diff --git a/util/deephash/deephash_test.go b/util/deephash/deephash_test.go index 3d2efd443..74321bf58 100644 --- a/util/deephash/deephash_test.go +++ b/util/deephash/deephash_test.go @@ -8,9 +8,11 @@ "archive/tar" "bufio" "bytes" + "crypto/sha256" "fmt" "math" "reflect" + "runtime" "testing" "inet.af/netaddr" @@ -332,15 +334,32 @@ func TestArrayAllocs(t *testing.T) { if version.IsRace() { t.Skip("skipping test under race detector") } + + // In theory, there should be no allocations. However, escape analysis on + // certain architectures fails to detect that certain cases do not escape. + // This discrepency currently affects sha256.digest.Sum. + // Measure the number of allocations in sha256 to ensure that Hash does + // not allocate on top of its usage of sha256. + // See https://golang.org/issue/48055. + var b []byte + h := sha256.New() + want := int(testing.AllocsPerRun(1000, func() { + b = h.Sum(b[:0]) + })) + switch runtime.GOARCH { + case "amd64", "arm64": + want = 0 // ensure no allocations on popular architectures + } + type T struct { X [32]byte } x := &T{X: [32]byte{1: 1, 2: 2, 3: 3, 4: 4}} - n := int(testing.AllocsPerRun(1000, func() { + got := int(testing.AllocsPerRun(1000, func() { sink = Hash(x) })) - if n > 0 { - t.Errorf("allocs = %v; want 0", n) + if got > want { + t.Errorf("allocs = %v; want %v", got, want) } }