This package provides access to platform dependent file locking APIs:
Open file descriptor locking on Linux (Lukko.OFD
)
BSD-style flock(2)
locks on UNIX platforms (Lukko.FLock
)
Windows locking via 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.