timer-wheel

A timer wheel

https://github.com/awkward-squad/timer-wheel

LTS Haskell 24.0:1.0.0.1@rev:2
Stackage Nightly 2025-07-15:1.0.0.1@rev:2
Latest on Hackage:1.0.0.1@rev:2

See all snapshots timer-wheel appears in

BSD-3-Clause licensed by Mitchell Dalvi Rosen
Maintained by Mitchell Dalvi Rosen, Travis Staton
This version can be pinned in stack with:timer-wheel-1.0.0.1@sha256:b031a9865cf66a41e6d6195efb3fa73a0c614d82fe1ca4163b5c24ff670fb816,2883

Module documentation for 1.0.0.1

timer-wheel

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Changes

[1.0.0.1] - May 16, 2024

  • Fix term-variable-capture warnings
  • Require at least GHC 9.2

[1.0.0] - October 10, 2023

  • Add count, which returns the number of timers in a timer wheel
  • Add Seconds type alias for readability
  • Add Timer newtype for readability
  • Make create / with no longer throw an exception if given an invalid config; rather, the config’s invalid values are replaced with sensible defaults
  • Make recurring / recurring_ handle delays that are shorter than the wheel resolution more correctly
  • Make recurring / recurring_ no longer throw an exception if given a negative delay
  • Make calling cancel more than once on a recurring timer not enter an infinite loop
  • Make timers that expire in the same batch no longer fire in an arbitrary order
  • Improve the resolution of timers from microseconds to nanoseconds
  • Simplify and optimize internals

[0.4.0.1] - November 5, 2022

  • Fix inaccurate haddock on recurring

[0.4.0] - November 5, 2022

  • Add create
  • Rename Data.TimerWheel to TimerWheel
  • Swap out vector for array
  • Treat negative delays as 0
  • Drop support for GHC < 8.6

[0.3.0] - June 18, 2020

  • Add with
  • Add support for GHC 8.8, GHC 8.10
  • Change type of spokes from Natural to Int
  • Change order of delay and action arguments in register, register_, recurring, and recurring_
  • Simplify cancel to return True at most once
  • Throw an error if a negative delay is provided to register, register_, recurring, or recurring_
  • Fix underflow bug that affected recurring timers
  • Remove create, destroy
  • Remove TimerWheelDied exception. with now simply re-throws the exception that the timer wheel thread throws
  • Remove InvalidTimerWheelConfig exception. error is used instead
  • Remove support for GHC < 8.6

[0.2.0.1] - May 19, 2019

  • Swap out ghc-prim and primitive for vector

[0.2.0] - February 3, 2019

  • Add destroy function, for reaping the background thread
  • Add recurring_ function
  • If the timer wheel reaper thread crashes, it will propagate the exception to the thread that spawned it
  • new may now throw InvalidTimerWheelConfig
  • The cancel action returned by register is now memoized, which fixes a bug involving trying to cancel a recurring timer twice. The second call used to spin forever and peg a CPU
  • Use Config type for creating a timer wheel
  • Change argument order around
  • Rename new to create
  • Make recurring timers more accurate

[0.1.0] - July 18, 2018

  • Initial release