Use message-passing to implement throwTo in the RTS

This replaces some complicated locking schemes with message-passing
in the implementation of throwTo. The benefits are

 - previously it was impossible to guarantee that a throwTo from
   a thread running on one CPU to a thread running on another CPU
   would be noticed, and we had to rely on the GC to pick up these
   forgotten exceptions. This no longer happens.

 - the locking regime is simpler (though the code is about the same
   size)

 - threads can be unblocked from a blocked_exceptions queue without
   having to traverse the whole queue now.  It's a rare case, but
   replaces an O(n) operation with an O(1).

 - generally we move in the direction of sharing less between
   Capabilities (aka HECs), which will become important with other
   changes we have planned.

Also in this patch I replaced several STM-specific closure types with
a generic MUT_PRIM closure type, which allowed a lot of code in the GC
and other places to go away, hence the line-count reduction.  The
message-passing changes resulted in about a net zero line-count
difference.

1 files changed, 6 insertions, 0 deletions

diff --git a/rts/RtsMessages.c b/rts/RtsMessages.c
index e2a30a613f..6e75abc8a5 100644
--- a/rts/RtsMessages.c
+++ b/rts/RtsMessages.c
@@ -9,6 +9,8 @@
 #include "PosixSource.h"
 #include "Rts.h"
 
+#include "eventlog/EventLog.h"
+
 #include <stdio.h>
 #include <string.h>
 #include <errno.h>
@@ -161,6 +163,10 @@ rtsFatalInternalErrorFn(const char *s, va_list ap)
      fflush(stderr);
   }
 
+#ifdef TRACING
+  if (RtsFlags.TraceFlags.tracing == TRACE_EVENTLOG) endEventLogging();
+#endif
+
   abort();
   // stg_exit(EXIT_INTERNAL_ERROR);
 }