tailscale/wgengine/watchdog_test.go

76 lines
1.7 KiB
Go

// Copyright (c) 2020 Tailscale Inc & 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 wgengine
import (
"bytes"
"fmt"
"strings"
"testing"
"time"
)
func TestWatchdog(t *testing.T) {
t.Parallel()
t.Run("default watchdog does not fire", func(t *testing.T) {
t.Parallel()
e, err := NewFakeUserspaceEngine(t.Logf, 0, nil)
if err != nil {
t.Fatal(err)
}
e = NewWatchdog(e)
e.(*watchdogEngine).maxWait = 150 * time.Millisecond
e.(*watchdogEngine).logf = t.Logf
e.(*watchdogEngine).fatalf = t.Fatalf
e.RequestStatus()
e.RequestStatus()
e.RequestStatus()
e.Close()
})
t.Run("watchdog fires on blocked getStatus", func(t *testing.T) {
t.Parallel()
e, err := NewFakeUserspaceEngine(t.Logf, 0, nil)
if err != nil {
t.Fatal(err)
}
usEngine := e.(*userspaceEngine)
e = NewWatchdog(e)
wdEngine := e.(*watchdogEngine)
wdEngine.maxWait = 100 * time.Millisecond
logBuf := new(bytes.Buffer)
fatalCalled := make(chan struct{})
wdEngine.logf = func(format string, args ...interface{}) {
fmt.Fprintf(logBuf, format+"\n", args...)
}
wdEngine.fatalf = func(format string, args ...interface{}) {
t.Logf("FATAL: %s", fmt.Sprintf(format, args...))
fatalCalled <- struct{}{}
}
usEngine.wgLock.Lock() // blocks getStatus so the watchdog will fire
go e.RequestStatus()
select {
case <-fatalCalled:
if !strings.Contains(logBuf.String(), "goroutine profile: total ") {
t.Errorf("fatal called without watchdog stacks, got: %s", logBuf.String())
}
// expected
case <-time.After(3 * time.Second):
t.Fatalf("watchdog failed to fire")
}
usEngine.wgLock.Unlock()
wdEngine.fatalf = t.Fatalf
wdEngine.Close()
})
}