Ignore SIGPIPE process-wide — broken-pipe writes must not kill the server (Refs #320) - #328
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…the server
The default disposition killed the process in the kernel before write()
returned to Swift — unreachable by try?/do-catch — for any of ~26 stderr
sites or the stdout stdio transport (verified: delivered SIGPIPE → death
by signal 13, 2/2 on the pre-fix binary).
Sequenced per the diagnosis to avoid trading death-on-disconnect for
spin-on-disconnect:
1. verified stdin-EOF is the governing clean-shutdown path (rc=0,
independent of stdout state) BEFORE the change,
2. installed signal(SIGPIPE, SIG_IGN) in main.swift before any transport,
3. verified live that broken-pipe stdout + stdin EOF still exits rc=0.
SigpipeDispositionTests pins the disposition by delivering SIGPIPE to the
real spawned binary — deterministic and load-independent (pre 2/2 dead,
post 2/2 alive), unlike a bounded exit-after-EOF assertion, which
interleaved A/B showed would flake on pre-existing latency variance
(4s->40s+ on the unmodified binary; recorded as a separate observation).
Measurement honesty: an initial non-interleaved A/B wrongly suggested the
fix slowed shutdown; interleaving dissolved the signal into load noise.
Plan-tier note: implemented under unattended /idd-all — Plan deliberation
skipped per orchestrator contract, marked here.
1069 tests, 0 failures.
Refs #320
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Refs #320
Summary
No
SIGPIPEdisposition was ever set, so a broken-pipe write (any of ~26 stderr sites, or the stdout transport) killed the server in the kernel — unreachable by Swift error handling.signal(SIGPIPE, SIG_IGN)now installs at startup; broken-pipe writes becomeEPIPEerrnos the throwing write sites already swallow.Diagnosis-ordered safety sequence: (1) verified stdin-EOF is the clean-shutdown path before changing anything; (2) applied the fix; (3) verified live that broken-pipe stdout + stdin EOF still exits
rc=0(no spin).Verification
SigpipeDispositionTests: deliversSIGPIPEto the real spawned binary — pre-fix dies by signal 13 (2/2), post-fix survives (2/2). Deterministic and load-independent.Coordination
main.swiftis also touched by unmerged PR #307 (adds a--versioncase in the switch; this PR addssignal()above it) — different regions, trivial adjacency at merge.🤖 Generated by /idd-all. Do NOT add a GitHub close trailer — run /idd-close after merge.