“Sleeping Barber” in Humus

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The “Sleeping Barber” problem is another classic concurrency example. As with our previous discussion of “Dining Philosophers”, actors allow a novel approaching to solving this problem. We will adjust a few of the details to enhance the metaphor and have a bit of fun with it. Our metaphorical barber provides yak shaving services. Yaks arrive […]

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High Availability for Mutable Shared State

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Mutable shared state is the root of all evil in concurrent systems. The history of concurrent computation is a basically the story of approaches to managing mutable shared state. The thread model, which has long held the dominant position, leads to intractable complexity [1]. The actor model captures state in the behavior of an actor. […]

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“Dining Philosophers” in Humus

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The “Dining Philosophers” problem is a classic example used to illustrate various challenges with concurrency. We will approach this problem by incrementally designing the actors which model the problem and its solution in Humus. Through this example we will explore the avoidance of deadlock and starvation in the design of actor-based systems. Basic Thinking/Eating Cycle […]

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