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// 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.
// +build go1.13,!go1.16
//lint:file-ignore SA2001 the empty critical sections are part of triggering different internal mutex states
package syncs
import (
"sync"
"testing"
"time"
)
func wantPanic(t *testing.T, fn func()) {
t.Helper()
defer func() {
recover()
}()
fn()
t.Fatal("failed to panic")
}
func TestAssertLocked(t *testing.T) {
m := new(sync.Mutex)
wantPanic(t, func() { AssertLocked(m) })
m.Lock()
AssertLocked(m)
m.Unlock()
wantPanic(t, func() { AssertLocked(m) })
// Test correct handling of mutex with waiter.
m.Lock()
AssertLocked(m)
go func() {
m.Lock()
m.Unlock()
}()
// Give the goroutine above a few moments to get started.
// The test will pass whether or not we win the race,
// but we want to run sometimes, to get the test coverage.
time.Sleep(10 * time.Millisecond)
AssertLocked(m)
}
func TestAssertWLocked(t *testing.T) {
m := new(sync.RWMutex)
wantPanic(t, func() { AssertWLocked(m) })
m.Lock()
AssertWLocked(m)
m.Unlock()
wantPanic(t, func() { AssertWLocked(m) })
// Test correct handling of mutex with waiter.
m.Lock()
AssertWLocked(m)
go func() {
m.Lock()
m.Unlock()
}()
// Give the goroutine above a few moments to get started.
// The test will pass whether or not we win the race,
// but we want to run sometimes, to get the test coverage.
time.Sleep(10 * time.Millisecond)
AssertWLocked(m)
}
func TestAssertRLocked(t *testing.T) {
m := new(sync.RWMutex)
wantPanic(t, func() { AssertRLocked(m) })
m.Lock()
AssertRLocked(m)
m.Unlock()
m.RLock()
AssertRLocked(m)
m.RUnlock()
wantPanic(t, func() { AssertRLocked(m) })
// Test correct handling of mutex with waiter.
m.RLock()
AssertRLocked(m)
go func() {
m.RLock()
m.RUnlock()
}()
// Give the goroutine above a few moments to get started.
// The test will pass whether or not we win the race,
// but we want to run sometimes, to get the test coverage.
time.Sleep(10 * time.Millisecond)
AssertRLocked(m)
m.RUnlock()
// Test correct handling of rlock with write waiter.
m.RLock()
AssertRLocked(m)
go func() {
m.Lock()
m.Unlock()
}()
// Give the goroutine above a few moments to get started.
// The test will pass whether or not we win the race,
// but we want to run sometimes, to get the test coverage.
time.Sleep(10 * time.Millisecond)
AssertRLocked(m)
m.RUnlock()
// Test correct handling of rlock with other rlocks.
// This is a bit racy, but losing the race hurts nothing,
// and winning the race means correct test coverage.
m.RLock()
AssertRLocked(m)
go func() {
m.RLock()
time.Sleep(10 * time.Millisecond)
m.RUnlock()
}()
time.Sleep(5 * time.Millisecond)
AssertRLocked(m)
m.RUnlock()
}
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