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_TRACE_H_ 18 #define ART_RUNTIME_TRACE_H_ 19 20 #include <bitset> 21 #include <map> 22 #include <memory> 23 #include <ostream> 24 #include <set> 25 #include <string> 26 #include <unordered_map> 27 #include <vector> 28 29 #include "atomic.h" 30 #include "base/macros.h" 31 #include "globals.h" 32 #include "instrumentation.h" 33 #include "os.h" 34 #include "safe_map.h" 35 36 namespace art { 37 38 class ArtField; 39 class ArtMethod; 40 class DexFile; 41 class Thread; 42 43 using DexIndexBitSet = std::bitset<65536>; 44 using ThreadIDBitSet = std::bitset<65536>; 45 46 enum TracingMode { 47 kTracingInactive, 48 kMethodTracingActive, 49 kSampleProfilingActive, 50 }; 51 52 // File format: 53 // header 54 // record 0 55 // record 1 56 // ... 57 // 58 // Header format: 59 // u4 magic ('SLOW') 60 // u2 version 61 // u2 offset to data 62 // u8 start date/time in usec 63 // u2 record size in bytes (version >= 2 only) 64 // ... padding to 32 bytes 65 // 66 // Record format v1: 67 // u1 thread ID 68 // u4 method ID | method action 69 // u4 time delta since start, in usec 70 // 71 // Record format v2: 72 // u2 thread ID 73 // u4 method ID | method action 74 // u4 time delta since start, in usec 75 // 76 // Record format v3: 77 // u2 thread ID 78 // u4 method ID | method action 79 // u4 time delta since start, in usec 80 // u4 wall time since start, in usec (when clock == "dual" only) 81 // 82 // 32 bits of microseconds is 70 minutes. 83 // 84 // All values are stored in little-endian order. 85 86 enum TraceAction { 87 kTraceMethodEnter = 0x00, // method entry 88 kTraceMethodExit = 0x01, // method exit 89 kTraceUnroll = 0x02, // method exited by exception unrolling 90 // 0x03 currently unused 91 kTraceMethodActionMask = 0x03, // two bits 92 }; 93 94 class Trace FINAL : public instrumentation::InstrumentationListener { 95 public: 96 enum TraceFlag { 97 kTraceCountAllocs = 1, 98 }; 99 100 enum class TraceOutputMode { 101 kFile, 102 kDDMS, 103 kStreaming 104 }; 105 106 enum class TraceMode { 107 kMethodTracing, 108 kSampling 109 }; 110 111 ~Trace(); 112 113 static void SetDefaultClockSource(TraceClockSource clock_source); 114 115 static void Start(const char* trace_filename, int trace_fd, size_t buffer_size, int flags, 116 TraceOutputMode output_mode, TraceMode trace_mode, int interval_us) 117 REQUIRES(!Locks::mutator_lock_, !Locks::thread_list_lock_, !Locks::thread_suspend_count_lock_, 118 !Locks::trace_lock_); 119 static void Pause() REQUIRES(!Locks::trace_lock_, !Locks::thread_list_lock_); 120 static void Resume() REQUIRES(!Locks::trace_lock_); 121 122 // Stop tracing. This will finish the trace and write it to file/send it via DDMS. 123 static void Stop() 124 REQUIRES(!Locks::mutator_lock_, !Locks::thread_list_lock_, !Locks::trace_lock_); 125 // Abort tracing. This will just stop tracing and *not* write/send the collected data. 126 static void Abort() 127 REQUIRES(!Locks::mutator_lock_, !Locks::thread_list_lock_, !Locks::trace_lock_); 128 static void Shutdown() 129 REQUIRES(!Locks::mutator_lock_, !Locks::thread_list_lock_, !Locks::trace_lock_); 130 static TracingMode GetMethodTracingMode() REQUIRES(!Locks::trace_lock_); 131 132 bool UseWallClock(); 133 bool UseThreadCpuClock(); 134 void MeasureClockOverhead(); 135 uint32_t GetClockOverheadNanoSeconds(); 136 137 void CompareAndUpdateStackTrace(Thread* thread, std::vector<ArtMethod*>* stack_trace) 138 SHARED_REQUIRES(Locks::mutator_lock_) REQUIRES(!*unique_methods_lock_, !*streaming_lock_); 139 140 // InstrumentationListener implementation. 141 void MethodEntered(Thread* thread, mirror::Object* this_object, 142 ArtMethod* method, uint32_t dex_pc) 143 SHARED_REQUIRES(Locks::mutator_lock_) REQUIRES(!*unique_methods_lock_, !*streaming_lock_) 144 OVERRIDE; 145 void MethodExited(Thread* thread, mirror::Object* this_object, 146 ArtMethod* method, uint32_t dex_pc, 147 const JValue& return_value) 148 SHARED_REQUIRES(Locks::mutator_lock_) REQUIRES(!*unique_methods_lock_, !*streaming_lock_) 149 OVERRIDE; 150 void MethodUnwind(Thread* thread, mirror::Object* this_object, 151 ArtMethod* method, uint32_t dex_pc) 152 SHARED_REQUIRES(Locks::mutator_lock_) REQUIRES(!*unique_methods_lock_, !*streaming_lock_) 153 OVERRIDE; 154 void DexPcMoved(Thread* thread, mirror::Object* this_object, 155 ArtMethod* method, uint32_t new_dex_pc) 156 SHARED_REQUIRES(Locks::mutator_lock_) REQUIRES(!*unique_methods_lock_, !*streaming_lock_) 157 OVERRIDE; 158 void FieldRead(Thread* thread, mirror::Object* this_object, 159 ArtMethod* method, uint32_t dex_pc, ArtField* field) 160 SHARED_REQUIRES(Locks::mutator_lock_) REQUIRES(!*unique_methods_lock_) OVERRIDE; 161 void FieldWritten(Thread* thread, mirror::Object* this_object, 162 ArtMethod* method, uint32_t dex_pc, ArtField* field, 163 const JValue& field_value) 164 SHARED_REQUIRES(Locks::mutator_lock_) REQUIRES(!*unique_methods_lock_) OVERRIDE; 165 void ExceptionCaught(Thread* thread, mirror::Throwable* exception_object) 166 SHARED_REQUIRES(Locks::mutator_lock_) REQUIRES(!*unique_methods_lock_) OVERRIDE; 167 void Branch(Thread* thread, ArtMethod* method, uint32_t dex_pc, int32_t dex_pc_offset) 168 SHARED_REQUIRES(Locks::mutator_lock_) REQUIRES(!*unique_methods_lock_) OVERRIDE; 169 void InvokeVirtualOrInterface(Thread* thread, 170 mirror::Object* this_object, 171 ArtMethod* caller, 172 uint32_t dex_pc, 173 ArtMethod* callee) 174 SHARED_REQUIRES(Locks::mutator_lock_) REQUIRES(!*unique_methods_lock_) OVERRIDE; 175 // Reuse an old stack trace if it exists, otherwise allocate a new one. 176 static std::vector<ArtMethod*>* AllocStackTrace(); 177 // Clear and store an old stack trace for later use. 178 static void FreeStackTrace(std::vector<ArtMethod*>* stack_trace); 179 // Save id and name of a thread before it exits. 180 static void StoreExitingThreadInfo(Thread* thread); 181 182 static TraceOutputMode GetOutputMode() REQUIRES(!Locks::trace_lock_); 183 static TraceMode GetMode() REQUIRES(!Locks::trace_lock_); 184 static size_t GetBufferSize() REQUIRES(!Locks::trace_lock_); 185 186 // Used by class linker to prevent class unloading. 187 static bool IsTracingEnabled() REQUIRES(!Locks::trace_lock_); 188 189 private: 190 Trace(File* trace_file, const char* trace_name, size_t buffer_size, int flags, 191 TraceOutputMode output_mode, TraceMode trace_mode); 192 193 // The sampling interval in microseconds is passed as an argument. 194 static void* RunSamplingThread(void* arg) REQUIRES(!Locks::trace_lock_); 195 196 static void StopTracing(bool finish_tracing, bool flush_file) 197 REQUIRES(!Locks::mutator_lock_, !Locks::thread_list_lock_, !Locks::trace_lock_) 198 // There is an annoying issue with static functions that create a new object and call into 199 // that object that causes them to not be able to tell that we don't currently hold the lock. 200 // This causes the negative annotations to incorrectly have a false positive. TODO: Figure out 201 // how to annotate this. 202 NO_THREAD_SAFETY_ANALYSIS; 203 void FinishTracing() SHARED_REQUIRES(Locks::mutator_lock_) REQUIRES(!*unique_methods_lock_); 204 205 void ReadClocks(Thread* thread, uint32_t* thread_clock_diff, uint32_t* wall_clock_diff); 206 207 void LogMethodTraceEvent(Thread* thread, ArtMethod* method, 208 instrumentation::Instrumentation::InstrumentationEvent event, 209 uint32_t thread_clock_diff, uint32_t wall_clock_diff) 210 SHARED_REQUIRES(Locks::mutator_lock_) REQUIRES(!*unique_methods_lock_, !*streaming_lock_); 211 212 // Methods to output traced methods and threads. 213 void GetVisitedMethods(size_t end_offset, std::set<ArtMethod*>* visited_methods) 214 REQUIRES(!*unique_methods_lock_); 215 void DumpMethodList(std::ostream& os, const std::set<ArtMethod*>& visited_methods) 216 SHARED_REQUIRES(Locks::mutator_lock_) REQUIRES(!*unique_methods_lock_); 217 void DumpThreadList(std::ostream& os) REQUIRES(!Locks::thread_list_lock_); 218 219 // Methods to register seen entitites in streaming mode. The methods return true if the entity 220 // is newly discovered. 221 bool RegisterMethod(ArtMethod* method) 222 SHARED_REQUIRES(Locks::mutator_lock_) REQUIRES(streaming_lock_); 223 bool RegisterThread(Thread* thread) 224 REQUIRES(streaming_lock_); 225 226 // Copy a temporary buffer to the main buffer. Used for streaming. Exposed here for lock 227 // annotation. 228 void WriteToBuf(const uint8_t* src, size_t src_size) 229 REQUIRES(streaming_lock_); 230 231 uint32_t EncodeTraceMethod(ArtMethod* method) REQUIRES(!*unique_methods_lock_); 232 uint32_t EncodeTraceMethodAndAction(ArtMethod* method, TraceAction action) 233 REQUIRES(!*unique_methods_lock_); 234 ArtMethod* DecodeTraceMethod(uint32_t tmid) REQUIRES(!*unique_methods_lock_); 235 std::string GetMethodLine(ArtMethod* method) REQUIRES(!*unique_methods_lock_) 236 SHARED_REQUIRES(Locks::mutator_lock_); 237 238 void DumpBuf(uint8_t* buf, size_t buf_size, TraceClockSource clock_source) 239 SHARED_REQUIRES(Locks::mutator_lock_) REQUIRES(!*unique_methods_lock_); 240 241 // Singleton instance of the Trace or null when no method tracing is active. 242 static Trace* volatile the_trace_ GUARDED_BY(Locks::trace_lock_); 243 244 // The default profiler clock source. 245 static TraceClockSource default_clock_source_; 246 247 // Sampling thread, non-zero when sampling. 248 static pthread_t sampling_pthread_; 249 250 // Used to remember an unused stack trace to avoid re-allocation during sampling. 251 static std::unique_ptr<std::vector<ArtMethod*>> temp_stack_trace_; 252 253 // File to write trace data out to, null if direct to ddms. 254 std::unique_ptr<File> trace_file_; 255 256 // Buffer to store trace data. 257 std::unique_ptr<uint8_t[]> buf_; 258 259 // Flags enabling extra tracing of things such as alloc counts. 260 const int flags_; 261 262 // The kind of output for this tracing. 263 const TraceOutputMode trace_output_mode_; 264 265 // The tracing method. 266 const TraceMode trace_mode_; 267 268 const TraceClockSource clock_source_; 269 270 // Size of buf_. 271 const size_t buffer_size_; 272 273 // Time trace was created. 274 const uint64_t start_time_; 275 276 // Clock overhead. 277 const uint32_t clock_overhead_ns_; 278 279 // Offset into buf_. 280 AtomicInteger cur_offset_; 281 282 // Did we overflow the buffer recording traces? 283 bool overflow_; 284 285 // Map of thread ids and names that have already exited. 286 SafeMap<pid_t, std::string> exited_threads_; 287 288 // Sampling profiler sampling interval. 289 int interval_us_; 290 291 // Streaming mode data. 292 std::string streaming_file_name_; 293 Mutex* streaming_lock_; 294 std::map<const DexFile*, DexIndexBitSet*> seen_methods_; 295 std::unique_ptr<ThreadIDBitSet> seen_threads_; 296 297 // Bijective map from ArtMethod* to index. 298 // Map from ArtMethod* to index in unique_methods_; 299 Mutex* unique_methods_lock_ ACQUIRED_AFTER(streaming_lock_); 300 std::unordered_map<ArtMethod*, uint32_t> art_method_id_map_ GUARDED_BY(unique_methods_lock_); 301 std::vector<ArtMethod*> unique_methods_ GUARDED_BY(unique_methods_lock_); 302 303 DISALLOW_COPY_AND_ASSIGN(Trace); 304 }; 305 306 } // namespace art 307 308 #endif // ART_RUNTIME_TRACE_H_ 309
