Fix #2992: don't create a named event

Evidently I misread the docs for CreateEvent: if you pass a name to
CreateEvent, then it creates a single shared system-wide Event with
that name.  So all Haskell processes on the machine were sharing the
same Event object.  duh.

1 files changed, 1 insertions, 1 deletions

diff --git a/rts/win32/ThrIOManager.c b/rts/win32/ThrIOManager.c
index e2310ef9f3..c52928c3a2 100644
--- a/rts/win32/ThrIOManager.c
+++ b/rts/win32/ThrIOManager.c
@@ -34,7 +34,7 @@ getIOManagerEvent (void)
         hRes = CreateEvent ( NULL, // no security attrs

                              TRUE, // manual reset

                              FALSE, // initial state,

-                             "IO Manager Event" );

+                             NULL ); // event name: NULL for private events

         if (hRes == NULL) {

             sysErrorBelch("getIOManagerEvent");

             stg_exit(EXIT_FAILURE);