The keeper keeps each transition from its own goroutine, which reads the memory store's Fail field under the store's lock; tests assigned the exported field bare, so TestAnUnreadableStoreClearsNothing failed under -race whenever the goroutine appended in that window. The field is now set only through SetFail (and Told's likewise), and a test makes the race certain rather than rare. Test-only: the controller runs the bus store, never InMemory.
31 lines
986 B
Go
31 lines
986 B
Go
package conditions
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import (
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"errors"
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"fmt"
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"testing"
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)
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// **A test may take the store away while the keeper is still telling.** The keeper keeps every
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// transition from a goroutine of its own, so the memory store's failure is read there while a test
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// switches it: it is switched under the store's lock, or the race detector fails the suite at random
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// (it once failed TestAnUnreadableStoreClearsNothing). A hundred transitions still being kept while
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// the failure is switched a hundred times makes the race certain, not rare, when the lock is skipped.
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func TestTheStoreIsTakenAwayWhileTheKeeperIsTelling(t *testing.T) {
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k, store, told, _ := keeper(t)
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ctx := t.Context()
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const n = 100
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for i := range n {
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if _, err := k.Observe(ctx, silent(fmt.Sprintf("m%d", i))); err != nil {
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t.Fatal(err)
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}
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}
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for range n {
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store.SetFail(errors.New("the bus is away"))
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store.SetFail(nil)
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}
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told.SetFail(errors.New("no responders"))
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told.SetFail(nil)
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settled(t, told, n)
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}
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