Concurrent programming is increasingly important for achieving performance gains in the multi-core era, but it is also a difficult and error-prone task. Concurrency bugs are particularly difficult to avoid and diagnose, and therefore in order to improve methods for handling such bugs, we need a better understanding of their characteristics. In this paper we present a study of concurrency bugs in MySQL, a widely used database server. While previous studies of real-world concurrency bugs exist, they have centered their attention on the causes of these bugs. In this paper we provide a complementary focus on their effects, which is important for understanding how to detect or tolerate such bugs at run-time. Our study uncovered several interesting facts, such as the existence of a significant number of latent concurrency bugs, which silently corrupt data structures and are exposed to the user potentially much later. We also highlight several implications of our findings for the design of reliable concurrent systems.

Liquid-cooled microchannel heat sinks are regarded as being amongst the most effective solutions for handling high levels of heat dissipation in space-constrained electronics. However, obstacles to their successful incorporation into products have included their high pumping requirements and the limits on available space which precludes the use of conventional pumps. Moreover, the transport characteristics of microchannels can be different from macroscale channels because of different scaling of various forces affecting flow and heat transfer. The inherent potential of microchannel heat sinks, coupled with the gaps in understanding of relevant transport phenomena and difficulties in implementation, have guided significant research efforts towards the investigation of flow and heat transfer in microchannels and the development of microscale pumping technologies and novel diagnostics. In this paper, the potential and capabilities of microchannel heat sinks and micropumps are discussed. Their working principle, the state of the art, and unresolved issues are reviewed. Novel approaches for flow field measurement and for integrated micropumping are presented. Future developments necessary for wider incorporation of microchannel heat sinks and integrated micropumps in practical cooling solutions are outlined