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libxs_timer.md

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Timer

Header: libxs_timer.h

High-resolution timing via a calibrated TSC when available, with an OS real-time clock fallback.

Types

typedef unsigned long long libxs_timer_tick_t;

Integer type representing a single timer sample.

typedef struct libxs_timer_info_t {
  int tsc;   /* non-zero if a calibrated TSC is used */
} libxs_timer_info_t;

Functions

int libxs_timer_info(libxs_timer_info_t* info);

Query timer properties. info->tsc is non-zero when RDTSC (x86), CNTVCT_EL0 (AArch64), or MFTB (PPC64) is available. Triggers lazy library initialization if necessary.

libxs_timer_tick_t libxs_timer_tick(void);

Sample the current tick of the monotonic timer. The tick unit is platform-specific; convert with libxs_timer_duration or libxs_timer_ncycles.

libxs_timer_tick_t libxs_timer_ncycles(
  libxs_timer_tick_t tick0, libxs_timer_tick_t tick1);   /* inline */

Unsigned difference tick1 - tick0, handling wrap-around safely. Implemented via LIBXS_DELTA.

double libxs_timer_duration(
  libxs_timer_tick_t tick0, libxs_timer_tick_t tick1);

Convert a pair of ticks to elapsed wall-clock time in seconds.