Message158085
Extract of FreeBSD manpage of clock_gettime:
The clock_id argument can be one of the following values: CLOCK_REALTIME,
CLOCK_REALTIME_PRECISE, CLOCK_REALTIME_FAST for time that increments as a
wall clock should; CLOCK_MONOTONIC, CLOCK_MONOTONIC_PRECISE,
CLOCK_MONOTONIC_FAST which increments in SI seconds; CLOCK_UPTIME,
CLOCK_UPTIME_PRECISE, CLOCK_UPTIME_FAST which starts at zero when the
kernel boots and increments monotonically in SI seconds while the machine
is running; CLOCK_VIRTUAL for time that increments only when the CPU is
running in user mode on behalf of the calling process; CLOCK_PROF for
time that increments when the CPU is running in user or kernel mode; or
CLOCK_SECOND which returns the current second without performing a full
time counter query, using in-kernel cached value of current second.
The clock IDs CLOCK_REALTIME_FAST, CLOCK_MONOTONIC_FAST,
CLOCK_UPTIME_FAST are analogs of corresponding IDs without _FAST suffix
but do not perform a full time counter query, so their accuracy is one
timer tick. Similarly, CLOCK_REALTIME_PRECISE, CLOCK_MONOTONIC_PRECISE,
CLOCK_UPTIME_PRECISE are used to get the most exact value as possible, at
the expense of execution time. |
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2012-04-11 22:30:46 | vstinner | set | recipients:
+ vstinner |
2012-04-11 22:30:46 | vstinner | set | messageid: <1334183446.65.0.25603196181.issue14555@psf.upfronthosting.co.za> |
2012-04-11 22:30:46 | vstinner | link | issue14555 messages |
2012-04-11 22:30:45 | vstinner | create | |
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