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Orientador: Bruno Coraucci Filho / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e Urbanismo / Made available in DSpace on 2018-08-26T11:21:28Z (GMT). No. of bitstreams: 1 Buda_JoseFrancisco_D.pdf: 7168261 bytes, checksum: b9f15e39a51e5f756266765a99ec4830 (MD5) Previous issue date: 2014 / Resumo: A Política Nacional de Resíduos (PNRS), instituída pela Lei nº 12305 de 02 de agosto de 2010 e regulamentada pelo Decreto n° 7.404 de 23 de dezembro de 2010, apresenta a importância do tripé entre Poder Público, Empresas e Sociedade na gestão dos resíduos sólidos, incentivando a participação das cooperativas de catadores de material reciclável no processo de recebimento/coleta, triagem, enfardamento e comercialização dos materiais, como também pode-se destacar a importância que estas desempenham na inclusão social e geração de renda. Esta pesquisa teve como objetivo avaliar efeitos causados pela PNRS, nas condições e no ambiente de trabalho das cooperativas, as mudanças ocorridas nas relações com as empresas e sociedade quanto ao volume e qualidade dos resíduos recebidos, e com os órgãos municipais. Foram pesquisadas as cooperativas conveniadas com a Prefeitura do Município de São Paulo, onde estas responderam um formulário que levantou as variáveis: ambientais e sanitárias, econômicas, institucionais, infraestrutura e de saúde e segurança no trabalho. Foram entrevistados os presidentes das cooperativas, pois estes são os cooperados mais antigos e alguns até participarão na redação da lei. Foi possível assim retratar as condições das cooperativas e também conclui-se assim que a PNRS se configura como modeladora de novos paradigmas sociais, dentre os quais se destacam os princípios de responsabilidade social compartilhada e que as mudanças comportamentais pretendidas pelo documento legal não deverão ser obtidas de forma rápida, mas sim de forma gradual em avanços sucessivos. A aceleração deste processo somente será dada com o incremento da fiscalização e do apoio do poder público à questão da reciclagem, o que garantirá a efetividade da lei / Abstract: The National Waste Policy (PNRS), established by Law No. 12305 of August 2, 2010 and regulated by Decree No. 7,404 of December 23, 2010, shows the importance of the tripod between Government, the Companies and Society in waste management solid, encouraging the participation of waste pickers cooperatives in the receiving process / collection, sorting, baling and marketing of materials, but also can highlight the importance they play in the social inclusion and income generation. This research aimed to evaluate effects caused by PNRS under the conditions and in the work environment of cooperatives, changes in relationships with business and society about the size and quality of the waste received, and municipal agencies. The cooperatives were surveyed with the city of São Paulo City Hall, where they answered a form that lifted the variables: environmental, sanitary, economic, institutional, infrastructure, health and safety at work. We interviewed the presidents of cooperatives, as these are the oldest cooperative and some even participate in drafting the law. It was this possible to portray the conditions of cooperatives and concluded as soon as the PNRS is configured as shaping of new social paradigms, among which stand out the principle of shared social responsibility, required behavioral changes by the legal document should not be obtained quickly, but gradually in successive advances. The acceleration of this process will only be given to increasing the supervision and government support to the issue of recycling, which will ensure the effectiveness of the law / Doutorado / Saneamento e Ambiente / Doutor em Engenharia Civil

Computer systems now run drastically different workloads than they did two decades ago. The enormous advances in hardware power, such as processor speed, memory and storage capacity, and network bandwidth, enable them to run new kinds as well as a large number of applications simultaneously. Software technologies, such as garbage collection and multi-threading, also reshape applications and their behaviors, introducing more challenges to system resource management. However, existing general-purpose operating systems do not provide adequate support for these modern applications. These operating systems were designed over two decades ago, when garbage-collected applications were not prevalent and users interacted with systems using consoles and command lines, rather than graphical user interfaces. As a result, they fail to allow necessary coordinations among resource management components to ensure consistent performance guarantees. For example, garbage-collected applications cannot adjust themselves to maintain high throughput under dynamic memory pressure, simply because existing virtual memory managers do not collect and expose enough information to them. Furthermore, despite the increasing demand of supporting co-existing interactive applications in desktop environment, resource managers (especially memory and disk I/O) mostly focus on optimizing throughput. They each work independently, ignoring the response time requirements that the CPU scheduler attempts to satisfy. Consequently, pressure on any of these resources can significantly degrade application responsiveness. In order to deliver robust performance to these modern applications, an operating system has to coordinate its resource managers (e.g., CPU, memory, and disk I/O), as well as cooperate with resource managers in the user space, such as the garbage collector and the thread manger. To support garbage-collected applications, we present CRAMM, a system that enables them to predict an appropriate heap size using information supplied by the underlying operating system, allowing them to maintain high throughput in the face of changing memory pressure. To support highly interactive workloads, we present Redline, a system that manages CPU, memory, and disk I/O in an integrated manner. It uses lightweight specifications to drive CPU scheduling and to coordinate memory and disk I/O management to serve the needs of interactive applications. Such coordination enables it to maintain responsiveness in the face of extreme resource contention, without sacrificing resource utilization. We also show that Redline can be used to support response time sensitive multi-threaded server applications. Our experiences and extensive experiments show that we can coordinate resource managers, both inside and outside the operating system, efficiently without destroying the modularity of the existing system. Such coordination prevents resource managers from working at cross purposes, and dramatically improve the performance of applications when facing heavy resource contention, sometimes by orders of magnitude.

Due to the significant limitations of static analysis and the dynamic nature of pointers in weakly typed programming languages like C and C++, the points-to sets obtained at compile time are quite conservative. Most static pointer analysis methods trade the precision for the analysis speed. The methods that perform the analysis in a reasonable amount of time are often context and/or flow insensitive. Other methods that are context, flow, and field sensitive have to perform the whole program inter-procedural analysis, and do not scale with respect to the program size. A large class of problems involving optimizations such as instruction prefetching, control and data speculation, redundant load/store instructions removal, instruction scheduling, and memory disambiguation suffer due to the imprecise and conservative points-to sets computed statically. One could possibly live without optimizations, but in domains involving memory security and safety, lack of the precise points-to sets can jeopardize the security and safety. In particular, the lack of dynamic points-to sets drastically reduce the ability to reason about a program's memory access behavior, and thus illegal memory accesses can go unchecked leading to bugs as well as security holes. On the other hand, the points-to sets can be very useful for other domains such as the heap shape analysis and garbage collection. The knowledge of precise points-to sets is therefore becoming very important, but has received little attention so far beyond a few studies, which have shown that the pointers exhibit very interesting behaviors during execution. How to track such behaviors dynamically and benefit from them is the topic covered by this research. In this work, we propose a technique to compute the precise points-to sets through dynamic pointer tracking. First, the compiler performs the pointer analysis to obtain the static points-to sets. Then, the compiler analyzes the program, and inserts the necessary instructions to refine the points-to sets. At runtime, the inserted instructions automatically update the points-to sets. Dynamic pointer tracking in software can be expensive and can be a barrier to the practicality of such methods. Several optimizations including removal of redundant update, post-loop update, special pattern driven update removal, pointer initialization update removal, update propagation, invariant removal, and on demand update optimization are proposed. Our experimental results demonstrate that our mechanism is able to compute the points-to sets dynamically with tolerable overheads. Finally, the memory protection and garbage collection work are presented as the consumers of dynamic pointer tracking to illustrate its importance. In particular, it is shown how different memory properties can be easily tracked using the dynamic points-to sets opening newer possibilities.

Submitted by Luciana Ferreira (lucgeral@gmail.com) on 2017-02-01T14:10:55Z No. of bitstreams: 2 Dissertação - Valquíria Soares de Moura - 2016.pdf: 3879812 bytes, checksum: 7c84e35321e9f7643aa6215f981e7eaf (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2017-02-01T14:11:23Z (GMT) No. of bitstreams: 2 Dissertação - Valquíria Soares de Moura - 2016.pdf: 3879812 bytes, checksum: 7c84e35321e9f7643aa6215f981e7eaf (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-02-01T14:11:23Z (GMT). No. of bitstreams: 2 Dissertação - Valquíria Soares de Moura - 2016.pdf: 3879812 bytes, checksum: 7c84e35321e9f7643aa6215f981e7eaf (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2016-05-05 / The advent of disposable materials, both organic as inorgânico, wich associated to the self-consumtion model of our human society, has caused an excessive increase in the quantity of waste, called in technical language as solid or semi-liquid residues produced by men. In this context, some of the great challenges at the beginning of the millennium refer to what to do with this huge amount of garbage, since the increase in waste production occurs at an alarming rate and it is considered something to be overcome regarding the degradation environment. Given the exposed issues, the Public Power and even the human population are seeking possible solutions, such as creating Programs for Selective Collection and Recycling, but for this to occur in a sustainable way, of Environmental Education has fundamental importance because of the culture required to recycling, reuse and composting (post-collection separation) techniques. Thus, this research aims to understand the management of selective collection program conducted in Tupaciguara (MG), through its Department of Environment and ASCAMAT - (Collectors Association of Recyclable Materials) as well as their challenges faced and goals achieved, and yet, pointing to a number of possible solutions to the deficiencies in the Selective Collection Program found. For the development of this research and contemplation of the proposed objectives the methodology used was based on: theoretical reviews as support for analyzes to be carried out; the practice of field work at the ASCAMAT's office; survey with human population about selective collection program and its satisfaction level; and, research for information in the Municipality of Tupaciguara and the Public Institutions linked to the program, what is necessary for the development of the research. Considering that the selective collection system is new and still in the adaptation phase, it showed that the same has not yet been able to achieve an appropriate management model, as called for in the legislation related to the National Policy on Solid Waste. As environmental awareness measures, it developed a work of clarification from the population employing environmental education, emphasizing its importance in the process of separation of recyclable materials in order to guarantee the efficiency and the Selective Collection Program. Finally, the effective participation of the human population served by the program is also a point to be improved as well, because it was possible to see that, even though the population interviewed is aware of the importance of selective collection, almost half of respondents do not cooperate with the separation materials. The more people involved the separation of recyclable materials less waste arrives at the municipal landfill, thereby increasing its duration. Keywords: Selective Garbage Collection. Municipality of Tupaciguara (MG), Recycling. Environmental education. / O surgimento dos descartáveis, tanto de origem orgânica quanto inorgânica, associados ao modelo de autoconsumo da sociedade humana consumista, vem ocasionando um aumento excessivo do quantitativo de lixo, que na linguagem técnica significa sinônimo de resíduos em estado sólido ou semilíquido produzidos pelo homem. Nesse contexto, alguns dos grandes desafios neste início de milênio referem-se ao que fazer e qual a destinação da enorme quantidade de resíduos produzidos, visto que o aumento da produção de lixo ocorre de forma ameaçadora, sendo considerado algo a ser superado no que tange a degradação do ambiente. Diante do exposto, o Poder Público e a própria população humana buscam possíveis soluções, como a criação de Programas de Coleta Seletiva e reciclagem, mas para que isso ocorra de forma sustentável, o processo da Educação Ambiental é de fundamental importância para que a reciclagem, a reutilização e a própria compostagem (separação pós-coleta) possam ser efetuadas. Desse modo, a presente pesquisa visa compreender o gerenciamento do Programa de Coleta Seletiva realizado em Tupaciguara (MG), por meio da Secretaria de Meio Ambiente e ASCAMAT - Associação de Catadores de Materiais Recicláveis de Tupaciguara (MG), bem como seus desafios enfrentados e metas alcançadas, e ainda, apontamento de uma série de possíveis soluções para as deficiências no Programa de Coleta Seletiva encontradas. Para desenvolvimento da pesquisa e contemplar os objetivos propostos, a metodologia empregada pautou-se em revisões teóricas como suporte às análises a serem realizadas; a prática de trabalhos de campo na Sede da Associação dos Catadores do Município, aplicação de questionários com a população humana atendida pelo Programa de Coleta Seletiva, a fim de tomar conhecimento quanto a sua satisfação, bem como busca de informações na Prefeitura Municipal de Tupaciguara e demais Órgãos Públicos vinculados ao Programa, e necessários ao desenvolvimento da pesquisa. Considerando-se que o sistema de Coleta Seletiva é recente e ainda se encontra em fase de adaptação, evidenciou-se que o mesmo não tem ainda conseguido alcançar um modelo de gestão apropriada, conforme o preconizado na legislação relacionada à Política Nacional de Resíduos Sólidos. Como medidas de conscientização socioambiental, desenvolveu-se um trabalho de esclarecimentos junto a população empregando-se à Educação Ambiental, ressaltando sua importância no processo de separação dos materiais recicláveis visando a garantia e a eficiência do Programa de Coleta Seletiva. Para concluir, a participação efetiva da população humana atendida pelo Programa ainda é um ponto a ser melhorado também, pois foi possível perceber que, mesmo que a população entrevistada tenha consciência da importância da Coleta Seletiva, quase a metade dos entrevistados não colaboram com a separação dos materiais. Quanto mais pessoas participam da separação dos materiais recicláveis menos resíduos chega ao aterro sanitário municipal, aumentando assim, seu tempo de duração. Palavras-chave: Coleta Seletiva de Lixo. Município de Tupaciguara (MG). Reciclagem. Educação Ambiental.

Afin de maximiser la localité des accès mémoire pendant la phase de collection, un thread GC évite d’accéder un autre noeud mémoire en notifiant à la place un thread GC distant avec un message. Néanmoins, NumaGiC évite les inconvénients d’un design complètement distribué qui tend à diminuer le parallélisme et augmenter le déséquilibre des accès mémoire en permettant aux threads de voler depuis les autres noeuds quand ceux-ci sont inactifs. NumaGiC fait son possible pour trouver un équilibre parfait entre les accès distant, le déséquilibre des accès mémoire et le parallélisme. Dans ce travail, nous comparons NumaGiC avec Parallel Scavenge et certaines de ses variantes améliorées de façon incrémentale sur deux architectures ccNUMA en utilisant la machine virtuelle Hotspot d’OpenJDK 7. Sur Spark et Neo4j, deux applications d’informatique décisionnelle de niveau industriel, avec une taille de tas allant de 160 GB à 350 GB, et sur SPECjbb2013 et SPECjbb2005, NumaGiC améliore la performance globale jusqu’à 94% par rapport à Parallel Scavenge et améliore la performance du collecteur lui-même jusqu’à 5,4times par rapport à Parallel Scavenge. En terme de passage à l’échelle du débit du GC en augmentant le nombre de noeuds NUMA, NumaGiC passe à l’échelle beaucoup mieux qu’avec Parallel Scavenge pour toutes les applications. Dans le cas de SPECjbb2005, où les références inter-objets sont les moins nombreuses parmi toutes les applications, NumaGiC passe à l’échelle quasiment linéairement. / Large-scale multicore architectures create new challenges for garbage collectors (GCs). On con-temporary cache-coherent Non-Uniform Memory Access (ccNUMA) architectures, applications with a large memory footprint suffer from the cost of the garbage collector (GC), because, as the GC scans the reference graph, it makes many remote memory accesses, saturating the interconnect between memory nodes. In this thesis, we address this problem with NumaGiC, a GC with a mostly-distributed design. In order to maximise memory access locality during collection, a GC thread avoids accessing a different memory node, instead notifying a remote GC thread with a message; nonetheless, NumaGiC avoids the drawbacks of a pure distributed design, which tends to decrease parallelism and increase memory access imbalance, by allowing threads to steal from other nodes when they are idle. NumaGiC strives to find a perfect balance between local access, memory access balance, and parallelism. In this work, we compare NumaGiC with Parallel Scavenge and some of its incrementally improved variants on two different ccNUMA architectures running on the Hotspot Java Virtual Machine of OpenJDK 7. On Spark and Neo4j, two industry-strength analytics applications, with heap sizes ranging from 160 GB to 350 GB, and on SPECjbb2013 and SPECjbb2005, NumaGiC improves overall performance by up to 94% over Parallel Scavenge, and increases the performance of the collector itself by up to 5.4× over Parallel Scavenge. In terms of scalability of GC throughput with increasing number of NUMA nodes, NumaGiC scales substantially better than Parallel Scavenge for all the applications. In fact in case of SPECjbb2005, where inter-node object references are the least among all, NumaGiC scales almost linearly.

[pt] Inúmeras linguagens de programação oferecem suporte a finalizadores e referências fracas. Não obstante, de maneira geral esses mecanismos são relativamente pouco conhecidos e pouco usados por programadores. Mesmo entre pesquisadores e desenvolvedores de linguagens não existe muito consenso quanto à sua semântica, que varia consideravelmente entre diferentes implementações. Neste trabalho buscamos explorar os conceitos de finalizadores e de referências fracas, suprindo a ausência de uma especificação clara e abrangente, e permitindo uma melhor compreensão, implementação e uso dos mecanismos correspondentes. Como ponto de partida realizamos um amplo levantamento sobre como é feito o suporte a finalizadores e referências fracas em diferentes linguagens de programação, identificando as características comuns, os problemas, e as questões semânticas mais relevantes associadas às implementações consideradas. Para garantir uma maior precisão em nossa análise, utilizamos um modelo abstrato de uma linguagem de programação com gerenciamento automático de memória. Através deste modelo especificamos formalmente a semântica de finalizadores e referências fracas, incluindo descrições das suas principais variantes e mecanismos relacionados. Além disso, provamos certas propriedades inerentes a linguagens de programação com gerenciamento automático de memória, indicando como estas são afetadas pela introdução de finalizadores e referências fracas. Por fim, consideramos possíveis estratégias de implementação desses mecanismos em diferentes tipos de sistemas. Algumas das opções semânticas investigadas impõe um custo de processamento expressivo, o que frequentemente inviabiliza a sua adoção na prática. / [en] Most mainstream programming languages support finalizers and weak references. In spite of that, these abstractions are still modestly known by programmers in general. Even among language designers there seems to be no common view on how to define their semantics, and language implementations certainly reflect that. In this thesis we explore the concepts of finalizer and weak reference by discussing several important issues that, as far as we know, have not been explored by other authors. After presenting a survey on how finalizers and weak references are supported by actual programming languages, we thoroughly examine their semantics and discuss alternative implementation strategies. We also use an operational approach to develop a formal model for reasoning about garbage collection and its interaction with client programs. By explicitly representing low-level details, such as heap memory and its addresses, we were able to clearly specify memory management actions, and prove several important memory-related language invariants. Using this model we describe a formal semantics for finalizers and weak references, exploring some of its many subtleties. We believe that the topics covered here can serve as a relevant reference for further investigations, and also help to guide actual implementations.

This study evaluates the performance of Kotlin and Java on Android Runtime using four benchmarks from the Computer Language Benchmarks Game suite, for which a total of 12 benchmark implementations are studied. The metrics used to evaluate the performance includes runtime, memory consumption, garbage collection, boxing of primitives as well as bytecode n-grams. To benchmark the languages, a benchmark application has been developed intended to run on an Android phone. The results indicate that Kotlin is slower than Java for all studied benchmarks by a varying factor. Furthermore, the use of idiomatic Kotlin features and constructs results in additional heap pressure and the need of boxed primitives. Other interesting results indicate the existence of an underlying garbage collection overhead when reclaiming Kotlin objects compared to Java. Furthermore, Kotlin produces larger and more varied bytecode than Java for a majority of the benchmarks. / Denna studie utvärderar prestandan mellan Kotlin och Java på Android Runtime genom 12 implementationer av fyra benchmarks från The Computer Language Benchmarks Game. De mätvärden som använts för att utvärdera prestandan inkluderar körtid, minnesanvändning, garbage collection, boxing av primitiver samt bytekod n-grams. För att benchmarka språken har en benchmarkapplikation tagits fram för Android. Resultaten visar att Kotlin är långsammare än Java för samtliga benchmarks. Vidare resulterar användandet av idiomatiska Kotlin-funktioner i ökad minnesanvänding samt behovet att representera primitiver som klasser. Andra intressanta resultat inkluderar existensen av en overhead för garbage collectorn för frigörandet av objekt som allokerats av Kotlin jämfört med Java. Vidare producerar Kotlin större bytekodfiler och uppvisar mer varierad bytekod än Java för en majoritet av de benchmarks som studerats.

Today's mobile development resides in the two main operating systems Android and iOS. It is popular to develop mobile applications individually for each respective platform, referred to as native development. To reduce additional costs, cross-platform solutions have emerged that enable shared development for both platforms. Kotlin Multiplatform Mobile (KMM) is a relatively unexplored cross-platform tool developed by JetBrains. The purpose of this study is to evaluate the performance of iOS applications developed in KMM compared to native Swift. We compare the two approaches for developing iOS apps by compiling a benchmark suite and measuring the performance metrics execution time, memory consumption, and CPU usage. Our benchmark suite is a collection of 7 benchmarks consisting of high-level functionalities networking and database management, as well as low-level computational tasks from the Computer Language Benchmarks Game (CLBG) suite. For the studied benchmarks, the results indicate that KMM generally achieves faster execution times, as higher memory consumption and CPU usage. but with a trade-off overhead in higher memory consumption and CPU usage. We have found KMM to achieve up to 2,7 seconds faster execution time, consume up to 390MB more memory, and up to 30% more CPU than with native Swift. libraries achieve faster execution times, but with a trade-off overhead in increased memory consumption and CPU usage. Besides, our results highlight correlations between the garbage collection cycles of KMM with profiling patterns of memory consumption and CPU usage. the specific benchmark implementations analyzed, and the device used to benchmark them. studies are therefore needed to further generalize our conclusions. / Den nutida mobilutvecklingen domineras av de två huvudsakliga operativsystemen Android och iOS. Det är populärt att utveckla mobilapplikationer separat för varje plattform, så kallad native utveckling. För att minska kostnader relaterade till native utveckling har plattformsoberoende lösningar tillkommit, som istället möjliggör delad utveckling för båda plattformarna. Kotlin Multiplatform Mobile (KMM) är ett relativt outforskat plattformsoberoende verktyg utvecklat av JetBrains. Syftet med denna studie är att utvärdera prestandan hos iOS-applikationer utvecklade i KMM jämfört med native Swift. Vi jämför de två tillvägagångssätten för att utveckla iOS-appar genom att sammanställa en benchmark-svit och mäta prestandametrikerna exekveringstid, minnesanvändning och CPU-användning. Vår benchmark svit består av 7 benchmark-program som omfattar högnivåfunktionaliteter som nätverk- och databashantering, samt lågnivåfunktionaliteter med benchmark-algoritmer från Computer Language Benchmarks Game (CLBG)-sviten. För att exekvera benchmark-programmen och samla in prestandametriker har en applikation utvecklats och använts för att utföra våra experiment på en iOS-enhet. För de undersökta benchmark-programmen visar resultaten att KMM generellt uppnår snabbare exekveringstider, men med en kompromiss i form av ökad minnesanvändning och CPU-användning. Vi har observerat att KMM kan uppnå upp till 2,7 sekunder snabbare exekveringstid, förbruka upp till 390MB mer minne och upp till 30% mer CPU-användning jämfört med native Swift. Dessutom antyder våra resultat korrelationer mellan KMM Garbage Collection cykler och profileringsbeteendet i dess minnes- och CPU-användning.

Despite the built-in garbage collector, Java programs can still suffer the memory leak problem resulted from the unhealthy programming style of retaining unwanted references. This paper presents an aspect-based tool for assisting programmers in locating such references to fix the problem. This tool, FindLeaks, utilizes an aspect to collect memory consumption statistics and object references created during a program’s execution and analyzes them for detecting memory leaks. The distinctive feature of FindLeaks is that it reports not only suspected classes of leaked objects but also where in the source the unwanted references were created. Besides, this paper also reports our experience with FindLeaks on three open source Java programs and how we enhanced it to lower its overhead.