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arXiv · 2508.13399

Concurrent Double-Ended Priority Queues

Panagiota Fatourou·Eric Ruppert·Ioannis Xiradakis
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Abstract

This work provides the first concurrent implementation specifically designed for a double-ended priority queue (DEPQ). We do this by describing a general way to add an ExtractMax operation to any concurrent priority queue that already supports Insert and ExtractMin operations. The construction uses two linearizable single-consumer priority queues to build a linearizable dual-consumer DEPQ (only one process can perform Extract operations at each end). This construction preserves lock-freedom. We then describe how to use a lock-based combining scheme to allow multiple consumers at each end of the DEPQ. To illustrate the technique, we apply it to a list-based priority queue.

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Panagiota Fatourou, Eric Ruppert, Ioannis Xiradakis. 2025-08-18. Concurrent Double-Ended Priority Queues. https://arxiv.org/abs/2508.13399

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