diff --git a/vendor/go.uber.org/atomic/uint64.go b/vendor/go.uber.org/atomic/uint64.go
new file mode 100644
index 0000000..3b6c71f
--- /dev/null
+++ b/vendor/go.uber.org/atomic/uint64.go
@@ -0,0 +1,102 @@
+// @generated Code generated by gen-atomicint.
+
+// Copyright (c) 2020 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package atomic
+
+import (
+	"encoding/json"
+	"strconv"
+	"sync/atomic"
+)
+
+// Uint64 is an atomic wrapper around uint64.
+type Uint64 struct {
+	_ nocmp // disallow non-atomic comparison
+
+	v uint64
+}
+
+// NewUint64 creates a new Uint64.
+func NewUint64(i uint64) *Uint64 {
+	return &Uint64{v: i}
+}
+
+// Load atomically loads the wrapped value.
+func (i *Uint64) Load() uint64 {
+	return atomic.LoadUint64(&i.v)
+}
+
+// Add atomically adds to the wrapped uint64 and returns the new value.
+func (i *Uint64) Add(n uint64) uint64 {
+	return atomic.AddUint64(&i.v, n)
+}
+
+// Sub atomically subtracts from the wrapped uint64 and returns the new value.
+func (i *Uint64) Sub(n uint64) uint64 {
+	return atomic.AddUint64(&i.v, ^(n - 1))
+}
+
+// Inc atomically increments the wrapped uint64 and returns the new value.
+func (i *Uint64) Inc() uint64 {
+	return i.Add(1)
+}
+
+// Dec atomically decrements the wrapped uint64 and returns the new value.
+func (i *Uint64) Dec() uint64 {
+	return i.Sub(1)
+}
+
+// CAS is an atomic compare-and-swap.
+func (i *Uint64) CAS(old, new uint64) bool {
+	return atomic.CompareAndSwapUint64(&i.v, old, new)
+}
+
+// Store atomically stores the passed value.
+func (i *Uint64) Store(n uint64) {
+	atomic.StoreUint64(&i.v, n)
+}
+
+// Swap atomically swaps the wrapped uint64 and returns the old value.
+func (i *Uint64) Swap(n uint64) uint64 {
+	return atomic.SwapUint64(&i.v, n)
+}
+
+// MarshalJSON encodes the wrapped uint64 into JSON.
+func (i *Uint64) MarshalJSON() ([]byte, error) {
+	return json.Marshal(i.Load())
+}
+
+// UnmarshalJSON decodes JSON into the wrapped uint64.
+func (i *Uint64) UnmarshalJSON(b []byte) error {
+	var v uint64
+	if err := json.Unmarshal(b, &v); err != nil {
+		return err
+	}
+	i.Store(v)
+	return nil
+}
+
+// String encodes the wrapped value as a string.
+func (i *Uint64) String() string {
+	v := i.Load()
+	return strconv.FormatUint(uint64(v), 10)
+}