1 files changed, 102 insertions, 0 deletions
diff --git a/worker_watcher/container/queue/queue.go b/worker_watcher/container/queue/queue.go
new file mode 100644
index 00000000..a274a836
--- /dev/null
+++ b/worker_watcher/container/queue/queue.go
@@ -0,0 +1,102 @@
+package queue
+
+import (
+	"context"
+	"sync"
+	"sync/atomic"
+
+	"github.com/spiral/roadrunner/v2/worker"
+)
+
+const (
+	initialSize          = 1
+	maxInitialSize       = 8
+	maxInternalSliceSize = 10
+)
+
+type Node struct {
+	w []worker.BaseProcess
+	// LL
+	n *Node
+}
+
+type Queue struct {
+	mu sync.Mutex
+
+	head *Node
+	tail *Node
+
+	curr uint64
+	len  uint64
+
+	sliceSize uint64
+}
+
+func NewQueue() *Queue {
+	q := &Queue{
+		mu:        sync.Mutex{},
+		head:      nil,
+		tail:      nil,
+		curr:      0,
+		len:       0,
+		sliceSize: 0,
+	}
+
+	return q
+}
+
+func (q *Queue) Push(w worker.BaseProcess) {
+	q.mu.Lock()
+
+	if q.head == nil {
+		h := newNode(initialSize)
+		q.head = h
+		q.tail = h
+		q.sliceSize = maxInitialSize
+	} else if uint64(len(q.tail.w)) >= atomic.LoadUint64(&q.sliceSize) {
+		n := newNode(maxInternalSliceSize)
+		q.tail.n = n
+		q.tail = n
+		q.sliceSize = maxInternalSliceSize
+	}
+
+	q.tail.w = append(q.tail.w, w)
+
+	atomic.AddUint64(&q.len, 1)
+
+	q.mu.Unlock()
+}
+
+func (q *Queue) Pop(ctx context.Context) (worker.BaseProcess, error) {
+	q.mu.Lock()
+
+	if q.head == nil {
+		return nil, nil
+	}
+
+	w := q.head.w[q.curr]
+	q.head.w[q.curr] = nil
+	atomic.AddUint64(&q.len, ^uint64(0))
+	atomic.AddUint64(&q.curr, 1)
+
+	if atomic.LoadUint64(&q.curr) >= uint64(len(q.head.w)) {
+		n := q.head.n
+		q.head.n = nil
+		q.head = n
+		q.curr = 0
+	}
+
+	q.mu.Unlock()
+
+	return w, nil
+}
+
+func (q *Queue) Replace(oldPid int64, newWorker worker.BaseProcess) {
+
+}
+
+func (q *Queue) Destroy() {}
+
+func newNode(capacity int) *Node {
+	return &Node{w: make([]worker.BaseProcess, 0, capacity)}
+}