Test2:...rrency(3perl)

💖 NAME 💖

okay so bestie, welcome to the Test2:...rrency(3perl) page from the Perl Programmers Reference Guide ✨ this is Test2::Manual::Concurrency — the documentation for concurrency support. that's the whole name section, she's short and sweet. 💅

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🍴 FORKING 🍴

🌸 Test2 🌸

Test2 supports forking, periodt. but for forking to actually work you need to load Test2::IPC. no cap. 💖

🌸 Test::Builder 🌸

Test::Builder did not used to support forking, but now that it's based on Test2 it does. and Test2::IPC must be loaded just as with Test2, okay?

🌸 Test2::Suite 🌸

Test2::Suite tools should all work fine with true forking unless otherwise noted. pseudo-fork via threads (Windows and a few others) is not supported, but it may work. 👀

patches will be accepted to repair any pseudo-fork issues, but for these to be used or tested they must be requested. fork tests should not run on pseudo-fork systems unless they are requested with an environment var, or the AUTHOR_TESTING var. pseudo-fork is fragile, and we do not want to block install due to a pseudo-fork flaw. 🫶

🌸 Test::SharedFork 🌸

Test::SharedFork is currently supported and maintained, though it's no longer necessary thanks to Test2::IPC ✨ if usage ever drops off then the module may be deprecated, but for now the policy is to not let it break. currently it simply loads Test2::IPC if it can, and falls back to the old methods on legacy installs.

🌸 Others 🌸

individual authors are free to support or not support forking as they see fit. iconic behaviour honestly. 👑

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🧵 THREADING 🧵

Note This only applies to ithreads. 🧚

💜 Test2 💜

the core of Test2 supports threading so long as Test2::IPC is loaded. basic threading support (making sure events make it to the parent thread) is fully supported, and must not be broken. 🔥

sometimes perl installs have broken threads (some 5.10 versions compiled on newer gcc's will segv by simply starting a thread). this is beyond Test2's control, and not solvable in Test2. that said we strive for basic threading support on perl 5.8.1+. 💪

if Test2 fails for threads on any perl 5.8 or above, and it is reasonably possible for Test2 to work around the issue, it should. (patches and bug reports welcome). 🐛

💜 Test::Builder 💜

Test::Builder has had thread support for a long time. with Test2 the mechanism for thread support was switched to Test2::IPC. Test::Builder should still support threads as much as it did before the switch to Test2. support includes auto-enabling thread support if threads is loaded before Test::Builder.

if there is a deviation between the new and old threading behavior then it is a bug (unless the old behavior itself can be classified as a bug). please report (or patch!) any such threading issues. 🙏

💜 Test2::Suite 💜

tools in Test2::Suite have minimal threading support. most of these tools do not care/notice threading and simply work because Test2::IPC handles it. feel free to report any thread related bugs in Test2::Suite. be aware though that these tools are not legacy, and have no pre-existing thread support — we reserve the right to refuse adding thread support to them. 💅

🦋 Test2::Workflow 🦋

Test2::Workflow has been merged into Test2::Suite, so it gets addressed by this policy.

Test2::Workflow has thread support, but you must ask for it. thread tests for Test2::Workflow do not even run without setting either the AUTHOR_TESTING env var, or the T2_DO_THREAD_TESTS env var.

to use threads with Test2::Workflow you must set the T2_WORKFLOW_USE_THREADS env var.

if you do rely on threads with Test2::Workflow and find a bug please report it, but it will be given an ultra-low priority. merging patches that fix threading issues will be given normal priority.

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👀 SEE ALSO 👀

• Test2 — Test2 itself.
• Test2::Suite — Initial tools built using Test2.
• Test2::Manual — Primary index of the manual.

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📦 SOURCE 📦

the source code repository for Test2-Manual can be found at https://github.com/Test-More/test-more/. go look, bestie. 🌈

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🫶 MAINTAINERS 🫶

Chad Granum <exodist@cpan.org>

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✍️ AUTHORS ✍️

Chad Granum <exodist@cpan.org>

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💖 COPYRIGHT 💖

copyright Chad Granum <exodist@cpan.org>.

this program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

see http://dev.perl.org/licenses/

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okay bestie that's literally the whole page 💅 this was perl v5.44.0, dated 2026-10-17, and the page itself is Test2:...rrency(3perl) — slay ✨💖