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 "profile_compilation_info.h"
23 #include "profile_saver_options.h"
24 #include "safe_map.h"
25 
26 namespace art {
27 
28 class ProfileSaver {
29  public:
30   // Starts the profile saver thread if not already started.
31   // If the saver is already running it adds (output_filename, code_paths) to its tracked locations.
32   static void Start(const ProfileSaverOptions& options,
33                     const std::string& output_filename,
34                     jit::JitCodeCache* jit_code_cache,
35                     const std::vector<std::string>& code_paths)
36       REQUIRES(!Locks::profiler_lock_, !wait_lock_);
37 
38   // Stops the profile saver thread.
39   // NO_THREAD_SAFETY_ANALYSIS for static function calling into member function with excludes lock.
40   static void Stop(bool dump_info_)
41       REQUIRES(!Locks::profiler_lock_, !wait_lock_)
42       NO_THREAD_SAFETY_ANALYSIS;
43 
44   // Returns true if the profile saver is started.
45   static bool IsStarted() REQUIRES(!Locks::profiler_lock_);
46 
47   // If the profile saver is running, dumps statistics to the `os`. Otherwise it does nothing.
48   static void DumpInstanceInfo(std::ostream& os);
49 
50   // NO_THREAD_SAFETY_ANALYSIS for static function calling into member function with excludes lock.
51   static void NotifyJitActivity()
52       REQUIRES(!Locks::profiler_lock_, !wait_lock_)
53       NO_THREAD_SAFETY_ANALYSIS;
54 
55   // For testing or manual purposes (SIGUSR1).
56   static void ForceProcessProfiles();
57 
58   // Just for testing purpose.
59   static bool HasSeenMethod(const std::string& profile,
60                             const DexFile* dex_file,
61                             uint16_t method_idx);
62 
63  private:
64   ProfileSaver(const ProfileSaverOptions& options,
65                const std::string& output_filename,
66                jit::JitCodeCache* jit_code_cache,
67                const std::vector<std::string>& code_paths);
68   ~ProfileSaver();
69 
70   // NO_THREAD_SAFETY_ANALYSIS for static function calling into member function with excludes lock.
71   static void* RunProfileSaverThread(void* arg)
72       REQUIRES(!Locks::profiler_lock_, !wait_lock_)
73       NO_THREAD_SAFETY_ANALYSIS;
74 
75   // The run loop for the saver.
76   void Run() REQUIRES(!Locks::profiler_lock_, !wait_lock_);
77 
78   // Processes the existing profiling info from the jit code cache and returns
79   // true if it needed to be saved to disk.
80   // If number_of_new_methods is not null, after the call it will contain the number of new methods
81   // written to disk.
82   // If force_save is true, the saver will ignore any constraints which limit IO (e.g. will write
83   // the profile to disk even if it's just one new method).
84   bool ProcessProfilingInfo(bool force_save, /*out*/uint16_t* number_of_new_methods)
85     REQUIRES(!Locks::profiler_lock_)
86     REQUIRES(!Locks::mutator_lock_);
87 
88   void NotifyJitActivityInternal() REQUIRES(!wait_lock_);
89   void WakeUpSaver() REQUIRES(wait_lock_);
90 
91   // Returns true if the saver is shutting down (ProfileSaver::Stop() has been called).
92   bool ShuttingDown(Thread* self) REQUIRES(!Locks::profiler_lock_);
93 
94   void AddTrackedLocations(const std::string& output_filename,
95                            const std::vector<std::string>& code_paths)
96       REQUIRES(Locks::profiler_lock_);
97 
98   // Fetches the current resolved classes and methods from the ClassLinker and stores them in the
99   // profile_cache_ for later save.
100   void FetchAndCacheResolvedClassesAndMethods();
101 
102   void DumpInfo(std::ostream& os);
103 
104   // Resolve the realpath of the locations stored in tracked_dex_base_locations_to_be_resolved_
105   // and put the result in tracked_dex_base_locations_.
106   void ResolveTrackedLocations() REQUIRES(!Locks::profiler_lock_);
107 
108   // The only instance of the saver.
109   static ProfileSaver* instance_ GUARDED_BY(Locks::profiler_lock_);
110   // Profile saver thread.
111   static pthread_t profiler_pthread_ GUARDED_BY(Locks::profiler_lock_);
112 
113   jit::JitCodeCache* jit_code_cache_;
114 
115   // Collection of code paths that the profiler tracks.
116   // It maps profile locations to code paths (dex base locations).
117   SafeMap<std::string, std::set<std::string>> tracked_dex_base_locations_
118       GUARDED_BY(Locks::profiler_lock_);
119 
120   // Collection of code paths that the profiler tracks but may note have been resolved
121   // to their realpath. The resolution is done async to minimize the time it takes for
122   // someone to register a path.
123   SafeMap<std::string, std::set<std::string>> tracked_dex_base_locations_to_be_resolved_
124       GUARDED_BY(Locks::profiler_lock_);
125 
126   bool shutting_down_ GUARDED_BY(Locks::profiler_lock_);
127   uint64_t last_time_ns_saver_woke_up_ GUARDED_BY(wait_lock_);
128   uint32_t jit_activity_notifications_;
129 
130   // A local cache for the profile information. Maps each tracked file to its
131   // profile information. This is used to cache the startup classes so that
132   // we don't hammer the disk to save them right away.
133   // The size of this cache is usually very small and tops
134   // to just a few hundreds entries in the ProfileCompilationInfo objects.
135   SafeMap<std::string, ProfileCompilationInfo*> profile_cache_;
136 
137   // Save period condition support.
138   Mutex wait_lock_ DEFAULT_MUTEX_ACQUIRED_AFTER;
139   ConditionVariable period_condition_ GUARDED_BY(wait_lock_);
140 
141   uint64_t total_bytes_written_;
142   uint64_t total_number_of_writes_;
143   uint64_t total_number_of_code_cache_queries_;
144   uint64_t total_number_of_skipped_writes_;
145   uint64_t total_number_of_failed_writes_;
146   uint64_t total_ms_of_sleep_;
147   uint64_t total_ns_of_work_;
148   // TODO(calin): replace with an actual size.
149   uint64_t max_number_of_profile_entries_cached_;
150   uint64_t total_number_of_hot_spikes_;
151   uint64_t total_number_of_wake_ups_;
152 
153   const ProfileSaverOptions options_;
154   DISALLOW_COPY_AND_ASSIGN(ProfileSaver);
155 };
156 
157 }  // namespace art
158 
159 #endif  // ART_RUNTIME_JIT_PROFILE_SAVER_H_
160