This is similar to the `queryObjects()` console API provided by the
Chromium DevTools console. It can be used to search for objects that
have the matching constructor on its prototype chain in the entire
heap, which can be useful for memory leak regression tests. To avoid
surprising results, users should avoid using this API on constructors
whose implementation they don't control, or on constructors that can
be invoked by other parties in the application.
To avoid accidental leaks, this API does not return raw references to
the objects found. By default, it returns the count of the objects
found. If `options.format` is `'summary'`, it returns an array
containing brief string representations for each object. The visibility
provided in this API is similar to what the heap snapshot provides,
while users can save the cost of serialization and parsing and directly
filer the target objects during the search.
We have been using this API internally for the test suite, which
has been more stable than any other leak regression testing
strategies in the CI. With a public implementation we can now
use the public API instead.
PR-URL: https://github.com/nodejs/node/pull/51927
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Stephen Belanger <admin@stephenbelanger.com>
Reviewed-By: Vinícius Lourenço Claro Cardoso <contact@viniciusl.com.br>
Reviewed-By: Gerhard Stöbich <deb2001-github@yahoo.de>
Reviewed-By: Rafael Gonzaga <rafael.nunu@hotmail.com>
Previously we simply create a lot of the target objects and check
if the process crash due to OOM. Due to how we use emphemeron GC
to handle memory management, which is inefficient but necessary
for correctness, the tests can produce false positives as
the GC isn't efficient enough to catch up with a very fast
heap growth.
This patch uses a new checkIfCollectable() utility to terminate the
test early once we detect that any of the target object can actually
be garbage collected. This should lower the chance of false positives.
As a drive-by this also allows us to use setImmediate() to grow the
heap even faster to make the tests run faster.
PR-URL: https://github.com/nodejs/node/pull/49671
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
Reviewed-By: Yagiz Nizipli <yagiz@nizipli.com>
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Joyee Cheung