Derivation and evaluation of concurrent collectors

Abstract. There are many algorithms for concurrent garbage collection, but they are complex to describe, verify, and implement. This has resulted in a poor understanding of the relationships between the algorithms, and has precluded systematic concurrent garbage collection algorithm, and show how existing snapshot and incremental update collectors, can be derived from the abstract algorithm by reducing precision. We also derive a new hybrid algorithm that reduces floating garbage while terminating quickly. We have implemented a concurrent collector framework and the resulting algorithms in IBM’s J9 Java virtual machine product and compared their performance in terms of space, time, and incrementality. The results show that incremental update algorithms sometimes reduce memory requirements (on 3 of 5 benchmarks) but they also sometimes take longer due to recomputation in the termination phase (on 4 of 5 benchmarks). Our new hybrid algorithm has memory requirements similar to the incremental update collectors while avoiding recomputation in the termination phase.

Revisiting the Mamlūk empire : political action, relationships of power, entangled networks, and the sultanate of Cairo in late medieval Syro-Egypt

This chapter’s questions the commonly assumed link between political practices of integration and integrity on the one hand – which appear as empirical realities from many sources and studies – and the Syro-Egyptian Sultanate of Cairo (13th-16th centuries) as a dominant, autonomous and imperial historical actor on the other. It problematizes in particular the holistic nature of these assumptions, their merely descriptive value for understanding the region’s history, and the potentially misleading consequences of their normative character. At the same time, this chapter proposes to reflect further on the powerful idea of the Sultanate as an empire. It actually considers this notion of “empire” as a useful way out of this predicament, because it invites to engage with insights from other fields of historical research and to define valuable analytical tools, including from social network theory, to further and refine current assumptions about and understandings of late medieval Syro-Egyptian political action. Confronting such tools with various cases from the center and the peripheries of that Syro-Egyptian political action, this chapter argues that the imperial appearances of the Syro-Egyptian Sultanate were always constructed in the micro-history of people and their negotiation of particular cultural, socio-economic and political relationships, which were extremely fluid and multivalent, permeable, and continuously organized around the court in Cairo

Income and Quality of Life: Does the Love of Money Make a Difference?

This paper examines a model of income and quality of life that controls the love of money, job satisfaction, gender, and marital status and treats employment status (full-time versus part-time), income level, and gender as moderators. For the whole sample, income was not significantly related to quality of life when this path was examined alone. When all variables were controlled, income was negatively related to quality of life. When (1) the love of money was negatively correlated to job satisfaction and (2) job satisfaction was positively related to both income and quality of life, income was negatively related to quality of life for full-time, high-income, and male employees. When these two conditions failed to exist, income was not related to quality of life for part-time, median- or low-income, and female employees. This model provides new insights regarding the impact of the love of money and job satisfaction on the income–quality of life relationship. Copyright Springer Science+Business Media, Inc. 2007income, quality of life, the love of money, job satisfaction, employment status, income level, gender, marital status,