get rid of the unsafeInterleaveIO at start up (#4167)

ghcide/src/Development/IDE/LSP/LanguageServer.hs

@@ -42,7 +42,6 @@ import Ide.Logger
 import Language.LSP.Server (LanguageContextEnv,
  LspServerLog,
  type (<~>))
-import System.IO.Unsafe (unsafeInterleaveIO)
 data Log
  = LogRegisteringIdeConfig !IdeConfiguration
  | LogReactorThreadException !SomeException
@@ -197,18 +196,10 @@ handleInit recorder getHieDbLoc getIdeState lifetime exitClientMsg clearReqId wa
  let root = LSP.resRootPath env
  dir <- maybe getCurrentDirectory return root
  dbLoc <- getHieDbLoc dir
-
- -- The database needs to be open for the duration of the reactor thread, but we need to pass in a reference
- -- to 'getIdeState', so we use this dirty trick
- dbMVar <- newEmptyMVar
- ~(WithHieDbShield withHieDb,hieChan) <- unsafeInterleaveIO $ takeMVar dbMVar
-
- ide <- getIdeState env root withHieDb hieChan
-
  let initConfig = parseConfiguration params
-
  logWith recorder Info $ LogRegisteringIdeConfig initConfig
- registerIdeConfiguration (shakeExtras ide) initConfig
+ dbMVar <- newEmptyMVar
+
 
  let handleServerException (Left e) = do
  logWith recorder Error $ LogReactorThreadException e
@@ -245,6 +236,10 @@ handleInit recorder getHieDbLoc getIdeState lifetime exitClientMsg clearReqId wa
  ReactorNotification act -> handle exceptionInHandler act
  ReactorRequest _id act k -> void $ async $ checkCancelled _id act k
  logWith recorder Info LogReactorThreadStopped
+
+ (WithHieDbShield withHieDb,hieChan) <- takeMVar dbMVar
+ ide <- getIdeState env root withHieDb hieChan
+ registerIdeConfiguration (shakeExtras ide) initConfig
  pure $ Right (env,ide)