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As we learn from the literature,

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Traditional data structure designs, whether lock-based or lock-free, provide parallelism via fine grained synchronization among threads.We introduce a new synchronization paradigm based on coarse locking, which we call flat combining. The cost of synchronization in flat combining is so low, that having a single thread holding a lock perform the combined access requests of all others, delivers, up to a certain non-negligible concurrency level, better performance than the most effective parallel finely synchronized implementations. We use flat-combining to devise, among other structures, new linearizable stack, queue, and priority queue algorithms that greatly outperform all prior algorithms.

From birth to adulthood, an animal's nervous system changes as its body grows and its behaviours mature. However, the extent of circuit remodelling across the connectome is poorly understood. Here, we used serial-section electron microscopy to reconstruct the brain of eight isogenic C. elegans individuals at different ages to learn how an entire wiring diagram changes with maturation. We found that the overall geometry of the nervous system is preserved from birth to adulthood, establishing a constant scaffold upon which synaptic change is built. We observed substantial connectivity differences among individuals that make each brain partly unique. We also observed developmental connectivity changes that are consistent between animals but different among neurons, altering the strengths of existing connections and creating additional connections. Collective synaptic changes alter information processing of the brain. Across maturation, the decision-making circuitry is maintained whereas sensory and motor pathways are substantially remodelled, and the brain becomes progressively more modular and feedforward. These synaptic changes reveal principles that underlie brain maturation.

An atomic snapshot memory is a shared data structure allowing concurrent processes to store information in a collection of shared registers, all of which may be read in a single atomic scan operation. This paper presents three wait-free implementations of atomic snapshot memory. Two constructions implement wait-free single-writer atomic snapshot memory from wait-free atomic single-writer, n-reader registers. A third construction implements a wait-free n-writer atomic snapshot memory from n-writer, n-reader registers. The first implementation uses unbounded

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We give necessary and sufficient combinatorial conditions characterizing the computational tasks that can be solved by N asynchronous processes, up to t of which can fail by halting.