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 45 constexpr size_t kMaxThreadIdNumber = kIsTargetBuild ? 65536U : 1048576U; 46 using ThreadIDBitSet = std::bitset<kMaxThreadIdNumber>; 47 48 enum TracingMode { 49 kTracingInactive, 50 kMethodTracingActive, 51 kSampleProfilingActive, 52 }; 53 54 // File format: 55 // header 56 // record 0 57 // record 1 58 // ... 59 // 60 // Header format: 61 // u4 magic ('SLOW') 62 // u2 version 63 // u2 offset to data 64 // u8 start date/time in usec 65 // u2 record size in bytes (version >= 2 only) 66 // ... padding to 32 bytes 67 // 68 // Record format v1: 69 // u1 thread ID 70 // u4 method ID | method action 71 // u4 time delta since start, in usec 72 // 73 // Record format v2: 74 // u2 thread ID 75 // u4 method ID | method action 76 // u4 time delta since start, in usec 77 // 78 // Record format v3: 79 // u2 thread ID 80 // u4 method ID | method action 81 // u4 time delta since start, in usec 82 // u4 wall time since start, in usec (when clock == "dual" only) 83 // 84 // 32 bits of microseconds is 70 minutes. 85 // 86 // All values are stored in little-endian order. 87 88 enum TraceAction { 89 kTraceMethodEnter = 0x00, // method entry 90 kTraceMethodExit = 0x01, // method exit 91 kTraceUnroll = 0x02, // method exited by exception unrolling 92 // 0x03 currently unused 93 kTraceMethodActionMask = 0x03, // two bits 94 }; 95 96 class Trace FINAL : public instrumentation::InstrumentationListener { 97 public: 98 enum TraceFlag { 99 kTraceCountAllocs = 1, 100 }; 101 102 enum class TraceOutputMode { 103 kFile, 104 kDDMS, 105 kStreaming 106 }; 107 108 enum class TraceMode { 109 kMethodTracing, 110 kSampling 111 }; 112 113 ~Trace(); 114 115 static void SetDefaultClockSource(TraceClockSource clock_source); 116 117 static void Start(const char* trace_filename, int trace_fd, size_t buffer_size, int flags, 118 TraceOutputMode output_mode, TraceMode trace_mode, int interval_us) 119 REQUIRES(!Locks::mutator_lock_, !Locks::thread_list_lock_, !Locks::thread_suspend_count_lock_, 120 !Locks::trace_lock_); 121 static void Pause() REQUIRES(!Locks::trace_lock_, !Locks::thread_list_lock_); 122 static void Resume() REQUIRES(!Locks::trace_lock_); 123 124 // Stop tracing. This will finish the trace and write it to file/send it via DDMS. 125 static void Stop() 126 REQUIRES(!Locks::mutator_lock_, !Locks::thread_list_lock_, !Locks::trace_lock_); 127 // Abort tracing. This will just stop tracing and *not* write/send the collected data. 128 static void Abort() 129 REQUIRES(!Locks::mutator_lock_, !Locks::thread_list_lock_, !Locks::trace_lock_); 130 static void Shutdown() 131 REQUIRES(!Locks::mutator_lock_, !Locks::thread_list_lock_, !Locks::trace_lock_); 132 static TracingMode GetMethodTracingMode() REQUIRES(!Locks::trace_lock_); 133 134 bool UseWallClock(); 135 bool UseThreadCpuClock(); 136 void MeasureClockOverhead(); 137 uint32_t GetClockOverheadNanoSeconds(); 138 139 void CompareAndUpdateStackTrace(Thread* thread, std::vector<ArtMethod*>* stack_trace) 140 REQUIRES_SHARED(Locks::mutator_lock_) REQUIRES(!*unique_methods_lock_, !*streaming_lock_); 141 142 // InstrumentationListener implementation. 143 void MethodEntered(Thread* thread, mirror::Object* this_object, 144 ArtMethod* method, uint32_t dex_pc) 145 REQUIRES_SHARED(Locks::mutator_lock_) REQUIRES(!*unique_methods_lock_, !*streaming_lock_) 146 OVERRIDE; 147 void MethodExited(Thread* thread, mirror::Object* this_object, 148 ArtMethod* method, uint32_t dex_pc, 149 const JValue& return_value) 150 REQUIRES_SHARED(Locks::mutator_lock_) REQUIRES(!*unique_methods_lock_, !*streaming_lock_) 151 OVERRIDE; 152 void MethodUnwind(Thread* thread, mirror::Object* this_object, 153 ArtMethod* method, uint32_t dex_pc) 154 REQUIRES_SHARED(Locks::mutator_lock_) REQUIRES(!*unique_methods_lock_, !*streaming_lock_) 155 OVERRIDE; 156 void DexPcMoved(Thread* thread, mirror::Object* this_object, 157 ArtMethod* method, uint32_t new_dex_pc) 158 REQUIRES_SHARED(Locks::mutator_lock_) REQUIRES(!*unique_methods_lock_, !*streaming_lock_) 159 OVERRIDE; 160 void FieldRead(Thread* thread, mirror::Object* this_object, 161 ArtMethod* method, uint32_t dex_pc, ArtField* field) 162 REQUIRES_SHARED(Locks::mutator_lock_) REQUIRES(!*unique_methods_lock_) OVERRIDE; 163 void FieldWritten(Thread* thread, mirror::Object* this_object, 164 ArtMethod* method, uint32_t dex_pc, ArtField* field, 165 const JValue& field_value) 166 REQUIRES_SHARED(Locks::mutator_lock_) REQUIRES(!*unique_methods_lock_) OVERRIDE; 167 void ExceptionCaught(Thread* thread, mirror::Throwable* exception_object) 168 REQUIRES_SHARED(Locks::mutator_lock_) REQUIRES(!*unique_methods_lock_) OVERRIDE; 169 void Branch(Thread* thread, ArtMethod* method, uint32_t dex_pc, int32_t dex_pc_offset) 170 REQUIRES_SHARED(Locks::mutator_lock_) REQUIRES(!*unique_methods_lock_) OVERRIDE; 171 void InvokeVirtualOrInterface(Thread* thread, 172 mirror::Object* this_object, 173 ArtMethod* caller, 174 uint32_t dex_pc, 175 ArtMethod* callee) 176 REQUIRES_SHARED(Locks::mutator_lock_) REQUIRES(!*unique_methods_lock_) OVERRIDE; 177 // Reuse an old stack trace if it exists, otherwise allocate a new one. 178 static std::vector<ArtMethod*>* AllocStackTrace(); 179 // Clear and store an old stack trace for later use. 180 static void FreeStackTrace(std::vector<ArtMethod*>* stack_trace); 181 // Save id and name of a thread before it exits. 182 static void StoreExitingThreadInfo(Thread* thread); 183 184 static TraceOutputMode GetOutputMode() REQUIRES(!Locks::trace_lock_); 185 static TraceMode GetMode() REQUIRES(!Locks::trace_lock_); 186 static size_t GetBufferSize() REQUIRES(!Locks::trace_lock_); 187 188 // Used by class linker to prevent class unloading. 189 static bool IsTracingEnabled() REQUIRES(!Locks::trace_lock_); 190 191 private: 192 Trace(File* trace_file, const char* trace_name, size_t buffer_size, int flags, 193 TraceOutputMode output_mode, TraceMode trace_mode); 194 195 // The sampling interval in microseconds is passed as an argument. 196 static void* RunSamplingThread(void* arg) REQUIRES(!Locks::trace_lock_); 197 198 static void StopTracing(bool finish_tracing, bool flush_file) 199 REQUIRES(!Locks::mutator_lock_, !Locks::thread_list_lock_, !Locks::trace_lock_) 200 // There is an annoying issue with static functions that create a new object and call into 201 // that object that causes them to not be able to tell that we don't currently hold the lock. 202 // This causes the negative annotations to incorrectly have a false positive. TODO: Figure out 203 // how to annotate this. 204 NO_THREAD_SAFETY_ANALYSIS; 205 void FinishTracing() 206 REQUIRES_SHARED(Locks::mutator_lock_) REQUIRES(!*unique_methods_lock_, !*streaming_lock_); 207 208 void ReadClocks(Thread* thread, uint32_t* thread_clock_diff, uint32_t* wall_clock_diff); 209 210 void LogMethodTraceEvent(Thread* thread, ArtMethod* method, 211 instrumentation::Instrumentation::InstrumentationEvent event, 212 uint32_t thread_clock_diff, uint32_t wall_clock_diff) 213 REQUIRES_SHARED(Locks::mutator_lock_) REQUIRES(!*unique_methods_lock_, !*streaming_lock_); 214 215 // Methods to output traced methods and threads. 216 void GetVisitedMethods(size_t end_offset, std::set<ArtMethod*>* visited_methods) 217 REQUIRES(!*unique_methods_lock_); 218 void DumpMethodList(std::ostream& os, const std::set<ArtMethod*>& visited_methods) 219 REQUIRES_SHARED(Locks::mutator_lock_) REQUIRES(!*unique_methods_lock_); 220 void DumpThreadList(std::ostream& os) REQUIRES(!Locks::thread_list_lock_); 221 222 // Methods to register seen entitites in streaming mode. The methods return true if the entity 223 // is newly discovered. 224 bool RegisterMethod(ArtMethod* method) 225 REQUIRES_SHARED(Locks::mutator_lock_) REQUIRES(streaming_lock_); 226 bool RegisterThread(Thread* thread) 227 REQUIRES(streaming_lock_); 228 229 // Copy a temporary buffer to the main buffer. Used for streaming. Exposed here for lock 230 // annotation. 231 void WriteToBuf(const uint8_t* src, size_t src_size) 232 REQUIRES(streaming_lock_); 233 // Flush the main buffer to file. Used for streaming. Exposed here for lock annotation. 234 void FlushBuf() 235 REQUIRES(streaming_lock_); 236 237 uint32_t EncodeTraceMethod(ArtMethod* method) REQUIRES(!*unique_methods_lock_); 238 uint32_t EncodeTraceMethodAndAction(ArtMethod* method, TraceAction action) 239 REQUIRES(!*unique_methods_lock_); 240 ArtMethod* DecodeTraceMethod(uint32_t tmid) REQUIRES(!*unique_methods_lock_); 241 std::string GetMethodLine(ArtMethod* method) REQUIRES(!*unique_methods_lock_) 242 REQUIRES_SHARED(Locks::mutator_lock_); 243 244 void DumpBuf(uint8_t* buf, size_t buf_size, TraceClockSource clock_source) 245 REQUIRES_SHARED(Locks::mutator_lock_) REQUIRES(!*unique_methods_lock_); 246 247 // Singleton instance of the Trace or null when no method tracing is active. 248 static Trace* volatile the_trace_ GUARDED_BY(Locks::trace_lock_); 249 250 // The default profiler clock source. 251 static TraceClockSource default_clock_source_; 252 253 // Sampling thread, non-zero when sampling. 254 static pthread_t sampling_pthread_; 255 256 // Used to remember an unused stack trace to avoid re-allocation during sampling. 257 static std::unique_ptr<std::vector<ArtMethod*>> temp_stack_trace_; 258 259 // File to write trace data out to, null if direct to ddms. 260 std::unique_ptr<File> trace_file_; 261 262 // Buffer to store trace data. 263 std::unique_ptr<uint8_t[]> buf_; 264 265 // Flags enabling extra tracing of things such as alloc counts. 266 const int flags_; 267 268 // The kind of output for this tracing. 269 const TraceOutputMode trace_output_mode_; 270 271 // The tracing method. 272 const TraceMode trace_mode_; 273 274 const TraceClockSource clock_source_; 275 276 // Size of buf_. 277 const size_t buffer_size_; 278 279 // Time trace was created. 280 const uint64_t start_time_; 281 282 // Clock overhead. 283 const uint32_t clock_overhead_ns_; 284 285 // Offset into buf_. 286 AtomicInteger cur_offset_; 287 288 // Did we overflow the buffer recording traces? 289 bool overflow_; 290 291 // Map of thread ids and names that have already exited. 292 SafeMap<pid_t, std::string> exited_threads_; 293 294 // Sampling profiler sampling interval. 295 int interval_us_; 296 297 // Streaming mode data. 298 std::string streaming_file_name_; 299 Mutex* streaming_lock_; 300 std::map<const DexFile*, DexIndexBitSet*> seen_methods_; 301 std::unique_ptr<ThreadIDBitSet> seen_threads_; 302 303 // Bijective map from ArtMethod* to index. 304 // Map from ArtMethod* to index in unique_methods_; 305 Mutex* unique_methods_lock_ ACQUIRED_AFTER(streaming_lock_); 306 std::unordered_map<ArtMethod*, uint32_t> art_method_id_map_ GUARDED_BY(unique_methods_lock_); 307 std::vector<ArtMethod*> unique_methods_ GUARDED_BY(unique_methods_lock_); 308 309 DISALLOW_COPY_AND_ASSIGN(Trace); 310 }; 311 312 } // namespace art 313 314 #endif // ART_RUNTIME_TRACE_H_ 315
