Elaborate on winner {} and multiple *channels* (only)

Raku · Apr 7, 2014 · 8b9265f · 8b9265f
1 parent f6d09ab
commit 8b9265f
Showing 1 changed file with 3 additions and 0 deletions.
diff --git a/S17-concurrency/winner.t b/S17-concurrency/winner.t
@@ -37,6 +37,9 @@ plan 3;
     loop {
         winner * {
             more @c { @a.push: $:v }
+# When using multiple channels, and they don't close simultaneously, there is a chance
+# that the "done" section of a closed channel is executed more than once.  Hence the
+# the use of a hash, rather than just a simple counter.
             done @c { %done{$:k}++; last if +%done == 2 }
         }
     }