Communication cost is the most commonly used metric in assessing the efficiency of operations in distributed algorithms for message-passing environments. In doing so, the standing assumption is that the cost of local computation is negligible compared to the cost of communication. However, in many cases, operation implementations rely on complex computations that should not be ignored. Therefore, a more accurate assessment of operation efficiency should account for both computation and communication costs. This paper focuses on the efficiency of read and write operations in emulations of atomic read/write shared memory in the asynchronous, message-passing, crash-prone environment. The much celebrated work by Dutta et al. presented an implementation in this setting where all read and write operations could complete in just a single communication round-trip. Such operations where characterized for the first time as fast . At its heart, the work by Dutta et al. used a predicate to achieve that performance. We show that the predicate is computationally intractable by defining an equivalent problem and reducing it to Maximum Biclique , a known NP-hard problem. We derive a new, computationally tractable predicate , and an algorithm to compute it in linear time . The proposed predicate is used to develop three algorithms: ccFast , ccHybrid , and OhFast . ccFast is similar to the algorithm of Dutta et al. with the main difference being the use of the new predicate for reduced computational complexity. All operations in ccFast are fast, and particular constraints apply in the number of participants. ccHybrid and OhFast , allow some operations to be “slow”, enabling unbounded participants in the service. ccHybrid is a “multi-speed” version of ccFast , where the reader determines when it is not safe to complete a read operation in a single communication round-trip. OhFast , expedites algorithm OhSam of Hadjistasi et al. by placing the developed predicate at the servers instead of clients and avoiding excessive server communication when possible. An experimental evaluation using NS3 compares algorithms ccHybrid and OhFast to the classic algorithm ABD of Attiya et al., the algorithm Sf of Georgiou et al. (the first “semifast” algorithm, allowing both fast and slow operations), and algorithm OhSam . In summary, this work gives the new meaning to the term fast by assessing both the communication and the computation efficiency of each operation.

中文翻译：

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易处理的低延迟原子存储器

通信成本是评估消息传递环境的分布式算法中操作效率的最常用指标。这样做的前提是，与通信成本相比，本地计算的成本可以忽略不计。然而，在许多情况下，操作实现依赖于不应被忽略的复杂计算。因此，对运行效率的更准确评估应考虑计算和通信成本。本文重点介绍异步、消息传递、易崩溃环境中原子读/写共享内存仿真中读写操作的效率。Dutta 等人著名的工作。在此设置中提出了一个实现，其中所有读取和写入操作都可以在一次通信往返中完成。此类操作首次以快速为特征。Dutta 等人的工作的核心。使用谓词来实现该性能。我们通过定义一个等效问题并将其减少到最大 Biclique 来证明谓词在计算上是难以处理的，这是一个已知的 NP-hard 问题。我们推导出一个新的、计算上易于处理的谓词 ，以及一种在线性时间内计算它的算法。提议的谓词用于开发三种算法： ccFast 、 ccHybrid 和 OhFast 。ccFast 类似于 Dutta 等人的算法。主要区别在于使用新谓词来降低计算复杂度。ccFast 中的所有操作都很快，参加人数有特殊限制。ccHybrid 和 OhFast 允许某些操作“缓慢”，从而使服务中的参与者不受限制。ccHybrid 是 ccFast 的“多速”版本，其中读取器确定何时在单次通信往返中完成读取操作不安全。OhFast 加速了 Hadjistasi 等人的 OhSam 算法。通过将开发的谓词放在服务器而不是客户端，并尽可能避免过度的服务器通信。使用 NS3 的实验评估将算法 ccHybrid 和 OhFast 与 Attiya 等人的经典算法 ABD、Georgiou 等人的算法 Sf 进行了比较。（第一个“半快速”算法，允许快速和慢速操作）和算法 OhSam 。总之，