CSR: Small: Extending Smartphone Battery Life via Prescriptive Energy Profiling

智能手机在全球拥有超过20亿用户，在bb0和苹果的数字市场上各有超过200万个应用程序（app），将人类社会推进到了移动时代。尽管智能手机对社会产生了深远的影响，但用户体验却受到智能手机电池寿命的严重限制。延长智能手机电池寿命的一个显而易见的想法是改进电池技术，然而，在过去的15年里，电池技术一直停滞不前，电池容量通常被认为接近物理极限。相反，这个项目追求的是通过减少智能手机上运行的各种软件的能量消耗来显著延长智能手机电池寿命的研究过程。该项目旨在解决智能手机电池消耗的主要因素，即应用程序在前台运行时的能量消耗，目标是将其减少2倍。拟议的研究包括将开发第一套规定性能量分析技术的主要重点，这些技术将把能量分析从“被动”的应用程序开发步骤转变为“主动”的过程：(a)它将开发第一个自动发现参数配置和框架/库方法调用之间因果关系的能力，这是基于框架的移动编程中一个独特而困难的程序分析问题；(b)它将开发第一个自动识别类似任务的节能实现的能力，这通常是一个棘手的问题，但通过比较在庞大的移动应用程序市场上广泛使用的类似应用程序，移动应用程序可以实现。智能手机是发达国家和发展中国家弱势群体接入互联网的重要手段，因此是克服“数字鸿沟”的重要工具，因此，本项目的重要性得到了加强。从技术上讲，这项工作将通过增加一般事件驱动计算机程序的编译能力，在开发节能移动应用程序领域之外产生深远的影响。将维持一个项目储存库，以提供访问代码、显示所开发技术有效性的原始实验数据以及处理过的结果和技术出版物。该储存库将在三年项目期间和之后两年保持，以促进其他人在这一重要领域的研究活动。

With over 2 billion users worldwide and over 2 million applications (apps) each in Google and Apple's digital marketplaces, smartphones have advanced human society into the mobile era. Despite the far-reaching societal impact of smartphones, the user experience has been severely limited by smartphone battery life. The obvious idea of extending smartphone battery life is to improve the battery technology, which, however, has stagnated in the past 15 years, and battery capacity is generally viewed as nearing the limits of physics. Instead, this project pursues a course of research to significantly extend smartphone battery life by reducing the energy drain of various software running on the smartphone.This project aims to tackle a major smartphone battery drain contributor, app energy drain when running in the foreground, with the goal of reducing it by 2x. The proposed research includes major thrusts that will develop the first set of prescriptive energy profiling techniques that will transform energy profiling from a "passive" app development step into a "proactive" process: (a) It will develop the first capability to automatically uncover the causal relationship between parameter configurations and framework/library method invocations, a unique and hard program analysis problem in framework-based mobile programming; (b) It will develop the first capability to automatically identify an energy-efficient implementation of similar tasks, a generally intractable problem but attainable for mobile apps by comparing similar apps that are widely available in the huge mobile app marketplace.The importance of this project is heightened by smartphones being an important enabler of Internet access for disadvantaged people in both developed and developing countries, and hence being an important tool in overcoming the "digital divide". Technically, this work will have a far-reaching impact outside of the area of developing energy efficient mobile apps by increasing compiler capabilities for general event-driven computer programs. A project repository will be maintained to provide access to code, raw experimental data showcasing the effectiveness of the developed techniques, and processed results and technical publications. The repository will be maintained during the three-year project period and the two years afterwards, to foster research activities by others in this important area.