# \[ANN\] An efficient priority queue with low integer priorities

**URL:** <https://discuss.ocaml.org/t/ann-an-efficient-priority-queue-with-low-integer-priorities/17323>\
**Category:** Ecosystem\
**Tags:** announce\
**Created:** [September 26, 2025, 2:20pm UTC](https://discuss.ocaml.org/t/ann-an-efficient-priority-queue-with-low-integer-priorities/17323 "2025-09-26T14:20:43Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![fpottier](https://sea2.discourse-cdn.com/flex020/user_avatar/discuss.ocaml.org/fpottier/32/677_2.png) [@fpottier](https://discuss.ocaml.org/u/fpottier)\
**Post date:** [September 26, 2025, 2:20pm UTC](https://discuss.ocaml.org/t/ann-an-efficient-priority-queue-with-low-integer-priorities/17323/1 "2025-09-26T14:20:43Z")

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Hello,

I am happy to announce the release of `intPQueue`, a package that offers (two variants of) an efficient priority queue, which is restricted to scenarios where the priorities are low integers. See the [documentation](https://cambium.inria.fr/~fpottier/intPQueue/doc/intPQueue/).

```auto
  opam update && opam install intPQueue

```

Happy queueing,  
François.

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**Author:** ![ancolie](https://sea2.discourse-cdn.com/flex020/user_avatar/discuss.ocaml.org/ancolie/32/6189_2.png) [@ancolie](https://discuss.ocaml.org/u/ancolie)\
**Post date:** [September 26, 2025, 3:07pm UTC](https://discuss.ocaml.org/t/ann-an-efficient-priority-queue-with-low-integer-priorities/17323/2 "2025-09-26T15:07:38Z")

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Hi @fpottier,

The library seems quite interesting! I was wondering if the library is thread-safe and did not find an answer in the documentation. Reading the source, I see it depends on `Hector` which is not thread-safe so I guess it isn’t either. I think it would be worth to mention it in the documentation.

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**Author:** ![fpottier](https://sea2.discourse-cdn.com/flex020/user_avatar/discuss.ocaml.org/fpottier/32/677_2.png) [@fpottier](https://discuss.ocaml.org/u/fpottier)\
**Post date:** [November 17, 2025, 9:34am UTC](https://discuss.ocaml.org/t/ann-an-efficient-priority-queue-with-low-integer-priorities/17323/3 "2025-11-17T09:34:01Z")

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You are correct, it is not thread-safe. I will mention it; thanks for this suggestion.