title: Memory and energy optimization strategies for multithreaded operating system on the resource-constrained wireless sensor node.
abstract: Memory and energy optimization strategies are essential for the resource-constrained wireless sensor network (WSN) nodes. In this article, a new memory-optimized and energy-optimized multithreaded WSN operating system (OS) LiveOS is designed and implemented. Memory cost of LiveOS is optimized by using the stack-shifting hybrid scheduling approach. Different from the traditional multithreaded OS in which thread stacks are allocated statically by the pre-reservation, thread stacks in LiveOS are allocated dynamically by using the stack-shifting technique. As a result, memory waste problems caused by the static pre-reservation can be avoided. In addition to the stack-shifting dynamic allocation approach, the hybrid scheduling mechanism which can decrease both the thread scheduling overhead and the thread stack number is also implemented in LiveOS. With these mechanisms, the stack memory cost of LiveOS can be reduced more than 50% if compared to that of a traditional multithreaded OS. Not is memory cost optimized, but also the energy cost is optimized in LiveOS, and this is achieved by using the multi-core "context aware" and multi-core "power-off/wakeup" energy conservation approaches. By using these approaches, energy cost of LiveOS can be reduced more than 30% when compared to the single-core WSN system. Memory and energy optimization strategies in LiveOS not only prolong the lifetime of WSN nodes, but also make the multithreaded OS feasible to run on the memory-constrained WSN nodes.
authors.affiliation: LIMOS Laboratory, CNRS UMR 6158, Blaise Pascal University, Les Cézeaux, BP 10125, Clermont-Ferrand 63173, France. liu@isima.fr.
authors.forename: Xing
authors.initials: X
authors.lastname: Liu
authors.affiliation: LIMOS Laboratory, CNRS UMR 6158, Blaise Pascal University, Les Cézeaux, BP 10125, Clermont-Ferrand 63173, France. kun-mean.hou@isima.fr.
authors.forename: Kun Mean
authors.initials: KM
authors.lastname: Hou
authors.affiliation: LIMOS Laboratory, CNRS UMR 6158, Blaise Pascal University, Les Cézeaux, BP 10125, Clermont-Ferrand 63173, France. devaulx@isima.fr.
authors.forename: Christophe
authors.initials: C
authors.lastname: de Vaulx
authors.affiliation: Internet and Information Technology Laboratory, Electronic Information School, Wuhan University, Road LuoJia, Wuhan 430072, China. eisxujun@whu.edu.cn.
authors.forename: Jun
authors.initials: J
authors.lastname: Xu
authors.affiliation: Internet and Information Technology Laboratory, Electronic Information School, Wuhan University, Road LuoJia, Wuhan 430072, China. eisxujun@whu.edu.cn.
authors.forename: Jianfeng
authors.initials: J
authors.lastname: Yang
authors.affiliation: School of Electrical & Information, Hubei University of Automotive Technology, Shiyan 442002, China. haiyingzhou@hit.edu.cn.
authors.forename: Haiying
authors.initials: H
authors.lastname: Zhou
authors.affiliation: LIMOS Laboratory, CNRS UMR 6158, Blaise Pascal University, Les Cézeaux, BP 10125, Clermont-Ferrand 63173, France. shi@isima.fr.
authors.forename: Hongling
authors.initials: H
authors.lastname: Shi
authors.affiliation: LIMOS Laboratory, CNRS UMR 6158, Blaise Pascal University, Les Cézeaux, BP 10125, Clermont-Ferrand 63173, France. peng.zhou@isima.fr.
authors.forename: Peng
authors.initials: P
authors.lastname: Zhou