From 16588ffe1e54e23d4475fe5a871000e8266d54a9 Mon Sep 17 00:00:00 2001
From: Jeremy Kong <jeremykong@hotmail.com>
Date: Tue, 14 Dec 2021 21:22:57 +0000
Subject: [PATCH] [Exclusion Hunter] Part 21: ModifyCollectionInEnhancedForLoop
 (#5795)

* shady-removal

* fix

Co-authored-by: Glenn Sheasby <gsheasby@palantir.com>
---
 .../atlasdb/keyvalue/cassandra/Blacklist.java         | 11 ++++++++---
 build.gradle                                          |  1 -
 2 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/atlasdb-cassandra/src/main/java/com/palantir/atlasdb/keyvalue/cassandra/Blacklist.java b/atlasdb-cassandra/src/main/java/com/palantir/atlasdb/keyvalue/cassandra/Blacklist.java
index 0f61be3cfc7..5e2474cbe62 100644
--- a/atlasdb-cassandra/src/main/java/com/palantir/atlasdb/keyvalue/cassandra/Blacklist.java
+++ b/atlasdb-cassandra/src/main/java/com/palantir/atlasdb/keyvalue/cassandra/Blacklist.java
@@ -26,8 +26,10 @@
 import java.net.InetSocketAddress;
 import java.time.Clock;
 import java.util.Collection;
+import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
+import java.util.Map.Entry;
 import java.util.Set;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.TimeUnit;
@@ -54,17 +56,20 @@ public Blacklist(CassandraKeyValueServiceConfig config) {
 
     void checkAndUpdate(Map<InetSocketAddress, CassandraClientPoolingContainer> pools) {
         // Check blacklist and re-integrate or continue to wait as necessary
-        for (Map.Entry<InetSocketAddress, Long> blacklistedEntry : blacklist.entrySet()) {
+        Iterator<Entry<InetSocketAddress, Long>> blacklistIterator =
+                blacklist.entrySet().iterator();
+        while (blacklistIterator.hasNext()) {
+            Map.Entry<InetSocketAddress, Long> blacklistedEntry = blacklistIterator.next();
             if (coolOffPeriodExpired(blacklistedEntry)) {
                 InetSocketAddress host = blacklistedEntry.getKey();
                 if (!pools.containsKey(host)) {
                     // Probably the pool changed underneath us
-                    blacklist.remove(host);
+                    blacklistIterator.remove();
                     log.info(
                             "Removing host {} from the blacklist as it wasn't found in the pool.",
                             SafeArg.of("host", CassandraLogHelper.host(host)));
                 } else if (isHostHealthy(pools.get(host))) {
-                    blacklist.remove(host);
+                    blacklistIterator.remove();
                     log.info(
                             "Added host {} back into the pool after a waiting period and successful health check.",
                             SafeArg.of("host", CassandraLogHelper.host(host)));
diff --git a/build.gradle b/build.gradle
index a3c894e470f..a21db633f3d 100644
--- a/build.gradle
+++ b/build.gradle
@@ -102,7 +102,6 @@ allprojects {
                 'FutureReturnValueIgnored',
                 'InlineFormatString',
                 'MixedMutabilityReturnType',
-                'ModifyCollectionInEnhancedForLoop',
                 'NarrowingCompoundAssignment',
                 'PreconditionsConstantMessage',
                 'PreconditionsInvalidPlaceholder',