djmil
81f5a49cea
- wrap existing errors with context + file:line, newline-separated for readable error chains - dual mode philosophy: panics + if err != nil - unify Expect for goexit and panic cases
57 lines
1.8 KiB
Go
57 lines
1.8 KiB
Go
//go:build result_goexit
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// Optional runtime.Goexit implementation, enabled with -tags result_goexit.
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//
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// Expect and Expectf exit the goroutine via runtime.Goexit instead of panic.
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// Goexit runs all deferred functions but is invisible to recover() — no
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// recover() call anywhere in the call chain can accidentally swallow a result
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// failure, making this build safe to use alongside frameworks or user code
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// that uses bare recover() inside Go/Run closures.
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//
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// Cost: error path ≈ 5.5 µs / ~536 B per failure (goroutineID parse +
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// sync.Map store/load + Goexit unwind) — about 4× the default panic build.
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// Happy-path cost is identical to the default.
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package result
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import (
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"runtime"
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"sync"
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)
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// gErrors stores errors set by exitGoroutine before calling runtime.Goexit,
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// keyed by goroutine ID. Entries are consumed by the enclosing Async call.
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var gErrors sync.Map
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// goroutineID returns the current goroutine's numeric ID by parsing the first
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// line of runtime.Stack output ("goroutine NNN [...]"). Called only on error
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// paths so the runtime.Stack overhead is acceptable.
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func goroutineID() uint64 {
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var buf [64]byte
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n := runtime.Stack(buf[:], false)
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var id uint64
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for _, b := range buf[10:n] { // skip "goroutine "
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if b < '0' || b > '9' {
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break
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}
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id = id*10 + uint64(b-'0')
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}
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return id
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}
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// exitGoroutine stores se in gErrors and exits the goroutine via Goexit.
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// The stored error is retrieved by collectGoexitFailure in the enclosing Async.
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func exitGoroutine(se *stackError) {
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gErrors.Store(goroutineID(), se)
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runtime.Goexit()
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}
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// collectGoexitFailure retrieves any failure stored by exitGoroutine for the
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// current goroutine, consuming the entry.
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func collectGoexitFailure() error {
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if stored, ok := gErrors.LoadAndDelete(goroutineID()); ok {
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return stored.(error)
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}
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return nil
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}
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