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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 <atomic>
9 #include <fstream>
10 #include <memory>
11 #include <unordered_set>
12 #include <vector>
13 
14 #include "libplatform/libplatform-export.h"
15 #include "v8-platform.h"  // NOLINT(build/include_directory)
16 
17 namespace perfetto {
18 namespace trace_processor {
19 class TraceProcessorStorage;
20 }
21 class TracingSession;
22 }
23 
24 namespace v8 {
25 
26 namespace base {
27 class Mutex;
28 }  // namespace base
29 
30 namespace platform {
31 namespace tracing {
32 
33 class TraceEventListener;
34 
35 const int kTraceMaxNumArgs = 2;
36 
37 class V8_PLATFORM_EXPORT TraceObject {
38  public:
39   union ArgValue {
40     V8_DEPRECATED("use as_uint ? true : false") bool as_bool;
41     uint64_t as_uint;
42     int64_t as_int;
43     double as_double;
44     const void* as_pointer;
45     const char* as_string;
46   };
47 
48   TraceObject() = default;
49   ~TraceObject();
50   void Initialize(
51       char phase, const uint8_t* category_enabled_flag, const char* name,
52       const char* scope, uint64_t id, uint64_t bind_id, int num_args,
53       const char** arg_names, const uint8_t* arg_types,
54       const uint64_t* arg_values,
55       std::unique_ptr<v8::ConvertableToTraceFormat>* arg_convertables,
56       unsigned int flags, int64_t timestamp, int64_t cpu_timestamp);
57   void UpdateDuration(int64_t timestamp, int64_t cpu_timestamp);
58   void InitializeForTesting(
59       char phase, const uint8_t* category_enabled_flag, const char* name,
60       const char* scope, uint64_t id, uint64_t bind_id, int num_args,
61       const char** arg_names, const uint8_t* arg_types,
62       const uint64_t* arg_values,
63       std::unique_ptr<v8::ConvertableToTraceFormat>* arg_convertables,
64       unsigned int flags, int pid, int tid, int64_t ts, int64_t tts,
65       uint64_t duration, uint64_t cpu_duration);
66 
pid()67   int pid() const { return pid_; }
tid()68   int tid() const { return tid_; }
phase()69   char phase() const { return phase_; }
category_enabled_flag()70   const uint8_t* category_enabled_flag() const {
71     return category_enabled_flag_;
72   }
name()73   const char* name() const { return name_; }
scope()74   const char* scope() const { return scope_; }
id()75   uint64_t id() const { return id_; }
bind_id()76   uint64_t bind_id() const { return bind_id_; }
num_args()77   int num_args() const { return num_args_; }
arg_names()78   const char** arg_names() { return arg_names_; }
arg_types()79   uint8_t* arg_types() { return arg_types_; }
arg_values()80   ArgValue* arg_values() { return arg_values_; }
arg_convertables()81   std::unique_ptr<v8::ConvertableToTraceFormat>* arg_convertables() {
82     return arg_convertables_;
83   }
flags()84   unsigned int flags() const { return flags_; }
ts()85   int64_t ts() { return ts_; }
tts()86   int64_t tts() { return tts_; }
duration()87   uint64_t duration() { return duration_; }
cpu_duration()88   uint64_t cpu_duration() { return cpu_duration_; }
89 
90  private:
91   int pid_;
92   int tid_;
93   char phase_;
94   const char* name_;
95   const char* scope_;
96   const uint8_t* category_enabled_flag_;
97   uint64_t id_;
98   uint64_t bind_id_;
99   int num_args_ = 0;
100   const char* arg_names_[kTraceMaxNumArgs];
101   uint8_t arg_types_[kTraceMaxNumArgs];
102   ArgValue arg_values_[kTraceMaxNumArgs];
103   std::unique_ptr<v8::ConvertableToTraceFormat>
104       arg_convertables_[kTraceMaxNumArgs];
105   char* parameter_copy_storage_ = nullptr;
106   unsigned int flags_;
107   int64_t ts_;
108   int64_t tts_;
109   uint64_t duration_;
110   uint64_t cpu_duration_;
111 
112   // Disallow copy and assign
113   TraceObject(const TraceObject&) = delete;
114   void operator=(const TraceObject&) = delete;
115 };
116 
117 class V8_PLATFORM_EXPORT TraceWriter {
118  public:
119   TraceWriter() = default;
120   virtual ~TraceWriter() = default;
121   virtual void AppendTraceEvent(TraceObject* trace_event) = 0;
122   virtual void Flush() = 0;
123 
124   static TraceWriter* CreateJSONTraceWriter(std::ostream& stream);
125   static TraceWriter* CreateJSONTraceWriter(std::ostream& stream,
126                                             const std::string& tag);
127 
128  private:
129   // Disallow copy and assign
130   TraceWriter(const TraceWriter&) = delete;
131   void operator=(const TraceWriter&) = delete;
132 };
133 
134 class V8_PLATFORM_EXPORT TraceBufferChunk {
135  public:
136   explicit TraceBufferChunk(uint32_t seq);
137 
138   void Reset(uint32_t new_seq);
IsFull()139   bool IsFull() const { return next_free_ == kChunkSize; }
140   TraceObject* AddTraceEvent(size_t* event_index);
GetEventAt(size_t index)141   TraceObject* GetEventAt(size_t index) { return &chunk_[index]; }
142 
seq()143   uint32_t seq() const { return seq_; }
size()144   size_t size() const { return next_free_; }
145 
146   static const size_t kChunkSize = 64;
147 
148  private:
149   size_t next_free_ = 0;
150   TraceObject chunk_[kChunkSize];
151   uint32_t seq_;
152 
153   // Disallow copy and assign
154   TraceBufferChunk(const TraceBufferChunk&) = delete;
155   void operator=(const TraceBufferChunk&) = delete;
156 };
157 
158 class V8_PLATFORM_EXPORT TraceBuffer {
159  public:
160   TraceBuffer() = default;
161   virtual ~TraceBuffer() = default;
162 
163   virtual TraceObject* AddTraceEvent(uint64_t* handle) = 0;
164   virtual TraceObject* GetEventByHandle(uint64_t handle) = 0;
165   virtual bool Flush() = 0;
166 
167   static const size_t kRingBufferChunks = 1024;
168 
169   static TraceBuffer* CreateTraceBufferRingBuffer(size_t max_chunks,
170                                                   TraceWriter* trace_writer);
171 
172  private:
173   // Disallow copy and assign
174   TraceBuffer(const TraceBuffer&) = delete;
175   void operator=(const TraceBuffer&) = delete;
176 };
177 
178 // Options determines how the trace buffer stores data.
179 enum TraceRecordMode {
180   // Record until the trace buffer is full.
181   RECORD_UNTIL_FULL,
182 
183   // Record until the user ends the trace. The trace buffer is a fixed size
184   // and we use it as a ring buffer during recording.
185   RECORD_CONTINUOUSLY,
186 
187   // Record until the trace buffer is full, but with a huge buffer size.
188   RECORD_AS_MUCH_AS_POSSIBLE,
189 
190   // Echo to console. Events are discarded.
191   ECHO_TO_CONSOLE,
192 };
193 
194 class V8_PLATFORM_EXPORT TraceConfig {
195  public:
196   typedef std::vector<std::string> StringList;
197 
198   static TraceConfig* CreateDefaultTraceConfig();
199 
TraceConfig()200   TraceConfig() : enable_systrace_(false), enable_argument_filter_(false) {}
GetTraceRecordMode()201   TraceRecordMode GetTraceRecordMode() const { return record_mode_; }
GetEnabledCategories()202   const StringList& GetEnabledCategories() const {
203     return included_categories_;
204   }
IsSystraceEnabled()205   bool IsSystraceEnabled() const { return enable_systrace_; }
IsArgumentFilterEnabled()206   bool IsArgumentFilterEnabled() const { return enable_argument_filter_; }
207 
SetTraceRecordMode(TraceRecordMode mode)208   void SetTraceRecordMode(TraceRecordMode mode) { record_mode_ = mode; }
EnableSystrace()209   void EnableSystrace() { enable_systrace_ = true; }
EnableArgumentFilter()210   void EnableArgumentFilter() { enable_argument_filter_ = true; }
211 
212   void AddIncludedCategory(const char* included_category);
213 
214   bool IsCategoryGroupEnabled(const char* category_group) const;
215 
216  private:
217   TraceRecordMode record_mode_;
218   bool enable_systrace_ : 1;
219   bool enable_argument_filter_ : 1;
220   StringList included_categories_;
221 
222   // Disallow copy and assign
223   TraceConfig(const TraceConfig&) = delete;
224   void operator=(const TraceConfig&) = delete;
225 };
226 
227 #if defined(_MSC_VER)
228 #define V8_PLATFORM_NON_EXPORTED_BASE(code) \
229   __pragma(warning(suppress : 4275)) code
230 #else
231 #define V8_PLATFORM_NON_EXPORTED_BASE(code) code
232 #endif  // defined(_MSC_VER)
233 
234 class V8_PLATFORM_EXPORT TracingController
V8_PLATFORM_NON_EXPORTED_BASE(v8::TracingController)235     : public V8_PLATFORM_NON_EXPORTED_BASE(v8::TracingController) {
236  public:
237   TracingController();
238   ~TracingController() override;
239 
240 #if defined(V8_USE_PERFETTO)
241   // Must be called before StartTracing() if V8_USE_PERFETTO is true. Provides
242   // the output stream for the JSON trace data.
243   void InitializeForPerfetto(std::ostream* output_stream);
244   // Provide an optional listener for testing that will receive trace events.
245   // Must be called before StartTracing().
246   void SetTraceEventListenerForTesting(TraceEventListener* listener);
247 #else   // defined(V8_USE_PERFETTO)
248   // The pointer returned from GetCategoryGroupEnabled() points to a value with
249   // zero or more of the following bits. Used in this class only. The
250   // TRACE_EVENT macros should only use the value as a bool. These values must
251   // be in sync with macro values in TraceEvent.h in Blink.
252   enum CategoryGroupEnabledFlags {
253     // Category group enabled for the recording mode.
254     ENABLED_FOR_RECORDING = 1 << 0,
255     // Category group enabled by SetEventCallbackEnabled().
256     ENABLED_FOR_EVENT_CALLBACK = 1 << 2,
257     // Category group enabled to export events to ETW.
258     ENABLED_FOR_ETW_EXPORT = 1 << 3
259   };
260 
261   // Takes ownership of |trace_buffer|.
262   void Initialize(TraceBuffer* trace_buffer);
263 
264   // v8::TracingController implementation.
265   const uint8_t* GetCategoryGroupEnabled(const char* category_group) override;
266   uint64_t AddTraceEvent(
267       char phase, const uint8_t* category_enabled_flag, const char* name,
268       const char* scope, uint64_t id, uint64_t bind_id, int32_t num_args,
269       const char** arg_names, const uint8_t* arg_types,
270       const uint64_t* arg_values,
271       std::unique_ptr<v8::ConvertableToTraceFormat>* arg_convertables,
272       unsigned int flags) override;
273   uint64_t AddTraceEventWithTimestamp(
274       char phase, const uint8_t* category_enabled_flag, const char* name,
275       const char* scope, uint64_t id, uint64_t bind_id, int32_t num_args,
276       const char** arg_names, const uint8_t* arg_types,
277       const uint64_t* arg_values,
278       std::unique_ptr<v8::ConvertableToTraceFormat>* arg_convertables,
279       unsigned int flags, int64_t timestamp) override;
280   void UpdateTraceEventDuration(const uint8_t* category_enabled_flag,
281                                 const char* name, uint64_t handle) override;
282 
283   static const char* GetCategoryGroupName(const uint8_t* category_enabled_flag);
284 #endif  // !defined(V8_USE_PERFETTO)
285 
286   void AddTraceStateObserver(
287       v8::TracingController::TraceStateObserver* observer) override;
288   void RemoveTraceStateObserver(
289       v8::TracingController::TraceStateObserver* observer) override;
290 
291   void StartTracing(TraceConfig* trace_config);
292   void StopTracing();
293 
294  protected:
295 #if !defined(V8_USE_PERFETTO)
296   virtual int64_t CurrentTimestampMicroseconds();
297   virtual int64_t CurrentCpuTimestampMicroseconds();
298 #endif  // !defined(V8_USE_PERFETTO)
299 
300  private:
301 #if !defined(V8_USE_PERFETTO)
302   void UpdateCategoryGroupEnabledFlag(size_t category_index);
303   void UpdateCategoryGroupEnabledFlags();
304 #endif  // !defined(V8_USE_PERFETTO)
305 
306   std::unique_ptr<base::Mutex> mutex_;
307   std::unique_ptr<TraceConfig> trace_config_;
308   std::atomic_bool recording_{false};
309   std::unordered_set<v8::TracingController::TraceStateObserver*> observers_;
310 
311 #if defined(V8_USE_PERFETTO)
312   std::ostream* output_stream_ = nullptr;
313   std::unique_ptr<perfetto::trace_processor::TraceProcessorStorage>
314       trace_processor_;
315   TraceEventListener* listener_for_testing_ = nullptr;
316   std::unique_ptr<perfetto::TracingSession> tracing_session_;
317 #else   // !defined(V8_USE_PERFETTO)
318   std::unique_ptr<TraceBuffer> trace_buffer_;
319 #endif  // !defined(V8_USE_PERFETTO)
320 
321   // Disallow copy and assign
322   TracingController(const TracingController&) = delete;
323   void operator=(const TracingController&) = delete;
324 };
325 
326 #undef V8_PLATFORM_NON_EXPORTED_BASE
327 
328 }  // namespace tracing
329 }  // namespace platform
330 }  // namespace v8
331 
332 #endif  // V8_LIBPLATFORM_V8_TRACING_H_
333