Flow-ID dependency checking logic

摘要

Systems and methods for maintaining an order of transactions in the coherence point. The coherence point stores attributes associated with received transactions in an input request queue (IRQ). When a new transaction is received with a device ordered attribute, the IRQ is searched for other entries with the same flow ID as the new transaction. If one or more matches are found, the new transaction entry points to the entry for the most recently received transaction with the same flow ID. The new transaction is prevented from exiting the coherence point until the transaction it points to has been sent to its destination.

主权项

1. An apparatus comprising:
one or more queues, wherein each queue stores a plurality of outstanding transactions; and a dependency logic unit coupled to the one or more queues, wherein the dependency logic unit is configured to:
determine whether a received first transaction has a device ordered attribute, wherein a device ordered attribute is an attribute applied to a given transaction by a source of the given transaction that indicates the given transaction is to be processed in order with respect to other transactions issued by the source that also have a device ordered attribute and have a same flow identifier (ID); andin response to determining the first transaction has a device ordered attribute:
search the one or more queues for transactions with a flow ID that matches a flow ID of the first transaction; andmark the first transaction as dependent on a second transaction responsive to determining the second transaction is a most recently received transaction in the one or more queues with a flow ID matching the flow ID of the first transaction.