src: give Http2Session JS fields their own backing store#31648
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It looks like it’s virtually impossible at this point to create “fake” backing stores for objects that don’t fully own their memory allocations, like the sub-field `js_fields_` of `Http2Session`. In particular, it turns out that an `ArrayBuffer` cannot always be easily separated from its backing store in that situation through by detaching it. This commit gives the JS-exposed parts of the class its own memory allocation and its own backing store, simplifying the code a bit and fixing flakiness coming from it, at the cost of one additional layer of indirection when accessing the data. Refs: nodejs#30782Fixes: nodejs#31107
nodejs-github-bot added c++ 
jasnell approved these changes Feb 5, 2020
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nodejs-github-bot commented Feb 7, 2020
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nodejs-github-bot commented Feb 7, 2020
lundibundi approved these changes Feb 7, 2020
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nodejs-github-bot commented Feb 7, 2020
addaleax added author ready Collaborator
nodejs-github-bot commented Feb 7, 2020
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nodejs-github-bot commented Feb 7, 2020
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nodejs-github-bot commented Feb 7, 2020
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addaleax commented Feb 8, 2020
Landed in f368210 |
addaleax added a commit that referenced this pull request Feb 8, 2020
It looks like it’s virtually impossible at this point to create “fake” backing stores for objects that don’t fully own their memory allocations, like the sub-field `js_fields_` of `Http2Session`. In particular, it turns out that an `ArrayBuffer` cannot always be easily separated from its backing store in that situation through by detaching it. This commit gives the JS-exposed parts of the class its own memory allocation and its own backing store, simplifying the code a bit and fixing flakiness coming from it, at the cost of one additional layer of indirection when accessing the data. Refs: #30782Fixes: #31107 PR-URL: #31648 Reviewed-By: James M Snell <[email protected]> Reviewed-By: Denys Otrishko <[email protected]>
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MylesBorins commented Mar 9, 2020
@addaleax this doesn't appear to land cleanly on 13.x, would you be open to backport? |
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addaleax commented Mar 10, 2020
I don’t think this needs to be backported, it fixes a bug introduced in a semver-major PR (#30782). |
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It looks like it’s virtually impossible at this point to
create “fake” backing stores for objects that don’t fully
own their memory allocations, like the sub-field
js_fields_of
Http2Session. In particular, it turns out that anArrayBuffercannot always be easily separated from itsbacking store in that situation through by detaching it.
This commit gives the JS-exposed parts of the class its own
memory allocation and its own backing store, simplifying the
code a bit and fixing flakiness coming from it, at the cost
of one additional layer of indirection when accessing the data.
Refs: #30782
Fixes: #31107
Checklist
make -j4 test(UNIX), orvcbuild test(Windows) passes