Merge pull request #6345 from haskell/lukko

Use lukko for file-locking

Author: phadej

cabal-install/Distribution/Client/Compat/FileLock.hsc

@@ -1,4 +1,4 @@
-{-# LANGUAGE RecordWildCards, NamedFieldPuns #-}
+{-# LANGUAGE CPP, RecordWildCards, NamedFieldPuns #-}
 
 
 -- | Management for the installed package store.
@@ -23,7 +23,6 @@ module Distribution.Client.Store (
 
 import Prelude ()
 import Distribution.Client.Compat.Prelude
-import Distribution.Client.Compat.FileLock
 
 import           Distribution.Client.DistDirLayout
 import           Distribution.Client.RebuildMonad
@@ -41,8 +40,16 @@ import           Control.Exception
 import           Control.Monad (forM_)
 import           System.FilePath
 import           System.Directory
-import           System.IO
 
+#ifdef MIN_VERSION_lukko
+import Lukko
+#else
+import System.IO (openFile, IOMode(ReadWriteMode), hClose)
+import GHC.IO.Handle.Lock (hLock, hTryLock, LockMode(ExclusiveLock))
+#if MIN_VERSION_base(4,11,0)
+import GHC.IO.Handle.Lock (hUnlock)
+#endif
+#endif
 
 -- $concurrency
 --
@@ -235,6 +242,26 @@ withIncomingUnitIdLock verbosity StoreDirLayout{storeIncomingLock}
                        compid unitid action =
     bracket takeLock releaseLock (\_hnd -> action)
   where
+#ifdef MIN_VERSION_lukko
+    takeLock
+        | fileLockingSupported = do
+            fd <- fdOpen (storeIncomingLock compid unitid)
+            gotLock <- fdTryLock fd ExclusiveLock
+            unless gotLock  $ do
+                info verbosity $ "Waiting for file lock on store entry "
+                              ++ display compid </> display unitid
+                fdLock fd ExclusiveLock
+            return fd
+
+        -- if there's no locking, do nothing. Be careful on AIX.
+        | otherwise = return undefined -- :(
+
+    releaseLock fd
+        | fileLockingSupported = do
+            fdUnlock fd
+            fdClose fd
+        | otherwise = return ()
+#else
     takeLock = do
       h <- openFile (storeIncomingLock compid unitid) ReadWriteMode
       -- First try non-blocking, but if we would have to wait then
@@ -246,5 +273,5 @@ withIncomingUnitIdLock verbosity StoreDirLayout{storeIncomingLock}
         hLock h ExclusiveLock
       return h
 
-    releaseLock = hClose
-
+    releaseLock h = hUnlock h >> hClose h
+#endif

cabal-install/Distribution/Client/Store.hs

@@ -266,8 +266,8 @@ TAR_VER="0.5.1.0";     TAR_VER_REGEXP="0\.5\.([1-9]|1[0-9]|0\.[3-9]|0\.1[0-9])\.
                        # >= 0.5.0.3  && < 0.6
 DIGEST_VER="0.0.1.2"; DIGEST_REGEXP="0\.0\.(1\.[2-9]|[2-9]\.?)"
                        # >= 0.0.1.2 && < 0.1
-ZIP_ARCHIVE_VER="0.3.3"; ZIP_ARCHIVE_REGEXP="0\.3\.[3-9]"
-                       # >= 0.3.3 && < 0.4
+LUKKO_VER="0.1.1";     LUKKO_VER_REGEXP="0\.1\.[1-9]"
+                       # >= 0.1.1 && <0.2
 
 HACKAGE_URL="https://hackage.haskell.org/package"
 
@@ -471,7 +471,7 @@ info_pkg "edit-distance" ${EDIT_DISTANCE_VER} ${EDIT_DISTANCE_VER_REGEXP}
 info_pkg "ed25519"           ${ED25519_VER}          ${ED25519_VER_REGEXP}
 info_pkg "tar"               ${TAR_VER}              ${TAR_VER_REGEXP}
 info_pkg "digest"            ${DIGEST_VER}           ${DIGEST_REGEXP}
-info_pkg "zip-archive"       ${ZIP_ARCHIVE_VER}      ${ZIP_ARCHIVE_REGEXP}
+info_pkg "lukko"        ${LUKKO_VER}   ${LUKKO_REGEXP}
 info_pkg "hackage-security"  ${HACKAGE_SECURITY_VER} \
     ${HACKAGE_SECURITY_VER_REGEXP}
 
@@ -509,7 +509,7 @@ do_pkg "edit-distance" ${EDIT_DISTANCE_VER} ${EDIT_DISTANCE_VER_REGEXP}
 do_pkg   "ed25519"           ${ED25519_VER}          ${ED25519_VER_REGEXP}
 do_pkg   "tar"               ${TAR_VER}              ${TAR_VER_REGEXP}
 do_pkg   "digest"            ${DIGEST_VER}           ${DIGEST_REGEXP}
-do_pkg   "zip-archive"       ${ZIP_ARCHIVE_VER}      ${ZIP_ARCHIVE_REGEXP}
+do_pkg   "lukko"       ${LUKKO_VER}      ${LUKKO_REGEXP}
 do_pkg   "hackage-security"  ${HACKAGE_SECURITY_VER} \
     ${HACKAGE_SECURITY_VER_REGEXP}
 

cabal-install/bootstrap.sh

@@ -21,7 +21,6 @@ Category:           Distribution
 Build-type:         Custom
 Extra-Source-Files:
   README.md bash-completion/cabal bootstrap.sh changelog
-  tests/README.md
 
   -- Generated with 'make gen-extra-source-files'
   -- Do NOT edit this section manually; instead, run the script.
@@ -122,6 +121,11 @@ Flag debug-tracetree
   default:      False
   manual:       True
 
+Flag lukko
+  description:  Use @lukko@ for file-locking
+  default:      True
+  manual:       True
+
 custom-setup
    setup-depends:
        Cabal     >= 2.2,
@@ -176,7 +180,6 @@ executable cabal
         Distribution.Client.CmdSdist
         Distribution.Client.Compat.Directory
         Distribution.Client.Compat.ExecutablePath
-        Distribution.Client.Compat.FileLock
         Distribution.Client.Compat.FilePerms
         Distribution.Client.Compat.Prelude
         Distribution.Client.Compat.Process
@@ -352,6 +355,11 @@ executable cabal
     else
       build-depends: unix >= 2.5 && < 2.9
 
+    if flag(lukko)
+      build-depends: lukko >= 0.1 && <0.2
+    else
+      build-depends: base >= 4.10
+
     if flag(debug-expensive-assertions)
       cpp-options: -DDEBUG_EXPENSIVE_ASSERTIONS
 

cabal-install/cabal-install.cabal

@@ -61,6 +61,11 @@
       build-depends: Win32 >= 2 && < 3
     else
       build-depends: unix >= 2.5 && < 2.9
+
+    if flag(lukko)
+      build-depends: lukko >= 0.1 && <0.2
+    else
+      build-depends: base >= 4.10
 %enddef
 %def CABAL_COMPONENTCOMMON
     default-language: Haskell2010
@@ -106,7 +111,6 @@
         Distribution.Client.CmdSdist
         Distribution.Client.Compat.Directory
         Distribution.Client.Compat.ExecutablePath
-        Distribution.Client.Compat.FileLock
         Distribution.Client.Compat.FilePerms
         Distribution.Client.Compat.Prelude
         Distribution.Client.Compat.Process
@@ -275,7 +279,6 @@
 %endif
 Extra-Source-Files:
   README.md bash-completion/cabal bootstrap.sh changelog
-  tests/README.md
 
   -- Generated with 'make gen-extra-source-files'
   -- Do NOT edit this section manually; instead, run the script.
@@ -376,6 +379,11 @@
   default:      False
   manual:       True
 
+Flag lukko
+  description:  Use @lukko@ for file-locking
+  default:      True
+  manual:       True
+
 %if CABAL_FLAG_LIB
 %else
 custom-setup