fix: 동시성 테스트 스레드 획득 에러 수정

- 스레드 풀의 크기를 16으로 감소

Author: 7zrv

src/test/java/com/somemore/domains/volunteer/service/UpdateVolunteerLockServiceTest.java

@@ -12,9 +12,11 @@
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
+import java.util.concurrent.TimeUnit;
 
 import static com.somemore.global.auth.oauth.domain.OAuthProvider.NAVER;
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Fail.fail;
 
 class UpdateVolunteerLockServiceTest extends IntegrationTestSupport {
 
@@ -59,7 +61,8 @@ void updateVolunteerStatsWithConcurrency() throws InterruptedException {
         int hours = 4;
         int threadCnt = 100;
 
-        ExecutorService executorService = Executors.newFixedThreadPool(32);
+        // 스레드 풀 크기를 줄여서 경합 감소 32 -> 16
+        ExecutorService executorService = Executors.newFixedThreadPool(16);
         CountDownLatch latch = new CountDownLatch(threadCnt);
 
         // when
@@ -74,6 +77,11 @@ void updateVolunteerStatsWithConcurrency() throws InterruptedException {
         }
         latch.await();
 
+        // 대기 시간을 충분히 늘림
+        if (!latch.await(10, TimeUnit.SECONDS)) {
+            fail("작업 완료 대기");
+        }
+
         // then
         Volunteer find = volunteerRepository.findById(id).orElseThrow();
         assertThat(find.getTotalVolunteerCount()).isEqualTo(threadCnt);