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4.16.25 Timeouts

To use the bindings from this module:

(import :std/misc/timeout)

4.16.25.1 make-timeout

(make-timeout t [def = absent-obj]) -> time object | def | error

  t   := real number in seconds | time object | #f (false value)
  def := default value returned in case t is #f

Creates a time object representing a time point relative to the current time. These time objects are used as timeout input parameters for synchronization primitives in modules such as :gerbil/gambit/threads or :std/misc/channel:

  • (thread-sleep! timeout)
  • (thread-join! thread [timeout [timeout-val]])
  • (mutex-lock! mutex [timeout [thread]])
  • (mutex-unlock! mutex [condition-variable [timeout]])
  • (channel-put channel value [time-object])
  • (channel-get channel [time-object [default]])

make-timeout expects t to be exact or inexact real number in seconds; a time point object satisfying time?, in which case it returns t itself; or #f, which is often the case for gerbil’s internal usage of make-timeout, returning the optional default parameter def instead.

Signals an error when t is something other than a real number, a time object or #f.

Examples:

> (import :gerbil/gambit/threads)
> (thread-sleep! (make-timeout 10))
  ; no output, but will take ten seconds to complete