Add support for the IO manager thread on Windows

Fixes #637.
The implications of this change are:
  - threadDelay on Windows no longer creates a new OS thread each time,
    instead it communicates with the IO manager thread in the same way as
    on Unix.
  - deadlock detection now works the same way on Windows as on Unix; that
    is the timer interrupt wakes up the IO manager thread, which causes
    the scheduler to check for deadlock.
  - Console events now get sent to the IO manager thread, in the same way as
    signals do on Unix.  This means that console events should behave more
    reliably with -threaded on Windows.

All this applies only with -threaded.  Without -threaded, the old
ConsoleEvent code is still used.

After some testing, this could be pushed to the 6.6 branch.

1 files changed, 10 insertions, 1 deletions

diff --git a/includes/RtsExternal.h b/includes/RtsExternal.h
index 8e1a26acab..bf581b7a2b 100644
--- a/includes/RtsExternal.h
+++ b/includes/RtsExternal.h
@@ -73,10 +73,19 @@ extern void rts_ConsoleHandlerDone  ( int ev );
 extern int stg_sig_install (int, int, StgStablePtr *, void *);
 #endif
 
-#if !defined(mingw32_HOST_OS)
+#if defined(mingw32_HOST_OS)
+extern StgInt console_handler;
+#else
 extern StgInt *signal_handlers;
 #endif
+
+#if defined(mingw32_HOST_OS)
+void *getIOManagerEvent (void);
+StgWord32 readIOManagerEvent (void);
+void sendIOManagerEvent (StgWord32 event);
+#else
 extern void setIOManagerPipe (int fd);
+#endif
 
 extern void* allocateExec(unsigned int len);