PCRE2: allocate jit stack/match data once per thread#15955
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ysbaddaden wants to merge 6 commits intocrystal-lang:masterfrom
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PCRE2: allocate jit stack/match data once per thread#15955ysbaddaden wants to merge 6 commits intocrystal-lang:masterfrom
ysbaddaden wants to merge 6 commits intocrystal-lang:masterfrom
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straight-shoota
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Jul 3, 2025
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Grmbl. macOS CI is acting up again 😡 |
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macOS seems still broken. Any idea what's happening? Can someone with a mac check if this reproduces locally (and optionally investigate)? |
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Sigh. I'll have to start a tmate-action to see what's happening 😞 |
It seems to avoid a segfault on Darwin on CI, which may just be related to the old LLVM 11 version that we still use in shell.nix that's only use on the macOS CI woprkflow.
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Hum, it still segfaults on x86_64-darwin but not on aarch64-darwin 🤨 |
This reverts commit b85d9be.
Trying to set the struct's `@key` in the `#initialize` methods leads to a segfault when the struct will be set as a global (for example a class variable).
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Progress on macOS: I tried everything I could think of, and it eventually worked correctly on x86_64-darwin, but the process will segfault whenever we unwind the stack (e.g. we raise an exception). On the other hand, |
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Allocates the PCRE2 jit stack scratch space and match data once per thread, instead of once per thread and per regular expression.
Uses the new internal
Thread::Local(T)type to store the allocations, along with a destructor to make sure that the allocations will be freed when a thread terminates — no strong dependency, the library won't be linked if PCRE2 isn't used.Bonuses:
Removes the last usage of
Crystal::ThreadLocalValueoutside ofIO::Evented(used by libevent and wasi).Creating and accessing the jit stack and match data no longer needs to go through a Mutex (contention) or a Hash (complexity), we just go through a libc fun call.
Regular expressions shall thus be faster, at the expense of some memory, maybe (large allocated match data).
Follow up to #15616.
Obsoletes #15395 (where there are more details)