diff options
Diffstat (limited to 'include/perfetto/tracing/track_event.h')
| -rw-r--r-- | include/perfetto/tracing/track_event.h | 194 |
1 files changed, 63 insertions, 131 deletions
diff --git a/include/perfetto/tracing/track_event.h b/include/perfetto/tracing/track_event.h index 7e226f0d1..8eebf76ba 100644 --- a/include/perfetto/tracing/track_event.h +++ b/include/perfetto/tracing/track_event.h @@ -21,7 +21,6 @@ #include "perfetto/tracing/internal/track_event_data_source.h" #include "perfetto/tracing/internal/track_event_internal.h" #include "perfetto/tracing/internal/track_event_macros.h" -#include "perfetto/tracing/string_helpers.h" #include "perfetto/tracing/track.h" #include "perfetto/tracing/track_event_category_registry.h" #include "protos/perfetto/trace/track_event/track_event.pbzero.h" @@ -152,6 +151,32 @@ constexpr bool IsDynamicCategory(const ::perfetto::DynamicCategory&) { } // namespace internal } // namespace PERFETTO_TRACK_EVENT_NAMESPACE +namespace perfetto { + +// A wrapper for marking strings that can't be determined to be static at build +// time, but are in fact static. +class PERFETTO_EXPORT StaticString final { + public: + const char* value; + + operator const char*() const { return value; } +}; + +namespace internal { + +template <typename T = void> +constexpr bool IsStaticString(const char*) { + return true; +} + +template <typename T = void> +constexpr bool IsStaticString(...) { + return false; +} + +} // namespace internal +} // namespace perfetto + // Normally all categories are defined statically at build-time (see // PERFETTO_DEFINE_CATEGORIES). However, some categories are only used for // testing, and we shouldn't publish them to the tracing service or include them @@ -193,9 +218,36 @@ constexpr bool IsDynamicCategory(const ::perfetto::DynamicCategory&) { perfetto::internal::TrackEventDataSourceTraits) // Ignore GCC warning about a missing argument for a variadic macro parameter. -#if defined(__GNUC__) || defined(__clang__) #pragma GCC system_header -#endif + +// Ensure that |string| is a static constant string. +// +// If you get a compiler failure here, you are most likely trying to use +// TRACE_EVENT with a dynamic event name. There are two ways to fix this: +// +// 1) If the event name is actually dynamic (e.g., std::string), write it into +// the event manually: +// +// TRACE_EVENT("category", nullptr, [&](perfetto::EventContext ctx) { +// ctx.event()->set_name(dynamic_name); +// }); +// +// 2) If the name is static, but the pointer is computed at runtime, wrap it +// with perfetto::StaticString: +// +// TRACE_EVENT("category", perfetto::StaticString{name}); +// +// DANGER: Using perfetto::StaticString with strings whose contents change +// dynamically can cause silent trace data corruption. +// +#define PERFETTO_GET_STATIC_STRING(string) \ + [&]() { \ + static_assert( \ + std::is_same<decltype(string), ::perfetto::StaticString>::value || \ + ::perfetto::internal::IsStaticString(string), \ + "String must be static"); \ + return static_cast<const char*>(string); \ + }() // Begin a slice under |category| with the title |name|. Both strings must be // static constants. The track event is only recorded if |category| is enabled @@ -212,93 +264,15 @@ constexpr bool IsDynamicCategory(const ::perfetto::DynamicCategory&) { // ctx.event()->set_name(dynamic_name); // }); // -// The following optional arguments can be passed to `TRACE_EVENT` to add extra -// information to events: -// -// TRACE_EVENT("cat", "name"[, track][, timestamp] -// [, "debug_name1", debug_value1] -// [, "debug_name2", debug_value2] -// ... -// [, "debug_nameN", debug_valueN] -// [, lambda]); -// -// Some examples of valid combinations: -// -// 1. A lambda for writing custom TrackEvent fields: -// -// TRACE_EVENT("category", "Name", [&](perfetto::EventContext ctx) { -// ctx.event()->set_custom_value(...); -// }); -// -// 2. A timestamp and a lambda: -// -// TRACE_EVENT("category", "Name", time_in_nanoseconds, -// [&](perfetto::EventContext ctx) { -// ctx.event()->set_custom_value(...); -// }); -// -// |time_in_nanoseconds| should be an uint64_t by default. To support custom -// timestamp types, -// |perfetto::TraceTimestampTraits<T>::ConvertTimestampToTraceTimeNs| -// should be defined. See |ConvertTimestampToTraceTimeNs| for more details. -// -// 3. Arbitrary number of debug annotations: -// -// TRACE_EVENT("category", "Name", "arg", value); -// TRACE_EVENT("category", "Name", "arg", value, "arg2", value2); -// TRACE_EVENT("category", "Name", "arg", value, "arg2", value2, -// "arg3", value3); -// -// See |TracedValue| for recording custom types as debug annotations. -// -// 4. Arbitrary number of debug annotations and a lambda: -// -// TRACE_EVENT("category", "Name", "arg", value, -// [&](perfetto::EventContext ctx) { -// ctx.event()->set_custom_value(...); -// }); -// -// 5. An overridden track: -// -// TRACE_EVENT("category", "Name", perfetto::Track(1234)); -// -// See |Track| for other types of tracks which may be used. -// -// 6. A track and a lambda: -// -// TRACE_EVENT("category", "Name", perfetto::Track(1234), -// [&](perfetto::EventContext ctx) { -// ctx.event()->set_custom_value(...); -// }); -// -// 7. A track and a timestamp: -// -// TRACE_EVENT("category", "Name", perfetto::Track(1234), -// time_in_nanoseconds); -// -// 8. A track, a timestamp and a lambda: -// -// TRACE_EVENT("category", "Name", perfetto::Track(1234), -// time_in_nanoseconds, [&](perfetto::EventContext ctx) { -// ctx.event()->set_custom_value(...); -// }); -// -// 9. A track and an arbitrary number of debug annotions: -// -// TRACE_EVENT("category", "Name", perfetto::Track(1234), -// "arg", value); -// TRACE_EVENT("category", "Name", perfetto::Track(1234), -// "arg", value, "arg2", value2); -// -#define TRACE_EVENT_BEGIN(category, name, ...) \ - PERFETTO_INTERNAL_TRACK_EVENT( \ - category, ::perfetto::internal::GetStaticString(name), \ +#define TRACE_EVENT_BEGIN(category, name, ...) \ + PERFETTO_INTERNAL_TRACK_EVENT( \ + category, PERFETTO_GET_STATIC_STRING(name), \ ::perfetto::protos::pbzero::TrackEvent::TYPE_SLICE_BEGIN, ##__VA_ARGS__) // End a slice under |category|. #define TRACE_EVENT_END(category, ...) \ PERFETTO_INTERNAL_TRACK_EVENT( \ - category, /*name=*/nullptr, \ + category, nullptr, \ ::perfetto::protos::pbzero::TrackEvent::TYPE_SLICE_END, ##__VA_ARGS__) // Begin a slice which gets automatically closed when going out of scope. @@ -306,9 +280,9 @@ constexpr bool IsDynamicCategory(const ::perfetto::DynamicCategory&) { PERFETTO_INTERNAL_SCOPED_TRACK_EVENT(category, name, ##__VA_ARGS__) // Emit a slice which has zero duration. -#define TRACE_EVENT_INSTANT(category, name, ...) \ - PERFETTO_INTERNAL_TRACK_EVENT( \ - category, ::perfetto::internal::GetStaticString(name), \ +#define TRACE_EVENT_INSTANT(category, name, ...) \ + PERFETTO_INTERNAL_TRACK_EVENT( \ + category, PERFETTO_GET_STATIC_STRING(name), \ ::perfetto::protos::pbzero::TrackEvent::TYPE_INSTANT, ##__VA_ARGS__) // Efficiently determine if the given static or dynamic trace category or @@ -316,49 +290,7 @@ constexpr bool IsDynamicCategory(const ::perfetto::DynamicCategory&) { #define TRACE_EVENT_CATEGORY_ENABLED(category) \ PERFETTO_INTERNAL_CATEGORY_ENABLED(category) -// Time-varying numeric data can be recorded with the TRACE_COUNTER macro: -// -// TRACE_COUNTER("cat", counter_track[, timestamp], value); -// -// For example, to record a single value for a counter called "MyCounter": -// -// TRACE_COUNTER("category", "MyCounter", 1234.5); -// -// This data is displayed as a counter track in the Perfetto UI. -// -// Both integer and floating point counter values are supported. Counters can -// also be annotated with additional information such as units, for example, for -// tracking the rendering framerate in terms of frames per second or "fps": -// -// TRACE_COUNTER("category", perfetto::CounterTrack("Framerate", "fps"), 120); -// -// As another example, a memory counter that records bytes but accepts samples -// as kilobytes (to reduce trace binary size) can be defined like this: -// -// perfetto::CounterTrack memory_track = perfetto::CounterTrack("Memory") -// .set_unit("bytes") -// .set_multiplier(1024); -// TRACE_COUNTER("category", memory_track, 4 /* = 4096 bytes */); -// -// See /protos/perfetto/trace/track_event/counter_descriptor.proto -// for the full set of attributes for a counter track. -// -// To record a counter value at a specific point in time (instead of the current -// time), you can pass in a custom timestamp: -// -// // First record the current time and counter value. -// uint64_t timestamp = perfetto::TrackEvent::GetTraceTimeNs(); -// int64_t value = 1234; -// -// // Later, emit a sample at that point in time. -// TRACE_COUNTER("category", "MyCounter", timestamp, value); -// -#define TRACE_COUNTER(category, track, ...) \ - PERFETTO_INTERNAL_TRACK_EVENT( \ - category, /*name=*/nullptr, \ - ::perfetto::protos::pbzero::TrackEvent::TYPE_COUNTER, \ - ::perfetto::CounterTrack(track), ##__VA_ARGS__) - // TODO(skyostil): Add flow events. +// TODO(skyostil): Add counters. #endif // INCLUDE_PERFETTO_TRACING_TRACK_EVENT_H_ |