Prioritized Garbage Collection: Explicit GC Support for Software Caches

Programmers routinely trade space for time to increase performance, often in the form of caching or memoization. In managed languages like Java or JavaScript, however, this space-time tradeoff is complex. Using more space translates into higher garbage collection costs, especially at the limit of available memory. Existing runtime systems provide limited support for space-sensitive algorithms, forcing programmers into difficult and often brittle choices about provisioning. This paper presents prioritized garbage collection, a cooperative programming language and runtime solution to this problem. Prioritized GC provides an interface similar to soft references, called priority references, which identify objects that the collector can reclaim eagerly if necessary. The key difference is an API for defining the policy that governs when priority references are cleared and in what order. Application code specifies a priority value for each reference and a target memory bound. The collector reclaims references, lowest priority first, until the total memory footprint of the cache fits within the bound. We use this API to implement a space-aware least-recently-used (LRU) cache, called a Sache, that is a drop-in replacement for existing caches, such as Google's Guava library. The garbage collector automatically grows and shrinks the Sache in response to available memory and workload with minimal provisioning information from the programmer. Using a Sache, it is almost impossible for an application to experience a memory leak, memory pressure, or an out-of-memory crash caused by software caching.Comment: to appear in OOPSLA 201

Liveness-Based Garbage Collection for Lazy Languages

We consider the problem of reducing the memory required to run lazy first-order functional programs. Our approach is to analyze programs for liveness of heap-allocated data. The result of the analysis is used to preserve only live data---a subset of reachable data---during garbage collection. The result is an increase in the garbage reclaimed and a reduction in the peak memory requirement of programs. While this technique has already been shown to yield benefits for eager first-order languages, the lack of a statically determinable execution order and the presence of closures pose new challenges for lazy languages. These require changes both in the liveness analysis itself and in the design of the garbage collector. To show the effectiveness of our method, we implemented a copying collector that uses the results of the liveness analysis to preserve live objects, both evaluated (i.e., in WHNF) and closures. Our experiments confirm that for programs running with a liveness-based garbage collector, there is a significant decrease in peak memory requirements. In addition, a sizable reduction in the number of collections ensures that in spite of using a more complex garbage collector, the execution times of programs running with liveness and reachability-based collectors remain comparable

Understanding circular economy in everyday life : Perceptions of young adults in the Finnish context

It is generally accepted that governments, municipalities, businesses and citizens alike have a role to play in transitioning towards a circular economy (CE). Yet most academic and policy discussions of CE revolve around technological solutions and business models. Although CE also means significant changes to ways of living, these aspects of CE are barely addressed. The citizen role is traditionally assumed to be that of a consumer or user of the newly developed solutions, while also following the guidelines for sorting and recycling. Little is known about how citizens envision being part of the CE, and what skills and competences are relevant for CE. Our study addresses this gap by exploring the perceptions of young adults in Finland on how CE reflects into their everyday lives. Our dataset consists of 249 responses from high school students in Finland to open-ended questions regarding CE. The results highlight that young adults in Finland strongly associate CE with recycling, waste sorting and re-selling/buying second-hand, which is in line with the conventional roles of efficient recyclers and consumers. Although CE harbors wider potential for more active citizen roles related to repair, maintenance and upcycling, these aspects are often overlooked in favor of more familiar lifestyles. Building on the 5R framework for CE and emerging themes from student responses, we bring forward the new roles of upcycler, thrifter, expert/learner, giver/benefactor and conservationist. Supporting these emerging roles is an opportunity for cooperation between young adults, other citizen groups, cities, policy makers and businesses, and a key for jointly advancing the transition to CE. (c) 2021 The Authors. Published by Elsevier B.V. on behalf of Institution of Chemical Engineers. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/)peerReviewe

Freedom To, From, and for Whom: Analyzing Freedom Discourse in Tiny House Blogs

The Tiny House movement, characterized by the primary dwelling it is named for, is an emerging field of academic study. The movement encompasses a diverse spectrum of simple living practices that typically serve participants\u27 pursuit of self-defined freedom. Using framing methodologies to root the Tiny House movement as a specific articulation of Voluntary Simplicity, an intersectional approach to understand power and identity, and critical discourse analysis, this study analyzes freedom discourse in publicly available Tiny House blogs to discern positive descriptors of freedom (freedom to); negative descriptors of freedom (freedom from); applications of said freedom (freedom for whom) based on privileges and access to capitals, including financial, social, and human; and whether/how freedom discourse relates to other simple living movements

The Poverty of Simplicity: Austerity, Alienation, and Tiny Houses

Tiny houses – stand-alone, fully functional dwellings generally between 100 and 400 square-feet – are increasingly popular in the United States. The degradation of working class life wrought through neoliberal policy and then punctuated by the Great Recession propels this popularity. Next to traditional houses, tiny houses are significantly cheaper. Those among the middle stratum of the working class have sought out tiny houses as a means to ease their financial anxiety. Rather than merely a newer form of cheaper housing, an entire lifestyle movement has emerged around tiny houses. Anti-consumerism is the keystone to this lifestyle movement. For enthusiasts, environmental destruction, their indebtedness and financial precarity, their stress and alienation from work and life, in short, their lack of happiness or sense of purpose, originate in overconsumption. Tiny houses, because so few commodities can fit inside them, become a tool by which dwellers facilitate anti-consumerist lifestyle. Decreased consumer spending not only helps dwellers save money, it also proceeds, through the discourse of minimalism, as a spiritualistic method of practicing and signaling the virtues of prudence and self-restraint. With more savings and fewer expenses, enthusiasts endeavor to avoid alienating work and hasten retirement, leaving more time for hobbies and leisure. Because tiny houses are cheaper, they can be owned more quickly outright, and ownership permits dwellers a sense if economic security and feeling at home. Homeownership allows dwellers to customize or even build their tiny home, offering an opportunity for un-alienated, self-affirming labor of a bygone era. Given that they typically require less materials and energy to build and maintain than a traditional house, tiny houses, and the anti-consumerism they embody, shrink dwellers ecological footprint. Drawing from interviews and textual analysis, I argue that the tiny house movement is essentially one of working class retreat as it attempts to navigate several contradictions of the capitalist system. When it comes to these contradictions – capital\u27s need to pay workers as little as possible despite their need for social reproduction, to dehumanize them at work notwithstanding their humanity, to isolate workers through competition no matter their innate sociality, to despoil the environment without thought of future survival – all of them come to rest on the shoulders of the working class itself. Like recurrent movements throughout American history, in the face of economic crises and rising inequality the tiny house movement proposes anti-consumption as protean savior. And just like its historical predecessors, the tiny house movement\u27s anti-consumerism – its call for the working class to embrace thrift as a way of life – has been adorned by and rebranded through the discourse of simplicity. Financially enforced asceticism is, upon being dragged through liberal (and now neoliberal) ideology, an opportunity for spiritual transcendence, savvy entrepreneurship, rugged self-reliance, and exceptional individuality. The tiny house movement\u27s call to embrace thrift as virtuous simplicity, then, encapsulates a recurrent if sublimated critique of capitalism. It cries out against capitalism\u27s commercialism, social isolation, environmental destruction, and the overall misery of life due to overwork and insufficient leisure time. All of these symptoms are worthy of critique. But the tiny house movement\u27s critique is altogether superficial and impoverished. Wedded as it is to a lifestyle politics focused on personal consumption, and thus privileging individual consumer decisions above that of collective political actions, it leaves the root causes of alienation, austerity, and abstract domination – the capitalist mode of production itself – unchallenged. The tiny house movement is thus ultimately more interesting in how it reproduces neoliberal ideology than its desire or capacity to combat it – and how such a sad state of social surrender can so easily be rebranded as a countercultural route to material and spiritual salvation

BUILDING SUSTAINABLE SOCIETIES: EXPLORING SUSTAINABILITY POLICY AND PRACTICE IN THE AGE OF HIGH CONSUMPTION

This dissertation is an attempt to examine how humans in wealthy, post-industrial urban contexts understand sustainability and respond to their concerns given their sphere of influence. I focus specifically on sustainable consumption policy and practice in Sweden, where concerns for sustainability and consumer-based responses are strong. This case raises interesting questions about the relative strength of sustainability movements in different cultural and geo-political contexts as well as the specific factors that have motivated the movement toward sustainable living in Sweden. The data presented here supports the need for multigenic theories of sustainable consumerism. Rather than relying on dominant theories of reflexive modernization, there is a need for locally and historically grounded analyses. The Swedish case illustrates that the relative strength of sustainable living is linked not only to high levels of awareness about social, economic and ecological threats to sustainability, but also to a strong and historically rooted emphasis on equality in Sweden. In this context, sustainable living is often driven by concerns for global equity and justice. The research therefore affirms the findings of those like Hobson (2002) and Berglund and Matti (2005) who argue that concerns for social justice often have more resonance with citizen-consumers - driving more progressive lifestyle changes than personal self-interest. Yet despite the power of moral appeals, this research also suggests that the devolution of responsibility for sustainability - to citizens in their roles as consumers on the free market – has failed to produce significant change. While many attribute this failure to “Gidden’s Paradox” or the assumption that people will not change their lifestyles until they see and feel risks personally, the data presented here illustrates that even those most committed to sustainable living confront structural barriers that they do not have the power to overcome. The paradox is not that people can’t understand or act upon threats to sustainability from afar; but rather that it is extremely difficult to live more sustainably without strong social support, market regulation and political leadership. Sustainability policy must work to confront the illusion of choice by breaking down structural barriers, particularly for people who do not have the luxury of choosing alternatives

Attaining Sustainable Behavior among Non-environmentally-motivated Individuals: A Formative Experiment

Experts agree that overconsumption is a major problem in Western culture today, particularly in the United States. Thus, it is important to promote sustainable behavior among the general public. And yet, existing educational programming geared toward promoting such behavior changes remains appealing largely to environmentally-motivated audiences, as opposed to individuals with alternative (i.e., social and economic) motivations. In response to this discrepancy, I conducted a formative experiment with the goals of: 1) fostering participation among non-environmentally-motivated individuals in sustainable living educational programming; and 2) obtaining behavior change commitments, in the direction of more sustainable lifestyles, from those participants. As part of the formative process, I conducted four sequential iterations of my chosen intervention. That intervention consisted not only of the presentation of an existing curriculum designed to promote sustainable living, but also of the process of organization selection, key informant involvement, participant recruitment, and program evaluation. In order to evaluate and improve levels of goal achievement within the study, I used multiple data sources, including: key informant interviews, survey questionnaires, and qualitative observations. Those data sources contained measures of numerous constructs, which were used to: provide a deep understanding of the context of the study; evaluate the outcomes of the project\u27s four iterations; identify and overcome enhancing and inhibiting factors that may have affected goal achievement; and define the scope of the findings. Across four iterations of the intervention, levels of goal achievement improved as adaptations were made to various aspects of the intervention (i.e., the processes of organization selection, key informant involvement, participant recruitment, and program evaluation). The outcomes obtained suggested the value, within the study context, of targeting and collaborating with faith-based and faith-affiliated organizations in the effort to promote sustainable behavior at the individual level. Recommendations for effectively working with such groups, as informed by my findings, include: acknowledging and overcoming existing perceptions of terminology such as sustainability and sustainable living; recognizing and appealing to existing values, priorities, and motivations among target audiences and participants; and utilizing personal influence, leadership involvement, and word of mouth promotion to secure participation at all stages of a given intervention