2 files changed, 78 insertions, 2 deletions
diff --git a/lib/pure/actors.nim b/lib/pure/actors.nim
index c07adfd93..d51b973b7 100644
--- a/lib/pure/actors.nim
+++ b/lib/pure/actors.nim
@@ -119,15 +119,25 @@ proc createActorPool*[TIn, TOut](a: var TActorPool[TIn, TOut], poolSize = 4) =
 
 proc sync*[TIn, TOut](a: var TActorPool[TIn, TOut], polling=50) =
   ## waits for every actor of `a` to finish with its work. Currently this is
-  ## implemented as polling every `polling` ms. This will change in a later
+  ## implemented as polling every `polling` ms and has a slight chance 
+  ## of failing since we check for every actor to be in `ready` state and not
+  ## for messages still in ether. This will change in a later
   ## version, however.
+  var allReadyCount = 0
   while true:
     var wait = false
     for i in 0..high(a.actors):
       if not a.actors[i].i.ready: 
         wait = true
+        allReadyCount = 0
         break
-    if not wait: break
+    if not wait:
+      # it's possible that some actor sent a message to some other actor but
+      # both appeared to be non-working as the message takes some time to
+      # arrive. We assume that this won't take longer than `polling` and
+      # simply attempt a second time and declare victory then. ;-)
+      inc allReadyCount
+      if allReadyCount > 1: break
     sleep(polling)
 
 proc terminate*[TIn, TOut](a: var TActorPool[TIn, TOut]) =
diff --git a/tests/compile/talias.nim b/tests/compile/talias.nim
new file mode 100644
index 000000000..1a93e5249
--- /dev/null
+++ b/tests/compile/talias.nim
@@ -0,0 +1,66 @@
+# Test the alias analysis
+
+type
+  TAnalysisResult* = enum
+    arNo, arMaybe, arYes
+
+proc isPartOf*[S, T](a: S, b: T): TAnalysisResult {.
+  magic: "IsPartOf", noSideEffect.}
+  ## not yet exported properly. 
+
+template compileTimeAssert(cond: expr) =
+  when not cond:
+    {.compile: "is false: " & astToStr(cond).}
+
+template `<|` (a, b: expr) =
+  compileTimeAssert isPartOf(a, b) == arYes
+
+template `!<|` (a, b: expr) =
+  compileTimeAssert isPartOf(a, b) == arNo
+
+template `?<|` (a, b: expr) =
+  compileTimeAssert isPartOf(a, b) == arMaybe
+
+type
+  TA = object
+  TC = object of TA
+    arr: array[0..3, int]
+    le, ri: ref TC
+    f: string
+    c: char
+    se: seq[TA]
+
+proc p(param1, param2: TC): TC =
+  var
+    local: TC
+    plocal: ptr TC
+    plocal2: ptr TA
+    
+  local.arr <| local
+  local.arr[0] <| local
+  local.arr[2] !<| local.arr[1]
+  
+  plocal2[] ?<| local
+
+  param1 ?<| param2
+  
+  local.arr[0] !<| param1
+  local.arr !<| param1
+  local.le[] ?<| param1
+  
+  param1 !<| local.arr[0]
+  param1 !<| local.arr
+  param1 ?<| local.le[]
+  
+  result !<| local
+  result <| result
+
+var
+  a, b: int
+  x: TC
+  
+a <| a
+a !<| b
+
+discard p(x, x)
+