[Bug #21170] st_table reserves -1 as a special hash value to indicate that an entry has been deleted. So that that's a valid value to be returned from the hash function, do_hash replaces -1 with 0 so that it is not mistaken for the sentinel. Previously, when upgrading an AR table to an ST table, rb_st_add_direct_with_hash was used which did not perform the same conversion, this could lead to a hash in a broken state where one if its entries which was supposed to exist being marked as a tombstone. The hash could then become further corrupted when the ST table required resizing as the falsely tombstoned entry would be skipped but it would be counted in num entries, leading to an uninitialized entry at index 15. In most cases this will be really rare, unless using a very poorly implemented custom hash function. This also adds two debug assertions, one that st_add_direct_with_hash does not receive the reserved hash value, and a second in rebuild_table_with, which ensures that after we rebuild/compact a table it contains the expected number of elements. Co-authored-by: Alan Wu <alanwu@ruby-lang.org>
Merged into master in 7ba2506232d3fa6c4e82e3708c0ff746a1a8de5c [Bug #20050]
[Bug #19969] Compact st_table after deleted if possible --- hash.c | 19 +++++++++++++++++++ st.c | 40 +++++++++++++++++++++++++++++----------- test/ruby/test_hash.rb | 9 +++++++++ 3 files changed, 57 insertions(+), 11 deletions(-)
Use an st table for "too complex" objects st tables will maintain insertion order so we can marshal dump / load objects with instance variables in the same order they were set on that particular instance [ruby-core:112926] [Bug #19535] Co-Authored-By: Jemma Issroff <jemmaissroff@gmail.com> --- gc.c | 10 ++++------ include/ruby/st.h | 2 ++ object.c | 2 +- ractor.c | 43 ++++++++++++++++++++++--------------------- shape.h | 6 +++--- st.c | 6 ++++++ test/ruby/test_shapes.rb | 21 +++++++++++++++++++++ variable.c | 28 ++++++++++++++-------------- vm_insnhelper.c | 2 +- 9 files changed, 74 insertions(+), 46 deletions(-)
When the generic_iv_tbl is resized up, rebuild_table performs allocations that can trigger GC. If autocompaction is enabled, then moved objects are removed from and inserted into the generic_iv_tbl. This may cause another call to rebuild_table to resize the generic_iv_tbl. When returning back to the original rebuild_table, some of the data may be stale, causing the generic_iv_tbl to be corrupted. This commit changes rebuild_table to only read data from the st_table after the allocations have completed. Co-Authored-By: Matt Valentine-House <matt@eightbitraptor.com>
[Misc #18891]
tab->entries_bound is used to check if the bins are full in rebuild_table_if_necessary. Hash#shift against an empty hash assigned 0 to tab->entries_bound, but didn't clear the bins. Thus, the table is not rebuilt even when the bins are full. Attempting to add a new element into full-bin hash gets stuck. This change stops clearing tab->entries_bound in Hash#shift. [Bug #18578]
* --braces-after-func-def-line * --dont-cuddle-else * --procnames-start-lines * --space-after-for * --space-after-if * --space-after-while