How BIND 9 schedules callbacks — isc_job_run (same loop), isc_async_run (any thread → any loop), isc_work_enqueue (offload to a worker thread). Use when deciding where a callback should run, deferring a call to break lock re-entrancy or unwind the stack,…
The full commit workflow for BIND 9 repositories — pre-commit clang-format sequence, message shape and 72-column wrapping, trailer rules (Assisted-by and the forbidden ones), amend/fixup discipline, and the never-push boundary. Use EVERY time you are about to…
Drafting BIND 9 merge-request titles and descriptions — they feed the generated release notes, so the audience is system administrators. Use whenever writing or reviewing an MR title/description, when a change "needs a release note", or when tempted to touch…
BIND 9's memory allocator wrapper (isc_mem memory contexts and isc_mempool fixed-size pools). Use when writing or reviewing code that allocates/frees memory anywhere in BIND 9, when choosing between isc_mem_get/put and isc_mem_allocate/free, when debugging…
Methodology for root-causing hard concurrency / memory-ordering bugs (intermittent races, use-after-free, RCU/lock-free publish-order defects, "impossible" stale reads) with LTTng flight-recorder (snapshot) tracing — when static analysis, printf, and a…
Design pattern for per-loop (per-thread) sharded data structures in BIND 9 — isc_tid() affinity replaces locking, foreign mutation becomes mark + owner lazy-reap, and eviction pressure must spread across shards. Use when designing or reviewing sharded…
Correct discipline for mutating an RCU / lock-free pointer-based data structure (trie, tree, list, graph) that has concurrent readers — build a new node cluster invisibly, publish it, then reclaim the old nodes after a grace period. Use when writing or…
Measure and fix C struct layout in BIND 9 — pahole on the build's DWARF for sizes, padding holes, and cacheline boundaries, plus the house cacheline-padding idiom. Use when asked about struct size, padding, false sharing, or when adding/reordering members in…