In reply to warnerrs:
I have a test where I do the following
I have attached a frontdoor sequence to this register and hence there is one sequence instance for this register. Everytime I do an operation on this register, the same sequence instance will be executed. In this case, since there is a chance of putting more than one key to the semaphore, two threads get the key and since the same sequence instance is used, I am getting UVM FATAL for the second one saying sequence is already started.
This is the actual error I am getting
UVM_FATAL @ 10000030: uvm_test_top.m_env.m_agent.m_seqr@@seq [SEQ_NOT_DONE] Sequence uvm_test_top.m_env.m_agent.m_seqr.seq already started