propellor spin

1 files changed, 34 insertions, 0 deletions

diff --git a/src/System/Process/Concurrent.hs b/src/System/Process/Concurrent.hs
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+++ b/src/System/Process/Concurrent.hs
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+-- | 
+-- Copyright: 2015 Joey Hess <id@joeyh.name>
+-- License: BSD-2-clause
+-- 
+-- The functions exported by this module are intended to be drop-in
+-- replacements for those from System.Process, when converting a whole
+-- program to use System.Console.Concurrent.
+
+module System.Process.Concurrent where
+
+import System.Console.Concurrent
+import System.Console.Concurrent.Internal (ConcurrentProcessHandle(..))
+import System.Process hiding (createProcess, waitForProcess)
+import System.IO
+import System.Exit
+
+-- | Calls `createProcessConcurrent`
+--
+-- You should use the waitForProcess in this module on the resulting
+-- ProcessHandle. Using System.Process.waitForProcess instead can have
+-- mildly unexpected results.
+createProcess :: CreateProcess -> IO (Maybe Handle, Maybe Handle, Maybe Handle, ProcessHandle)
+createProcess p = do
+	(i, o, e, ConcurrentProcessHandle h) <- createProcessConcurrent p
+	return (i, o, e, h)
+
+-- | Calls `waitForProcessConcurrent`
+--
+-- You should only use this on a ProcessHandle obtained by calling
+-- createProcess from this module. Using this with a ProcessHandle
+-- obtained from System.Process.createProcess etc will have extremely
+-- unexpected results; it can wait a very long time before returning.
+waitForProcess :: ProcessHandle -> IO ExitCode
+waitForProcess = waitForProcessConcurrent . ConcurrentProcessHandle