Dave Allison | 0aded08 | 2013-11-07 13:15:11 -0800 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2011 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_PROFILER_H_ |
| 18 | #define ART_RUNTIME_PROFILER_H_ |
| 19 | |
| 20 | #include <ostream> |
| 21 | #include <set> |
| 22 | #include <string> |
| 23 | #include <vector> |
| 24 | |
Ian Rogers | 719d1a3 | 2014-03-06 12:13:39 -0800 | [diff] [blame] | 25 | #include "barrier.h" |
Dave Allison | 0aded08 | 2013-11-07 13:15:11 -0800 | [diff] [blame] | 26 | #include "base/macros.h" |
Ian Rogers | 719d1a3 | 2014-03-06 12:13:39 -0800 | [diff] [blame] | 27 | #include "base/mutex.h" |
Dave Allison | 0aded08 | 2013-11-07 13:15:11 -0800 | [diff] [blame] | 28 | #include "globals.h" |
| 29 | #include "instrumentation.h" |
| 30 | #include "os.h" |
| 31 | #include "safe_map.h" |
Dave Allison | 0aded08 | 2013-11-07 13:15:11 -0800 | [diff] [blame] | 32 | #include "UniquePtr.h" |
Dave Allison | 0aded08 | 2013-11-07 13:15:11 -0800 | [diff] [blame] | 33 | |
| 34 | namespace art { |
| 35 | |
| 36 | namespace mirror { |
| 37 | class ArtMethod; |
| 38 | class Class; |
| 39 | } // namespace mirror |
| 40 | class Thread; |
| 41 | |
Dave Allison | 0aded08 | 2013-11-07 13:15:11 -0800 | [diff] [blame] | 42 | // |
| 43 | // This class holds all the results for all runs of the profiler. It also |
| 44 | // counts the number of null methods (where we can't determine the method) and |
| 45 | // the number of methods in the boot path (where we have already compiled the method). |
| 46 | // |
| 47 | // This object is an internal profiler object and uses the same locking as the profiler |
| 48 | // itself. |
| 49 | class ProfileSampleResults { |
| 50 | public: |
| 51 | explicit ProfileSampleResults(Mutex& lock); |
| 52 | ~ProfileSampleResults(); |
| 53 | |
| 54 | void Put(mirror::ArtMethod* method); |
| 55 | uint32_t Write(std::ostream &os); |
Dave Allison | 39c3bfb | 2014-01-28 18:33:52 -0800 | [diff] [blame] | 56 | void ReadPrevious(int fd); |
Dave Allison | 0aded08 | 2013-11-07 13:15:11 -0800 | [diff] [blame] | 57 | void Clear(); |
| 58 | uint32_t GetNumSamples() { return num_samples_; } |
| 59 | void NullMethod() { ++num_null_methods_; } |
| 60 | void BootMethod() { ++num_boot_methods_; } |
Dave Allison | 39c3bfb | 2014-01-28 18:33:52 -0800 | [diff] [blame] | 61 | |
Dave Allison | 0aded08 | 2013-11-07 13:15:11 -0800 | [diff] [blame] | 62 | private: |
| 63 | uint32_t Hash(mirror::ArtMethod* method); |
| 64 | static constexpr int kHashSize = 17; |
Calin Juravle | 9dae5b4 | 2014-04-07 16:36:21 +0300 | [diff] [blame] | 65 | Mutex& lock_; // Reference to the main profiler lock - we don't need two of them. |
Dave Allison | 0aded08 | 2013-11-07 13:15:11 -0800 | [diff] [blame] | 66 | uint32_t num_samples_; // Total number of samples taken. |
| 67 | uint32_t num_null_methods_; // Number of samples where can don't know the method. |
| 68 | uint32_t num_boot_methods_; // Number of samples in the boot path. |
| 69 | |
| 70 | typedef std::map<mirror::ArtMethod*, uint32_t> Map; // Map of method vs its count. |
| 71 | Map *table[kHashSize]; |
Dave Allison | 39c3bfb | 2014-01-28 18:33:52 -0800 | [diff] [blame] | 72 | |
| 73 | struct PreviousValue { |
| 74 | PreviousValue() : count_(0), method_size_(0) {} |
| 75 | PreviousValue(uint32_t count, uint32_t method_size) : count_(count), method_size_(method_size) {} |
| 76 | uint32_t count_; |
| 77 | uint32_t method_size_; |
| 78 | }; |
| 79 | |
| 80 | typedef std::map<std::string, PreviousValue> PreviousProfile; |
| 81 | PreviousProfile previous_; |
| 82 | uint32_t previous_num_samples_; |
| 83 | uint32_t previous_num_null_methods_; // Number of samples where can don't know the method. |
| 84 | uint32_t previous_num_boot_methods_; // Number of samples in the boot path. |
Dave Allison | 0aded08 | 2013-11-07 13:15:11 -0800 | [diff] [blame] | 85 | }; |
| 86 | |
| 87 | // |
| 88 | // The BackgroundMethodSamplingProfiler runs in a thread. Most of the time it is sleeping but |
| 89 | // occasionally wakes up and counts the number of times a method is called. Each time |
| 90 | // it ticks, it looks at the current method and records it in the ProfileSampleResults |
| 91 | // table. |
| 92 | // |
| 93 | // The timing is controlled by a number of variables: |
| 94 | // 1. Period: the time between sampling runs. |
| 95 | // 2. Interval: the time between each sample in a run. |
| 96 | // 3. Duration: the duration of a run. |
| 97 | // |
| 98 | // So the profiler thread is sleeping for the 'period' time. It wakes up and runs for the |
| 99 | // 'duration'. The run consists of a series of samples, each of which is 'interval' microseconds |
| 100 | // apart. At the end of a run, it writes the results table to a file and goes back to sleep. |
| 101 | |
| 102 | class BackgroundMethodSamplingProfiler { |
| 103 | public: |
Dave Allison | 39c3bfb | 2014-01-28 18:33:52 -0800 | [diff] [blame] | 104 | static void Start(int period, int duration, const std::string& profile_filename, |
| 105 | const std::string& procName, int interval_us, |
Dave Allison | 0aded08 | 2013-11-07 13:15:11 -0800 | [diff] [blame] | 106 | double backoff_coefficient, bool startImmediately) |
| 107 | LOCKS_EXCLUDED(Locks::mutator_lock_, |
| 108 | Locks::thread_list_lock_, |
| 109 | Locks::thread_suspend_count_lock_, |
| 110 | Locks::profiler_lock_); |
| 111 | |
| 112 | static void Stop() LOCKS_EXCLUDED(Locks::profiler_lock_, wait_lock_); |
| 113 | static void Shutdown() LOCKS_EXCLUDED(Locks::profiler_lock_); |
| 114 | |
| 115 | void RecordMethod(mirror::ArtMethod *method) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); |
| 116 | |
| 117 | Barrier& GetBarrier() { |
| 118 | return *profiler_barrier_; |
| 119 | } |
| 120 | |
| 121 | private: |
Dave Allison | 39c3bfb | 2014-01-28 18:33:52 -0800 | [diff] [blame] | 122 | explicit BackgroundMethodSamplingProfiler(int period, int duration, |
| 123 | const std::string& profile_filename, |
| 124 | const std::string& process_name, |
| 125 | double backoff_coefficient, int interval_us, bool startImmediately); |
Dave Allison | 0aded08 | 2013-11-07 13:15:11 -0800 | [diff] [blame] | 126 | |
| 127 | // The sampling interval in microseconds is passed as an argument. |
| 128 | static void* RunProfilerThread(void* arg) LOCKS_EXCLUDED(Locks::profiler_lock_); |
| 129 | |
| 130 | uint32_t WriteProfile() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); |
| 131 | |
| 132 | void CleanProfile(); |
| 133 | uint32_t DumpProfile(std::ostream& os) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); |
| 134 | static bool ShuttingDown(Thread* self) LOCKS_EXCLUDED(Locks::profiler_lock_); |
| 135 | |
| 136 | static BackgroundMethodSamplingProfiler* profiler_ GUARDED_BY(Locks::profiler_lock_); |
| 137 | |
| 138 | // We need to shut the sample thread down at exit. Setting this to true will do that. |
| 139 | static volatile bool shutting_down_ GUARDED_BY(Locks::profiler_lock_); |
| 140 | |
| 141 | // Sampling thread, non-zero when sampling. |
| 142 | static pthread_t profiler_pthread_; |
| 143 | |
| 144 | // Some measure of the number of samples that are significant |
| 145 | static constexpr uint32_t kSignificantSamples = 10; |
| 146 | |
| 147 | // File to write profile data out to. Cannot be empty if we are profiling. |
| 148 | std::string profile_file_name_; |
| 149 | |
Dave Allison | 39c3bfb | 2014-01-28 18:33:52 -0800 | [diff] [blame] | 150 | // Process name. |
| 151 | std::string process_name_; |
| 152 | |
Dave Allison | 0aded08 | 2013-11-07 13:15:11 -0800 | [diff] [blame] | 153 | // Number of seconds between profile runs. |
| 154 | uint32_t period_s_; |
| 155 | |
| 156 | // Most of the time we want to delay the profiler startup to prevent everything |
| 157 | // running at the same time (all processes). This is the default, but if we |
| 158 | // want to override this, set the 'start_immediately_' to true. This is done |
| 159 | // if the -Xprofile option is given on the command line. |
| 160 | bool start_immediately_; |
| 161 | |
| 162 | uint32_t interval_us_; |
| 163 | |
| 164 | // A backoff coefficent to adjust the profile period based on time. |
| 165 | double backoff_factor_; |
| 166 | |
| 167 | // How much to increase the backoff by on each profile iteration. |
| 168 | double backoff_coefficient_; |
| 169 | |
| 170 | // Duration of each profile run. The profile file will be written at the end |
| 171 | // of each run. |
| 172 | uint32_t duration_s_; |
| 173 | |
| 174 | // Profile condition support. |
| 175 | Mutex wait_lock_ DEFAULT_MUTEX_ACQUIRED_AFTER; |
| 176 | ConditionVariable period_condition_ GUARDED_BY(wait_lock_); |
| 177 | |
| 178 | ProfileSampleResults profile_table_; |
| 179 | |
| 180 | UniquePtr<Barrier> profiler_barrier_; |
| 181 | |
| 182 | // Set of methods to be filtered out. This will probably be rare because |
| 183 | // most of the methods we want to be filtered reside in the boot path and |
| 184 | // are automatically filtered. |
| 185 | typedef std::set<std::string> FilteredMethods; |
| 186 | FilteredMethods filtered_methods_; |
| 187 | |
| 188 | DISALLOW_COPY_AND_ASSIGN(BackgroundMethodSamplingProfiler); |
| 189 | }; |
| 190 | |
Calin Juravle | 9dae5b4 | 2014-04-07 16:36:21 +0300 | [diff] [blame] | 191 | // TODO: incorporate in ProfileSampleResults |
| 192 | |
| 193 | // Profile data. This is generated from previous runs of the program and stored |
| 194 | // in a file. It is used to determine whether to compile a particular method or not. |
| 195 | class ProfileData { |
| 196 | public: |
| 197 | ProfileData() : count_(0), method_size_(0), usedPercent_(0) {} |
| 198 | ProfileData(const std::string& method_name, uint32_t count, uint32_t method_size, |
| 199 | double usedPercent, double topKUsedPercentage) : |
| 200 | method_name_(method_name), count_(count), method_size_(method_size), |
| 201 | usedPercent_(usedPercent), topKUsedPercentage_(topKUsedPercentage) { |
| 202 | // TODO: currently method_size_ and count_ are unused. |
| 203 | UNUSED(method_size_); |
| 204 | UNUSED(count_); |
| 205 | } |
| 206 | |
| 207 | bool IsAbove(double v) const { return usedPercent_ >= v; } |
| 208 | double GetUsedPercent() const { return usedPercent_; } |
| 209 | uint32_t GetCount() const { return count_; } |
| 210 | double GetTopKUsedPercentage() const { return topKUsedPercentage_; } |
| 211 | |
| 212 | private: |
| 213 | std::string method_name_; // Method name. |
| 214 | uint32_t count_; // Number of times it has been called. |
| 215 | uint32_t method_size_; // Size of the method on dex instructions. |
| 216 | double usedPercent_; // Percentage of how many times this method was called. |
| 217 | double topKUsedPercentage_; // The percentage of the group that comprise K% of the total used |
| 218 | // methods this methods belongs to. |
| 219 | }; |
| 220 | |
| 221 | // Profile data is stored in a map, indexed by the full method name. |
| 222 | typedef std::map<std::string, ProfileData> ProfileMap; |
| 223 | |
| 224 | class ProfileHelper { |
| 225 | private: |
| 226 | ProfileHelper(); |
| 227 | |
| 228 | public: |
| 229 | // Read the profile data from the given file. Calculates the percentage for each method. |
| 230 | // Returns false if there was no profile file or it was malformed. |
| 231 | static bool LoadProfileMap(ProfileMap& profileMap, const std::string& fileName); |
| 232 | |
| 233 | // Read the profile data from the given file and computes the group that comprise |
| 234 | // topKPercentage of the total used methods. |
| 235 | static bool LoadTopKSamples(std::set<std::string>& topKMethods, const std::string& fileName, |
| 236 | double topKPercentage); |
| 237 | }; |
| 238 | |
Dave Allison | 0aded08 | 2013-11-07 13:15:11 -0800 | [diff] [blame] | 239 | } // namespace art |
| 240 | |
| 241 | #endif // ART_RUNTIME_PROFILER_H_ |