Dont use workers for swc & esbuild minify

[ronakj]

Modification Proposal

SWC and ESBuild minify both run off-thread though native bindings. We don't need to create workers to parallelize workloads for them, unlike terser or uglify-js which block the event loop if not run on separate worker. This should have performance improvement for people who have many output chunk files. I will try this out later and add some numbers to verify.

Expected Behavior / Situation

We simply use promise concurrenctly instead of workers to parallelize.

Actual Behavior / Situation

Workers are created regardless of minification implementation.

[alexander-akait]

@ronakj Can you provide profiling? Because we use parallelization to compress multiple files and avoid memory problems with real big files

[kdy1]

@alexander-akait

Will you accept a PR? SWC uses thread locals, and the worker thread causes segfaults on some platforms.

As a side note, next.js does not use workers for the SWC minifier because it's better for performance. I don't have the perf profile at the moment, but the parallelism of SWC is primarily managed by node.js worker threads (using napi), so it should be faster to call directly.

[kdy1]

I tried, and using false in

terser-webpack-plugin/src/index.js

Line 415 in be98c73

enableWorkerThreads: true,

was enough to fix the issue.

swc-project/swc#9855 (comment)