Fold the rebind counter and traffic flags into one atomic word - #1820
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nbrownus wants to merge 2 commits into
Open
Fold the rebind counter and traffic flags into one atomic word#1820nbrownus wants to merge 2 commits into
nbrownus wants to merge 2 commits into
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JackDoan
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July 24, 2026 16:21
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Reduces the size of the
HostInfostruct (shaved 24 bytes off on my computer) and fixes a known/accepted data race withrebindCountwhich is more interesting now that we are using it on more than just iOS.The
HostInforeduction comes about by turning manyatomic.Bools into a singleatomic.Uint32(which is what anatomic.Boolis under the hood) and ordering the struct to reduce padding.rebindCountsafety comes about because 29 bits of theatomic.Uint32are allocated for it instead of the old rawuint8vialastRebindCount, and it becomes an atomic for free.The rebind counter comparison is handled in
ConnectionManager.Outnow in the same atomic operation that records outbound traffic.There was no change in throughput or CPU in my linux perf tests (a c8a.16xlarge server with 16 c8a.xlarge clients running iperf/reverse iperf for 5 minutes. I do expect some memory savings on highly connected hosts.