V8 API Reference, 7.2.502.16 (for Deno 0.2.4)
v8-tracing.h
1 // Copyright 2016 the V8 project authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4 
5 #ifndef V8_LIBPLATFORM_V8_TRACING_H_
6 #define V8_LIBPLATFORM_V8_TRACING_H_
7 
8 #include <fstream>
9 #include <memory>
10 #include <unordered_set>
11 #include <vector>
12 
13 #include "libplatform/libplatform-export.h"
14 #include "v8-platform.h" // NOLINT(build/include)
15 
16 namespace v8 {
17 
18 namespace base {
19 class Mutex;
20 } // namespace base
21 
22 namespace platform {
23 namespace tracing {
24 
25 const int kTraceMaxNumArgs = 2;
26 
27 class V8_PLATFORM_EXPORT TraceObject {
28  public:
29  union ArgValue {
30  bool as_bool;
31  uint64_t as_uint;
32  int64_t as_int;
33  double as_double;
34  const void* as_pointer;
35  const char* as_string;
36  };
37 
38  TraceObject() = default;
39  ~TraceObject();
40  void Initialize(
41  char phase, const uint8_t* category_enabled_flag, const char* name,
42  const char* scope, uint64_t id, uint64_t bind_id, int num_args,
43  const char** arg_names, const uint8_t* arg_types,
44  const uint64_t* arg_values,
45  std::unique_ptr<v8::ConvertableToTraceFormat>* arg_convertables,
46  unsigned int flags, int64_t timestamp, int64_t cpu_timestamp);
47  void UpdateDuration(int64_t timestamp, int64_t cpu_timestamp);
48  void InitializeForTesting(
49  char phase, const uint8_t* category_enabled_flag, const char* name,
50  const char* scope, uint64_t id, uint64_t bind_id, int num_args,
51  const char** arg_names, const uint8_t* arg_types,
52  const uint64_t* arg_values,
53  std::unique_ptr<v8::ConvertableToTraceFormat>* arg_convertables,
54  unsigned int flags, int pid, int tid, int64_t ts, int64_t tts,
55  uint64_t duration, uint64_t cpu_duration);
56 
57  int pid() const { return pid_; }
58  int tid() const { return tid_; }
59  char phase() const { return phase_; }
60  const uint8_t* category_enabled_flag() const {
61  return category_enabled_flag_;
62  }
63  const char* name() const { return name_; }
64  const char* scope() const { return scope_; }
65  uint64_t id() const { return id_; }
66  uint64_t bind_id() const { return bind_id_; }
67  int num_args() const { return num_args_; }
68  const char** arg_names() { return arg_names_; }
69  uint8_t* arg_types() { return arg_types_; }
70  ArgValue* arg_values() { return arg_values_; }
71  std::unique_ptr<v8::ConvertableToTraceFormat>* arg_convertables() {
72  return arg_convertables_;
73  }
74  unsigned int flags() const { return flags_; }
75  int64_t ts() { return ts_; }
76  int64_t tts() { return tts_; }
77  uint64_t duration() { return duration_; }
78  uint64_t cpu_duration() { return cpu_duration_; }
79 
80  private:
81  int pid_;
82  int tid_;
83  char phase_;
84  const char* name_;
85  const char* scope_;
86  const uint8_t* category_enabled_flag_;
87  uint64_t id_;
88  uint64_t bind_id_;
89  int num_args_ = 0;
90  const char* arg_names_[kTraceMaxNumArgs];
91  uint8_t arg_types_[kTraceMaxNumArgs];
92  ArgValue arg_values_[kTraceMaxNumArgs];
93  std::unique_ptr<v8::ConvertableToTraceFormat>
94  arg_convertables_[kTraceMaxNumArgs];
95  char* parameter_copy_storage_ = nullptr;
96  unsigned int flags_;
97  int64_t ts_;
98  int64_t tts_;
99  uint64_t duration_;
100  uint64_t cpu_duration_;
101 
102  // Disallow copy and assign
103  TraceObject(const TraceObject&) = delete;
104  void operator=(const TraceObject&) = delete;
105 };
106 
107 class V8_PLATFORM_EXPORT TraceWriter {
108  public:
109  TraceWriter() = default;
110  virtual ~TraceWriter() = default;
111  virtual void AppendTraceEvent(TraceObject* trace_event) = 0;
112  virtual void Flush() = 0;
113 
114  static TraceWriter* CreateJSONTraceWriter(std::ostream& stream);
115  static TraceWriter* CreateJSONTraceWriter(std::ostream& stream,
116  const std::string& tag);
117 
118  private:
119  // Disallow copy and assign
120  TraceWriter(const TraceWriter&) = delete;
121  void operator=(const TraceWriter&) = delete;
122 };
123 
124 class V8_PLATFORM_EXPORT TraceBufferChunk {
125  public:
126  explicit TraceBufferChunk(uint32_t seq);
127 
128  void Reset(uint32_t new_seq);
129  bool IsFull() const { return next_free_ == kChunkSize; }
130  TraceObject* AddTraceEvent(size_t* event_index);
131  TraceObject* GetEventAt(size_t index) { return &chunk_[index]; }
132 
133  uint32_t seq() const { return seq_; }
134  size_t size() const { return next_free_; }
135 
136  static const size_t kChunkSize = 64;
137 
138  private:
139  size_t next_free_ = 0;
140  TraceObject chunk_[kChunkSize];
141  uint32_t seq_;
142 
143  // Disallow copy and assign
144  TraceBufferChunk(const TraceBufferChunk&) = delete;
145  void operator=(const TraceBufferChunk&) = delete;
146 };
147 
148 class V8_PLATFORM_EXPORT TraceBuffer {
149  public:
150  TraceBuffer() = default;
151  virtual ~TraceBuffer() = default;
152 
153  virtual TraceObject* AddTraceEvent(uint64_t* handle) = 0;
154  virtual TraceObject* GetEventByHandle(uint64_t handle) = 0;
155  virtual bool Flush() = 0;
156 
157  static const size_t kRingBufferChunks = 1024;
158 
159  static TraceBuffer* CreateTraceBufferRingBuffer(size_t max_chunks,
160  TraceWriter* trace_writer);
161 
162  private:
163  // Disallow copy and assign
164  TraceBuffer(const TraceBuffer&) = delete;
165  void operator=(const TraceBuffer&) = delete;
166 };
167 
168 // Options determines how the trace buffer stores data.
169 enum TraceRecordMode {
170  // Record until the trace buffer is full.
171  RECORD_UNTIL_FULL,
172 
173  // Record until the user ends the trace. The trace buffer is a fixed size
174  // and we use it as a ring buffer during recording.
175  RECORD_CONTINUOUSLY,
176 
177  // Record until the trace buffer is full, but with a huge buffer size.
178  RECORD_AS_MUCH_AS_POSSIBLE,
179 
180  // Echo to console. Events are discarded.
181  ECHO_TO_CONSOLE,
182 };
183 
184 class V8_PLATFORM_EXPORT TraceConfig {
185  public:
186  typedef std::vector<std::string> StringList;
187 
188  static TraceConfig* CreateDefaultTraceConfig();
189 
190  TraceConfig() : enable_systrace_(false), enable_argument_filter_(false) {}
191  TraceRecordMode GetTraceRecordMode() const { return record_mode_; }
192  bool IsSystraceEnabled() const { return enable_systrace_; }
193  bool IsArgumentFilterEnabled() const { return enable_argument_filter_; }
194 
195  void SetTraceRecordMode(TraceRecordMode mode) { record_mode_ = mode; }
196  void EnableSystrace() { enable_systrace_ = true; }
197  void EnableArgumentFilter() { enable_argument_filter_ = true; }
198 
199  void AddIncludedCategory(const char* included_category);
200 
201  bool IsCategoryGroupEnabled(const char* category_group) const;
202 
203  private:
204  TraceRecordMode record_mode_;
205  bool enable_systrace_ : 1;
206  bool enable_argument_filter_ : 1;
207  StringList included_categories_;
208 
209  // Disallow copy and assign
210  TraceConfig(const TraceConfig&) = delete;
211  void operator=(const TraceConfig&) = delete;
212 };
213 
214 #if defined(_MSC_VER)
215 #define V8_PLATFORM_NON_EXPORTED_BASE(code) \
216  __pragma(warning(suppress : 4275)) code
217 #else
218 #define V8_PLATFORM_NON_EXPORTED_BASE(code) code
219 #endif // defined(_MSC_VER)
220 
221 class V8_PLATFORM_EXPORT TracingController
222  : public V8_PLATFORM_NON_EXPORTED_BASE(v8::TracingController) {
223  public:
224  enum Mode { DISABLED = 0, RECORDING_MODE };
225 
226  // The pointer returned from GetCategoryGroupEnabledInternal() points to a
227  // value with zero or more of the following bits. Used in this class only.
228  // The TRACE_EVENT macros should only use the value as a bool.
229  // These values must be in sync with macro values in TraceEvent.h in Blink.
230  enum CategoryGroupEnabledFlags {
231  // Category group enabled for the recording mode.
232  ENABLED_FOR_RECORDING = 1 << 0,
233  // Category group enabled by SetEventCallbackEnabled().
234  ENABLED_FOR_EVENT_CALLBACK = 1 << 2,
235  // Category group enabled to export events to ETW.
236  ENABLED_FOR_ETW_EXPORT = 1 << 3
237  };
238 
240  ~TracingController() override;
241  void Initialize(TraceBuffer* trace_buffer);
242 
243  // v8::TracingController implementation.
244  const uint8_t* GetCategoryGroupEnabled(const char* category_group) override;
245  uint64_t AddTraceEvent(
246  char phase, const uint8_t* category_enabled_flag, const char* name,
247  const char* scope, uint64_t id, uint64_t bind_id, int32_t num_args,
248  const char** arg_names, const uint8_t* arg_types,
249  const uint64_t* arg_values,
250  std::unique_ptr<v8::ConvertableToTraceFormat>* arg_convertables,
251  unsigned int flags) override;
252  uint64_t AddTraceEventWithTimestamp(
253  char phase, const uint8_t* category_enabled_flag, const char* name,
254  const char* scope, uint64_t id, uint64_t bind_id, int32_t num_args,
255  const char** arg_names, const uint8_t* arg_types,
256  const uint64_t* arg_values,
257  std::unique_ptr<v8::ConvertableToTraceFormat>* arg_convertables,
258  unsigned int flags, int64_t timestamp) override;
259  void UpdateTraceEventDuration(const uint8_t* category_enabled_flag,
260  const char* name, uint64_t handle) override;
261  void AddTraceStateObserver(
262  v8::TracingController::TraceStateObserver* observer) override;
263  void RemoveTraceStateObserver(
264  v8::TracingController::TraceStateObserver* observer) override;
265 
266  void StartTracing(TraceConfig* trace_config);
267  void StopTracing();
268 
269  static const char* GetCategoryGroupName(const uint8_t* category_enabled_flag);
270 
271  protected:
272  virtual int64_t CurrentTimestampMicroseconds();
273  virtual int64_t CurrentCpuTimestampMicroseconds();
274 
275  private:
276  const uint8_t* GetCategoryGroupEnabledInternal(const char* category_group);
277  void UpdateCategoryGroupEnabledFlag(size_t category_index);
278  void UpdateCategoryGroupEnabledFlags();
279 
280  std::unique_ptr<TraceBuffer> trace_buffer_;
281  std::unique_ptr<TraceConfig> trace_config_;
282  std::unique_ptr<base::Mutex> mutex_;
283  std::unordered_set<v8::TracingController::TraceStateObserver*> observers_;
284  Mode mode_ = DISABLED;
285 
286  // Disallow copy and assign
287  TracingController(const TracingController&) = delete;
288  void operator=(const TracingController&) = delete;
289 };
290 
291 #undef V8_PLATFORM_NON_EXPORTED_BASE
292 
293 } // namespace tracing
294 } // namespace platform
295 } // namespace v8
296 
297 #endif // V8_LIBPLATFORM_V8_TRACING_H_
Definition: libplatform.h:13