1// Copyright 2017 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 <pthread.h>
13
14extern void CallbackNumGoroutine();
15
16static void* thread2(void* arg __attribute__ ((unused))) {
17	CallbackNumGoroutine();
18	return NULL;
19}
20
21static void CheckNumGoroutine() {
22	pthread_t tid;
23	pthread_create(&tid, NULL, thread2, NULL);
24	pthread_join(tid, NULL);
25}
26*/
27import "C"
28
29import (
30	"fmt"
31	"runtime"
32	"strings"
33)
34
35var baseGoroutines int
36
37func init() {
38	register("NumGoroutine", NumGoroutine)
39}
40
41func NumGoroutine() {
42	// Test that there are just the expected number of goroutines
43	// running. Specifically, test that the spare M's goroutine
44	// doesn't show up.
45	if _, ok := checkNumGoroutine("first", 1+baseGoroutines); !ok {
46		return
47	}
48
49	// Test that the goroutine for a callback from C appears.
50	if C.CheckNumGoroutine(); !callbackok {
51		return
52	}
53
54	// Make sure we're back to the initial goroutines.
55	if _, ok := checkNumGoroutine("third", 1+baseGoroutines); !ok {
56		return
57	}
58
59	fmt.Println("OK")
60}
61
62func checkNumGoroutine(label string, want int) (string, bool) {
63	n := runtime.NumGoroutine()
64	if n != want {
65		fmt.Printf("%s NumGoroutine: want %d; got %d\n", label, want, n)
66		return "", false
67	}
68
69	sbuf := make([]byte, 32<<10)
70	sbuf = sbuf[:runtime.Stack(sbuf, true)]
71	n = strings.Count(string(sbuf), "goroutine ")
72	if n != want {
73		fmt.Printf("%s Stack: want %d; got %d:\n%s\n", label, want, n, sbuf)
74		return "", false
75	}
76	return string(sbuf), true
77}
78
79var callbackok bool
80
81//export CallbackNumGoroutine
82func CallbackNumGoroutine() {
83	stk, ok := checkNumGoroutine("second", 2+baseGoroutines)
84	if !ok {
85		return
86	}
87	if !strings.Contains(stk, "CallbackNumGoroutine") {
88		fmt.Printf("missing CallbackNumGoroutine from stack:\n%s\n", stk)
89		return
90	}
91
92	callbackok = true
93}
94