SECONDS(9) SECONDS(9)
NAME
seconds, ticks, fastticks, HZ, MS2HZ, MS2TK, TK2MS, TK2SEC -
kernel times and time conversions
SYNOPSIS
long seconds(void)
vlong fastticks(uvlong *hz)
#define HZ ...
#define MS2HZ (1000/HZ)
#define TK2SEC(t) ((t)/HZ)
#define TK2MS(t) ((t)*(1000/HZ))
DESCRIPTION
Seconds returns the system's idea of the current time as the
number of seconds since the start of the epoch (00:00:00
GMT, January 1, 1970).
The ticks field of the Mach structure returns the number of
system-dependent clock ticks on the given processor since
system boot. On a multiprocessor, MACHP(0) is sometimes
used to provide a reference time, since the tick value might
vary slightly across processors.
Fastticks returns the number of ticks since boot as measured
by the fastest clock provided by the platform. The fre-
quency of the clock, in ticks per second, is returned
through hz, unless it is nil.
The system clock frequencies are platform-dependent. Sev-
eral symbolic constants and macro functions are defined by
the file mem.h to convert between different time units:
HZ The number of clock ticks per second.
MS2HZ Milliseconds per clock tick.
TK2SEC(t) Convert t clock ticks to seconds (truncating not
rounding).
TK2MS(t) Convert t clock ticks to milliseconds.
SOURCE
/sys/src/9/*/mem.h
/sys/src/9/*/clock.c
/sys/src/9/*/devarch.c
/sys/src/9/*/timer.c
/sys/src/9/port/tod.c
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