aboutsummaryrefslogtreecommitdiff
path: root/libgo/go/sync/cond_test.go
blob: 846f98bf39de292352e9151a2c57f3f178dd705f (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
// Copyright 2011 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.
package sync_test

import (
	. "sync"
	"testing"
)

func TestCondSignal(t *testing.T) {
	var m Mutex
	c := NewCond(&m)
	n := 2
	running := make(chan bool, n)
	awake := make(chan bool, n)
	for i := 0; i < n; i++ {
		go func() {
			m.Lock()
			running <- true
			c.Wait()
			awake <- true
			m.Unlock()
		}()
	}
	for i := 0; i < n; i++ {
		<-running // Wait for everyone to run.
	}
	for n > 0 {
		select {
		case <-awake:
			t.Fatal("goroutine not asleep")
		default:
		}
		m.Lock()
		c.Signal()
		m.Unlock()
		<-awake // Will deadlock if no goroutine wakes up
		select {
		case <-awake:
			t.Fatal("too many goroutines awake")
		default:
		}
		n--
	}
	c.Signal()
}

func TestCondBroadcast(t *testing.T) {
	var m Mutex
	c := NewCond(&m)
	n := 200
	running := make(chan int, n)
	awake := make(chan int, n)
	exit := false
	for i := 0; i < n; i++ {
		go func(g int) {
			m.Lock()
			for !exit {
				running <- g
				c.Wait()
				awake <- g
			}
			m.Unlock()
		}(i)
	}
	for i := 0; i < n; i++ {
		for i := 0; i < n; i++ {
			<-running // Will deadlock unless n are running.
		}
		if i == n-1 {
			m.Lock()
			exit = true
			m.Unlock()
		}
		select {
		case <-awake:
			t.Fatal("goroutine not asleep")
		default:
		}
		m.Lock()
		c.Broadcast()
		m.Unlock()
		seen := make([]bool, n)
		for i := 0; i < n; i++ {
			g := <-awake
			if seen[g] {
				t.Fatal("goroutine woke up twice")
			}
			seen[g] = true
		}
	}
	select {
	case <-running:
		t.Fatal("goroutine did not exit")
	default:
	}
	c.Broadcast()
}