From de3405c275898c8cd528a636dbd40e1b685cfaa5 Mon Sep 17 00:00:00 2001 From: Paul Buetow Date: Wed, 13 May 2026 14:41:28 +0300 Subject: use errgroup instead of WaitGroup for concurrent snapshot builders Replace sync.WaitGroup with errgroup.Group in buildSubSnapshots so errors from sub-builders (buildSyscallSnapshots, buildFileSnapshots, buildProcessSnapshots, buildHistogramSnapshot) are captured and propagated rather than silently dropped. Change Engine.Snapshot() to return (*Snapshot, error), update runtime.SnapshotSource and dashboard.SnapshotSource interfaces accordingly, and adjust all callers in tui.go, dashboard/model.go, and the test helpers. Each sub-builder now returns (result, error); the error return is currently always nil but establishes the contract for future validation. The per-type Snapshot() convenience methods (histogram, syscall, file, process) panic on error since they are internal helpers where failure would be a programming bug. Co-Authored-By: Claude Sonnet 4.6 --- internal/statsengine/syscall.go | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) (limited to 'internal/statsengine/syscall.go') diff --git a/internal/statsengine/syscall.go b/internal/statsengine/syscall.go index 2ef929a..d58e8c9 100644 --- a/internal/statsengine/syscall.go +++ b/internal/statsengine/syscall.go @@ -99,12 +99,18 @@ func (a *syscallAccumulator) Add(pair *event.Pair) { } } +// Snapshot returns a slice of SyscallSnapshots for all tracked syscalls. +// It panics on build error, which should never happen for a valid accumulator. func (a *syscallAccumulator) Snapshot(elapsed time.Duration) []SyscallSnapshot { if a == nil { return nil } - return buildSyscallSnapshots(a.snapshotInputs(), elapsed) + snap, err := buildSyscallSnapshots(a.snapshotInputs(), elapsed) + if err != nil { + panic("buildSyscallSnapshots: " + err.Error()) + } + return snap } func (a *syscallAccumulator) snapshotInputs() []syscallSnapshotInput { @@ -132,7 +138,10 @@ func (a *syscallAccumulator) snapshotInputs() []syscallSnapshotInput { return inputs } -func buildSyscallSnapshots(inputs []syscallSnapshotInput, elapsed time.Duration) []SyscallSnapshot { +// buildSyscallSnapshots converts raw syscall accumulator inputs into sorted +// SyscallSnapshot slices. The error return is reserved for future validation; +// currently this function always succeeds. +func buildSyscallSnapshots(inputs []syscallSnapshotInput, elapsed time.Duration) ([]SyscallSnapshot, error) { rateDiv := elapsed.Seconds() result := make([]SyscallSnapshot, 0, len(inputs)) for _, in := range inputs { @@ -144,7 +153,7 @@ func buildSyscallSnapshots(inputs []syscallSnapshotInput, elapsed time.Duration) } return cmp.Compare(a.Name, b.Name) }) - return result + return result, nil } func (s *syscallStats) updateMinMax(duration uint64) { -- cgit v1.2.3