Module B0_std.MtimeSource

Monotonic time stamps and spans.

This module provides support for representing monotonic wall-clock time. This time increases monotonically and is not subject to operating system calendar time adjustement. Its absolute value is meaningless.

To obtain and measure monotonic time use B0_std.Os.Mtime.

Time spans

Sourcemodule Span : sig ... end

Monotonic time spans

Timestamps

Note. Only use timestamps if you need inter-process time correlation, otherwise prefer B0_std.Os.Mtime.elapsed and counters to measure time.

Sourcetype t

The type for monotonic timestamps relative to an indeterminate system-wide event (e.g. last startup). Their absolute value has no meaning but can be used for inter-process time correlation.

Sourceval to_uint64_ns : t -> int64

to_uint64_ns t is t as an unsigned 64-bit integer nanosecond timestamp. The absolute value is meaningless.

Sourceval of_uint64_ns : int64 -> t

to_uint64_ns t is t is an unsigned 64-bit integer nanosecond timestamp as a timestamp.

Warning. Timestamps returned by this function should only be used with other timestamp values that are know to come from the same operating system run.

Sourceval min_stamp : t

min_stamp is the earliest timestamp.

Sourceval max_stamp : t

max_stamp is the latest timestamp.

Sourceval pp : t Fmt.t

pp is a formatter for timestamps.

Predicates

Sourceval equal : t -> t -> bool

equal t t' is true iff t and t' are equal.

Sourceval compare : t -> t -> int

compare t t' orders timestamps by increasing time.

Sourceval is_earlier : t -> than:t -> bool

is_earlier t ~than is true iff t occurred before than.

Sourceval is_later : t -> than:t -> bool

is_later t ~than is true iff t occurred after than.

Arithmetic

Sourceval span : t -> t -> Span.t

span t t' is the span between t and t' regardless of the order between t and t'.

Sourceval add_span : t -> Span.t -> t option

add_span t s is the timestamp s units later than t or None if the result overflows.

Sourceval sub_span : t -> Span.t -> t option

sub_span t s is the timestamp s units earlier than t or None if overflows.