Home | History | Annotate | Download | only in jit
      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 "base/safe_map.h"
     22 #include "dex/method_reference.h"
     23 #include "jit_code_cache.h"
     24 #include "profile/profile_compilation_info.h"
     25 #include "profile_saver_options.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   // Notify that startup has completed.
     63   static void NotifyStartupCompleted();
     64 
     65  private:
     66   ProfileSaver(const ProfileSaverOptions& options,
     67                const std::string& output_filename,
     68                jit::JitCodeCache* jit_code_cache,
     69                const std::vector<std::string>& code_paths);
     70   ~ProfileSaver();
     71 
     72   // NO_THREAD_SAFETY_ANALYSIS for static function calling into member function with excludes lock.
     73   static void* RunProfileSaverThread(void* arg)
     74       REQUIRES(!Locks::profiler_lock_, !wait_lock_)
     75       NO_THREAD_SAFETY_ANALYSIS;
     76 
     77   // The run loop for the saver.
     78   void Run() REQUIRES(!Locks::profiler_lock_, !wait_lock_);
     79 
     80   // Processes the existing profiling info from the jit code cache and returns
     81   // true if it needed to be saved to disk.
     82   // If number_of_new_methods is not null, after the call it will contain the number of new methods
     83   // written to disk.
     84   // If force_save is true, the saver will ignore any constraints which limit IO (e.g. will write
     85   // the profile to disk even if it's just one new method).
     86   bool ProcessProfilingInfo(bool force_save, /*out*/uint16_t* number_of_new_methods)
     87     REQUIRES(!Locks::profiler_lock_)
     88     REQUIRES(!Locks::mutator_lock_);
     89 
     90   void NotifyJitActivityInternal() REQUIRES(!wait_lock_);
     91   void WakeUpSaver() REQUIRES(wait_lock_);
     92 
     93   // Returns true if the saver is shutting down (ProfileSaver::Stop() has been called).
     94   bool ShuttingDown(Thread* self) REQUIRES(!Locks::profiler_lock_);
     95 
     96   void AddTrackedLocations(const std::string& output_filename,
     97                            const std::vector<std::string>& code_paths)
     98       REQUIRES(Locks::profiler_lock_);
     99 
    100   // Fetches the current resolved classes and methods from the ClassLinker and stores them in the
    101   // profile_cache_ for later save.
    102   void FetchAndCacheResolvedClassesAndMethods(bool startup);
    103 
    104   void DumpInfo(std::ostream& os);
    105 
    106   // Resolve the realpath of the locations stored in tracked_dex_base_locations_to_be_resolved_
    107   // and put the result in tracked_dex_base_locations_.
    108   void ResolveTrackedLocations() REQUIRES(!Locks::profiler_lock_);
    109 
    110   // The only instance of the saver.
    111   static ProfileSaver* instance_ GUARDED_BY(Locks::profiler_lock_);
    112   // Profile saver thread.
    113   static pthread_t profiler_pthread_ GUARDED_BY(Locks::profiler_lock_);
    114 
    115   jit::JitCodeCache* jit_code_cache_;
    116 
    117   // Collection of code paths that the profiler tracks.
    118   // It maps profile locations to code paths (dex base locations).
    119   SafeMap<std::string, std::set<std::string>> tracked_dex_base_locations_
    120       GUARDED_BY(Locks::profiler_lock_);
    121 
    122   // Collection of code paths that the profiler tracks but may note have been resolved
    123   // to their realpath. The resolution is done async to minimize the time it takes for
    124   // someone to register a path.
    125   SafeMap<std::string, std::set<std::string>> tracked_dex_base_locations_to_be_resolved_
    126       GUARDED_BY(Locks::profiler_lock_);
    127 
    128   bool shutting_down_ GUARDED_BY(Locks::profiler_lock_);
    129   uint64_t last_time_ns_saver_woke_up_ GUARDED_BY(wait_lock_);
    130   uint32_t jit_activity_notifications_;
    131 
    132   // A local cache for the profile information. Maps each tracked file to its
    133   // profile information. This is used to cache the startup classes so that
    134   // we don't hammer the disk to save them right away.
    135   // The size of this cache is usually very small and tops
    136   // to just a few hundreds entries in the ProfileCompilationInfo objects.
    137   SafeMap<std::string, ProfileCompilationInfo*> profile_cache_;
    138 
    139   // Save period condition support.
    140   Mutex wait_lock_ DEFAULT_MUTEX_ACQUIRED_AFTER;
    141   ConditionVariable period_condition_ GUARDED_BY(wait_lock_);
    142 
    143   uint64_t total_bytes_written_;
    144   uint64_t total_number_of_writes_;
    145   uint64_t total_number_of_code_cache_queries_;
    146   uint64_t total_number_of_skipped_writes_;
    147   uint64_t total_number_of_failed_writes_;
    148   uint64_t total_ms_of_sleep_;
    149   uint64_t total_ns_of_work_;
    150   // TODO(calin): replace with an actual size.
    151   uint64_t max_number_of_profile_entries_cached_;
    152   uint64_t total_number_of_hot_spikes_;
    153   uint64_t total_number_of_wake_ups_;
    154 
    155   const ProfileSaverOptions options_;
    156   DISALLOW_COPY_AND_ASSIGN(ProfileSaver);
    157 };
    158 
    159 }  // namespace art
    160 
    161 #endif  // ART_RUNTIME_JIT_PROFILE_SAVER_H_
    162