ffi: reuse the callable created per symbol - #64971
Merged
Merged
Conversation
Collaborator
|
Review requested:
|
Codecov Report❌ Patch coverage is
Additional details and impacted files@@ Coverage Diff @@
## main #64971 +/- ##
==========================================
+ Coverage 90.31% 90.33% +0.02%
==========================================
Files 760 760
Lines 248496 248522 +26
Branches 46894 46904 +10
==========================================
+ Hits 224428 224513 +85
+ Misses 15492 15444 -48
+ Partials 8576 8565 -11
🚀 New features to boost your workflow:
|
ShogunPanda
approved these changes
Aug 3, 2026
This comment was marked as outdated.
This comment was marked as outdated.
Collaborator
trivikr
marked this pull request as draft
August 3, 2026 15:07
This comment was marked as outdated.
This comment was marked as outdated.
trivikr
marked this pull request as ready for review
August 4, 2026 14:47
CreateFunction() ran on every getFunction() call, every getFunctions() call, and every read of the functions accessor, each time emitting a trampoline, allocating an FFIFunctionInfo, and on the SharedBuffer path an ArrayBuffer. lib.functions.foo was therefore a different function on each read, and calling through the accessor in a loop leaked a page per iteration until GC: 20000 calls grew RSS by 58 MiB. Cache the created callable per symbol in function_wrappers_, and memoize the JS wrapper composed around it. Both entries are weak, so dropping the last user reference still releases the wrapper and its trampoline. The JS side stores a WeakRef because V8 can keep a raw function alive after the wrapper is gone, and a strong value would pin every wrapper for the lifetime of the library. Signed-off-by: Trivikram Kamat <16024985+trivikr@users.noreply.github.com> Assisted-by: claude:opus-5 PR-URL: nodejs#64971 Fixes: nodejs#64970 Reviewed-By: Paolo Insogna <paolo@cowtech.it>
trivikr
force-pushed
the
ffi-get-function-reuse-wrapper
branch
from
August 9, 2026 23:19
16a5d6e to
bf2f995
Compare
Member
Author
|
Landed in bf2f995 |
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
3 participants
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Fixes: #64970
CreateFunction() ran on every getFunction() call, every getFunctions() call, and every read of the functions accessor, each time emitting a trampoline, allocating an FFIFunctionInfo, and on the SharedBuffer path an ArrayBuffer. lib.functions.foo was therefore a different function on each read, and calling through the accessor in a loop leaked a page per iteration until GC: 20000 calls grew RSS by 58 MiB.
Cache the created callable per symbol in function_wrappers_, and memoize the JS wrapper composed around it. Both entries are weak, so dropping the last user reference still releases the wrapper and its trampoline. The JS side stores a WeakRef because V8 can keep a raw function alive after the wrapper is gone, and a strong value would pin every wrapper for the lifetime of the library.
Before
After
Assisted-by: claude:opus-5