Using key object opportunism to collect old objects
Using key object opportunism to collect old objects
复制标题
利用关键对象机会主义收集旧对象
DOI：
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复制
发表时间：
1991
期刊：
影响因子：
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通讯作者：
Barry Hayes
中科院分区：
文献类型：
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作者：
Barry Hayes
在Xerox Dorados上收集的雪松系统的对象分配和数据支持弱创建的物体的生存率要低得多。大约在同一时间分配，并通过巧妙地选择群集的时间大致相同。为了找到它们代表的群集的好机会。新创建的物体的生存率要比年龄较大的对象低得多。 ，ACM版权通知和出版物的标题及其日期出现，并通知复制是通过协会的允许进行计算机机械。 1991 ACM 89791-446.5/9110010/0033 ... $ 1.50，基于此假设，基于时间的世代收集器ILH83，MOO84，UNG84）。如果所讨论的对象不是新创建的，那么相对年轻的对象的存活率低于相对较旧的对象。随着对象的年龄，它们被晋升为一代人，在某个时候，它们可能在基于时间的收藏家永远不会尝试收集它们的一代人中“终身”。
Object allocation and deallocation data gathered for the Cedar system on Xerox Dorados supports the weak generational hypothesis! newly-created objects have a much lower survival rate than objects that are older. The survivors at all collections thresholds are highly organized; large clusters of objects are allocated at roughly the same time, and live for roughly the same length of time. By cleverly selecting representatives from the clusters and examining the reachability of these key objects more frequently than the cluster itself, the storage system can use the death of these key objects to find good opportunities to collect the clusters they represent. 1 The Generational Hypotheses Some observations of the relative lifetimes of newlycreated objects and older objects leads to the weak generational hypothesis [Han77]. This hypothesis seems to hold across a wide variety of systems: newly-created objects have a ,much lower survival rate than objects that are older. This led researchers to develop storage management systems Permission to copy without fee all or part of this material is granted provided that the copies are not made or distributed for direct commercial advantage, the ACM copyright notice and the title of the publication and its date appear, and notice is given that copying is by permission of the Association for Computing Machinery. To copy otherwise, or to republish, requires a fee and/or specific permission. @ 1991 ACM 89791-446.5/9110010/0033...$1.50 based on this hypothesis, the time-based generational collectors iLH83, Moo84, Ung84]. The designs of these are actually based on a leap of faith to the strong generational hypothesis: even if the objects in question are not newly-created, the relatively younger objects have a lower survival rate than the relatively older objects. These collectors allow many generations and segregate objects into multiple classes by age, not just “new” and “old.” As objects age, they are promoted from one generation to the next, and at some point they may be “tenured” in a generation where the time-based collector will never attempt to collect them.