- Fixed a bug when updating the value of a STM var.

- Refactored the tests for lux/concurrency/stm.

2 files changed, 40 insertions, 61 deletions

diff --git a/stdlib/source/lux/concurrency/stm.lux b/stdlib/source/lux/concurrency/stm.lux
index c3e5fad3a..914920773 100644
--- a/stdlib/source/lux/concurrency/stm.lux
+++ b/stdlib/source/lux/concurrency/stm.lux
@@ -91,7 +91,7 @@
             (:! (Var ($ +0)) _var))
       (#;Cons [(:! (Var ($ +0)) _var)
                (:! ($ +0) _original)
-               (:! ($ +0) _current)]
+               (:! ($ +0) value)]
               tx')
       (#;Cons [_var _original _current]
               (update-tx-value var value tx')))
diff --git a/stdlib/test/test/lux/concurrency/stm.lux b/stdlib/test/test/lux/concurrency/stm.lux
index 71c82dfab..2f0b7d99c 100644
--- a/stdlib/test/test/lux/concurrency/stm.lux
+++ b/stdlib/test/test/lux/concurrency/stm.lux
@@ -8,7 +8,7 @@
   (lux (codata [io])
        (control monad)
        (data [number]
-             (struct [list "" Functor<List>])
+             (struct [list "" Functor<List> "List/" Fold<List>])
              text/format)
        (concurrency ["&" stm]
                     [promise])
@@ -17,67 +17,46 @@
        pipe)
   lux/test)
 
-(def: vars Int 5)
-(def: processes/vars Int 5)
 (def: iterations/processes Int 100)
 
 (test: "STM"
-  (let [_var (&;var 0)
-        changes (io;run (&;follow "test" _var))
-        tests (: (List Test)
-                 (map (lambda [_]
-                        (let [_concurrency-var (&;var 0)]
-                          (do promise;Monad<Promise>
-                            [_ (seqM @
-                                     (map (lambda [_]
-                                            (mapM @ (lambda [_] (&;commit (&;update i.inc _concurrency-var)))
-                                                  (list;i.range 1 iterations/processes)))
-                                          (list;i.range 1 processes/vars)))
-                             _ (&;commit (&;read _concurrency-var))]
-                            (assert "" true))))
-                      (list;i.range 1 vars)))]
+  (do promise;Monad<Promise>
+    [#let [_var (&;var 0)
+           changes (io;run (&;follow "test" _var))]
+     output1 (&;commit (&;read _var))
+     output2 (&;commit (do &;Monad<STM>
+                         [_ (&;write 5 _var)]
+                         (&;read _var)))
+     output3 (&;commit (do &;Monad<STM>
+                         [temp (&;read _var)
+                          _ (&;update (i.* 3) _var)]
+                         (&;read _var)))
+     ?c1+changes' changes
+     #let [[c1 changes'] (default [-1 changes] ?c1+changes')]
+     ?c2+changes' changes'
+     #let [[c2 changes'] (default [-1 changes] ?c2+changes')]]
     ($_ seq
-        (do promise;Monad<Promise>
-          [output (&;commit (do &;Monad<STM>
-                              [value (&;read _var)]
-                              (wrap value)))]
-          (assert "" (i.= 0 output)))
-
-        (do promise;Monad<Promise>
-          [output (&;commit (do &;Monad<STM>
-                              [_ (&;write 5 _var)
-                               value (&;read _var)]
-                              (wrap value)))]
-          (assert "" (i.= 5 output)))
-
-        (do promise;Monad<Promise>
-          [output (&;commit (do &;Monad<STM>
-                              [value (&;read _var)]
-                              (wrap value)))]
-          (assert "" (i.= 5 output)))
-
-        (do promise;Monad<Promise>
-          [output (&;commit (do &;Monad<STM>
-                              [_ (&;update (i.* 3) _var)
-                               value (&;read _var)]
-                              (wrap value)))]
-          (assert "" (i.= 15 output)))
-
-        (do promise;Monad<Promise>
-          [output (&;commit (do &;Monad<STM>
-                              [value (&;read _var)]
-                              (wrap value)))]
-          (assert "" (i.= 15 output)))
-
-        (do promise;Monad<Promise>
-          [?c1+changes' changes
-           #let [[c1 changes'] (default [-1 changes] ?c1+changes')]
-           ?c2+changes' changes'
-           #let [[c2 changes'] (default [-1 changes] ?c2+changes')]]
-          (assert ""
-                  (and (i.= 5 c1)
-                       (i.= 15 c2))))
-        ## Temporarily commented-out due to type-checking bug in
-        ## compiler...
-        ## (match+ _ (seqM Monad<Test> tests))
+        (assert "Can read STM vars."
+                (i.= 0 output1))
+        
+        (assert "Can write STM vars."
+                (i.= 5 output2))
+        
+        (assert "Can update STM vars."
+                (i.= 15 output3))
+        
+        (assert "Can follow all the changes to STM vars."
+                (and (i.= 5 c1) (i.= 15 c2)))
+
+        (let [_concurrency-var (&;var 0)]
+          (do promise;Monad<Promise>
+            [_ (seqM @
+                     (map (lambda [_]
+                            (mapM @ (lambda [_] (&;commit (&;update i.inc _concurrency-var)))
+                                  (list;i.range 1 iterations/processes)))
+                          (list;i.range 1 (nat-to-int promise;concurrency-level))))
+             last-val (&;commit (&;read _concurrency-var))]
+            (assert "Can modify STM vars concurrently from multiple threads."
+                    (i.= (i.* iterations/processes (nat-to-int promise;concurrency-level))
+                         last-val))))
         )))