define: DUK_USE_GET_MONOTONIC_TIME
introduced: 2.2.0
default: false
tags:
  - portability
description: >
  Optional macro for getting monotonic time in milliseconds from an arbitrary
  starting point (device startup, program startup, script startup, etc).
  Fractional time values are allowed (and even recommended).  The time returned
  must increase monotonically, and must not jump discontinuously even if system
  date/time is reset.  The semantics are similar to POSIX clock_gettime()
  CLOCK_MONOTONIC.

  Monotonic time is used by Duktape for its internal needs, such as rate
  limiting debugger transport peek callbacks.  It is also used to provide
  performance.now().  If this option is not provided, Duktape falls back to
  using DUK_USE_DATE_GET_NOW() which is usually fine.

  If DUK_USE_DATE_GET_NOW() experiences time jumps or doesn't run in realtime
  (which may be useful for some time virtualization cases) it's recommended
  to provide this config option so that internals which need a reliable
  realtime rate have a reliable time basis.