From 8b15effd9ec6091feb9ec554ebe38cc02e765560 Mon Sep 17 00:00:00 2001 From: Jamie Liu Date: Tue, 15 Sep 2020 15:57:38 -0700 Subject: [PATCH] Improve syserror_test. - It's very difficult to prevent returnErrnoAsError and returnError from being optimized out. Instead, replace BenchmarkReturn* with BenchmarkAssign*, which store to globalError. - Compare to a non-nil globalError in BenchmarkCompare* and BenchmarkSwitch*. New results: BenchmarkAssignErrno BenchmarkAssignErrno-12 1000000000 0.615 ns/op BenchmarkAssignError BenchmarkAssignError-12 1000000000 0.626 ns/op BenchmarkCompareErrno BenchmarkCompareErrno-12 1000000000 0.522 ns/op BenchmarkCompareError BenchmarkCompareError-12 1000000000 3.54 ns/op BenchmarkSwitchErrno BenchmarkSwitchErrno-12 1000000000 1.45 ns/op BenchmarkSwitchError BenchmarkSwitchError-12 536315757 10.9 ns/op PiperOrigin-RevId: 331875387 --- pkg/syserror/syserror_test.go | 20 ++++++++------------ 1 file changed, 8 insertions(+), 12 deletions(-) diff --git a/pkg/syserror/syserror_test.go b/pkg/syserror/syserror_test.go index 29719752e..7036467c4 100644 --- a/pkg/syserror/syserror_test.go +++ b/pkg/syserror/syserror_test.go @@ -24,27 +24,20 @@ import ( var globalError error -func returnErrnoAsError() error { - return syscall.EINVAL -} - -func returnError() error { - return syserror.EINVAL -} - -func BenchmarkReturnErrnoAsError(b *testing.B) { +func BenchmarkAssignErrno(b *testing.B) { for i := b.N; i > 0; i-- { - returnErrnoAsError() + globalError = syscall.EINVAL } } -func BenchmarkReturnError(b *testing.B) { +func BenchmarkAssignError(b *testing.B) { for i := b.N; i > 0; i-- { - returnError() + globalError = syserror.EINVAL } } func BenchmarkCompareErrno(b *testing.B) { + globalError = syscall.EAGAIN j := 0 for i := b.N; i > 0; i-- { if globalError == syscall.EINVAL { @@ -54,6 +47,7 @@ func BenchmarkCompareErrno(b *testing.B) { } func BenchmarkCompareError(b *testing.B) { + globalError = syserror.EAGAIN j := 0 for i := b.N; i > 0; i-- { if globalError == syserror.EINVAL { @@ -63,6 +57,7 @@ func BenchmarkCompareError(b *testing.B) { } func BenchmarkSwitchErrno(b *testing.B) { + globalError = syscall.EPERM j := 0 for i := b.N; i > 0; i-- { switch globalError { @@ -77,6 +72,7 @@ func BenchmarkSwitchErrno(b *testing.B) { } func BenchmarkSwitchError(b *testing.B) { + globalError = syserror.EPERM j := 0 for i := b.N; i > 0; i-- { switch globalError {