Thread report in test program.

1 files changed, 41 insertions, 0 deletions

diff --git a/src/DebugUtil.hs b/src/DebugUtil.hs
new file mode 100644
index 00000000..e7a10397
--- /dev/null
+++ b/src/DebugUtil.hs
@@ -0,0 +1,41 @@
+{-# LANGUAGE CPP #-}
+module DebugUtil where
+
+import Control.Monad
+import Data.Time.Clock
+import Data.List
+import Text.Printf
+import GHC.Conc (threadStatus,ThreadStatus(..))
+#ifdef THREAD_DEBUG
+import Control.Concurrent.Lifted.Instrument
+#else
+import Control.Concurrent.Lifted
+import GHC.Conc                  (labelThread)
+#endif
+
+showReport :: [(String,String)] -> String
+showReport kvs = showColumns $ map (\(x,y)->[x,y]) kvs
+
+showColumns :: [[String]] -> String
+showColumns rows = do
+    let cols = transpose rows
+        ws = map (maximum . map (succ . length)) cols
+    fs <- rows
+    _ <- take 1 fs -- Guard against empty rows so that 'last' is safe.
+    "  " ++ concat (zipWith (printf "%-*s") (init ws) (init fs)) ++ last fs ++ "\n"
+
+
+threadReport :: Bool -> IO String
+threadReport want_ss = do
+    threads <- threadsInformation
+    tm <- getCurrentTime
+    let (ss,ts) = partition (("search" `isPrefixOf`) . lbl . snd)
+                            threads
+    r <- forM (if want_ss then threads else ts) $ \(tid,PerThread{..}) -> do
+        stat <- threadStatus tid
+        let showStat (ThreadBlocked reason) = show reason
+            showStat stat                   = show stat
+        return [show lbl,show (diffUTCTime tm startTime),showStat stat]
+    return $ unlines [ showColumns r
+                     , (if want_ss then "  There are " else "  and ")
+                        ++ show (length ss) ++ " search threads." ]