公开(公告)号：US20140181827A1

公开(公告)日：2014-06-26

申请号：US13722811

申请日：2012-12-20

Applicant: ORACLE INTERNATIONAL CORPORATION

Inventor： David Dice ,  Yosef Lev ,  Mark S. Moir

IPC: G06F9/48

CPC classification number: G06F9/4881 ,  G06F9/52 ,  G06F9/526

Abstract: The systems and methods described herein may implement scalable statistics counters that are adaptive to the amount of contention for the counters. The counters may be accessible within transactions. Methods for determining whether or when to increment the counters in response to initiation of an increment operation and/or methods for updating the counters may be selected dependent on current, recent, or historical amounts of contention. Various contention management policies or retry conditions may be applied to select between multiple methods. One counter may include a precise counter portion that is incremented under low contention and a probabilistic counter portion that is updated under high contention. Amounts by which probabilistic counters are incremented may be contention-dependent. Another counter may include a node identifier portion that encourages consecutive increments by threads on a single node only when under contention. Another counter may be inflated in response to contention for the counter.

Abstract translation: 本文描述的系统和方法可以实现可自适应于计数器的争用量的可伸缩统计计数器。 柜台可能在交易中可访问。 可以根据当前，最近或历史的争用量来选择用于响应于增量操作的启动来确定是否或何时增加计数器的方法和/或用于更新计数器的方法。 可以应用各种争用管理策略或重试条件来在多种方法之间进行选择。 一个计数器可以包括在低争用下递增的精确计数器部分和在高争用下更新的概率计数器部分。 概率计数器增加的金额可能是争用依赖的。 另一个计数器可以包括节点标识符部分，其仅在竞争时才鼓励单个节点上的线程的连续增量。 响应于柜台的争用，另一个柜台可能会膨胀。