dgram: extract cluster lazy loading method to make it testable

[pd4d10]

There is no need to ensure cluster loaded in bindServerHandle because
it's already loaded before calling it.

This PR makes cluster as an argument to remind developers that cluster
needs to be loaded before calling this function.

Update:
The lazy load parts in bindServerHandle is unreachable because cluster has been loaded before calling it. Extract it to a seperated method to make the code testable.

Refs:
https://coverage.nodejs.org/coverage-26e318a321a872bc/lib/dgram.js.html#L202

[RaisinTen]

Instead of using the raw cluster object, what do you think about using lazyLoadCluster()?

function lazyLoadCluster() {
  return cluster ??= require('cluster');
}

That way, the check for whether the module has been loaded is abstracted away and the original internal API too does not change.

[pd4d10]

Instead of using the raw cluster object, what do you think about using lazyLoadCluster()?

function lazyLoadCluster() {
  return cluster ??= require('cluster');
}

That way, the check for whether the module has been loaded is abstracted away and the original internal API too does not change.

Good idea. In this way the lazy load method can be tested.

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/37960/ 💚

[github-actions]

Fast-track has been requested by @jasnell. Please 👍 to approve.

[Trott]

I don't think any of this touches a hot code path, but just to be extra cautious, I'll kick off a benchmark CI.

[Trott]

Totally unnecessary benchmark CI: https://ci.nodejs.org/view/Node.js%20benchmark/job/benchmark-node-micro-benchmarks/1017/

Results

                                                                       confidence improvement accuracy (*)    (**)   (***)
dgram/array-vs-concat.js dur=5 type='concat' chunks=1 num=100 len=1024                 8.00 %      ±15.78% ±21.00% ±27.34%
dgram/array-vs-concat.js dur=5 type='concat' chunks=1 num=100 len=256                  0.45 %      ±12.49% ±16.62% ±21.63%
dgram/array-vs-concat.js dur=5 type='concat' chunks=1 num=100 len=512                 -4.97 %      ±15.09% ±20.08% ±26.13%
dgram/array-vs-concat.js dur=5 type='concat' chunks=1 num=100 len=64                   1.47 %       ±5.64%  ±7.51%  ±9.77%
dgram/array-vs-concat.js dur=5 type='concat' chunks=2 num=100 len=1024                13.31 %      ±18.14% ±24.13% ±31.41%
dgram/array-vs-concat.js dur=5 type='concat' chunks=2 num=100 len=256                 -6.94 %      ±10.92% ±14.54% ±18.92%
dgram/array-vs-concat.js dur=5 type='concat' chunks=2 num=100 len=512                 -9.03 %      ±16.36% ±21.77% ±28.35%
dgram/array-vs-concat.js dur=5 type='concat' chunks=2 num=100 len=64                   4.37 %       ±5.73%  ±7.65% ±10.01%
dgram/array-vs-concat.js dur=5 type='concat' chunks=4 num=100 len=1024                 7.34 %      ±19.17% ±25.51% ±33.21%
dgram/array-vs-concat.js dur=5 type='concat' chunks=4 num=100 len=256                 -1.29 %      ±14.79% ±19.68% ±25.62%
dgram/array-vs-concat.js dur=5 type='concat' chunks=4 num=100 len=512                 -5.58 %      ±17.42% ±23.18% ±30.17%
dgram/array-vs-concat.js dur=5 type='concat' chunks=4 num=100 len=64                   0.75 %       ±3.65%  ±4.85%  ±6.32%
dgram/array-vs-concat.js dur=5 type='concat' chunks=8 num=100 len=1024                 4.99 %      ±18.52% ±24.64% ±32.07%
dgram/array-vs-concat.js dur=5 type='concat' chunks=8 num=100 len=256                  0.33 %      ±12.84% ±17.08% ±22.23%
dgram/array-vs-concat.js dur=5 type='concat' chunks=8 num=100 len=512                 -9.71 %      ±16.64% ±22.15% ±28.82%
dgram/array-vs-concat.js dur=5 type='concat' chunks=8 num=100 len=64                   3.16 %       ±3.90%  ±5.19%  ±6.78%
dgram/array-vs-concat.js dur=5 type='multi' chunks=1 num=100 len=1024                 -1.46 %      ±12.50% ±16.63% ±21.65%
dgram/array-vs-concat.js dur=5 type='multi' chunks=1 num=100 len=256                   0.89 %      ±10.17% ±13.53% ±17.61%
dgram/array-vs-concat.js dur=5 type='multi' chunks=1 num=100 len=512                   0.24 %      ±10.33% ±13.75% ±17.90%
dgram/array-vs-concat.js dur=5 type='multi' chunks=1 num=100 len=64                   -0.06 %       ±3.37%  ±4.48%  ±5.84%
dgram/array-vs-concat.js dur=5 type='multi' chunks=2 num=100 len=1024                  3.17 %       ±5.85%  ±7.80% ±10.20%
dgram/array-vs-concat.js dur=5 type='multi' chunks=2 num=100 len=256                  -3.69 %       ±9.14% ±12.17% ±15.85%
dgram/array-vs-concat.js dur=5 type='multi' chunks=2 num=100 len=512                  -2.61 %       ±8.71% ±11.59% ±15.09%
dgram/array-vs-concat.js dur=5 type='multi' chunks=2 num=100 len=64                   -0.80 %       ±3.40%  ±4.54%  ±5.94%
dgram/array-vs-concat.js dur=5 type='multi' chunks=4 num=100 len=1024                 -1.57 %       ±5.46%  ±7.29%  ±9.54%
dgram/array-vs-concat.js dur=5 type='multi' chunks=4 num=100 len=256                  -0.96 %       ±6.37%  ±8.49% ±11.07%
dgram/array-vs-concat.js dur=5 type='multi' chunks=4 num=100 len=512                   0.66 %       ±3.42%  ±4.55%  ±5.92%
dgram/array-vs-concat.js dur=5 type='multi' chunks=4 num=100 len=64                    1.35 %       ±2.67%  ±3.56%  ±4.64%
dgram/array-vs-concat.js dur=5 type='multi' chunks=8 num=100 len=1024                  4.05 %       ±8.61% ±11.47% ±14.94%
dgram/array-vs-concat.js dur=5 type='multi' chunks=8 num=100 len=256                  -6.52 %      ±10.01% ±13.33% ±17.37%
dgram/array-vs-concat.js dur=5 type='multi' chunks=8 num=100 len=512                  -5.69 %       ±9.82% ±13.06% ±17.00%
dgram/array-vs-concat.js dur=5 type='multi' chunks=8 num=100 len=64                    0.56 %       ±4.09%  ±5.45%  ±7.09%
dgram/bind-params.js address='false' port='false' n=10000                             -0.03 %       ±5.28%  ±7.04%  ±9.17%
dgram/bind-params.js address='false' port='true' n=10000                              -2.77 %       ±3.97%  ±5.29%  ±6.88%
dgram/bind-params.js address='true' port='true' n=10000                               -4.45 %       ±4.64%  ±6.17%  ±8.04%
dgram/multi-buffer.js dur=5 type='recv' chunks=1 num=100 len=1024                      1.37 %      ±13.43% ±17.87% ±23.25%
dgram/multi-buffer.js dur=5 type='recv' chunks=1 num=100 len=256                      -5.82 %       ±9.66% ±12.85% ±16.73%
dgram/multi-buffer.js dur=5 type='recv' chunks=1 num=100 len=64                       -0.29 %       ±2.24%  ±2.98%  ±3.88%
dgram/multi-buffer.js dur=5 type='recv' chunks=2 num=100 len=1024                     -2.83 %       ±8.68% ±11.55% ±15.04%
dgram/multi-buffer.js dur=5 type='recv' chunks=2 num=100 len=256                       0.93 %       ±8.01% ±10.66% ±13.88%
dgram/multi-buffer.js dur=5 type='recv' chunks=2 num=100 len=64                        1.65 %       ±3.51%  ±4.68%  ±6.13%
dgram/multi-buffer.js dur=5 type='recv' chunks=4 num=100 len=1024                     -0.43 %       ±3.52%  ±4.69%  ±6.12%
dgram/multi-buffer.js dur=5 type='recv' chunks=4 num=100 len=256                       3.22 %       ±3.38%  ±4.52%  ±5.93%
dgram/multi-buffer.js dur=5 type='recv' chunks=4 num=100 len=64                       -2.96 %       ±3.71%  ±4.96%  ±6.49%
dgram/multi-buffer.js dur=5 type='recv' chunks=8 num=100 len=1024                     -6.57 %       ±8.92% ±11.88% ±15.48%
dgram/multi-buffer.js dur=5 type='recv' chunks=8 num=100 len=256                       0.21 %       ±9.23% ±12.28% ±15.99%
dgram/multi-buffer.js dur=5 type='recv' chunks=8 num=100 len=64                        1.94 %       ±4.87%  ±6.48%  ±8.45%
dgram/multi-buffer.js dur=5 type='send' chunks=1 num=100 len=1024                      5.05 %      ±13.85% ±18.43% ±23.98%
dgram/multi-buffer.js dur=5 type='send' chunks=1 num=100 len=256                       1.15 %      ±10.30% ±13.71% ±17.84%
dgram/multi-buffer.js dur=5 type='send' chunks=1 num=100 len=64                       -1.75 %       ±2.35%  ±3.15%  ±4.12%
dgram/multi-buffer.js dur=5 type='send' chunks=2 num=100 len=1024                     -5.01 %       ±8.76% ±11.65% ±15.16%
dgram/multi-buffer.js dur=5 type='send' chunks=2 num=100 len=256                       2.41 %       ±7.36%  ±9.79% ±12.74%
dgram/multi-buffer.js dur=5 type='send' chunks=2 num=100 len=64                        1.69 %       ±3.63%  ±4.83%  ±6.29%
dgram/multi-buffer.js dur=5 type='send' chunks=4 num=100 len=1024                     -0.46 %       ±5.25%  ±6.99%  ±9.12%
dgram/multi-buffer.js dur=5 type='send' chunks=4 num=100 len=256                       3.16 %       ±3.89%  ±5.20%  ±6.82%
dgram/multi-buffer.js dur=5 type='send' chunks=4 num=100 len=64                       -0.41 %       ±4.05%  ±5.38%  ±7.01%
dgram/multi-buffer.js dur=5 type='send' chunks=8 num=100 len=1024                      0.69 %      ±10.89% ±14.50% ±18.87%
dgram/multi-buffer.js dur=5 type='send' chunks=8 num=100 len=256                       8.60 %       ±9.46% ±12.63% ±16.52%
dgram/multi-buffer.js dur=5 type='send' chunks=8 num=100 len=64                        1.48 %       ±3.87%  ±5.16%  ±6.71%
dgram/offset-length.js dur=5 type='recv' num=100 len=1                                 0.84 %       ±1.88%  ±2.50%  ±3.25%
dgram/offset-length.js dur=5 type='recv' num=100 len=1024                              4.81 %      ±12.48% ±16.61% ±21.62%
dgram/offset-length.js dur=5 type='recv' num=100 len=256                               6.77 %      ±10.19% ±13.56% ±17.66%
dgram/offset-length.js dur=5 type='recv' num=100 len=64                               -0.26 %       ±2.97%  ±3.96%  ±5.16%
dgram/offset-length.js dur=5 type='send' num=100 len=1                                -1.36 %       ±2.28%  ±3.04%  ±3.96%
dgram/offset-length.js dur=5 type='send' num=100 len=1024                              8.38 %      ±10.28% ±13.68% ±17.83%
dgram/offset-length.js dur=5 type='send' num=100 len=256                        *    -12.43 %       ±9.51% ±12.66% ±16.49%
dgram/offset-length.js dur=5 type='send' num=100 len=64                               -0.96 %       ±1.93%  ±2.58%  ±3.37%
dgram/single-buffer.js dur=5 type='recv' num=100 len=1                                -0.10 %       ±3.29%  ±4.38%  ±5.70%
dgram/single-buffer.js dur=5 type='recv' num=100 len=1024                              2.33 %      ±15.12% ±20.12% ±26.19%
dgram/single-buffer.js dur=5 type='recv' num=100 len=256                              -3.00 %      ±15.35% ±20.43% ±26.59%
dgram/single-buffer.js dur=5 type='recv' num=100 len=64                               -0.89 %       ±3.76%  ±5.00%  ±6.50%
dgram/single-buffer.js dur=5 type='send' num=100 len=1                                -1.92 %       ±4.19%  ±5.58%  ±7.28%
dgram/single-buffer.js dur=5 type='send' num=100 len=1024                              0.56 %      ±13.72% ±18.25% ±23.75%
dgram/single-buffer.js dur=5 type='send' num=100 len=256                               4.81 %      ±18.09% ±24.07% ±31.33%
dgram/single-buffer.js dur=5 type='send' num=100 len=64                                1.70 %       ±3.76%  ±5.01%  ±6.53%

Be aware that when doing many comparisons the risk of a false-positive
result increases. In this case, there are 75 comparisons, you can thus
expect the following amount of false-positive results:
  3.75 false positives, when considering a   5% risk acceptance (*, **, ***),
  0.75 false positives, when considering a   1% risk acceptance (**, ***),
  0.07 false positives, when considering a 0.1% risk acceptance (***)

[aduh95]

Landed in 1b11398