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synced 2026-11-08 01:20:26 +08:00
eb92159d72
This reverts commits: 10d6a3aca7 8ba48c1b85 fba8627dc1 dd883de5ba
6c6a25feca 167e6b48f1 7cb96d41a5 3207979278 595b3c4fdd 1521f7cf89
c11c5e69ac cf33608203 3632a812c0 f56506be0d 86427a3219 .
The reason for the revert is that we observe ABA problem around
inline method cache. When a cache misshits, we search for a
method entry. And if the entry is identical to what was cached
before, we reuse the cache. But the commits we are reverting here
introduced situations where a method entry is freed, then the
identical memory region is used for another method entry. An
inline method cache cannot detect that ABA.
Here is a code that reproduce such situation:
```ruby
require 'prime'
class << Integer
alias org_sqrt sqrt
def sqrt(n)
raise
end
GC.stress = true
Prime.each(7*37){} rescue nil # <- Here we populate CC
class << Object.new; end
# These adjacent remove-then-alias maneuver
# frees a method entry, then immediately
# reuses it for another.
remove_method :sqrt
alias sqrt org_sqrt
end
Prime.each(7*37).to_a # <- SEGV
```
35 lines
1.5 KiB
C
35 lines
1.5 KiB
C
#ifndef RUBY_ID_TABLE_H
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#define RUBY_ID_TABLE_H 1
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#include "ruby/ruby.h"
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struct rb_id_table;
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/* compatible with ST_* */
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enum rb_id_table_iterator_result {
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ID_TABLE_CONTINUE = ST_CONTINUE,
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ID_TABLE_STOP = ST_STOP,
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ID_TABLE_DELETE = ST_DELETE,
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ID_TABLE_REPLACE = ST_REPLACE,
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ID_TABLE_ITERATOR_RESULT_END
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};
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struct rb_id_table *rb_id_table_create(size_t size);
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void rb_id_table_free(struct rb_id_table *tbl);
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void rb_id_table_clear(struct rb_id_table *tbl);
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size_t rb_id_table_size(const struct rb_id_table *tbl);
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size_t rb_id_table_memsize(const struct rb_id_table *tbl);
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int rb_id_table_insert(struct rb_id_table *tbl, ID id, VALUE val);
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int rb_id_table_lookup(struct rb_id_table *tbl, ID id, VALUE *valp);
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int rb_id_table_delete(struct rb_id_table *tbl, ID id);
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typedef enum rb_id_table_iterator_result rb_id_table_update_callback_func_t(ID *id, VALUE *val, void *data, int existing);
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typedef enum rb_id_table_iterator_result rb_id_table_foreach_func_t(ID id, VALUE val, void *data);
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typedef enum rb_id_table_iterator_result rb_id_table_foreach_values_func_t(VALUE val, void *data);
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void rb_id_table_foreach(struct rb_id_table *tbl, rb_id_table_foreach_func_t *func, void *data);
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void rb_id_table_foreach_with_replace(struct rb_id_table *tbl, rb_id_table_foreach_func_t *func, rb_id_table_update_callback_func_t *replace, void *data);
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void rb_id_table_foreach_values(struct rb_id_table *tbl, rb_id_table_foreach_values_func_t *func, void *data);
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#endif /* RUBY_ID_TABLE_H */
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