1 // Copyright (c) 2014 Google Inc.
2 //
3 // Use of this source code is governed by a BSD-style license that can be
4 // found in the LICENSE file.
5
6 // This header file defines implementation details of how the trace macros in
7 // SkTraceEventCommon.h collect and store trace events. Anything not
8 // implementation-specific should go in SkTraceEventCommon.h instead of here.
9
10 #ifndef SkTraceEvent_DEFINED
11 #define SkTraceEvent_DEFINED
12
13 #include "SkAtomics.h"
14 #include "SkEventTracer.h"
15 #include "SkTraceEventCommon.h"
16
17 ////////////////////////////////////////////////////////////////////////////////
18 // Implementation specific tracing API definitions.
19
20 // By default, const char* argument values are assumed to have long-lived scope
21 // and will not be copied. Use this macro to force a const char* to be copied.
22 #define TRACE_STR_COPY(str) \
23 skia::tracing_internals::TraceStringWithCopy(str)
24
25 // By default, uint64 ID argument values are not mangled with the Process ID in
26 // TRACE_EVENT_ASYNC macros. Use this macro to force Process ID mangling.
27 #define TRACE_ID_MANGLE(id) \
28 skia::tracing_internals::TraceID::ForceMangle(id)
29
30 // By default, pointers are mangled with the Process ID in TRACE_EVENT_ASYNC
31 // macros. Use this macro to prevent Process ID mangling.
32 #define TRACE_ID_DONT_MANGLE(id) \
33 skia::tracing_internals::TraceID::DontMangle(id)
34
35 // Sets the current sample state to the given category and name (both must be
36 // constant strings). These states are intended for a sampling profiler.
37 // Implementation note: we store category and name together because we don't
38 // want the inconsistency/expense of storing two pointers.
39 // |thread_bucket| is [0..2] and is used to statically isolate samples in one
40 // thread from others.
41 #define TRACE_EVENT_SET_SAMPLING_STATE_FOR_BUCKET( \
42 bucket_number, category, name) \
43 skia::tracing_internals:: \
44 TraceEventSamplingStateScope<bucket_number>::Set(category "\0" name)
45
46 // Returns a current sampling state of the given bucket.
47 #define TRACE_EVENT_GET_SAMPLING_STATE_FOR_BUCKET(bucket_number) \
48 skia::tracing_internals::TraceEventSamplingStateScope<bucket_number>::Current()
49
50 // Creates a scope of a sampling state of the given bucket.
51 //
52 // { // The sampling state is set within this scope.
53 // TRACE_EVENT_SAMPLING_STATE_SCOPE_FOR_BUCKET(0, "category", "name");
54 // ...;
55 // }
56 #define TRACE_EVENT_SCOPED_SAMPLING_STATE_FOR_BUCKET( \
57 bucket_number, category, name) \
58 skia::tracing_internals::TraceEventSamplingStateScope<bucket_number> \
59 traceEventSamplingScope(category "\0" name);
60
61
62 #define INTERNAL_TRACE_EVENT_CATEGORY_GROUP_ENABLED_FOR_RECORDING_MODE() \
63 *INTERNAL_TRACE_EVENT_UID(category_group_enabled) & \
64 (SkEventTracer::kEnabledForRecording_CategoryGroupEnabledFlags | \
65 SkEventTracer::kEnabledForEventCallback_CategoryGroupEnabledFlags)
66
67 // Get a pointer to the enabled state of the given trace category. Only
68 // long-lived literal strings should be given as the category group. The
69 // returned pointer can be held permanently in a local static for example. If
70 // the unsigned char is non-zero, tracing is enabled. If tracing is enabled,
71 // TRACE_EVENT_API_ADD_TRACE_EVENT can be called. It's OK if tracing is disabled
72 // between the load of the tracing state and the call to
73 // TRACE_EVENT_API_ADD_TRACE_EVENT, because this flag only provides an early out
74 // for best performance when tracing is disabled.
75 // const uint8_t*
76 // TRACE_EVENT_API_GET_CATEGORY_GROUP_ENABLED(const char* category_group)
77 #define TRACE_EVENT_API_GET_CATEGORY_GROUP_ENABLED \
78 SkEventTracer::GetInstance()->getCategoryGroupEnabled
79
80 // Get the number of times traces have been recorded. This is used to implement
81 // the TRACE_EVENT_IS_NEW_TRACE facility.
82 // unsigned int TRACE_EVENT_API_GET_NUM_TRACES_RECORDED()
83 #define TRACE_EVENT_API_GET_NUM_TRACES_RECORDED \
84 SkEventTracer::GetInstance()->getNumTracesRecorded
85
86 // Add a trace event to the platform tracing system.
87 // SkEventTracer::Handle TRACE_EVENT_API_ADD_TRACE_EVENT(
88 // char phase,
89 // const uint8_t* category_group_enabled,
90 // const char* name,
91 // uint64_t id,
92 // int num_args,
93 // const char** arg_names,
94 // const uint8_t* arg_types,
95 // const uint64_t* arg_values,
96 // unsigned char flags)
97 #define TRACE_EVENT_API_ADD_TRACE_EVENT \
98 SkEventTracer::GetInstance()->addTraceEvent
99
100 // Set the duration field of a COMPLETE trace event.
101 // void TRACE_EVENT_API_UPDATE_TRACE_EVENT_DURATION(
102 // const uint8_t* category_group_enabled,
103 // const char* name,
104 // SkEventTracer::Handle id)
105 #define TRACE_EVENT_API_UPDATE_TRACE_EVENT_DURATION \
106 SkEventTracer::GetInstance()->updateTraceEventDuration
107
108 #define TRACE_EVENT_API_ATOMIC_WORD intptr_t
109 #define TRACE_EVENT_API_ATOMIC_LOAD(var) sk_atomic_load(&var, sk_memory_order_relaxed)
110 #define TRACE_EVENT_API_ATOMIC_STORE(var, value) \
111 sk_atomic_store(&var, value, sk_memory_order_relaxed)
112
113 // Defines visibility for classes in trace_event.h
114 #define TRACE_EVENT_API_CLASS_EXPORT SK_API
115
116 // The thread buckets for the sampling profiler.
117 TRACE_EVENT_API_CLASS_EXPORT extern \
118 TRACE_EVENT_API_ATOMIC_WORD g_trace_state[3];
119
120 #define TRACE_EVENT_API_THREAD_BUCKET(thread_bucket) \
121 g_trace_state[thread_bucket]
122
123 ////////////////////////////////////////////////////////////////////////////////
124
125 // Implementation detail: trace event macros create temporary variables
126 // to keep instrumentation overhead low. These macros give each temporary
127 // variable a unique name based on the line number to prevent name collisions.
128 #define INTERNAL_TRACE_EVENT_UID3(a,b) \
129 trace_event_unique_##a##b
130 #define INTERNAL_TRACE_EVENT_UID2(a,b) \
131 INTERNAL_TRACE_EVENT_UID3(a,b)
132 #define INTERNAL_TRACE_EVENT_UID(name_prefix) \
133 INTERNAL_TRACE_EVENT_UID2(name_prefix, __LINE__)
134
135 // Implementation detail: internal macro to create static category.
136 // No barriers are needed, because this code is designed to operate safely
137 // even when the unsigned char* points to garbage data (which may be the case
138 // on processors without cache coherency).
139 #define INTERNAL_TRACE_EVENT_GET_CATEGORY_INFO_CUSTOM_VARIABLES( \
140 category_group, atomic, category_group_enabled) \
141 category_group_enabled = \
142 reinterpret_cast<const uint8_t*>(TRACE_EVENT_API_ATOMIC_LOAD( \
143 atomic)); \
144 if (!category_group_enabled) { \
145 category_group_enabled = \
146 TRACE_EVENT_API_GET_CATEGORY_GROUP_ENABLED(category_group); \
147 TRACE_EVENT_API_ATOMIC_STORE(atomic, \
148 reinterpret_cast<TRACE_EVENT_API_ATOMIC_WORD>( \
149 category_group_enabled)); \
150 }
151
152 #define INTERNAL_TRACE_EVENT_GET_CATEGORY_INFO(category_group) \
153 static TRACE_EVENT_API_ATOMIC_WORD INTERNAL_TRACE_EVENT_UID(atomic) = 0; \
154 const uint8_t* INTERNAL_TRACE_EVENT_UID(category_group_enabled); \
155 INTERNAL_TRACE_EVENT_GET_CATEGORY_INFO_CUSTOM_VARIABLES(category_group, \
156 INTERNAL_TRACE_EVENT_UID(atomic), \
157 INTERNAL_TRACE_EVENT_UID(category_group_enabled));
158
159 // Implementation detail: internal macro to create static category and add
160 // event if the category is enabled.
161 #define INTERNAL_TRACE_EVENT_ADD(phase, category_group, name, flags, ...) \
162 do { \
163 INTERNAL_TRACE_EVENT_GET_CATEGORY_INFO(category_group); \
164 if (INTERNAL_TRACE_EVENT_CATEGORY_GROUP_ENABLED_FOR_RECORDING_MODE()) { \
165 skia::tracing_internals::AddTraceEvent( \
166 phase, INTERNAL_TRACE_EVENT_UID(category_group_enabled), name, \
167 skia::tracing_internals::kNoEventId, flags, ##__VA_ARGS__); \
168 } \
169 } while (0)
170
171 // Implementation detail: internal macro to create static category and add begin
172 // event if the category is enabled. Also adds the end event when the scope
173 // ends.
174 #define INTERNAL_TRACE_EVENT_ADD_SCOPED(category_group, name, ...) \
175 INTERNAL_TRACE_EVENT_GET_CATEGORY_INFO(category_group); \
176 skia::tracing_internals::ScopedTracer INTERNAL_TRACE_EVENT_UID(tracer); \
177 if (INTERNAL_TRACE_EVENT_CATEGORY_GROUP_ENABLED_FOR_RECORDING_MODE()) { \
178 SkEventTracer::Handle h = skia::tracing_internals::AddTraceEvent( \
179 TRACE_EVENT_PHASE_COMPLETE, \
180 INTERNAL_TRACE_EVENT_UID(category_group_enabled), \
181 name, skia::tracing_internals::kNoEventId, \
182 TRACE_EVENT_FLAG_NONE, ##__VA_ARGS__); \
183 INTERNAL_TRACE_EVENT_UID(tracer).Initialize( \
184 INTERNAL_TRACE_EVENT_UID(category_group_enabled), name, h); \
185 }
186
187 // Implementation detail: internal macro to create static category and add
188 // event if the category is enabled.
189 #define INTERNAL_TRACE_EVENT_ADD_WITH_ID(phase, category_group, name, id, \
190 flags, ...) \
191 do { \
192 INTERNAL_TRACE_EVENT_GET_CATEGORY_INFO(category_group); \
193 if (INTERNAL_TRACE_EVENT_CATEGORY_GROUP_ENABLED_FOR_RECORDING_MODE()) { \
194 unsigned char trace_event_flags = flags | TRACE_EVENT_FLAG_HAS_ID; \
195 skia::tracing_internals::TraceID trace_event_trace_id( \
196 id, &trace_event_flags); \
197 skia::tracing_internals::AddTraceEvent( \
198 phase, INTERNAL_TRACE_EVENT_UID(category_group_enabled), \
199 name, trace_event_trace_id.data(), trace_event_flags, \
200 ##__VA_ARGS__); \
201 } \
202 } while (0)
203
204 // Implementation detail: internal macro to create static category and add
205 // event if the category is enabled.
206 #define INTERNAL_TRACE_EVENT_ADD_WITH_ID_TID_AND_TIMESTAMP(phase, \
207 category_group, name, id, thread_id, flags, ...) \
208 do { \
209 INTERNAL_TRACE_EVENT_GET_CATEGORY_INFO(category_group); \
210 if (INTERNAL_TRACE_EVENT_CATEGORY_GROUP_ENABLED_FOR_RECORDING_MODE()) { \
211 unsigned char trace_event_flags = flags | TRACE_EVENT_FLAG_HAS_ID; \
212 skia::tracing_internals::TraceID trace_event_trace_id( \
213 id, &trace_event_flags); \
214 skia::tracing_internals::AddTraceEventWithThreadIdAndTimestamp( \
215 phase, INTERNAL_TRACE_EVENT_UID(category_group_enabled), \
216 name, trace_event_trace_id.data(), \
217 thread_id, base::TimeTicks::FromInternalValue(timestamp), \
218 trace_event_flags, ##__VA_ARGS__); \
219 } \
220 } while (0)
221
222 #define INTERNAL_TRACE_MEMORY(category, name)
223
224 namespace skia {
225 namespace tracing_internals {
226
227 // Specify these values when the corresponding argument of AddTraceEvent is not
228 // used.
229 const int kZeroNumArgs = 0;
230 const uint64_t kNoEventId = 0;
231
232 // TraceID encapsulates an ID that can either be an integer or pointer. Pointers
233 // are by default mangled with the Process ID so that they are unlikely to
234 // collide when the same pointer is used on different processes.
235 class TraceID {
236 public:
237 class DontMangle {
238 public:
DontMangle(const void * id)239 explicit DontMangle(const void* id)
240 : data_(static_cast<uint64_t>(
241 reinterpret_cast<uintptr_t>(id))) {}
DontMangle(uint64_t id)242 explicit DontMangle(uint64_t id) : data_(id) {}
DontMangle(unsigned int id)243 explicit DontMangle(unsigned int id) : data_(id) {}
DontMangle(unsigned short id)244 explicit DontMangle(unsigned short id) : data_(id) {}
DontMangle(unsigned char id)245 explicit DontMangle(unsigned char id) : data_(id) {}
DontMangle(long long id)246 explicit DontMangle(long long id)
247 : data_(static_cast<uint64_t>(id)) {}
DontMangle(long id)248 explicit DontMangle(long id)
249 : data_(static_cast<uint64_t>(id)) {}
DontMangle(int id)250 explicit DontMangle(int id)
251 : data_(static_cast<uint64_t>(id)) {}
DontMangle(short id)252 explicit DontMangle(short id)
253 : data_(static_cast<uint64_t>(id)) {}
DontMangle(signed char id)254 explicit DontMangle(signed char id)
255 : data_(static_cast<uint64_t>(id)) {}
data()256 uint64_t data() const { return data_; }
257 private:
258 uint64_t data_;
259 };
260
261 class ForceMangle {
262 public:
ForceMangle(uint64_t id)263 explicit ForceMangle(uint64_t id) : data_(id) {}
ForceMangle(unsigned int id)264 explicit ForceMangle(unsigned int id) : data_(id) {}
ForceMangle(unsigned short id)265 explicit ForceMangle(unsigned short id) : data_(id) {}
ForceMangle(unsigned char id)266 explicit ForceMangle(unsigned char id) : data_(id) {}
ForceMangle(long long id)267 explicit ForceMangle(long long id)
268 : data_(static_cast<uint64_t>(id)) {}
ForceMangle(long id)269 explicit ForceMangle(long id)
270 : data_(static_cast<uint64_t>(id)) {}
ForceMangle(int id)271 explicit ForceMangle(int id)
272 : data_(static_cast<uint64_t>(id)) {}
ForceMangle(short id)273 explicit ForceMangle(short id)
274 : data_(static_cast<uint64_t>(id)) {}
ForceMangle(signed char id)275 explicit ForceMangle(signed char id)
276 : data_(static_cast<uint64_t>(id)) {}
data()277 uint64_t data() const { return data_; }
278 private:
279 uint64_t data_;
280 };
281
TraceID(const void * id,unsigned char * flags)282 TraceID(const void* id, unsigned char* flags)
283 : data_(static_cast<uint64_t>(
284 reinterpret_cast<uintptr_t>(id))) {
285 *flags |= TRACE_EVENT_FLAG_MANGLE_ID;
286 }
TraceID(ForceMangle id,unsigned char * flags)287 TraceID(ForceMangle id, unsigned char* flags) : data_(id.data()) {
288 *flags |= TRACE_EVENT_FLAG_MANGLE_ID;
289 }
TraceID(DontMangle id,unsigned char * flags)290 TraceID(DontMangle id, unsigned char* flags) : data_(id.data()) {
291 }
TraceID(uint64_t id,unsigned char * flags)292 TraceID(uint64_t id, unsigned char* flags)
293 : data_(id) { (void)flags; }
TraceID(unsigned int id,unsigned char * flags)294 TraceID(unsigned int id, unsigned char* flags)
295 : data_(id) { (void)flags; }
TraceID(unsigned short id,unsigned char * flags)296 TraceID(unsigned short id, unsigned char* flags)
297 : data_(id) { (void)flags; }
TraceID(unsigned char id,unsigned char * flags)298 TraceID(unsigned char id, unsigned char* flags)
299 : data_(id) { (void)flags; }
TraceID(long long id,unsigned char * flags)300 TraceID(long long id, unsigned char* flags)
301 : data_(static_cast<uint64_t>(id)) { (void)flags; }
TraceID(long id,unsigned char * flags)302 TraceID(long id, unsigned char* flags)
303 : data_(static_cast<uint64_t>(id)) { (void)flags; }
TraceID(int id,unsigned char * flags)304 TraceID(int id, unsigned char* flags)
305 : data_(static_cast<uint64_t>(id)) { (void)flags; }
TraceID(short id,unsigned char * flags)306 TraceID(short id, unsigned char* flags)
307 : data_(static_cast<uint64_t>(id)) { (void)flags; }
TraceID(signed char id,unsigned char * flags)308 TraceID(signed char id, unsigned char* flags)
309 : data_(static_cast<uint64_t>(id)) { (void)flags; }
310
data()311 uint64_t data() const { return data_; }
312
313 private:
314 uint64_t data_;
315 };
316
317 // Simple union to store various types as uint64_t.
318 union TraceValueUnion {
319 bool as_bool;
320 uint64_t as_uint;
321 long long as_int;
322 double as_double;
323 const void* as_pointer;
324 const char* as_string;
325 };
326
327 // Simple container for const char* that should be copied instead of retained.
328 class TraceStringWithCopy {
329 public:
TraceStringWithCopy(const char * str)330 explicit TraceStringWithCopy(const char* str) : str_(str) {}
331 operator const char* () const { return str_; }
332 private:
333 const char* str_;
334 };
335
336 // Define SetTraceValue for each allowed type. It stores the type and
337 // value in the return arguments. This allows this API to avoid declaring any
338 // structures so that it is portable to third_party libraries.
339 #define INTERNAL_DECLARE_SET_TRACE_VALUE(actual_type, \
340 union_member, \
341 value_type_id) \
342 static inline void SetTraceValue( \
343 actual_type arg, \
344 unsigned char* type, \
345 uint64_t* value) { \
346 TraceValueUnion type_value; \
347 type_value.union_member = arg; \
348 *type = value_type_id; \
349 *value = type_value.as_uint; \
350 }
351 // Simpler form for int types that can be safely casted.
352 #define INTERNAL_DECLARE_SET_TRACE_VALUE_INT(actual_type, \
353 value_type_id) \
354 static inline void SetTraceValue( \
355 actual_type arg, \
356 unsigned char* type, \
357 uint64_t* value) { \
358 *type = value_type_id; \
359 *value = static_cast<uint64_t>(arg); \
360 }
361
INTERNAL_DECLARE_SET_TRACE_VALUE_INT(uint64_t,TRACE_VALUE_TYPE_UINT)362 INTERNAL_DECLARE_SET_TRACE_VALUE_INT(uint64_t, TRACE_VALUE_TYPE_UINT)
363 INTERNAL_DECLARE_SET_TRACE_VALUE_INT(unsigned int, TRACE_VALUE_TYPE_UINT)
364 INTERNAL_DECLARE_SET_TRACE_VALUE_INT(unsigned short, TRACE_VALUE_TYPE_UINT)
365 INTERNAL_DECLARE_SET_TRACE_VALUE_INT(unsigned char, TRACE_VALUE_TYPE_UINT)
366 INTERNAL_DECLARE_SET_TRACE_VALUE_INT(long long, TRACE_VALUE_TYPE_INT)
367 INTERNAL_DECLARE_SET_TRACE_VALUE_INT(long, TRACE_VALUE_TYPE_INT)
368 INTERNAL_DECLARE_SET_TRACE_VALUE_INT(int, TRACE_VALUE_TYPE_INT)
369 INTERNAL_DECLARE_SET_TRACE_VALUE_INT(short, TRACE_VALUE_TYPE_INT)
370 INTERNAL_DECLARE_SET_TRACE_VALUE_INT(signed char, TRACE_VALUE_TYPE_INT)
371 INTERNAL_DECLARE_SET_TRACE_VALUE(bool, as_bool, TRACE_VALUE_TYPE_BOOL)
372 INTERNAL_DECLARE_SET_TRACE_VALUE(double, as_double, TRACE_VALUE_TYPE_DOUBLE)
373 INTERNAL_DECLARE_SET_TRACE_VALUE(const void*, as_pointer,
374 TRACE_VALUE_TYPE_POINTER)
375 INTERNAL_DECLARE_SET_TRACE_VALUE(const char*, as_string,
376 TRACE_VALUE_TYPE_STRING)
377 INTERNAL_DECLARE_SET_TRACE_VALUE(const TraceStringWithCopy&, as_string,
378 TRACE_VALUE_TYPE_COPY_STRING)
379
380 #undef INTERNAL_DECLARE_SET_TRACE_VALUE
381 #undef INTERNAL_DECLARE_SET_TRACE_VALUE_INT
382
383 // These AddTraceEvent and AddTraceEvent template
384 // functions are defined here instead of in the macro, because the arg_values
385 // could be temporary objects, such as std::string. In order to store
386 // pointers to the internal c_str and pass through to the tracing API,
387 // the arg_values must live throughout these procedures.
388
389 static inline SkEventTracer::Handle
390 AddTraceEvent(
391 char phase,
392 const uint8_t* category_group_enabled,
393 const char* name,
394 uint64_t id,
395 unsigned char flags) {
396 return TRACE_EVENT_API_ADD_TRACE_EVENT(
397 phase, category_group_enabled, name, id,
398 kZeroNumArgs, nullptr, nullptr, nullptr, flags);
399 }
400
401 template<class ARG1_TYPE>
402 static inline SkEventTracer::Handle
AddTraceEvent(char phase,const uint8_t * category_group_enabled,const char * name,uint64_t id,unsigned char flags,const char * arg1_name,const ARG1_TYPE & arg1_val)403 AddTraceEvent(
404 char phase,
405 const uint8_t* category_group_enabled,
406 const char* name,
407 uint64_t id,
408 unsigned char flags,
409 const char* arg1_name,
410 const ARG1_TYPE& arg1_val) {
411 const int num_args = 1;
412 uint8_t arg_types[1];
413 uint64_t arg_values[1];
414 SetTraceValue(arg1_val, &arg_types[0], &arg_values[0]);
415 return TRACE_EVENT_API_ADD_TRACE_EVENT(
416 phase, category_group_enabled, name, id,
417 num_args, &arg1_name, arg_types, arg_values, flags);
418 }
419
420 template<class ARG1_TYPE, class ARG2_TYPE>
421 static inline SkEventTracer::Handle
AddTraceEvent(char phase,const uint8_t * category_group_enabled,const char * name,uint64_t id,unsigned char flags,const char * arg1_name,const ARG1_TYPE & arg1_val,const char * arg2_name,const ARG2_TYPE & arg2_val)422 AddTraceEvent(
423 char phase,
424 const uint8_t* category_group_enabled,
425 const char* name,
426 uint64_t id,
427 unsigned char flags,
428 const char* arg1_name,
429 const ARG1_TYPE& arg1_val,
430 const char* arg2_name,
431 const ARG2_TYPE& arg2_val) {
432 const int num_args = 2;
433 const char* arg_names[2] = { arg1_name, arg2_name };
434 unsigned char arg_types[2];
435 uint64_t arg_values[2];
436 SetTraceValue(arg1_val, &arg_types[0], &arg_values[0]);
437 SetTraceValue(arg2_val, &arg_types[1], &arg_values[1]);
438 return TRACE_EVENT_API_ADD_TRACE_EVENT(
439 phase, category_group_enabled, name, id,
440 num_args, arg_names, arg_types, arg_values, flags);
441 }
442
443 // Used by TRACE_EVENTx macros. Do not use directly.
444 class TRACE_EVENT_API_CLASS_EXPORT ScopedTracer {
445 public:
446 // Note: members of data_ intentionally left uninitialized. See Initialize.
ScopedTracer()447 ScopedTracer() : p_data_(nullptr) {}
448
~ScopedTracer()449 ~ScopedTracer() {
450 if (p_data_ && *data_.category_group_enabled)
451 TRACE_EVENT_API_UPDATE_TRACE_EVENT_DURATION(
452 data_.category_group_enabled, data_.name, data_.event_handle);
453 }
454
Initialize(const uint8_t * category_group_enabled,const char * name,SkEventTracer::Handle event_handle)455 void Initialize(const uint8_t* category_group_enabled,
456 const char* name,
457 SkEventTracer::Handle event_handle) {
458 data_.category_group_enabled = category_group_enabled;
459 data_.name = name;
460 data_.event_handle = event_handle;
461 p_data_ = &data_;
462 }
463
464 private:
465 // This Data struct workaround is to avoid initializing all the members
466 // in Data during construction of this object, since this object is always
467 // constructed, even when tracing is disabled. If the members of Data were
468 // members of this class instead, compiler warnings occur about potential
469 // uninitialized accesses.
470 struct Data {
471 const uint8_t* category_group_enabled;
472 const char* name;
473 SkEventTracer::Handle event_handle;
474 };
475 Data* p_data_;
476 Data data_;
477 };
478
479 // Used by TRACE_EVENT_BINARY_EFFICIENTx macro. Do not use directly.
480 class TRACE_EVENT_API_CLASS_EXPORT ScopedTraceBinaryEfficient {
481 public:
482 ScopedTraceBinaryEfficient(const char* category_group, const char* name);
483 ~ScopedTraceBinaryEfficient();
484
485 private:
486 const uint8_t* category_group_enabled_;
487 const char* name_;
488 SkEventTracer::Handle event_handle_;
489 };
490
491 // This macro generates less code then TRACE_EVENT0 but is also
492 // slower to execute when tracing is off. It should generally only be
493 // used with code that is seldom executed or conditionally executed
494 // when debugging.
495 // For now the category_group must be "gpu".
496 #define TRACE_EVENT_BINARY_EFFICIENT0(category_group, name) \
497 skia::tracing_internals::ScopedTraceBinaryEfficient \
498 INTERNAL_TRACE_EVENT_UID(scoped_trace)(category_group, name);
499
500 // TraceEventSamplingStateScope records the current sampling state
501 // and sets a new sampling state. When the scope exists, it restores
502 // the sampling state having recorded.
503 template<size_t BucketNumber>
504 class TraceEventSamplingStateScope {
505 public:
TraceEventSamplingStateScope(const char * category_and_name)506 TraceEventSamplingStateScope(const char* category_and_name) {
507 previous_state_ = TraceEventSamplingStateScope<BucketNumber>::Current();
508 TraceEventSamplingStateScope<BucketNumber>::Set(category_and_name);
509 }
510
~TraceEventSamplingStateScope()511 ~TraceEventSamplingStateScope() {
512 TraceEventSamplingStateScope<BucketNumber>::Set(previous_state_);
513 }
514
Current()515 static inline const char* Current() {
516 return reinterpret_cast<const char*>(TRACE_EVENT_API_ATOMIC_LOAD(
517 g_trace_state[BucketNumber]));
518 }
519
Set(const char * category_and_name)520 static inline void Set(const char* category_and_name) {
521 TRACE_EVENT_API_ATOMIC_STORE(
522 g_trace_state[BucketNumber],
523 reinterpret_cast<TRACE_EVENT_API_ATOMIC_WORD>(
524 const_cast<char*>(category_and_name)));
525 }
526
527 private:
528 const char* previous_state_;
529 };
530
531 } // namespace tracing_internals
532 } // namespace skia
533
534 #endif
535