add lock table to ensure ordered locks

weed/util/lock_table_test.go

@@ -0,0 +1,42 @@
+package util
+
+import (
+	"fmt"
+	"math/rand"
+	"sync"
+	"testing"
+	"time"
+)
+
+func TestOrderedLock(t *testing.T) {
+	lt := NewLockTable[string]()
+
+	var wg sync.WaitGroup
+	// Simulate transactions requesting locks
+	for i := 1; i <= 50; i++ {
+		wg.Add(1)
+		go func(i int) {
+			defer wg.Done()
+			key := "resource"
+			lockType := SharedLock
+			if i%5 == 0 {
+				lockType = ExclusiveLock
+			}
+
+			// Simulate attempting to acquire the lock
+			lock := lt.AcquireLock("", key, lockType)
+
+			// Lock acquired, perform some work
+			fmt.Printf("ActiveLock %d acquired the lock.\n", lock.ID)
+
+			// Simulate some work
+			time.Sleep(time.Duration(rand.Int31n(10)*10) * time.Millisecond)
+
+			// Release the lock
+			lt.ReleaseLock(key, lock)
+			fmt.Printf("ActiveLock %d released the lock.\n", lock.ID)
+		}(i)
+	}
+
+	wg.Wait()
+}