Managing locks and transactions

摘要

An indication of refusal of a lock request is received with a first operation identifier for a resource that is already locked with a lock associated with a second operation identifier from an agent that controls the resource, wherein the agent returns a value that determines how long the lock request is to stay on the queue. The lock request is placed in a queue with a lock queue timeout period based on the value from the agent. The lock request is reissued if the lock associated with the second operation identifier has been released and the lock request reaches a position of the queue from which the lock request is processed within the lock queue timeout period. The lock request is re-queued if the reissued lock request is not granted based on how many times the lock request has been previously placed in the queue.

主权项

1. A system for deadlock management, comprising:
a processor; a computer readable storage medium accessible to the processor, wherein the computer readable storage medium stores code, and wherein the code causes the processor to perform:
receiving, from an agent that controls a resource, an indication of refusal of a lock request with a first operation identifier for the resource that is already locked with a lock associated with a second operation identifier, wherein the agent that controls the resource returns a value that determines how long the lock request is to stay on a queue, wherein the first operation identifier and the second operation identifier are each a compound key with a first part indicating whether that operation identifier was generated by a transaction manager, with a second part being one of a lock management group name and a transaction manager name, and with a third part being a unique number in a context of one of the lock management group and the transaction manager;placing the lock request in the queue with a lock queue timeout period based on the value from the agent; andin response to determining that the lock associated with the second operation identifier has been released and the lock request reaches a position of the queue from which the lock request is processed within the lock queue timeout period,
reissuing the lock request; andin response to determining that the reissued lock request is not granted, based on how many times the lock request has been previously placed in the queue, denying re-queuing of the lock request.