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Release DNS cache iterators before expired-entry removal - #420
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j-mendez merged 1 commit intoOct 18, 2026
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Expired-entry eviction could deterministically deadlock HostDnsCache and ChromeNxdomainCache when a new host exceeded capacity. Dropping the yielded entry left the DashMap iterator’s shard read guard alive while removal waited for that same shard’s write lock. Select an owned victim key, exit the iterator scope, then remove. Preserve expired-first eviction, oldest fallback, TTLs, and concurrent capacity behavior. Validation: 21 targeted cache tests passed, including bounded-progress regressions for expired overflow, zero TTL/capacity one, oldest fallback, and concurrent overflow in both caches. Independent Claude review approved. Tests use the actual caches without DNS, browsers, or live sites.
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Expired-entry eviction could deterministically deadlock HostDnsCache and ChromeNxdomainCache when a new host exceeded capacity. Dropping the yielded entry left the DashMap iterator’s shard read guard alive while removal waited for that same shard’s write lock.
Select an owned victim key, exit the iterator scope, then remove. Preserve expired-first eviction, oldest fallback, TTLs, and concurrent capacity behavior.
Validation: 21 targeted cache tests passed, including bounded-progress regressions for expired overflow, zero TTL/capacity one, oldest fallback, and concurrent overflow in both caches. Independent Claude review approved. Tests use the actual caches without DNS, browsers, or live sites.