Package Info


File locking


This package provides access to platform dependent file locking APIs:

  • Open file descriptor locking on Linux ("Lukko.OFD") 'flock' locking on unix platforms ("Lukko.FLock") Windows locking 'LockFileEx' ("Lukko.Windows") No-op locking, which throws exceptions ("Lukko.NoOp") "Lukko" module exports the best option for the target platform with uniform API.

There are alternative file locking packages:

  • "GHC.IO.Handle.Lock" in 'base >= 4.10' is good enough for most use cases. However, uses only 'Handle's so these locks cannot be used for intra-process locking. (You should use e.g. 'MVar' in addition).

  • < filelock> doesn't support OFD locking.

/Lukko/ means lock in Finnish.

Submodules "Lukko.OFD", "Lukko.Windows" etc are available based on following conditions.

' if os(windows) cpp-options: -DHAS_WINDOWS_LOCK

elif (os(linux) && flag(ofd-locking)) cpp-options: -DHAS_OFD_LOCKING cpp-options: -DHAS_FLOCK

elif !(os(solaris) || os(aix)) cpp-options: -DHAS_FLOCK '

"Lukko.FLock" is available on not (Windows or Solaris or AIX). "Lukko.NoOp" is always available.

License: GPL-2.0-or-later AND BSD-3-Clause



Package Version Update ID Released Package Hub Version Platforms Subpackages info GA Release 2020-06-16 15 SP2
  • AArch64
  • ppc64le
  • x86-64
  • ghc-lukko
  • ghc-lukko-devel info GA Release 2021-04-08 15 SP3
  • AArch64
  • ppc64le
  • x86-64
  • ghc-lukko
  • ghc-lukko-devel