J.L.
My daughter used to cry non stop and it was the only thing that made me loose control. At 2 they understand everything but can't always communicate with words. Is he able to tell you what he wants in other ways? If so I would tell him it's ok to cry (that may be how he vents) but he will need to do it in his room. Then put him in his room. Let him know that as soon as he calms down he can come out. After a week of this my daughter usually stopped crying the minute I told her if she needed to cry to please go to her room. Good luck. If it doesn't work try something else. Not every child reacts the same way, you may need to try various things until you find what works.