BlockingCache may produce OutOfMemoryError

[liuyueve]

MyBatis version

3.5.5

Database vendor and version

Mysql

Test case or example project

====

SqlSession sqlSession = sqlSessionFactory.openSession();
BasicMapper mapper = sqlSession.getMapper(BasicMapper.class);
for (int i = 0; i < 2000000; i++) {
System.out.println(mapper.queryName(i));
}
sqlSession.commit();

====

@CacheNamespace(blocking = true)
public interface BasicMapper {
@select("select value from demo where id = #{id}")
String queryName(@param("id") int id);
}

Steps to reproduce

Running test case. Set jvm options -Xms20m -Xmx20m(this option just make result more easy to appear)
To make a compare.we can set blocking = flase then see whether OutOfMemoryErro happen.

Expected result

no error.

Actual result

Programe has been OutOfMemoryError.

[harawata]

This may be a duplicate of #1261 .