[minor] add comment to the "Fix locking in script definition provider" commit

2019-01-07 11:48:05 +01:00
parent e5febddaf7
commit 01f2a21192
1 changed files with 3 additions and 1 deletions
@@ -128,7 +128,9 @@ private class CachingSequence<T>(from: Sequence<T>) : Sequence<T> {
        private var cacheCursor = 0

        override fun hasNext(): Boolean =
-            lock.read { cacheCursor < cache.size } || lock.write { cacheCursor < cache.size || sequenceIterator.hasNext() }
+            lock.read { cacheCursor < cache.size }
+                    // iterator's hasNext can mutate the iterator's state, therefore write lock is needed
+                    || lock.write { cacheCursor < cache.size || sequenceIterator.hasNext() }

        override fun next(): T {
            lock.read {