Operate on immutable copy of logs in AdvancedShardAwarenessIT

Not doing so can lead to concurrent modification exception, since the
collection may change during the iteration. Those changes itself are not
relevant at that point in time.

Author: Bouncheck

integration-tests/src/test/java/com/datastax/oss/driver/core/pool/AdvancedShardAwarenessIT.java

@@ -17,6 +17,7 @@
 import com.datastax.oss.driver.internal.core.pool.ChannelPool;
 import com.datastax.oss.driver.internal.core.util.concurrent.CompletableFutures;
 import com.datastax.oss.driver.internal.core.util.concurrent.Reconnection;
+import com.datastax.oss.driver.shaded.guava.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.ImmutableSet;
 import com.google.common.util.concurrent.Uninterruptibles;
@@ -128,9 +129,10 @@ public void should_initialize_all_channels(boolean reuseAddress) {
             .withConfigLoader(loader)
             .build()) {
       Uninterruptibles.sleepUninterruptibly(1, TimeUnit.SECONDS);
+      List<ILoggingEvent> logsCopy = ImmutableList.copyOf(appender.list);
       expectedOccurences.forEach(
-          (pattern, times) -> assertMatchesExactly(pattern, times, appender.list));
-      forbiddenOccurences.forEach(pattern -> assertNoLogMatches(pattern, appender.list));
+          (pattern, times) -> assertMatchesExactly(pattern, times, logsCopy));
+      forbiddenOccurences.forEach(pattern -> assertNoLogMatches(pattern, logsCopy));
     }
   }
 
@@ -150,7 +152,8 @@ public void should_see_mismatched_shard() {
             .withConfigLoader(loader)
             .build()) {
       Uninterruptibles.sleepUninterruptibly(1, TimeUnit.SECONDS);
-      assertMatchesAtLeast(shardMismatchPattern, 5, appender.list);
+      List<ILoggingEvent> logsCopy = ImmutableList.copyOf(appender.list);
+      assertMatchesAtLeast(shardMismatchPattern, 5, logsCopy);
     }
   }
 
@@ -178,8 +181,9 @@ public void should_struggle_to_fill_pools() {
         CqlSession session3 = CompletableFutures.getUninterruptibly(stage3);
         CqlSession session4 = CompletableFutures.getUninterruptibly(stage4); ) {
       Uninterruptibles.sleepUninterruptibly(20, TimeUnit.SECONDS);
-      assertNoLogMatches(shardMismatchPattern, appender.list);
-      assertMatchesAtLeast(generalReconnectionPattern, 8, appender.list);
+      List<ILoggingEvent> logsCopy = ImmutableList.copyOf(appender.list);
+      assertNoLogMatches(shardMismatchPattern, logsCopy);
+      assertMatchesAtLeast(generalReconnectionPattern, 8, logsCopy);
     }
   }
 
@@ -226,11 +230,12 @@ public void should_not_struggle_to_fill_pools() {
                           + Pattern.quote(node2)
                           + ":19042.*Reconnection attempt complete, 66/66 channels.*"),
                   1 * sessions);
+      List<ILoggingEvent> logsCopy = ImmutableList.copyOf(appender.list);
       expectedOccurences.forEach(
-          (pattern, times) -> assertMatchesAtLeast(pattern, times, appender.list));
-      assertNoLogMatches(shardMismatchPattern, appender.list);
-      assertMatchesAtMost(reconnectionPattern1, tolerance, appender.list);
-      assertMatchesAtMost(reconnectionPattern2, tolerance, appender.list);
+          (pattern, times) -> assertMatchesAtLeast(pattern, times, logsCopy));
+      assertNoLogMatches(shardMismatchPattern, logsCopy);
+      assertMatchesAtMost(reconnectionPattern1, tolerance, logsCopy);
+      assertMatchesAtMost(reconnectionPattern2, tolerance, logsCopy);
     }
   }