gentoo-overlay/dev-haskell/lukko/metadata.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE pkgmetadata SYSTEM "http://www.gentoo.org/dtd/metadata.dtd">
<pkgmetadata>
	<maintainer type="project">
		<email>haskell@gentoo.org</email>
		<name>Gentoo Haskell</name>
	</maintainer>
	<use>
		<flag name="ofd-locking">Enable open file descriptor locking. Available on Linux (kernel 3.15, released Jun 8, 2014).</flag>
	</use>
	<longdescription>
		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 &gt;= 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).
		
		* &lt;https://hackage.haskell.org/package/filelock filelock&gt; 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) &amp;&amp; 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.
	</longdescription>
</pkgmetadata>