Fix thread lock detection bug

The effect of the bug was that a deadlock would be reported as long as the
current thread T0 that tries to acquire the ZK path P0 is in the following
situation:
  1. Thread T0 tries to acquire ZK path P0, held by T1.
  2. Thread T1 tries to acquire ZK path P1, held by T2.

Instead, T2 would need to equal T0.  Or,
  3. Thread T2 tries to acquire ZK path P2, held by T3 = one of (T0, T1).
etc.

1 files changed, 2 insertions, 2 deletions

diff --git a/zkfacade/src/main/java/com/yahoo/vespa/curator/stats/ThreadLockStats.java b/zkfacade/src/main/java/com/yahoo/vespa/curator/stats/ThreadLockStats.java
index 70442e4833d..73ce731390d 100644
--- a/zkfacade/src/main/java/com/yahoo/vespa/curator/stats/ThreadLockStats.java
+++ b/zkfacade/src/main/java/com/yahoo/vespa/curator/stats/ThreadLockStats.java
@@ -189,7 +189,7 @@ public class ThreadLockStats {
             if (threadAcquiringLockPath == threadHoldingLockPath) {
                 // reentry
                 return;
-            } else if (threadsAcquiring.contains(threadAcquiringLockPath)) {
+            } else if (threadsAcquiring.contains(threadHoldingLockPath)) {
                 // deadlock
                 getGlobalLockMetrics(pathToAcquire).incrementDeadlockCount();
                 logger.warning(errorMessage.toString());
@@ -201,7 +201,7 @@ public class ThreadLockStats {
                 return;
             }
 
-            threadsAcquiring.add(threadHoldingLockPath);
+            threadsAcquiring.add(threadAcquiringLockPath);
             lockPath = nextLockPath.get();
             threadAcquiringLockPath = threadHoldingLockPath;
         }