blob: 4a37c96e63a0ad66be60aff2e77a1a391a7c8f83 [file] [log] [blame]
// Copyright 2020 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.
//go:build linux && cgo
// On systems that use glibc, calling malloc can create a new arena,
// and creating a new arena can read /sys/devices/system/cpu/online.
// If we are using cgo, we will call malloc when creating a new thread.
// That can break TestExtraFiles if we create a new thread that creates
// a new arena and opens the /sys file while we are checking for open
// file descriptors. Work around the problem by creating threads up front.
// See issue 25628.
package exec_test
import (
func init() {
if os.Getenv("GO_WANT_HELPER_PROCESS") != "1" {
// Start some threads. 10 is arbitrary but intended to be enough
// to ensure that the code won't have to create any threads itself.
// In particular this should be more than the number of threads
// the garbage collector might create.
const threads = 10
var wg sync.WaitGroup
ts := syscall.NsecToTimespec((100 * time.Microsecond).Nanoseconds())
for i := 0; i < threads; i++ {
go func() {
defer wg.Done()
syscall.Nanosleep(&ts, nil)