systimeh

Systimeh is a term used in computing to denote a high-resolution representation of the system time. It is typically used for precise timing measurements, profiling, benchmarking, and event sequencing. The name combines elements of “system time” and “high resolution,” and in some contexts it appears as a generic label for a high-precision time value rather than a formal standard.

Definition and characteristics: A systimeh value encodes elapsed time with a resolution in microseconds or nanoseconds, often relative to a reference point. Many implementations emphasize monotonicity, meaning the value should not decrease as real time progresses, even when the wall clock is adjusted. Systimeh values are usually derived from an OS timer source or hardware counter, such as a monotonic clock or a high-resolution performance counter.

Relation to other time concepts: System time (or real-time) is the wall-clock time that can be adjusted by network time protocols or user changes. Monotonic time is designed for measuring elapsed durations and is preferred for benchmarking. Systimeh is commonly implemented as a monotonic, high-resolution clock suitable for accurate duration calculations and precise event ordering.

Typical uses: timing code sections, profiling and benchmarking, coordinating timeouts, sequencing events, and logging with fine-grained timestamps.

Cross-platform considerations: Operating systems expose various high-resolution time APIs, including monotonic clocks and performance counters. Developers may need to convert raw counter values into standard units and account for differences in clock frequency, epoch, and units.

Limitations: Hardware and OS variability can affect accuracy. Suspend/resume events, clock frequency changes, and leap seconds can complicate interpretation and require careful handling.

See also: system time, monotonic clock, high-resolution timer, clock_gettime, QueryPerformanceCounter.