chronon::observe

Namespaces

Name
chronon::observe::simd
chronon::observe::category
chronon::observe::DerivedFormula Convenience formulas for common derived-counter patterns.

Classes

	Name
struct	chronon::observe::ArgTypeOf< uint8_t >
struct	chronon::observe::ArgTypeOf< uint64_t >
struct	chronon::observe::ArgTypeOf< uint32_t >
struct	chronon::observe::ArgTypeOf< uint16_t >
struct	chronon::observe::ArgTypeOf< int8_t >
struct	chronon::observe::ArgTypeOf< int64_t >
struct	chronon::observe::ArgTypeOf< int32_t >
struct	chronon::observe::ArgTypeOf< int16_t >
struct	chronon::observe::ArgTypeOf< float >
struct	chronon::observe::ArgTypeOf< double >
struct	chronon::observe::ArgTypeOf< const char * >
struct	chronon::observe::ArgTypeOf< char * >
struct	chronon::observe::ArgTypeOf< bool >
struct	chronon::observe::ArgTypeOf< T * >
struct	chronon::observe::ArgTypeOf Maps a C++ type to its ArgType.
struct	chronon::observe::ArenaSnapshot Copy of the arena region referenced by a batch of flushed records.

Types

	Name
enum class uint8_t	OutputFormat { Text, Both, Binary} How an event channel writes its output.
enum class uint8_t	ObservationChannel { Warn = 3, Trace = 0, NumChannels = 5, Info = 2, Error = 4, Debug = 1} Identifies the observation channel for per-unit stats tracking.
enum class uint8_t	ObservationChannel { } Identifies the observation channel for per-unit stats tracking.
enum class uint8_t	LogLevel { Warn = 2, Info = 1, Error = 3, Debug = 0}
using uint32_t	FormatId Compile-time format-string registration for zero-copy trace/log.
enum class uint32_t	CounterId { } Strongly typed counter identifier; indexes into the counter storage array.
enum class uint8_t	CounterCsvFormat { Pivoted, Long} Counter CSV layout.
using std::function< double(std::span< const uint64_t >)>	ComputeFn
using uint64_t	CategoryMask Bitmask for observability categories.
enum class uint8_t	BackpressurePolicy { SpinWait, Drop, BoundedWait} Producer behavior when SPSC queues are full.
enum class uint8_t	ArgType { UInt8, UInt64, UInt32, UInt16, String, Pointer, None = 0, Int8, Int64, Int32, Int16, Float, Double, Bool}

Functions

	Name
template <FixedString Fmt,typename Cat ,typename... Args> void	tracePipe(ObservationContext * , Cat , const char * , Args && ...)
template <FixedString Fmt,typename Cat ,typename... Args> void	traceEvent(ObservationContext * , Cat , Args && ...)
void	traceCounter(ObservationContext * , const char * , int64_t )
template <FixedString Fmt,typename Cat ,typename... Args> void	trace(ObservationContext * ctx, Cat category, Args &&... args) Emit a trace event with compile-time format string.
uint32_t	toIndex(CounterId id)
CounterId	makeCounterId(uint32_t value)
template <FixedString Fmt,typename... Args> void	log_warn(ObservationContext * ctx, Args &&... args)
template <FixedString Fmt,typename... Args> void	log_info(ObservationContext * ctx, Args &&... args)
template <FixedString Fmt,typename... Args> void	log_error(ObservationContext * ctx, Args &&... args)
template <FixedString Fmt,typename... Args> void	log_debug(ObservationContext * ctx, Args &&... args)
CategoryMask	logLevelToCategory(LogLevel level)
template <size_t N>	FixedString(const char(&)[N])

Attributes

	Name
ObservationChannel	log_level_channel_v
size_t	MAX_FORMAT_ARGS
FormatId	INVALID_FORMAT_ID

Types Documentation

enum OutputFormat

Enumerator	Value	Description
Text
Both
Binary

How an event channel writes its output.

• Text: Human-readable (events.log).
• Binary: Compact binary (events.ctrace).
• Both: Both sinks.

enum ObservationChannel

Enumerator	Value	Description
Warn	3
Trace	0
NumChannels	5
Info	2
Error	4
Debug	1

Identifies the observation channel for per-unit stats tracking.

enum ObservationChannel

Enumerator	Value	Description

Identifies the observation channel for per-unit stats tracking.

enum LogLevel

Enumerator	Value	Description
Warn	2
Info	1
Error	3
Debug	0

using FormatId

using chronon::observe::FormatId =  uint32_t;

Compile-time format-string registration for zero-copy trace/log.

Format strings are registered at static-initialization time and assigned a unique 32-bit ID; the runtime transmits only ID + arg values, and the backend thread reconstructs formatted messages.

enum CounterId

Enumerator	Value	Description

Strongly typed counter identifier; indexes into the counter storage array.

enum CounterCsvFormat

Enumerator	Value	Description
Pivoted
Long

Counter CSV layout.

• Long: One row per (cycle, unit, counter, value); streaming-friendly.
• Pivoted: Rows are cycles, columns are counters; compact and readable.

using ComputeFn

using chronon::observe::ComputeFn =  std::function<double(std::span<const uint64_t>)>;

Receives snapshotted delta values for each source counter (declaration order) and returns the derived value. Invoked on the backend thread at CSV dump time.

using CategoryMask

using chronon::observe::CategoryMask =  uint64_t;

Bitmask for observability categories.

Bits 0-7 are reserved for built-in categories (counters, trace, log levels); bits 8-63 are user-defined unit-specific categories.

enum BackpressurePolicy

Enumerator	Value	Description
SpinWait
Drop
BoundedWait

Producer behavior when SPSC queues are full.

• Drop: Drop immediately when queue full (zero stall, data loss).
• SpinWait: Spin indefinitely until space available (zero data loss, may stall).
• BoundedWait: Spin up to max_spins iterations, then drop (recommended default).

enum ArgType

Enumerator	Value	Description
UInt8
UInt64
UInt32
UInt16
String
Pointer
None	0
Int8
Int64
Int32
Int16
Float
Double
Bool

Functions Documentation

function tracePipe

template <FixedString Fmt,
typename Cat ,
typename... Args>
inline void tracePipe(
    ObservationContext * ,
    Cat ,
    const char * ,
    Args && ...
)

function traceEvent

template <FixedString Fmt,
typename Cat ,
typename... Args>
inline void traceEvent(
    ObservationContext * ,
    Cat ,
    Args && ...
)

function traceCounter

inline void traceCounter(
    ObservationContext * ,
    const char * ,
    int64_t 
)

function trace

template <FixedString Fmt,
typename Cat ,
typename... Args>
inline void trace(
    ObservationContext * ctx,
    Cat category,
    Args &&... args
)

Emit a trace event with compile-time format string.

trace<"Cache HIT: addr=0x{:x}">(ctx, CACHE_HIT, addr);

function toIndex

uint32_t toIndex(
    CounterId id
)

function makeCounterId

CounterId makeCounterId(
    uint32_t value
)

function log_warn

template <FixedString Fmt,
typename... Args>
inline void log_warn(
    ObservationContext * ctx,
    Args &&... args
)

function log_info

template <FixedString Fmt,
typename... Args>
inline void log_info(
    ObservationContext * ctx,
    Args &&... args
)

function log_error

template <FixedString Fmt,
typename... Args>
inline void log_error(
    ObservationContext * ctx,
    Args &&... args
)

function log_debug

template <FixedString Fmt,
typename... Args>
inline void log_debug(
    ObservationContext * ctx,
    Args &&... args
)

function logLevelToCategory

CategoryMask logLevelToCategory(
    LogLevel level
)

function FixedString

template <size_t N>
FixedString(
    const  char(&)[N]
)

Attributes Documentation

variable log_level_channel_v

ObservationChannel log_level_channel_v = LogLevelToChannel<L>::value;

variable MAX_FORMAT_ARGS

size_t MAX_FORMAT_ARGS = 8;

variable INVALID_FORMAT_ID

FormatId INVALID_FORMAT_ID = 0;

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Updated on 2026-05-26 at 05:42:32 +0000