lib/sync: Add option for sasha-s/go-deadlock

vendor/github.com/sasha-s/go-deadlock/deadlock_test.go

@@ -0,0 +1,127 @@
+package deadlock
+
+import (
+	"log"
+	"math/rand"
+	"sync"
+	"sync/atomic"
+	"testing"
+	"time"
+)
+
+func TestNoDeadlocks(t *testing.T) {
+	defer restore()()
+	Opts.DeadlockTimeout = time.Millisecond * 5000
+	var a RWMutex
+	var b Mutex
+	var c RWMutex
+	var wg sync.WaitGroup
+	for i := 0; i < 10; i++ {
+		wg.Add(1)
+		go func() {
+			defer wg.Done()
+			for k := 0; k < 5; k++ {
+				func() {
+					a.Lock()
+					defer a.Unlock()
+					func() {
+						b.Lock()
+						defer b.Unlock()
+						func() {
+							c.RLock()
+							defer c.RUnlock()
+							time.Sleep(time.Duration((1000 + rand.Intn(1000))) * time.Millisecond / 200)
+						}()
+					}()
+				}()
+			}
+		}()
+		wg.Add(1)
+		go func() {
+			defer wg.Done()
+			for k := 0; k < 5; k++ {
+				func() {
+					a.RLock()
+					defer a.RUnlock()
+					func() {
+						b.Lock()
+						defer b.Unlock()
+						func() {
+							c.Lock()
+							defer c.Unlock()
+							time.Sleep(time.Duration((1000 + rand.Intn(1000))) * time.Millisecond / 200)
+						}()
+					}()
+				}()
+			}
+		}()
+	}
+	wg.Wait()
+}
+
+func TestLockOrder(t *testing.T) {
+	defer restore()()
+	Opts.DeadlockTimeout = 0
+	var deadlocks uint32
+	Opts.OnPotentialDeadlock = func() {
+		atomic.AddUint32(&deadlocks, 1)
+	}
+	var a RWMutex
+	var b Mutex
+	var wg sync.WaitGroup
+	wg.Add(1)
+	go func() {
+		defer wg.Done()
+		a.Lock()
+		b.Lock()
+		b.Unlock()
+		a.Unlock()
+	}()
+	wg.Wait()
+	wg.Add(1)
+	go func() {
+		defer wg.Done()
+		b.Lock()
+		a.RLock()
+		a.RUnlock()
+		b.Unlock()
+	}()
+	wg.Wait()
+	if deadlocks != 1 {
+		t.Fatalf("expected 1 deadlock, detected %d", deadlocks)
+	}
+}
+
+func TestHardDeadlock(t *testing.T) {
+	defer restore()()
+	Opts.DisableLockOrderDetection = true
+	Opts.DeadlockTimeout = time.Millisecond * 20
+	var deadlocks uint32
+	Opts.OnPotentialDeadlock = func() {
+		atomic.AddUint32(&deadlocks, 1)
+	}
+	var mu Mutex
+	mu.Lock()
+	ch := make(chan struct{})
+	go func() {
+		defer close(ch)
+		mu.Lock()
+		defer mu.Unlock()
+	}()
+	select {
+	case <-ch:
+	case <-time.After(time.Millisecond * 100):
+	}
+	if deadlocks != 1 {
+		t.Fatalf("expected 1 deadlock, detected %d", deadlocks)
+	}
+	log.Println("****************")
+	mu.Unlock()
+}
+
+func restore() func() {
+	opts := Opts
+	return func() {
+		Opts = opts
+	}
+}