io-sim: EventUnblock

When an stm transaction is committed, trace threads which are unblocked by
it.  This is useful for debugging 'IOSim' or 'IOSimpPOR' itself.

Author: coot

io-sim/src/Control/Monad/IOSim/Internal.hs

@@ -432,6 +432,7 @@ schedule thread@Thread{
                  $ traceMany
                      [ (time, tid, tlbl, EventLog tr)
                      | tr <- tvarTraces ]
+                 $ SimTrace time tid tlbl (EventUnblocked unblocked)
                  $ SimTrace time tid tlbl (EventDeschedule Yield)
                  $ trace
 

io-sim/src/Control/Monad/IOSim/Types.hs

@@ -782,6 +782,7 @@ data SimEventType
   | EventAwaitControl  StepId ScheduleControl
   | EventPerformAction StepId
   | EventReschedule           ScheduleControl
+  | EventUnblocked     [ThreadId]
   deriving Show
 
 type TraceEvent = SimEventType

io-sim/src/Control/Monad/IOSimPOR/Internal.hs

@@ -564,6 +564,7 @@ schedule thread@Thread{
               [ (time, tid, (-1), tlbl, EventLog tr)
               | tr <- tvarTraces
               ] $
+            SimPORTrace time tid tstep tlbl (EventUnblocked unblocked) $
             SimPORTrace time tid tstep tlbl (EventDeschedule Yield) $
               trace