arrow
Return

Hashed and hierarchical timing wheels: Efficient data structures for implementing a timer facility

delete1997-01-01
delete36
PRE
AI
G
George Varghese
A
A.G. Lauck
DOI:10.1109/90.650142delete
deleteOriginal
deleteOriginal request for help
deleteShare
deleteSave
Abstract

Abstract

En 中文
The performance of timer algorithms is crucial to many network protocol implementations that use timers for failure recovery and rate control, Conventional algorithms to implement an Operating System timer module take O(n) time to start or maintain a timer, where n is the number of outstanding timers: this is expensive for large n,;his paper shows that by using a circular buffer or timing wheel, it takes O(1) time to start, stop, and maintain timers within the range of the wheel, Two extensions for larger values of the interval are described. In the first, the timer interval is hashed into a slot on the timing wheel, In the second, a hierarchy of timing wheels with different granularities is used to span a greater range of intervals, The performance of these two schemes and various implementation tradeoffs are discussed. We have used one of our schemes to replace the current BSD UNIX callout and timer facilities, Our new implementation can support thousands of outstanding timers without much overhead. Our timer schemes have also been implemented in other operating systems and network protocol packages.
Keywords:
callout facilities
hashed wheels
hierarchical wheels
protocol implementations
Timers
Timer Facilities
AI Summary

AI Summary

Key information extracted from the uploaded paper, including a brief overview, abstract, background, key highlights, visual analysis, and future outlook.

Journal

I
IEEE-ACM Transactions on Networking
IF:
3.6
Papers:
4.4K
Citations:
9.5K

Organization

No organization information available
Cited Papers

Cited Papers

errShare
errSave
Rectal cancer concurrent with disseminated superficial porokeratosis in three brothers
err2015-04-28
err0
PREAI
errLi‐Ya Jiang; Zhen Guo; Yu‐Long Kong; Hong Luan; Jun‐Xiu Yu; Ke‐Yu Wang
errShare
errSave
errShare
errSave
Metabolic tumor volume by 18F-FDG PET/CT is prognostic for stage IVB endometrial carcinoma
err2012-06-01
err0
PREAI
errFeng-Yuan Liu; Angel Chao; Chyong-Huey Lai; Hung-Hsueh Chou; Tzu-Chen Yen
errShare
errSave
errShare
errSave
The Avoidance Responses of Daphnia magna to the Exposure of Organophosphorus Pesticides in an On-Line Biomonitoring System
err2008-01-12
err0
PREAI
errZong-Ming Ren; Zhi-Liang Li; Jin-Miao Zha; Kai-feng Rao; Mei Ma; Zijian Wang; Rong-Shu Fu
errShare
errSave
no more