Add a program with multiple threads

Author: harendra-kumar

examples/console-loop-multi-thread.hs

@@ -0,0 +1,35 @@
+import Control.Concurrent
+import Control.Monad
+import System.Posix.Process (getProcessID)
+
+consoleLoop :: IO ()
+consoleLoop = do
+    line <- getLine
+    putStrLn line
+    consoleLoop
+
+threadLoop :: IO ()
+threadLoop = do
+    tid <- myThreadId
+    putStrLn $ "running thread: " ++ show tid
+    -- tight loop  with occasional delay
+    forever $ go (0 :: Integer)
+
+    where
+
+    go n =
+        if n `mod` 1000000 == 0
+        then threadDelay 1
+        else go (n+1)
+
+main :: IO ()
+main = do
+    pid <- getProcessID
+    putStrLn $ "pid: " ++ show pid
+    tid <- myThreadId
+    putStrLn $ "main thread: " ++ show tid
+    tid1 <- forkIO threadLoop
+    putStrLn $ "forked thread: " ++ show tid1
+    tid2 <- forkIO threadLoop
+    putStrLn $ "forked thread: " ++ show tid2
+    consoleLoop -- `catch` (\(e :: IOException) -> return ())

haskell-perf.cabal

@@ -107,6 +107,15 @@ common compile-options
                     -Wall-missed-specialisations
                     -fno-ignore-asserts
 
+executable console-loop-multi-thread
+  import: compile-options
+  hs-source-dirs: examples
+  ghc-options: -threaded -rtsopts
+  main-is: console-loop-multi-thread.hs
+  build-depends:
+       base >= 4.9 && < 5
+     , unix
+
 executable hperf
   import: compile-options
   hs-source-dirs: src