Hardware transactional nesting method for supporting rollback of conditional part

Abstract

The invention discloses a hardware transactional nesting method for supporting rollback of a conditional part. According to the method, a global data set is maintained by each layer of nesting transaction, and the access condition of each layer of transaction to the data is recorded in the set. The method comprises the following steps: if the data set accessed by a conflict layer transaction has no superposition with the data sets of other transactions before the conflict layer transaction, rolling back to the initial position of the conflict layer transaction; and if the conflict layer transaction has the same conflict variable with the data set of the transaction before the conflict layer transaction, rolling back to the initial position of the first appearing transaction with the same conflict variable. The method of the invention reduces the great cost required for rolling back the transaction to the outmost layer in a closed nesting mode, and effectively improves the transactional nesting performance without greatly increasing the complexity of the hardware.

Description

technical field [0001] The invention relates to a multi-thread parallel programming method belonging to a computer system structure, in particular to a hardware transaction nesting processing method supporting conditional partial rollback. Background technique [0002] With the rapid development of multi-core processors, programs need to use more multi-threading mechanisms to make full use of multi-core resources to improve program performance. The traditional concurrent programming mode realizes the synchronization and mutual exclusion between processes / threads through mechanisms such as locks and semaphores. Improper use of synchronization or mutual exclusion often leads to program performance degradation and deadlocks, which makes it difficult and difficult to write multi-core concurrent programs. The debugging complexity is much higher than that of serial programs. [0003] Transactional Memory (TM) is a technology aimed at improving the programmability of parallel syst...

AI Technical Summary

Problems solved by technology

The commonly used processing method in hardware transactional storage systems is the flatten model, that is, a transaction and its inner transactions are treated as one transaction, and the commit operation is performed when the outermost transaction ends, and when the nested transaction occurs When there is a conflict, roll back to the beginning of the outermost transaction, which will have a great impact on system performance, especially when there are many nested transactions, the rollback overhead is large, and the probability of conflict is also high

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