trace.h revision 241a9588c6d7d0fcb4c92da40c7141863930083a 
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 <vector>
27
28#include "atomic.h"
29#include "base/macros.h"
30#include "globals.h"
31#include "instrumentation.h"
32#include "os.h"
33#include "safe_map.h"
34
35namespace art {
36
37namespace mirror {
38  class ArtMethod;
39  class DexCache;
40}  // namespace mirror
41
42class ArtField;
43class Thread;
44
45using DexIndexBitSet = std::bitset<65536>;
46using ThreadIDBitSet = std::bitset<65536>;
47
48enum TracingMode {
49  kTracingInactive,
50  kMethodTracingActive,
51  kSampleProfilingActive,
52};
53
54class Trace FINAL : public instrumentation::InstrumentationListener {
55 public:
56  enum TraceFlag {
57    kTraceCountAllocs = 1,
58  };
59
60  enum class TraceOutputMode {
61    kFile,
62    kDDMS,
63    kStreaming
64  };
65
66  enum class TraceMode {
67    kMethodTracing,
68    kSampling
69  };
70
71  ~Trace();
72
73  static void SetDefaultClockSource(TraceClockSource clock_source);
74
75  static void Start(const char* trace_filename, int trace_fd, size_t buffer_size, int flags,
76                    TraceOutputMode output_mode, TraceMode trace_mode, int interval_us)
77      LOCKS_EXCLUDED(Locks::mutator_lock_,
78                     Locks::thread_list_lock_,
79                     Locks::thread_suspend_count_lock_,
80                     Locks::trace_lock_);
81  static void Pause() LOCKS_EXCLUDED(Locks::trace_lock_, Locks::thread_list_lock_);
82  static void Resume() LOCKS_EXCLUDED(Locks::trace_lock_);
83
84  // Stop tracing. This will finish the trace and write it to file/send it via DDMS.
85  static void Stop()
86        LOCKS_EXCLUDED(Locks::mutator_lock_,
87                       Locks::thread_list_lock_,
88                       Locks::trace_lock_);
89  // Abort tracing. This will just stop tracing and *not* write/send the collected data.
90  static void Abort()
91      LOCKS_EXCLUDED(Locks::mutator_lock_,
92                     Locks::thread_list_lock_,
93                     Locks::trace_lock_);
94  static void Shutdown() LOCKS_EXCLUDED(Locks::trace_lock_);
95  static TracingMode GetMethodTracingMode() LOCKS_EXCLUDED(Locks::trace_lock_);
96
97  bool UseWallClock();
98  bool UseThreadCpuClock();
99  void MeasureClockOverhead();
100  uint32_t GetClockOverheadNanoSeconds();
101
102  void CompareAndUpdateStackTrace(Thread* thread, std::vector<mirror::ArtMethod*>* stack_trace)
103      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
104
105  // InstrumentationListener implementation.
106  void MethodEntered(Thread* thread, mirror::Object* this_object,
107                     mirror::ArtMethod* method, uint32_t dex_pc)
108      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) OVERRIDE;
109  void MethodExited(Thread* thread, mirror::Object* this_object,
110                    mirror::ArtMethod* method, uint32_t dex_pc,
111                    const JValue& return_value)
112      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) OVERRIDE;
113  void MethodUnwind(Thread* thread, mirror::Object* this_object,
114                    mirror::ArtMethod* method, uint32_t dex_pc)
115      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) OVERRIDE;
116  void DexPcMoved(Thread* thread, mirror::Object* this_object,
117                  mirror::ArtMethod* method, uint32_t new_dex_pc)
118      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) OVERRIDE;
119  void FieldRead(Thread* thread, mirror::Object* this_object,
120                 mirror::ArtMethod* method, uint32_t dex_pc, ArtField* field)
121      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) OVERRIDE;
122  void FieldWritten(Thread* thread, mirror::Object* this_object,
123                    mirror::ArtMethod* method, uint32_t dex_pc, ArtField* field,
124                    const JValue& field_value)
125      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) OVERRIDE;
126  void ExceptionCaught(Thread* thread, mirror::Throwable* exception_object)
127      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) OVERRIDE;
128  void BackwardBranch(Thread* thread, mirror::ArtMethod* method, int32_t dex_pc_offset)
129      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) OVERRIDE;
130  // Reuse an old stack trace if it exists, otherwise allocate a new one.
131  static std::vector<mirror::ArtMethod*>* AllocStackTrace();
132  // Clear and store an old stack trace for later use.
133  static void FreeStackTrace(std::vector<mirror::ArtMethod*>* stack_trace);
134  // Save id and name of a thread before it exits.
135  static void StoreExitingThreadInfo(Thread* thread);
136
137  static TraceOutputMode GetOutputMode() LOCKS_EXCLUDED(Locks::trace_lock_);
138  static TraceMode GetMode() LOCKS_EXCLUDED(Locks::trace_lock_);
139  static size_t GetBufferSize() LOCKS_EXCLUDED(Locks::trace_lock_);
140
141 private:
142  Trace(File* trace_file, const char* trace_name, size_t buffer_size, int flags,
143        TraceOutputMode output_mode, TraceMode trace_mode);
144
145  // The sampling interval in microseconds is passed as an argument.
146  static void* RunSamplingThread(void* arg) LOCKS_EXCLUDED(Locks::trace_lock_);
147
148  static void StopTracing(bool finish_tracing, bool flush_file);
149  void FinishTracing() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
150
151  void ReadClocks(Thread* thread, uint32_t* thread_clock_diff, uint32_t* wall_clock_diff);
152
153  void LogMethodTraceEvent(Thread* thread, mirror::ArtMethod* method,
154                           instrumentation::Instrumentation::InstrumentationEvent event,
155                           uint32_t thread_clock_diff, uint32_t wall_clock_diff)
156      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
157
158  // Methods to output traced methods and threads.
159  void GetVisitedMethods(size_t end_offset, std::set<mirror::ArtMethod*>* visited_methods);
160  void DumpMethodList(std::ostream& os, const std::set<mirror::ArtMethod*>& visited_methods)
161      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
162  void DumpThreadList(std::ostream& os) LOCKS_EXCLUDED(Locks::thread_list_lock_);
163
164  // Methods to register seen entitites in streaming mode. The methods return true if the entity
165  // is newly discovered.
166  bool RegisterMethod(mirror::ArtMethod* method)
167      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) EXCLUSIVE_LOCKS_REQUIRED(streaming_lock_);
168  bool RegisterThread(Thread* thread)
169      EXCLUSIVE_LOCKS_REQUIRED(streaming_lock_);
170
171  // Copy a temporary buffer to the main buffer. Used for streaming. Exposed here for lock
172  // annotation.
173  void WriteToBuf(const uint8_t* src, size_t src_size)
174      EXCLUSIVE_LOCKS_REQUIRED(streaming_lock_);
175
176  // Singleton instance of the Trace or null when no method tracing is active.
177  static Trace* volatile the_trace_ GUARDED_BY(Locks::trace_lock_);
178
179  // The default profiler clock source.
180  static TraceClockSource default_clock_source_;
181
182  // Sampling thread, non-zero when sampling.
183  static pthread_t sampling_pthread_;
184
185  // Used to remember an unused stack trace to avoid re-allocation during sampling.
186  static std::unique_ptr<std::vector<mirror::ArtMethod*>> temp_stack_trace_;
187
188  // File to write trace data out to, null if direct to ddms.
189  std::unique_ptr<File> trace_file_;
190
191  // Buffer to store trace data.
192  std::unique_ptr<uint8_t[]> buf_;
193
194  // Flags enabling extra tracing of things such as alloc counts.
195  const int flags_;
196
197  // The kind of output for this tracing.
198  const TraceOutputMode trace_output_mode_;
199
200  // The tracing method.
201  const TraceMode trace_mode_;
202
203  const TraceClockSource clock_source_;
204
205  // Size of buf_.
206  const size_t buffer_size_;
207
208  // Time trace was created.
209  const uint64_t start_time_;
210
211  // Clock overhead.
212  const uint32_t clock_overhead_ns_;
213
214  // Offset into buf_.
215  AtomicInteger cur_offset_;
216
217  // Did we overflow the buffer recording traces?
218  bool overflow_;
219
220  // Map of thread ids and names that have already exited.
221  SafeMap<pid_t, std::string> exited_threads_;
222
223  // Sampling profiler sampling interval.
224  int interval_us_;
225
226  // Streaming mode data.
227  std::string streaming_file_name_;
228  Mutex* streaming_lock_;
229  std::map<mirror::DexCache*, DexIndexBitSet*> seen_methods_;
230  std::unique_ptr<ThreadIDBitSet> seen_threads_;
231
232  DISALLOW_COPY_AND_ASSIGN(Trace);
233};
234
235}  // namespace art
236
237#endif  // ART_RUNTIME_TRACE_H_
238