Avoid pinning storage_head in iseq_mark_and_move
#568
Closed
+59
−31
Conversation
This file contains 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
This refactor changes the behavior of `iseq_mark_and_move` to avoid pinning the `storage_head`. Previously pinning was required because they could be gc'd during `iseq_set_sequence` it would be possible to end up with a half build array of instructions. However, in order to implement a moving immix algorithm we can't pin these objects so this rafactoring changes the code to mark and move. To accomplish this, it was required to add `iseq_size`, `iseq_encoded`, and the `mark_bits` union to the `iseq_compile_data` struct. In addition `iseq_compile_data` sets a bool for whether there is a single or list of mark bits. While this change is needed for moving immix, it should be better for Ruby's GC as well.
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
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Outdated suggestions cannot be applied.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.
This refactor changes the behavior of
iseq_mark_and_moveto avoid pinning thestorage_head. Previously pinning was required because they could be gc'd duringiseq_set_sequenceit would be possible to end up with a half build array of instructions. However, in order to implement a moving immix algorithm we can't pin these objects so this rafactoring changes the code to mark and move. To accomplish this, it was required to addiseq_size,iseq_encoded, and themark_bitsunion to theiseq_compile_datastruct. In additioniseq_compile_datasets a bool for whether there is a single or list of mark bits. While this change is needed for moving immix, it should be better for Ruby's GC as well.cc/ @tenderlove @peterzhu2118