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, 12 insertions, 3 deletions

diff --git a/rts/win32/ConsoleHandler.h b/rts/win32/ConsoleHandler.h
index b09adf71cb..33fa065733 100644
--- a/rts/win32/ConsoleHandler.h
+++ b/rts/win32/ConsoleHandler.h
@@ -9,9 +9,16 @@
  * Console control handlers lets an application handle Ctrl+C, Ctrl+Break etc.
  * in Haskell under Win32. Akin to the Unix signal SIGINT.
  *
- * The API offered by ConsoleHandler.h is identical to that of the signal handling
- * code (which isn't supported under win32.) Unsurprisingly, the underlying impl 
- * is derived from the signal handling code also.
+ * The API offered by ConsoleHandler.h is identical to that of the
+ * signal handling code (which isn't supported under win32.)
+ * Unsurprisingly, the underlying impl is derived from the signal
+ * handling code also.
+ */
+
+#if !defined(THREADED_RTS)
+/* 
+ * under THREADED_RTS, console events are passed to the IO manager
+ * thread, which starts up the handler.  See ThrIOManager.c.
  */
 
 /*
@@ -60,4 +67,6 @@ extern void handleSignalsInThisThread(void);
  */
 extern int rts_waitConsoleHandlerCompletion(void);
 
+#endif /* THREADED_RTS */
+
 #endif /* __CONSOLEHANDLER_H__ */