JPA同時性の問題

背景

コード#コード#

ろんり

DTO

		@Getter
    public static class CreateUpdate{

        private String status;
    }

Service

		public TaskEntity findTask(Long id) {

        Optional<TaskEntity> findTask = taskRepository.findById(id);
        return findTask.orElse(null);
    }	

		@Transactional
    public TaskEntity updateTask(Long id, TaskDto.CreateUpdate createUpdate, int sleepTime){

        TaskEntity taskEntity = findTask(id);
        threadSleep(sleepTime);
        taskEntity.updateStatus(createUpdate.getStatus());
        taskEntity.updateTime(createUpdate.getStatus());
        return taskEntity;
    }

		public void threadSleep(int sleepTime){
        try {
            Thread.sleep(sleepTime);
        } catch (Exception e){
            log.info(e.getMessage());
        }
    }

Repository

public interface TaskRepository extends JpaRepository<TaskEntity, Long> 

Domain

@Getter
@NoArgsConstructor(access = AccessLevel.PROTECTED)
@Entity
public class TaskEntity {

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Long id;

    private String status;

    @JsonFormat(shape = JsonFormat.Shape.STRING, pattern = "yyyy-MM-dd HH:mm:ss", timezone = "Asia/Seoul")
    private LocalDateTime startTime;

    @JsonFormat(shape = JsonFormat.Shape.STRING, pattern = "yyyy-MM-dd HH:mm:ss", timezone = "Asia/Seoul")
    private LocalDateTime endTime;

    private Long duration;

    @Builder
    public TaskEntity(String status){
        this.status = status;
    }

    public void updateStatus(String status){
            this.status = status;
    }

    public void updateTime(String status) {

        if (this.startTime == null){
            this.startTime = LocalDateTime.now().withNano(0);
        }

        if (status.equals("Succeeded")){
            this.endTime = LocalDateTime.now().withNano(0);
            this.duration = Duration.between(this.startTime,this.endTime).getSeconds();
        }
    }
}

Test

@Test
    @DisplayName("Lock 적용하기 전")
    void test1() throws Exception {

        // given
        TaskEntity newTask = TaskEntity.builder()
                .status("Created")
                .build();
        taskService.createTask(newTask);

        // when
        final ExecutorService executor = Executors.newFixedThreadPool(3);

        executor.execute(()->taskService.updateTask(newTask.getId(), TaskDto.CreateUpdate.builder().status("Started").build(), 2000));
        Thread.sleep(500);

        executor.execute(()->taskService.updateTask(newTask.getId(), TaskDto.CreateUpdate.builder().status("Running").build(), 1000));
        Thread.sleep(500);

        executor.execute(()->taskService.updateTask(newTask.getId(), TaskDto.CreateUpdate.builder().status("Succeeded").build(), 100));

        // Thread 작업이 다 끝날때까지 최대 10초 대기
        executor.shutdown();
        executor.awaitTermination(10, TimeUnit.SECONDS);

        //then
        TaskEntity findTask = taskService.findTask(newTask.getId());

        assertAll(
                ()-> assertEquals("Started", findTask.getStatus()),
                ()-> assertNotEquals(null,findTask.getStartTime()),
                ()-> assertEquals(null,findTask.getEndTime()),
                ()-> assertEquals(null,findTask.getDuration())
        );

    }

数式化

n/a.結論