concurrency bug: cached value can be set to null while the other thread has already computed it in the meantime. This leads to multiple unnecessary re-computations.

2026-09-27 10:03:11 +07:00 · 2017-02-16 10:28:14 +03:00
parent 2884a40691
commit 4c471669ee
1 changed files with 6 additions and 3 deletions
@@ -59,9 +59,12 @@ public class CachedValuesManagerImpl extends CachedValuesManager {
    if (dataHolder instanceof UserDataHolderEx) {
      UserDataHolderEx dh = (UserDataHolderEx)dataHolder;
      value = dh.getUserData(key);
-      if (isOutdated(value)) {
-        value = null;
-        dh.putUserData(key, null);
+      while (isOutdated(value)) {
+        if (dh.replace(key, value, null)) {
+          value = null;
+          break;
+        }
+        value = dh.getUserData(key);
      }
      if (value == null) {
        value = createCachedValue(provider, trackValue);