1// run
2
3// Copyright 2019 The Go Authors. All rights reserved.
4// Use of this source code is governed by a BSD-style
5// license that can be found in the LICENSE file.
6
7// Make sure the runtime can scan args of an unstarted goroutine
8// which starts with a reflect-generated function.
9
10package main
11
12import (
13	"reflect"
14	"runtime"
15)
16
17const N = 100
18
19func main() {
20	runtime.GOMAXPROCS(1)
21	// Run GC in a loop. This makes it more likely GC will catch
22	// an unstarted goroutine then if we were to GC after kicking
23	// everything off.
24	go func() {
25		for {
26			runtime.GC()
27		}
28	}()
29	c := make(chan bool, N)
30	for i := 0; i < N; i++ {
31		// Test both with an argument and without because this
32		// affects whether the compiler needs to generate a
33		// wrapper closure for the "go" statement.
34		f := reflect.MakeFunc(reflect.TypeOf(((func(*int))(nil))),
35			func(args []reflect.Value) []reflect.Value {
36				c <- true
37				return nil
38			}).Interface().(func(*int))
39		go f(nil)
40
41		g := reflect.MakeFunc(reflect.TypeOf(((func())(nil))),
42			func(args []reflect.Value) []reflect.Value {
43				c <- true
44				return nil
45			}).Interface().(func())
46		go g()
47	}
48	for i := 0; i < N*2; i++ {
49		<-c
50	}
51}
52