From 00a4cdf7db3ac722db2346416a1b3b891dbc9a0a Mon Sep 17 00:00:00 2001
From: Simon Marlow <marlowsd@gmail.com>
Date: Fri, 10 Dec 2010 09:39:51 +0000
Subject: [PATCH] Only reset the event log if logging is turned on (addendum
 to #4512)

---
 rts/Schedule.c |    8 ++++----
 rts/Trace.c    |    8 ++++++++
 rts/Trace.h    |    1 +
 3 files changed, 13 insertions(+), 4 deletions(-)

diff --git a/rts/Schedule.c b/rts/Schedule.c
index bf39c0a..0b1dec4 100644
--- a/rts/Schedule.c
+++ b/rts/Schedule.c
@@ -1566,11 +1566,11 @@ forkProcess(HsStablePtr *entry
         initMutex(&cap->running_task->lock);
 #endif
 
-#if defined(TRACING)
-        abortEventLogging(); // abort eventlog inherited from parent
-        initEventLogging(); // child starts its own eventlog
+#ifdef TRACING
+        resetTracing();
 #endif
-	// Now, all OS threads except the thread that forked are
+
+        // Now, all OS threads except the thread that forked are
 	// stopped.  We need to stop all Haskell threads, including
 	// those involved in foreign calls.  Also we need to delete
 	// all Tasks, because they correspond to OS threads that are
diff --git a/rts/Trace.c b/rts/Trace.c
index be3fff7..53fc25a 100644
--- a/rts/Trace.c
+++ b/rts/Trace.c
@@ -106,6 +106,14 @@ void freeTracing (void)
     }
 }
 
+void resetTracing (void)
+{
+    if (eventlog_enabled) {
+        abortEventLogging(); // abort eventlog inherited from parent
+        initEventLogging(); // child starts its own eventlog
+    }
+}
+
 /* ---------------------------------------------------------------------------
    Emitting trace messages/events
  --------------------------------------------------------------------------- */
diff --git a/rts/Trace.h b/rts/Trace.h
index 4f3ebce..97d9514 100644
--- a/rts/Trace.h
+++ b/rts/Trace.h
@@ -27,6 +27,7 @@
 void initTracing (void);
 void endTracing  (void);
 void freeTracing (void);
+void resetTracing (void);
 
 #endif /* TRACING */
 
-- 
1.7.10.4