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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 #ifndef ART_RUNTIME_JIT_PROFILE_SAVER_H_
     18 #define ART_RUNTIME_JIT_PROFILE_SAVER_H_
     19 
     20 #include "base/mutex.h"
     21 #include "jit_code_cache.h"
     22 #include "method_reference.h"
     23 #include "profile_compilation_info.h"
     24 #include "profile_saver_options.h"
     25 #include "safe_map.h"
     26 
     27 namespace art {
     28 
     29 class ProfileSaver {
     30  public:
     31   // Starts the profile saver thread if not already started.
     32   // If the saver is already running it adds (output_filename, code_paths) to its tracked locations.
     33   static void Start(const ProfileSaverOptions& options,
     34                     const std::string& output_filename,
     35                     jit::JitCodeCache* jit_code_cache,
     36                     const std::vector<std::string>& code_paths)
     37       REQUIRES(!Locks::profiler_lock_, !wait_lock_);
     38 
     39   // Stops the profile saver thread.
     40   // NO_THREAD_SAFETY_ANALYSIS for static function calling into member function with excludes lock.
     41   static void Stop(bool dump_info_)
     42       REQUIRES(!Locks::profiler_lock_, !wait_lock_)
     43       NO_THREAD_SAFETY_ANALYSIS;
     44 
     45   // Returns true if the profile saver is started.
     46   static bool IsStarted() REQUIRES(!Locks::profiler_lock_);
     47 
     48   // If the profile saver is running, dumps statistics to the `os`. Otherwise it does nothing.
     49   static void DumpInstanceInfo(std::ostream& os);
     50 
     51   // NO_THREAD_SAFETY_ANALYSIS for static function calling into member function with excludes lock.
     52   static void NotifyJitActivity()
     53       REQUIRES(!Locks::profiler_lock_, !wait_lock_)
     54       NO_THREAD_SAFETY_ANALYSIS;
     55 
     56   // For testing or manual purposes (SIGUSR1).
     57   static void ForceProcessProfiles();
     58 
     59   // Just for testing purposes.
     60   static bool HasSeenMethod(const std::string& profile, bool hot, MethodReference ref);
     61 
     62  private:
     63   ProfileSaver(const ProfileSaverOptions& options,
     64                const std::string& output_filename,
     65                jit::JitCodeCache* jit_code_cache,
     66                const std::vector<std::string>& code_paths);
     67   ~ProfileSaver();
     68 
     69   // NO_THREAD_SAFETY_ANALYSIS for static function calling into member function with excludes lock.
     70   static void* RunProfileSaverThread(void* arg)
     71       REQUIRES(!Locks::profiler_lock_, !wait_lock_)
     72       NO_THREAD_SAFETY_ANALYSIS;
     73 
     74   // The run loop for the saver.
     75   void Run() REQUIRES(!Locks::profiler_lock_, !wait_lock_);
     76 
     77   // Processes the existing profiling info from the jit code cache and returns
     78   // true if it needed to be saved to disk.
     79   // If number_of_new_methods is not null, after the call it will contain the number of new methods
     80   // written to disk.
     81   // If force_save is true, the saver will ignore any constraints which limit IO (e.g. will write
     82   // the profile to disk even if it's just one new method).
     83   bool ProcessProfilingInfo(bool force_save, /*out*/uint16_t* number_of_new_methods)
     84     REQUIRES(!Locks::profiler_lock_)
     85     REQUIRES(!Locks::mutator_lock_);
     86 
     87   void NotifyJitActivityInternal() REQUIRES(!wait_lock_);
     88   void WakeUpSaver() REQUIRES(wait_lock_);
     89 
     90   // Returns true if the saver is shutting down (ProfileSaver::Stop() has been called).
     91   bool ShuttingDown(Thread* self) REQUIRES(!Locks::profiler_lock_);
     92 
     93   void AddTrackedLocations(const std::string& output_filename,
     94                            const std::vector<std::string>& code_paths)
     95       REQUIRES(Locks::profiler_lock_);
     96 
     97   // Fetches the current resolved classes and methods from the ClassLinker and stores them in the
     98   // profile_cache_ for later save.
     99   void FetchAndCacheResolvedClassesAndMethods(bool startup);
    100 
    101   void DumpInfo(std::ostream& os);
    102 
    103   // Resolve the realpath of the locations stored in tracked_dex_base_locations_to_be_resolved_
    104   // and put the result in tracked_dex_base_locations_.
    105   void ResolveTrackedLocations() REQUIRES(!Locks::profiler_lock_);
    106 
    107   // The only instance of the saver.
    108   static ProfileSaver* instance_ GUARDED_BY(Locks::profiler_lock_);
    109   // Profile saver thread.
    110   static pthread_t profiler_pthread_ GUARDED_BY(Locks::profiler_lock_);
    111 
    112   jit::JitCodeCache* jit_code_cache_;
    113 
    114   // Collection of code paths that the profiler tracks.
    115   // It maps profile locations to code paths (dex base locations).
    116   SafeMap<std::string, std::set<std::string>> tracked_dex_base_locations_
    117       GUARDED_BY(Locks::profiler_lock_);
    118 
    119   // Collection of code paths that the profiler tracks but may note have been resolved
    120   // to their realpath. The resolution is done async to minimize the time it takes for
    121   // someone to register a path.
    122   SafeMap<std::string, std::set<std::string>> tracked_dex_base_locations_to_be_resolved_
    123       GUARDED_BY(Locks::profiler_lock_);
    124 
    125   bool shutting_down_ GUARDED_BY(Locks::profiler_lock_);
    126   uint64_t last_time_ns_saver_woke_up_ GUARDED_BY(wait_lock_);
    127   uint32_t jit_activity_notifications_;
    128 
    129   // A local cache for the profile information. Maps each tracked file to its
    130   // profile information. This is used to cache the startup classes so that
    131   // we don't hammer the disk to save them right away.
    132   // The size of this cache is usually very small and tops
    133   // to just a few hundreds entries in the ProfileCompilationInfo objects.
    134   SafeMap<std::string, ProfileCompilationInfo*> profile_cache_;
    135 
    136   // Save period condition support.
    137   Mutex wait_lock_ DEFAULT_MUTEX_ACQUIRED_AFTER;
    138   ConditionVariable period_condition_ GUARDED_BY(wait_lock_);
    139 
    140   uint64_t total_bytes_written_;
    141   uint64_t total_number_of_writes_;
    142   uint64_t total_number_of_code_cache_queries_;
    143   uint64_t total_number_of_skipped_writes_;
    144   uint64_t total_number_of_failed_writes_;
    145   uint64_t total_ms_of_sleep_;
    146   uint64_t total_ns_of_work_;
    147   // TODO(calin): replace with an actual size.
    148   uint64_t max_number_of_profile_entries_cached_;
    149   uint64_t total_number_of_hot_spikes_;
    150   uint64_t total_number_of_wake_ups_;
    151 
    152   const ProfileSaverOptions options_;
    153   DISALLOW_COPY_AND_ASSIGN(ProfileSaver);
    154 };
    155 
    156 }  // namespace art
    157 
    158 #endif  // ART_RUNTIME_JIT_PROFILE_SAVER_H_
    159