1// Copyright 2023 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// Tests CPU profiling.
6
7//go:build ignore
8
9package main
10
11/*
12#include <pthread.h>
13
14void go_callback();
15void go_callback2();
16
17static void *thr(void *arg) {
18    go_callback();
19    return 0;
20}
21
22static void foo() {
23    pthread_t th;
24    pthread_attr_t attr;
25    pthread_attr_init(&attr);
26    pthread_attr_setstacksize(&attr, 256 << 10);
27    pthread_create(&th, &attr, thr, 0);
28    pthread_join(th, 0);
29}
30
31static void bar() {
32    go_callback2();
33}
34*/
35import "C"
36
37import (
38	"log"
39	"os"
40	"runtime"
41	"runtime/trace"
42)
43
44//export go_callback
45func go_callback() {
46	// Do another call into C, just to test that path too.
47	C.bar()
48}
49
50//export go_callback2
51func go_callback2() {
52	runtime.GC()
53}
54
55func main() {
56	// Start tracing.
57	if err := trace.Start(os.Stdout); err != nil {
58		log.Fatalf("failed to start tracing: %v", err)
59	}
60
61	// Do a whole bunch of cgocallbacks.
62	const n = 10
63	done := make(chan bool)
64	for i := 0; i < n; i++ {
65		go func() {
66			C.foo()
67			done <- true
68		}()
69	}
70	for i := 0; i < n; i++ {
71		<-done
72	}
73
74	// Do something to steal back any Ps from the Ms, just
75	// for coverage.
76	runtime.GC()
77
78	// End of traced execution.
79	trace.Stop()
80}
81