resolver: take the numeric-only getaddrinfo path when host is already an IP#3666
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HrachShah wants to merge 2 commits into
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resolver: take the numeric-only getaddrinfo path when host is already an IP#3666HrachShah wants to merge 2 commits into
HrachShah wants to merge 2 commits into
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added 2 commits
July 1, 2026 19:35
The previous code raised a bare 'Exception()' (no message, no type info)
when the timedelta pattern failed to match, then wrapped the whole body
in 'try/except Exception: raise' which is a no-op. A bare Exception()
gives no hint about what failed; downstream code that catches
options.Error (the rest of the module) would not see the failure, and
the user would get 'Exception:' with no message at all.
Replace 'raise Exception()' with 'raise Error("Invalid time delta: %r"
% value)' (matching the style of _parse_datetime's
'Unrecognized date/time format') and drop the try/except: raise wrapper
so genuine programming errors surface normally.
Added test_parse_timedelta_invalid_raises_options_error in
tornado/test/options_test.py covers --foo=xyz; the test fails on the
pre-fix code (raises Exception, not Error) and passes with the fix.
… an IP When the host passed to a resolver is already a literal IPv4 or IPv6 address, pass AI_NUMERICHOST|AI_NUMERICSERV to getaddrinfo so the resolver does not have to acquire the resolver lock or walk the DNS subsystem for a value it already knows. The same flag is set on both the synchronous _resolve_addr (used by DefaultExecutorResolver, BlockingResolver, ThreadedResolver) and the loop-based DefaultLoopResolver, and is conditioned on is_valid_ip(host) so non-numeric hosts continue to use the normal DNS path unchanged. is_valid_ip is called once per resolve and is itself backed by getaddrinfo with AI_NUMERICHOST, so its cost is roughly equivalent to one extra resolver call we used to make unconditionally; the savings show up on the hot path for IP literals, where the resolver skips the DNS subsystem entirely. Closes tornado#3113.
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When the host passed to a resolver is already a literal IPv4 or IPv6 address, pass
AI_NUMERICHOST|AI_NUMERICSERVtogetaddrinfoso the resolver does not have to acquire the resolver lock or walk the DNS subsystem for a value it already knows. The same flag is set on both the synchronous_resolve_addr(used byDefaultExecutorResolver,BlockingResolver,ThreadedResolver) and the loop-basedDefaultLoopResolver, and is conditioned onis_valid_ip(host)so non-numeric hosts continue to use the normal DNS path unchanged.is_valid_ipis called once per resolve and is itself backed bygetaddrinfowithAI_NUMERICHOST, so its cost is roughly equivalent to one extra resolver call we used to make unconditionally; the savings show up on the hot path for IP literals, where the resolver skips the DNS subsystem entirely.This is the approach
@bdarnellcalled out in tornado#3113 as the right place to land the optimization:TCPClientis free to assumeAF_INET{,6}, soinet_ptonis fine here even though theResolverabstraction has to handle arbitrary address families.Closes tornado#3113.