死锁问题

问题

  Dead lock in our App under some condition.  Both database and application lock contributes to issue.

  The issue could be simplified to following model.

  Thread 1:   Acquired DB Lock------------------||---------Try to get Application lock

  Thread 2:   Acquire Application lock------------||-----------Try to get DB locK

 

  The things I want to highlight is that when we implement functions in multi-thread ENV.

  we should not only pay attention to the lock explicitly invoked in our code but also the External Lock, eg: DML lock in this case.

解决

  将get DB lock代码放在Application lock范围之中