Profiling backend that emits a Chrome Tracing JSON file. More...

#include <flamegraph.hpp>

Inheritance diagram for helios::profile::FlamegraphBackend:

Public Member Functions
	FlamegraphBackend (FlamegraphBackendConfig config={}) noexcept
	Constructs with a custom configuration.
	FlamegraphBackend (const FlamegraphBackend &)=delete
	FlamegraphBackend (FlamegraphBackend &&)=delete
	~FlamegraphBackend () noexcept override=default
FlamegraphBackend &	operator= (const FlamegraphBackend &)=delete
FlamegraphBackend &	operator= (FlamegraphBackend &&)=delete
size_t	ZoneStorageSize () const noexcept override
	Returns the per-zone storage size in bytes.
void	Startup () noexcept override
	Opens the output file and writes the JSON array prologue.
void	Shutdown () noexcept override
	Flushes all remaining events, writes the JSON array epilogue, and closes the output file.
void	BeginZone (const ZoneSpec &spec, std::span< std::byte > storage) noexcept override
	Records the start of an instrumented zone.
void	EndZone (std::span< std::byte > storage) noexcept override
	Records the end of an instrumented zone and enqueues a completed event.
void	ZoneText (std::span< std::byte > storage, std::string_view text) noexcept override
	Attaches a text annotation to the active zone.
void	ZoneValue (std::span< std::byte > storage, uint64_t value) noexcept override
	Attaches a numeric value to the active zone.
void	ZoneName (std::span< std::byte > storage, std::string_view name) noexcept override
	Overrides the name of the active zone.
void	FrameMark () noexcept override
	Enqueues an unnamed frame-mark instant event.
void	FrameMark (CStringView name) noexcept override
	Enqueues a named frame-mark instant event.
void	FrameMarkStart (CStringView name) noexcept override
	Enqueues a frame-region-start instant event.
void	FrameMarkEnd (CStringView name) noexcept override
	Enqueues a frame-region-end instant event.
void	Message (std::string_view text, uint32_t color) noexcept override
	Enqueues a message as an instant event.
void	SetThreadName (CStringView) noexcept override
	Thread name events are not emitted in the JSON format.
void	Plot (CStringView name, double value) noexcept override
	Enqueues a counter (plot) event with the given value.
void	PlotConfig (CStringView, PlotFormat, bool, bool, uint32_t) noexcept override
	Plot configuration is not represented in the JSON format.
void	Alloc (const void *, size_t, std::optional< CStringView >, int, std::source_location) noexcept override
	Memory allocation events are not emitted in the JSON format.
void	Free (const void *, std::optional< CStringView >, int, std::source_location) noexcept override
	Memory deallocation events are not emitted in the JSON format.
void	MemoryDiscard (CStringView) noexcept override
	Memory discard events are not emitted in the JSON format.
void	MemoryDiscard (CStringView, int) noexcept override
	Memory discard events are not emitted in the JSON format.
std::string_view	Name () const noexcept override
	Returns the backend identifier.
Public Member Functions inherited from helios::profile::Backend
virtual	~Backend () noexcept=default

Detailed Description

Profiling backend that emits a Chrome Tracing JSON file.

Collects zone begin/end, instant, and counter events into a lock-free concurrent queue. Batched JSON output is written to disk periodically (controlled by FlamegraphBackendConfig::flush_threshold) or at shutdown. The resulting file is compatible with about://tracing in Chromium-based browsers and https://ui.perfetto.dev.

Definition at line 48 of file flamegraph.hpp.

Constructor & Destructor Documentation

◆ FlamegraphBackend() [1/3]

helios::profile::FlamegraphBackend::FlamegraphBackend ( FlamegraphBackendConfig config = {} )

inlineexplicitnoexcept

Constructs with a custom configuration.

Parameters

config Configuration for output path and flush threshold

Definition at line 54 of file flamegraph.hpp.

◆ FlamegraphBackend() [2/3]

helios::profile::FlamegraphBackend::FlamegraphBackend ( const FlamegraphBackend & )

delete

◆ FlamegraphBackend() [3/3]

helios::profile::FlamegraphBackend::FlamegraphBackend ( FlamegraphBackend && )

delete

◆ ~FlamegraphBackend()

helios::profile::FlamegraphBackend::~FlamegraphBackend ( )

overridedefaultnoexcept

Member Function Documentation

◆ Alloc()

void helios::profile::FlamegraphBackend::Alloc	(	const void *	,
		size_t	,
		std::optional< CStringView >	,
		int	,
		std::source_location	)

inlineoverridevirtualnoexcept

Memory allocation events are not emitted in the JSON format.

Parameters

ptr	Pointer to allocated memory
size	Allocation size in bytes
name	Optional pool name
depth	Callstack depth
loc	Source location of the allocation

spec	Zone specification (name, source location, etc.)
storage	Per-zone byte slice for this backend

ptr	Pointer to freed memory
name	Optional pool name
depth	Callstack depth
loc	Source location of the deallocation

name	Counter name
type	Plot format type
step	Whether to use step interpolation
fill	Whether to fill the area
color	Display color

storage	Per-zone byte slice for this backend
text	Text to attach

storage	Per-zone byte slice for this backend
value	Numeric value to attach

Public Member Functions

Detailed Description

Constructor & Destructor Documentation

◆ FlamegraphBackend() [1/3]

◆ FlamegraphBackend() [2/3]

◆ FlamegraphBackend() [3/3]

◆ ~FlamegraphBackend()

Member Function Documentation

◆ Alloc()

◆ BeginZone()

◆ EndZone()

◆ FrameMark() [1/2]

◆ FrameMark() [2/2]

◆ FrameMarkEnd()

◆ FrameMarkStart()

◆ Free()

◆ MemoryDiscard() [1/2]

◆ MemoryDiscard() [2/2]

◆ Message()

◆ Name()

◆ operator=() [1/2]

◆ operator=() [2/2]

◆ Plot()

◆ PlotConfig()

◆ SetThreadName()

◆ Shutdown()

◆ Startup()

◆ ZoneName()

◆ ZoneStorageSize()

◆ ZoneText()

◆ ZoneValue()