// Copyright 2015 The Go Authors. All rights reserved. // Use of this source code is governed by a BSD-style // license that can be found in the LICENSE file. package runtime_test import ( "runtime" "sync" "testing" ) type response struct { } type myError struct { } func (myError) Error() string { return "" } func doRequest(useSelect bool) (*response, error) { type async struct { resp *response err error } ch := make(chan *async, 0) done := make(chan struct{}, 0) if useSelect { go func() { select { case ch <- &async{resp: nil, err: myError{}}: case <-done: } }() } else { go func() { ch <- &async{resp: nil, err: myError{}} }() } r := <-ch runtime.Gosched() return r.resp, r.err } func TestChanSendSelectBarrier(t *testing.T) { t.Parallel() testChanSendBarrier(true) } func TestChanSendBarrier(t *testing.T) { t.Parallel() testChanSendBarrier(false) } func testChanSendBarrier(useSelect bool) { var wg sync.WaitGroup outer := 100 inner := 100000 if testing.Short() || runtime.GOARCH == "wasm" { outer = 10 inner = 1000 } for i := 0; i < outer; i++ { wg.Add(1) go func() { defer wg.Done() var garbage []byte for j := 0; j < inner; j++ { _, err := doRequest(useSelect) _, ok := err.(myError) if !ok { panic(1) } garbage = makeByte() } _ = garbage }() } wg.Wait() } //go:noinline func makeByte() []byte { return make([]byte, 1<<10) }