Have samples, add to profile.
    201           const DexFile* dex_file =
    202               method.GetInterfaceMethodIfProxy(kRuntimePointerSize)->GetDexFile();
    203           methods_->push_back(MethodReference(dex_file, method.GetDexMethodIndex()));
    204         }
    205       }
    206     }
    207     return true;
    208   }
    209 
    210  private:
    211   std::vector<MethodReference>* const methods_;
    212   uint32_t startup_method_samples_;
    213 };
    214 
    215 void ProfileSaver::FetchAndCacheResolvedClassesAndMethods() {
    216   ScopedTrace trace(__PRETTY_FUNCTION__);
    217 
    218   // Resolve any new registered locations.
    219   ResolveTrackedLocations();
    220 
    221   Thread* const self = Thread::Current();
    222   std::vector<MethodReference> methods;
    223   std::set<DexCacheResolvedClasses> resolved_classes;
    224   {
    225     ScopedObjectAccess soa(self);
    226     gc::ScopedGCCriticalSection sgcs(self,
    227                                      gc::kGcCauseProfileSaver,
    228                                      gc::kCollectorTypeCriticalSection);
    229 
    230     ClassLinker* const class_linker = Runtime::Current()->GetClassLinker();
    231     resolved_classes = class_linker->GetResolvedClasses(/*ignore boot classes*/ true);
    232 
    233     {
    234       ScopedTrace trace2("Get hot methods");
    235       GetMethodsVisitor visitor(&methods, options_.GetStartupMethodSamples());
    236       class_linker->VisitClasses(&visitor);
    237       VLOG(profiler) << "Methods with samples greater than "
    238                      << options_.GetStartupMethodSamples() << " = " << methods.size();
    239     }
    240   }
    241   MutexLock mu(self, *Locks::profiler_lock_);
    242   uint64_t total_number_of_profile_entries_cached = 0;
    243 
    244   for (const auto& it : tracked_dex_base_locations_) {
    245     std::set<DexCacheResolvedClasses> resolved_classes_for_location;
    246     const std::string& filename = it.first;
    247     const std::set<std::string>& locations = it.second;
    248     std::vector<ProfileMethodInfo> profile_methods_for_location;
    249     for (const MethodReference& ref : methods) {
    250       if (locations.find(ref.dex_file->GetBaseLocation()) != locations.end()) {
    251         profile_methods_for_location.emplace_back(ref.dex_file, ref.dex_method_index);
    252       }
    253     }
    254     for (const DexCacheResolvedClasses& classes : resolved_classes) {
    255       if (locations.find(classes.GetBaseLocation()) != locations.end()) {
    256         VLOG(profiler) << "Added " << classes.GetClasses().size() << " classes for location "
    257                        << classes.GetBaseLocation() << " (" << classes.GetDexLocation() << ")";
    258         resolved_classes_for_location.insert(classes);
    259       } else {
    260         VLOG(profiler) << "Location not found " << classes.GetBaseLocation()
    261                        << " (" << classes.GetDexLocation() << ")";
    262       }
    263     }
    264     auto info_it = profile_cache_.Put(
    265         filename,
    266         new ProfileCompilationInfo(Runtime::Current()->GetArenaPool()));
    267 
    268     ProfileCompilationInfo* cached_info = info_it->second;
    269     cached_info->AddMethodsAndClasses(profile_methods_for_location,
    270                                       resolved_classes_for_location);
    271     total_number_of_profile_entries_cached += resolved_classes_for_location.size();
    272   }
    273   max_number_of_profile_entries_cached_ = std::max(
    274       max_number_of_profile_entries_cached_,
    275       total_number_of_profile_entries_cached);
    276 }
    277 
    278 bool ProfileSaver::ProcessProfilingInfo(bool force_save, /*out*/uint16_t* number_of_new_methods) {
    279   ScopedTrace trace(__PRETTY_FUNCTION__);
    280 
    281   // Resolve any new registered locations.
    282   ResolveTrackedLocations();
    283 
    284   SafeMap<std::string, std::set<std::string>> tracked_locations;
    285   {
    286     // Make a copy so that we don't hold the lock while doing I/O.
    287     MutexLock mu(Thread::Current(), *Locks::profiler_lock_);
    288     tracked_locations = tracked_dex_base_locations_;
    289   }
    290 
    291   bool profile_file_saved = false;
    292   if (number_of_new_methods != nullptr) {
    293     *number_of_new_methods = 0;
    294   }
    295 
    296   for (const auto& it : tracked_locations) {
    297     if (!force_save && ShuttingDown(Thread::Current())) {
    298       // The ProfileSaver is in shutdown mode, meaning a stop request was made and
    299       // we need to exit cleanly (by waiting for the saver thread to finish). Unless
    300       // we have a request for a forced save, do not do any processing so that we
    301       // speed up the exit.
    302       return true;
    303     }
    304     const std::string& filename = it.first;
    305     const std::set<std::string>& locations = it.second;
    306     std::vector<ProfileMethodInfo> profile_methods;
    307     {
    308       ScopedObjectAccess soa(Thread::Current());
    309       jit_code_cache_->GetProfiledMethods(locations, profile_methods);
    310       total_number_of_code_cache_queries_++;
    311     }
    312     {
    313       ProfileCompilationInfo info(Runtime::Current()->GetArenaPool());
    314       if (!info.Load(filename, /*clear_if_invalid*/ true)) {
    315         LOG(WARNING) << "Could not forcefully load profile " << filename;
    316         continue;
    317       }
    318       uint64_t last_save_number_of_methods = info.GetNumberOfMethods();
    319       uint64_t last_save_number_of_classes = info.GetNumberOfResolvedClasses();
    320 
    321       info.AddMethodsAndClasses(profile_methods,
    322                                 std::set<DexCacheResolvedClasses>());
    323       auto profile_cache_it = profile_cache_.find(filename);
    324       if (profile_cache_it != profile_cache_.end()) {
    325         info.MergeWith(*(profile_cache_it->second));
    326       }
    327 
    328       int64_t delta_number_of_methods =
    329           info.GetNumberOfMethods() - last_save_number_of_methods;
    330       int64_t delta_number_of_classes =
    331           info.GetNumberOfResolvedClasses() - last_save_number_of_classes;
    332 
    333       if (!force_save &&
    334           delta_number_of_methods < options_.GetMinMethodsToSave() &&
    335           delta_number_of_classes < options_.GetMinClassesToSave()) {
    336         VLOG(profiler) << "Not enough information to save to: " << filename
    337                        << " Number of methods: " << delta_number_of_methods
    338                        << " Number of classes: " << delta_number_of_classes;
    339         total_number_of_skipped_writes_++;
    340         continue;
    341       }
    342       if (number_of_new_methods != nullptr) {
    343         *number_of_new_methods =
    344             std::max(static_cast<uint16_t>(delta_number_of_methods),
    345                      *number_of_new_methods);
    346       }
    347       uint64_t bytes_written;
    348       // Force the save. In case the profile data is corrupted or the the profile
    349       // has the wrong version this will "fix" the file to the correct format.
    350       if (info.Save(filename, &bytes_written)) {
    351         // We managed to save the profile. Clear the cache stored during startup.
    352         if (profile_cache_it != profile_cache_.end()) {
    353           ProfileCompilationInfo *cached_info = profile_cache_it->second;
    354           profile_cache_.erase(profile_cache_it);
    355           delete cached_info;
    356         }
    357         if (bytes_written > 0) {
    358           total_number_of_writes_++;
    359           total_bytes_written_ += bytes_written;
    360           profile_file_saved = true;
    361         } else {
    362           // At this point we could still have avoided the write.
    363           // We load and merge the data from the file lazily at its first ever
    364           // save attempt. So, whatever we are trying to save could already be
    365           // in the file.
    366           total_number_of_skipped_writes_++;
    367         }
    368       } else {
    369         LOG(WARNING) << "Could not save profiling info to " << filename;
    370         total_number_of_failed_writes_++;
    371       }
    372     }
    373     // Trim the maps to madvise the pages used for profile info.
    374     // It is unlikely we will need them again in the near feature.
    375     Runtime::Current()->GetArenaPool()->TrimMaps();
    376   }
    377 
    378   return profile_file_saved;
    379 }
    380 
    381 void* ProfileSaver::RunProfileSaverThread(void* arg) {
    382   Runtime* runtime = Runtime::Current();
    383 
    384   bool attached = runtime->AttachCurrentThread("Profile Saver",
    385                                                /*as_daemon*/true,
    386                                                runtime->GetSystemThreadGroup(),
    387                                                /*create_peer*/true);
    388   if (!attached) {
    389     CHECK(runtime->IsShuttingDown(Thread::Current()));
    390     return nullptr;
    391   }
    392 
    393   ProfileSaver* profile_saver = reinterpret_cast<ProfileSaver*>(arg);
    394   profile_saver->Run();
    395 
    396   runtime->DetachCurrentThread();
    397   VLOG(profiler) << "Profile saver shutdown";
    398   return nullptr;
    399 }
    400 
    401 static bool ShouldProfileLocation(const std::string& location) {
    402   OatFileManager& oat_manager = Runtime::Current()->GetOatFileManager();
    403   const OatFile* oat_file = oat_manager.FindOpenedOatFileFromDexLocation(location);
    404   if (oat_file == nullptr) {
    405     // This can happen if we fallback to run code directly from the APK.
    406     // Profile it with the hope that the background dexopt will get us back into
    407     // a good state.
    408     VLOG(profiler) << "Asked to profile a location without an oat file:" << location;
    409     return true;
    410   }
    411   CompilerFilter::Filter filter = oat_file->GetCompilerFilter();
    412   if ((filter == CompilerFilter::kSpeed) || (filter == CompilerFilter::kEverything)) {
    413     VLOG(profiler)
    414         << "Skip profiling oat file because it's already speed|everything compiled: "
    415         << location << " oat location: " << oat_file->GetLocation();
    416     return false;
    417   }
    418   return true;
    419 }
    420 
    421 void ProfileSaver::Start(const ProfileSaverOptions& options,
    422                          const std::string& output_filename,
    423                          jit::JitCodeCache* jit_code_cache,
    424                          const std::vector<std::string>& code_paths) {
    425   DCHECK(options.IsEnabled());
    426   DCHECK(Runtime::Current()->GetJit() != nullptr);
    427   DCHECK(!output_filename.empty());
    428   DCHECK(jit_code_cache != nullptr);
    429 
    430   std::vector<std::string> code_paths_to_profile;
    431 
    432   for (const std::string& location : code_paths) {
    433     if (ShouldProfileLocation(location))  {
    434       code_paths_to_profile.push_back(location);
    435     }
    436   }
    437   if (code_paths_to_profile.empty()) {
    438     VLOG(profiler) << "No code paths should be profiled.";
    439     return;
    440   }
    441 
    442   MutexLock mu(Thread::Current(), *Locks::profiler_lock_);
    443   if (instance_ != nullptr) {
    444     // If we already have an instance, make sure it uses the same jit_code_cache.
    445     // This may be called multiple times via Runtime::registerAppInfo (e.g. for
    446     // apps which share the same runtime).
    447     DCHECK_EQ(instance_->jit_code_cache_, jit_code_cache);
    448     // Add the code_paths to the tracked locations.
    449     instance_->AddTrackedLocations(output_filename, code_paths_to_profile);
    450     return;
    451   }
    452 
    453   VLOG(profiler) << "Starting profile saver using output file: " << output_filename
    454       << ". Tracking: " << android::base::Join(code_paths_to_profile, ':');
    455 
    456   instance_ = new ProfileSaver(options,
    457                                output_filename,
    458                                jit_code_cache,
    459                                code_paths_to_profile);
    460 
    461   // Create a new thread which does the saving.
    462   CHECK_PTHREAD_CALL(
    463       pthread_create,
    464       (&profiler_pthread_, nullptr, &RunProfileSaverThread, reinterpret_cast<void*>(instance_)),
    465       "Profile saver thread");
    466 
    467 #if defined(ART_TARGET_ANDROID)
    468   // At what priority to schedule the saver threads. 9 is the lowest foreground priority on device.
    469   static constexpr int kProfileSaverPthreadPriority = 9;
    470   int result = setpriority(
    471       PRIO_PROCESS, pthread_gettid_np(profiler_pthread_), kProfileSaverPthreadPriority);
    472   if (result != 0) {
    473     PLOG(ERROR) << "Failed to setpriority to :" << kProfileSaverPthreadPriority;
    474   }
    475 #endif
    476 }
    477 
    478 void ProfileSaver::Stop(bool dump_info) {
    479   ProfileSaver* profile_saver = nullptr;
    480   pthread_t profiler_pthread = 0U;
    481 
    482   {
    483     MutexLock profiler_mutex(Thread::Current(), *Locks::profiler_lock_);
    484     VLOG(profiler) << "Stopping profile saver thread";
    485     profile_saver = instance_;
    486     profiler_pthread = profiler_pthread_;
    487     if (instance_ == nullptr) {
    488       DCHECK(false) << "Tried to stop a profile saver which was not started";
    489       return;
    490     }
    491     if (instance_->shutting_down_) {
    492       DCHECK(false) << "Tried to stop the profile saver twice";
    493       return;
    494     }
    495     instance_->shutting_down_ = true;
    496   }
    497 
    498   {
    499     // Wake up the saver thread if it is sleeping to allow for a clean exit.
    500     MutexLock wait_mutex(Thread::Current(), profile_saver->wait_lock_);
    501     profile_saver->period_condition_.Signal(Thread::Current());
    502   }
    503 
    504   // Wait for the saver thread to stop.
    505   CHECK_PTHREAD_CALL(pthread_join, (profiler_pthread, nullptr), "profile saver thread shutdown");
    506 
    507   // Force save everything before destroying the instance.
    508   instance_->ProcessProfilingInfo(/*force_save*/true, /*number_of_new_methods*/nullptr);
    509 
    510   {
    511     MutexLock profiler_mutex(Thread::Current(), *Locks::profiler_lock_);
    512     if (dump_info) {
    513       instance_->DumpInfo(LOG_STREAM(INFO));
    514     }
    515     instance_ = nullptr;
    516     profiler_pthread_ = 0U;
    517   }
    518   delete profile_saver;
    519 }
    520 
    521 bool ProfileSaver::ShuttingDown(Thread* self) {
    522   MutexLock mu(self, *Locks::profiler_lock_);
    523   return shutting_down_;
    524 }
    525 
    526 bool ProfileSaver::IsStarted() {
    527   MutexLock mu(Thread::Current(), *Locks::profiler_lock_);
    528   return instance_ != nullptr;
    529 }
    530 
    531 static void AddTrackedLocationsToMap(const std::string& output_filename,
    532                                      const std::vector<std::string>& code_paths,
    533                                      SafeMap<std::string, std::set<std::string>>* map) {
    534   auto it = map->find(output_filename);
    535   if (it == map->end()) {
    536     map->Put(output_filename, std::set<std::string>(code_paths.begin(), code_paths.end()));
    537   } else {
    538     it->second.insert(code_paths.begin(), code_paths.end());
    539   }
    540 }
    541 
    542 void ProfileSaver::AddTrackedLocations(const std::string& output_filename,
    543                                        const std::vector<std::string>& code_paths) {
    544   // Add the code paths to the list of tracked location.
    545   AddTrackedLocationsToMap(output_filename, code_paths, &tracked_dex_base_locations_);
    546   // The code paths may contain symlinks which could fool the profiler.
    547   // If the dex file is compiled with an absolute location but loaded with symlink
    548   // the profiler could skip the dex due to location mismatch.
    549   // To avoid this, we add the code paths to the temporary cache of 'to_be_resolved'
    550   // locations. When the profiler thread executes we will resolve the paths to their
    551   // real paths.
    552   // Note that we delay taking the realpath to avoid spending more time than needed
    553   // when registering location (as it is done during app launch).
    554   AddTrackedLocationsToMap(output_filename,
    555                            code_paths,
    556                            &tracked_dex_base_locations_to_be_resolved_);
    557 }
    558 
    559 void ProfileSaver::DumpInstanceInfo(std::ostream& os) {
    560   MutexLock mu(Thread::Current(), *Locks::profiler_lock_);
    561   if (instance_ != nullptr) {
    562     instance_->DumpInfo(os);
    563   }
    564 }
    565 
    566 void ProfileSaver::DumpInfo(std::ostream& os) {
    567   os << "ProfileSaver total_bytes_written=" << total_bytes_written_ << '\n'
    568      << "ProfileSaver total_number_of_writes=" << total_number_of_writes_ << '\n'
    569      << "ProfileSaver total_number_of_code_cache_queries="
    570      << total_number_of_code_cache_queries_ << '\n'
    571      << "ProfileSaver total_number_of_skipped_writes=" << total_number_of_skipped_writes_ << '\n'
    572      << "ProfileSaver total_number_of_failed_writes=" << total_number_of_failed_writes_ << '\n'
    573      << "ProfileSaver total_ms_of_sleep=" << total_ms_of_sleep_ << '\n'
    574      << "ProfileSaver total_ms_of_work=" << NsToMs(total_ns_of_work_) << '\n'
    575      << "ProfileSaver max_number_profile_entries_cached="
    576      << max_number_of_profile_entries_cached_ << '\n'
    577      << "ProfileSaver total_number_of_hot_spikes=" << total_number_of_hot_spikes_ << '\n'
    578      << "ProfileSaver total_number_of_wake_ups=" << total_number_of_wake_ups_ << '\n';
    579 }
    580 
    581 
    582 void ProfileSaver::ForceProcessProfiles() {
    583   ProfileSaver* saver = nullptr;
    584   {
    585     MutexLock mu(Thread::Current(), *Locks::profiler_lock_);
    586     saver = instance_;
    587   }
    588   // TODO(calin): this is not actually thread safe as the instance_ may have been deleted,
    589   // but we only use this in testing when we now this won't happen.
    590   // Refactor the way we handle the instance so that we don't end up in this situation.
    591   if (saver != nullptr) {
    592     saver->ProcessProfilingInfo(/*force_save*/true, /*number_of_new_methods*/nullptr);
    593   }
    594 }
    595 
    596 bool ProfileSaver::HasSeenMethod(const std::string& profile,
    597                                  const DexFile* dex_file,
    598                                  uint16_t method_idx) {
    599   MutexLock mu(Thread::Current(), *Locks::profiler_lock_);
    600   if (instance_ != nullptr) {
    601     ProfileCompilationInfo info(Runtime::Current()->GetArenaPool());
    602     if (!info.Load(profile, /*clear_if_invalid*/false)) {
    603       return false;
    604     }
    605     return info.ContainsMethod(MethodReference(dex_file, method_idx));
    606   }
    607   return false;
    608 }
    609 
    610 void ProfileSaver::ResolveTrackedLocations() {
    611   SafeMap<std::string, std::set<std::string>> locations_to_be_resolved;
    612   {
    613     // Make a copy so that we don't hold the lock while doing I/O.
    614     MutexLock mu(Thread::Current(), *Locks::profiler_lock_);
    615     locations_to_be_resolved = tracked_dex_base_locations_to_be_resolved_;
    616     tracked_dex_base_locations_to_be_resolved_.clear();
    617   }
    618 
    619   // Resolve the locations.
    620   SafeMap<std::string, std::vector<std::string>> resolved_locations_map;
    621   for (const auto& it : locations_to_be_resolved) {
    622     const std::string& filename = it.first;
    623     const std::set<std::string>& locations = it.second;
    624     auto resolved_locations_it = resolved_locations_map.Put(
    625         filename,
    626         std::vector<std::string>(locations.size()));
    627 
    628     for (const auto& location : locations) {
    629       UniqueCPtr<const char[]> location_real(realpath(location.c_str(), nullptr));
    630       // Note that it's ok if we cannot get the real path.
    631       if (location_real != nullptr) {
    632         resolved_locations_it->second.emplace_back(location_real.get());
    633       }
    634     }
    635   }
    636 
    637   // Add the resolved locations to the tracked collection.
    638   MutexLock mu(Thread::Current(), *Locks::profiler_lock_);
    639   for (const auto& it : resolved_locations_map) {
    640     AddTrackedLocationsToMap(it.first, it.second, &tracked_dex_base_locations_);
    641   }
    642 }
    643 
    644 }   // namespace art
    645