8214427: probable bug in logic of ConcurrentHashMap.addCount()
Reviewed-by: martin, dholmes
--- a/src/java.base/share/classes/java/util/concurrent/ConcurrentHashMap.java Tue Dec 11 19:55:27 2018 -0800
+++ b/src/java.base/share/classes/java/util/concurrent/ConcurrentHashMap.java Tue Dec 11 19:55:27 2018 -0800
@@ -2334,17 +2334,15 @@
Node<K,V>[] tab, nt; int n, sc;
while (s >= (long)(sc = sizeCtl) && (tab = table) != null &&
(n = tab.length) < MAXIMUM_CAPACITY) {
- int rs = resizeStamp(n);
+ int rs = resizeStamp(n) << RESIZE_STAMP_SHIFT;
if (sc < 0) {
- if ((sc >>> RESIZE_STAMP_SHIFT) != rs || sc == rs + 1 ||
- sc == rs + MAX_RESIZERS || (nt = nextTable) == null ||
- transferIndex <= 0)
+ if (sc == rs + MAX_RESIZERS || sc == rs + 1 ||
+ (nt = nextTable) == null || transferIndex <= 0)
break;
if (U.compareAndSetInt(this, SIZECTL, sc, sc + 1))
transfer(tab, nt);
}
- else if (U.compareAndSetInt(this, SIZECTL, sc,
- (rs << RESIZE_STAMP_SHIFT) + 2))
+ else if (U.compareAndSetInt(this, SIZECTL, sc, rs + 2))
transfer(tab, null);
s = sumCount();
}
@@ -2358,11 +2356,11 @@
Node<K,V>[] nextTab; int sc;
if (tab != null && (f instanceof ForwardingNode) &&
(nextTab = ((ForwardingNode<K,V>)f).nextTable) != null) {
- int rs = resizeStamp(tab.length);
+ int rs = resizeStamp(tab.length) << RESIZE_STAMP_SHIFT;
while (nextTab == nextTable && table == tab &&
(sc = sizeCtl) < 0) {
- if ((sc >>> RESIZE_STAMP_SHIFT) != rs || sc == rs + 1 ||
- sc == rs + MAX_RESIZERS || transferIndex <= 0)
+ if (sc == rs + MAX_RESIZERS || sc == rs + 1 ||
+ transferIndex <= 0)
break;
if (U.compareAndSetInt(this, SIZECTL, sc, sc + 1)) {
transfer(tab, nextTab);