1// Copyright 2015 The Go Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style
3// license that can be found in the LICENSE file.
4
5//go:build !plan9 && !windows
6// +build !plan9,!windows
7
8package main
9
10/*
11#include <stddef.h>
12#include <signal.h>
13#include <pthread.h>
14
15// Save the signal mask at startup so that we see what it is before
16// the Go runtime starts setting up signals.
17
18static sigset_t mask;
19
20static void init(void) __attribute__ ((constructor));
21
22static void init() {
23	sigemptyset(&mask);
24	pthread_sigmask(SIG_SETMASK, NULL, &mask);
25}
26
27int SIGINTBlocked() {
28	return sigismember(&mask, SIGINT);
29}
30*/
31import "C"
32
33import (
34	"fmt"
35	"io/fs"
36	"os"
37	"os/exec"
38	"os/signal"
39	"sync"
40	"syscall"
41)
42
43func init() {
44	register("CgoExecSignalMask", CgoExecSignalMask)
45}
46
47func CgoExecSignalMask() {
48	if len(os.Args) > 2 && os.Args[2] == "testsigint" {
49		if C.SIGINTBlocked() != 0 {
50			os.Exit(1)
51		}
52		os.Exit(0)
53	}
54
55	c := make(chan os.Signal, 1)
56	signal.Notify(c, syscall.SIGTERM)
57	go func() {
58		for range c {
59		}
60	}()
61
62	const goCount = 10
63	const execCount = 10
64	var wg sync.WaitGroup
65	wg.Add(goCount*execCount + goCount)
66	for i := 0; i < goCount; i++ {
67		go func() {
68			defer wg.Done()
69			for j := 0; j < execCount; j++ {
70				c2 := make(chan os.Signal, 1)
71				signal.Notify(c2, syscall.SIGUSR1)
72				syscall.Kill(os.Getpid(), syscall.SIGTERM)
73				go func(j int) {
74					defer wg.Done()
75					cmd := exec.Command(os.Args[0], "CgoExecSignalMask", "testsigint")
76					cmd.Stdin = os.Stdin
77					cmd.Stdout = os.Stdout
78					cmd.Stderr = os.Stderr
79					if err := cmd.Run(); err != nil {
80						// An overloaded system
81						// may fail with EAGAIN.
82						// This doesn't tell us
83						// anything useful; ignore it.
84						// Issue #27731.
85						if isEAGAIN(err) {
86							return
87						}
88						fmt.Printf("iteration %d: %v\n", j, err)
89						os.Exit(1)
90					}
91				}(j)
92				signal.Stop(c2)
93			}
94		}()
95	}
96	wg.Wait()
97
98	fmt.Println("OK")
99}
100
101// isEAGAIN reports whether err is an EAGAIN error from a process execution.
102func isEAGAIN(err error) bool {
103	if p, ok := err.(*fs.PathError); ok {
104		err = p.Err
105	}
106	return err == syscall.EAGAIN
107}
108