domain: allow concurrent user-land impl

[Trott]

Picking up #26326

Checklist

• make -j4 test (UNIX), or vcbuild test (Windows) passes
• tests and/or benchmarks are included
• documentation is changed or added
• commit message follows commit guidelines

[Trott]

A chunk of code that was deleted in the original pull request is restored here so that test/parallel/test-domain-emit-error-handler-stack.js will pass. Is that the right approach, or is the thing to do to delete/update the test as its behavior should change?

@misterdjules @vdeturckheim @addaleax @devsnek

[Trott]

Remaining to be done:

• Need to document isDomainLike symbol for end users
• Need to include use of isDomainLike symbol by end users in a test
• Proof-of-concept code for .isDomainLike by @misterdjules is at https://github.com/misterdjules/domaine/blob/a6b928c906245dd7a1d93b581c6286b298dfdc92/index.js#L178

[mscdex]

This produces some significant performance regressions:

                                                    confidence improvement accuracy (*)   (**)  (***)
events/ee-emit.js listeners=10 argc=0 n=2000000            ***    -25.42 %       ±1.07% ±1.43% ±1.88%
events/ee-emit.js listeners=10 argc=10 n=2000000           ***    -17.68 %       ±0.89% ±1.18% ±1.53%
events/ee-emit.js listeners=10 argc=2 n=2000000            ***    -14.36 %       ±2.09% ±2.81% ±3.71%
events/ee-emit.js listeners=10 argc=4 n=2000000            ***    -14.72 %       ±1.41% ±1.89% ±2.47%
events/ee-emit.js listeners=1 argc=0 n=2000000             ***    -19.82 %       ±3.42% ±4.56% ±5.94%
events/ee-emit.js listeners=1 argc=10 n=2000000            ***    -34.73 %       ±2.36% ±3.15% ±4.12%
events/ee-emit.js listeners=1 argc=2 n=2000000             ***    -32.23 %       ±3.10% ±4.14% ±5.43%
events/ee-emit.js listeners=1 argc=4 n=2000000             ***    -27.68 %       ±2.74% ±3.66% ±4.79%
events/ee-emit.js listeners=5 argc=0 n=2000000             ***    -14.22 %       ±1.69% ±2.25% ±2.94%
events/ee-emit.js listeners=5 argc=10 n=2000000            ***    -20.74 %       ±1.79% ±2.40% ±3.15%
events/ee-emit.js listeners=5 argc=2 n=2000000             ***    -13.06 %       ±1.46% ±1.95% ±2.54%
events/ee-emit.js listeners=5 argc=4 n=2000000             ***    -14.43 %       ±2.13% ±2.85% ±3.72%
events/ee-once.js argc=4 n=20000000                        ***     -4.64 %       ±1.85% ±2.48% ±3.25%
events/ee-once.js argc=5 n=20000000                        ***     -4.46 %       ±1.60% ±2.13% ±2.78%

Can we find a way to avoid these first?

[addaleax]

I’m surprised that the impact is that large, but yes, we should definitely address that first…

[Trott]

@mscdex Can you re-run the benchmark CI so I can see what parameters you use / it uses? I'm running locally and getting very different results, which may be correct--different platforms/environments having different benchmarks--but it seems striking.

 events/ee-add-remove.js n=1000000                                         0.93 %       ±3.44%  ±4.58%  ±5.97%
 events/ee-emit.js listeners=1 argc=0 n=2000000                            1.63 %      ±13.38% ±17.81% ±23.20%
 events/ee-emit.js listeners=1 argc=10 n=2000000                          -1.59 %      ±14.54% ±19.35% ±25.20%
 events/ee-emit.js listeners=1 argc=2 n=2000000                           -3.36 %      ±13.41% ±17.84% ±23.22%
 events/ee-emit.js listeners=1 argc=4 n=2000000                            0.36 %      ±13.42% ±17.85% ±23.24%
 events/ee-emit.js listeners=10 argc=0 n=2000000                           0.03 %      ±14.22% ±18.92% ±24.63%
 events/ee-emit.js listeners=10 argc=10 n=2000000                         -0.16 %      ±17.77% ±23.64% ±30.77%
 events/ee-emit.js listeners=10 argc=2 n=2000000                          -4.87 %      ±14.30% ±19.03% ±24.77%
 events/ee-emit.js listeners=10 argc=4 n=2000000                          -1.99 %      ±13.51% ±17.98% ±23.42%
 events/ee-emit.js listeners=5 argc=0 n=2000000                           -7.17 %      ±15.48% ±20.60% ±26.81%
 events/ee-emit.js listeners=5 argc=10 n=2000000                          -9.15 %      ±12.54% ±16.68% ±21.71%
 events/ee-emit.js listeners=5 argc=2 n=2000000                           -4.81 %      ±14.36% ±19.11% ±24.88%
 events/ee-emit.js listeners=5 argc=4 n=2000000                           -8.17 %      ±13.48% ±17.94% ±23.37%
 events/ee-listener-count-on-prototype.js n=50000000                       0.18 %       ±3.31%  ±4.41%  ±5.75%
 events/ee-listeners.js raw='false' listeners=5 n=5000000                 -0.98 %       ±3.63%  ±4.83%  ±6.29%
 events/ee-listeners.js raw='false' listeners=50 n=5000000                 2.08 %       ±3.95%  ±5.25%  ±6.83%
 events/ee-listeners.js raw='true' listeners=5 n=5000000                   0.06 %       ±3.60%  ±4.79%  ±6.25%
 events/ee-listeners.js raw='true' listeners=50 n=5000000           *      8.66 %       ±6.59%  ±8.77% ±11.43%
 events/ee-once.js argc=0 n=20000000                                      -3.79 %      ±11.45% ±15.26% ±19.92%
 events/ee-once.js argc=1 n=20000000                                      -3.11 %       ±7.93% ±10.55% ±13.74%
 events/ee-once.js argc=4 n=20000000                                      -2.75 %       ±8.40% ±11.18% ±14.56%
 events/ee-once.js argc=5 n=20000000                                       2.38 %       ±8.14% ±10.83% ±14.09%
 events/eventtarget.js listeners=1 n=1000000                        *     -6.82 %       ±6.76%  ±9.00% ±11.73%
 events/eventtarget.js listeners=10 n=1000000                              5.46 %       ±6.92%  ±9.21% ±12.01%
 events/eventtarget.js listeners=5 n=1000000                      ***    -17.82 %       ±5.94%  ±7.91% ±10.29%

I also ran this after rebasing against master so it's possible something else changed that caused this to have less impact.

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/32674/

[mscdex]

CI results look about the same as before for this PR:

                                                          confidence improvement accuracy (*)   (**)   (***)
events/ee-emit.js listeners=10 argc=0 n=2000000                  ***    -22.05 %       ±1.25% ±1.67%  ±2.18%
events/ee-emit.js listeners=10 argc=10 n=2000000                 ***    -15.45 %       ±2.06% ±2.76%  ±3.62%
events/ee-emit.js listeners=10 argc=2 n=2000000                  ***     -8.32 %       ±1.84% ±2.47%  ±3.26%
events/ee-emit.js listeners=10 argc=4 n=2000000                  ***     -9.01 %       ±0.89% ±1.18%  ±1.54%
events/ee-emit.js listeners=1 argc=0 n=2000000                   ***    -15.22 %       ±5.73% ±7.67% ±10.09%
events/ee-emit.js listeners=1 argc=10 n=2000000                  ***    -31.82 %       ±4.32% ±5.80%  ±7.67%
events/ee-emit.js listeners=1 argc=2 n=2000000                   ***    -26.61 %       ±2.35% ±3.14%  ±4.09%
events/ee-emit.js listeners=1 argc=4 n=2000000                   ***    -30.98 %       ±3.45% ±4.62%  ±6.09%
events/ee-emit.js listeners=5 argc=0 n=2000000                   ***    -15.69 %       ±3.59% ±4.79%  ±6.26%
events/ee-emit.js listeners=5 argc=10 n=2000000                  ***    -26.00 %       ±1.17% ±1.55%  ±2.02%
events/ee-emit.js listeners=5 argc=2 n=2000000                   ***     -8.70 %       ±1.45% ±1.93%  ±2.51%
events/ee-emit.js listeners=5 argc=4 n=2000000                   ***    -12.15 %       ±1.71% ±2.27%  ±2.96%
events/ee-once.js argc=1 n=20000000                              ***     -4.73 %       ±1.82% ±2.42%  ±3.16%
events/ee-once.js argc=4 n=20000000                              ***     -6.53 %       ±2.73% ±3.64%  ±4.75%
events/ee-once.js argc=5 n=20000000                              ***     -5.82 %       ±3.13% ±4.18%  ±5.48%

[Trott]

The parameters for the benchmark CI run, for when that link expires:

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/37013/

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/37020/ ✅

[mscdex]

FWIW there are still some significant regressions:

events/ee-emit.jslisteners=10 argc=0 n=2000000       ***    -19.07 %       ±1.58% ±2.10%  ±2.74%
events/ee-emit.jslisteners=10 argc=10 n=2000000      ***    -33.23 %       ±0.88% ±1.17%  ±1.52%
events/ee-emit.jslisteners=10 argc=2 n=2000000       ***    -23.71 %       ±0.76% ±1.02%  ±1.33%
events/ee-emit.jslisteners=10 argc=4 n=2000000       ***    -27.12 %       ±0.86% ±1.14%  ±1.49%
events/ee-emit.jslisteners=1 argc=0 n=2000000        ***    -20.25 %       ±3.37% ±4.50%  ±5.88%
events/ee-emit.jslisteners=1 argc=10 n=2000000       ***    -29.84 %       ±4.91% ±6.56%  ±8.58%
events/ee-emit.jslisteners=1 argc=2 n=2000000        ***    -27.89 %       ±2.60% ±3.46%  ±4.53%
events/ee-emit.jslisteners=1 argc=4 n=2000000        ***    -30.05 %       ±3.50% ±4.65%  ±6.06%
events/ee-emit.jslisteners=5 argc=0 n=2000000        ***    -13.61 %       ±1.67% ±2.23%  ±2.90%
events/ee-emit.jslisteners=5 argc=10 n=2000000       ***    -42.20 %       ±1.41% ±1.89%  ±2.50%
events/ee-emit.jslisteners=5 argc=2 n=2000000        ***    -31.84 %       ±1.39% ±1.85%  ±2.42%
events/ee-emit.jslisteners=5 argc=4 n=2000000        ***    -33.71 %       ±1.52% ±2.03%  ±2.66%
events/ee-once.jsargc=0 n=20000000                   ***     -2.04 %       ±0.93% ±1.23%  ±1.61%
events/ee-once.jsargc=5 n=20000000                   ***     -4.53 %       ±1.56% ±2.09%  ±2.73%

[Trott]

Benchmark CI: https://ci.nodejs.org/view/Node.js%20benchmark/job/benchmark-node-micro-benchmarks/987/

[Trott]

Whoops, @mscdex's results were from a benchmark CI run and not a local run, so my benchmark CI run was superfluous. Oh well, here are the results anyway:

22:12:45                                                          confidence improvement accuracy (*)   (**)  (***)
22:12:45 events/ee-add-remove.jsn=1000000                                         0.03 %       ±2.21% ±2.94% ±3.83%
22:12:45 events/ee-emit.jslisteners=10 argc=0 n=2000000                  ***    -17.66 %       ±2.83% ±3.81% ±5.04%
22:12:45 events/ee-emit.jslisteners=10 argc=10 n=2000000                 ***    -32.48 %       ±1.21% ±1.62% ±2.12%
22:12:45 events/ee-emit.jslisteners=10 argc=2 n=2000000                  ***    -24.41 %       ±1.02% ±1.36% ±1.77%
22:12:45 events/ee-emit.jslisteners=10 argc=4 n=2000000                  ***    -26.14 %       ±2.73% ±3.67% ±4.84%
22:12:45 events/ee-emit.jslisteners=1 argc=0 n=2000000                   ***    -20.79 %       ±3.38% ±4.52% ±5.93%
22:12:45 events/ee-emit.jslisteners=1 argc=10 n=2000000                  ***    -34.28 %       ±3.47% ±4.64% ±6.09%
22:12:45 events/ee-emit.jslisteners=1 argc=2 n=2000000                   ***    -27.86 %       ±2.94% ±3.92% ±5.10%
22:12:45 events/ee-emit.jslisteners=1 argc=4 n=2000000                   ***    -28.60 %       ±3.69% ±4.92% ±6.43%
22:12:45 events/ee-emit.jslisteners=5 argc=0 n=2000000                   ***    -11.99 %       ±1.83% ±2.44% ±3.17%
22:12:45 events/ee-emit.jslisteners=5 argc=10 n=2000000                  ***    -41.38 %       ±1.29% ±1.73% ±2.27%
22:12:45 events/ee-emit.jslisteners=5 argc=2 n=2000000                   ***    -31.60 %       ±2.03% ±2.73% ±3.60%
22:12:45 events/ee-emit.jslisteners=5 argc=4 n=2000000                   ***    -33.87 %       ±2.17% ±2.91% ±3.84%
22:12:45 events/ee-listener-count-on-prototype.jsn=50000000                       2.23 %       ±4.07% ±5.44% ±7.12%
22:12:45 events/ee-listeners.jsraw='false' listeners=50 n=5000000                -0.15 %       ±2.52% ±3.36% ±4.39%
22:12:45 events/ee-listeners.jsraw='false' listeners=5 n=5000000                  1.06 %       ±1.55% ±2.07% ±2.69%
22:12:45 events/ee-listeners.jsraw='true' listeners=50 n=5000000                 -0.02 %       ±1.82% ±2.43% ±3.16%
22:12:45 events/ee-listeners.jsraw='true' listeners=5 n=5000000                   1.66 %       ±3.92% ±5.22% ±6.82%
22:12:45 events/ee-once.jsargc=0 n=20000000                                      -1.25 %       ±3.90% ±5.19% ±6.76%
22:12:45 events/ee-once.jsargc=1 n=20000000                               **     -4.86 %       ±2.93% ±3.95% ±5.23%
22:12:45 events/ee-once.jsargc=4 n=20000000                              ***     -5.65 %       ±1.54% ±2.06% ±2.68%
22:12:45 events/ee-once.jsargc=5 n=20000000                              ***     -5.21 %       ±0.96% ±1.29% ±1.69%
22:12:45 events/eventtarget.jslisteners=10 n=1000000                              0.02 %       ±1.75% ±2.32% ±3.02%
22:12:45 events/eventtarget.jslisteners=1 n=1000000                              -2.71 %       ±3.96% ±5.33% ±7.06%
22:12:45 events/eventtarget.jslisteners=5 n=1000000                              -0.94 %       ±3.50% ±4.69% ±6.16%
22:12:45 
22:12:45 Be aware that when doing many comparisons the risk of a false-positive
22:12:45 result increases. In this case, there are 25 comparisons, you can thus
22:12:45 expect the following amount of false-positive results:
22:12:45   1.25 false positives, when considering a   5% risk acceptance (*, **, ***),
22:12:45   0.25 false positives, when considering a   1% risk acceptance (**, ***),
22:12:45   0.03 false positives, when considering a 0.1% risk acceptance (***)
22:12:45 ++ mv output280321-054823.csv /w/bnch-comp

[Trott]

I'm not seeing any obvious way to improve performance and this isn't something I'm inclined to seek out non-obvious ways to do it. So I'm inclined to close.

@mscdex Do you see anything obvious that might be worth trying to refactor into a more performant shape?