Mark config as immutable and interned to avoid refcounting race conditions #2516
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…tions Signed-off-by: Bob Weinand <bob.weinand@datadoghq.com>
Signed-off-by: Bob Weinand <bob.weinand@datadoghq.com>
Signed-off-by: Bob Weinand <bob.weinand@datadoghq.com>
| static void zai_config_intern_zval(zval *pzval) { | ||
| if (Z_TYPE_P(pzval) == IS_STRING) { | ||
| #if PHP_VERSION_ID >= 70400 | ||
| ZVAL_INTERNED_STR(pzval, zend_new_interned_string(Z_STR_P(pzval))); |
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During a request, zend_new_interned_string will store strings in an arena in CG(interned_strings) (well, at least on PHP 8.3). Is that long enough for the values being store during zai_config_first_time_rinit? I worry that it's not.
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That's why there's a zend_interned_strings_switch_storage call in zai_config_first_rinit, so that it'll actually store it in persistent storage.
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Ah, I missed that. Thanks!
realFlowControl
approved these changes
Feb 15, 2024
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Description
Multiple threads manipulating the refcount at once is a possible source of race conditions (especially with many small requests increasing the likeness).
Properly mark the strings as interned / arrays as immutable to avoid this.
Reviewer checklist