Skip to content

Fix infinite loop in flatmap resizing when bucket count is a power of two #3071

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
chenBright merged 1 commit into from
Aug 25, 2025
+6 −1
Merged

Fix infinite loop in flatmap resizing when bucket count is a power of two #3071

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
7 changes: 6 additions & 1 deletion src/butil/containers/flat_map_inl.h
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -714,8 +714,13 @@ template <typename _K, typename _T, typename _H, typename _E,
optional<typename FlatMap<_K, _T, _H, _E, _S, _A, _M>::NewBucketsInfo>
FlatMap<_K, _T, _H, _E, _S, _A, _M>::new_buckets_and_thumbnail(size_t size,
size_t new_nbucket) {
size_t bump = 0;
do {
new_nbucket = flatmap_round(new_nbucket);
// The first iteration uses 'new_nbucket + 0' ensures that when new_nbucket is a power
// of 2 and is already sufficient to accommodate `size`, it does not need to be doubled.
// Subsequent use of 'new_nbucket + 1' avoids an infinite loop.
new_nbucket = flatmap_round(new_nbucket + bump);
bump = 1;
} while (is_too_crowded(size, new_nbucket, _load_factor));
if (_nbucket == new_nbucket) {
return nullopt;
Expand Down
Loading