build: speed up startup with V8 code cache by joyeecheung · Pull Request #21405 · nodejs/node

This patch speeds up the startup time and reduce the startup memory
footprint by using V8 code cache when comiling builtin modules.

The current approach is demonstrated in the `with-code-cache`
Makefile target (no corresponding Windows target at the moment).

1. Build the binary normally (`src/node_code_cache_stub.cc` is used),
  by now `internalBinding('code_cache')` is an empty object
2. Run `tools/generate_code_cache.js` with the binary, which generates
  the code caches by reading source code of builtin modules off source
  code exposed by `require('internal/bootstrap/cache').builtinSource`
  and then generate a C++ file containing static char arrays of the
  code cache, using a format similar to `node_javascript.cc`
3. Run `configure` with the `--code-cache-path` option so that
  the newly generated C++ file will be used when compiling the
  new binary. The generated C++ file will put the cache into
  the `internalBinding('code_cache')` object with the module
  ids as keys
4. The new binary tries to read the code cache from
  `internalBinding('code_cache')` and use it to compile
  builtin modules. If the cache is used, it will put the id
  into `require('internal/bootstrap/cache').compiledWithCache`
  for bookkeeping, otherwise the id will be pushed into
  `require('internal/bootstrap/cache').compiledWithoutCache`

This patch also added tests that verify the code cache is
generated and used when compiling builtin modules.

The binary with code cache:

- Is ~1MB bigger than the binary without code cahe
- Consumes ~1MB less memory during start up
- Starts up about 60% faster

PR-URL: #21405
Reviewed-By: John-David Dalton <john.david.dalton@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Gus Caplan <me@gus.host>

This patch speeds up the startup time and reduce the startup memory
footprint by using V8 code cache when comiling builtin modules.

The current approach is demonstrated in the `with-code-cache`
Makefile target (no corresponding Windows target at the moment).

1. Build the binary normally (`src/node_code_cache_stub.cc` is used),
  by now `internalBinding('code_cache')` is an empty object
2. Run `tools/generate_code_cache.js` with the binary, which generates
  the code caches by reading source code of builtin modules off source
  code exposed by `require('internal/bootstrap/cache').builtinSource`
  and then generate a C++ file containing static char arrays of the
  code cache, using a format similar to `node_javascript.cc`
3. Run `configure` with the `--code-cache-path` option so that
  the newly generated C++ file will be used when compiling the
  new binary. The generated C++ file will put the cache into
  the `internalBinding('code_cache')` object with the module
  ids as keys
4. The new binary tries to read the code cache from
  `internalBinding('code_cache')` and use it to compile
  builtin modules. If the cache is used, it will put the id
  into `require('internal/bootstrap/cache').compiledWithCache`
  for bookkeeping, otherwise the id will be pushed into
  `require('internal/bootstrap/cache').compiledWithoutCache`

This patch also added tests that verify the code cache is
generated and used when compiling builtin modules.

The binary with code cache:

- Is ~1MB bigger than the binary without code cahe
- Consumes ~1MB less memory during start up
- Starts up about 60% faster

PR-URL: #21405
Reviewed-By: John-David Dalton <john.david.dalton@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Gus Caplan <me@gus.host>

Notable changes:

* build:
  * Node.js should now be about 60% faster to startup than the previous version,
    thanks to the use V8's code cache feature for core modules. [#21405](#21405)
* dns:
  * An experimental promisified version of the dns module is now available. Give
    it a try with `require('dns').promises`. [#21264](#21264)
* fs:
  * `fs.lchown` has been undeprecated now that libuv supports it. [#21498](#21498)
* lib:
  * `Atomics.wake` is being renamed to `Atomics.notify` in the ECMAScript
    specification ([reference](tc39/ecma262#1220)).
    Since Node.js now has experimental support for worker threads, we are being
    proactive and added a `notify` alias, while emitting a warning if
    `wake` is used. [#21413](#21413) [#21518](#21518)
* n-api:
  * Add API for asynchronous functions. [#17887](#17887)
* util:
  * `util.inspect` is now able to return a result instead of throwing when the
    maximum call stack size is exceeded during inspection. [#20725](#20725)
* vm:
  * Add `script.createCachedData()`. This API replaces the `produceCachedData`
    option of the `Script` constructor that is now deprecated. [#20300](#20300)
* worker:
  * Support for relative paths has been added to the `Worker` constructor. Paths
    are interpreted relative to the current working directory. [#21407](#21407)

PR-URL: #21629