4 files changed, 201 insertions, 68 deletions
diff --git a/pkg/worker_watcher/container/channel/vec.go b/pkg/worker_watcher/container/channel/vec.go
new file mode 100644
index 00000000..51093978
--- /dev/null
+++ b/pkg/worker_watcher/container/channel/vec.go
@@ -0,0 +1,99 @@
+package channel
+
+import (
+	"context"
+	"sync"
+	"sync/atomic"
+
+	"github.com/spiral/errors"
+	"github.com/spiral/roadrunner/v2/pkg/worker"
+)
+
+type Vec struct {
+	sync.RWMutex
+	// destroy signal
+	destroy uint64
+	// channel with the workers
+	workers chan worker.BaseProcess
+
+	len uint64
+}
+
+func NewVector(len uint64) *Vec {
+	vec := &Vec{
+		destroy: 0,
+		len:     len,
+		workers: make(chan worker.BaseProcess, len),
+	}
+
+	return vec
+}
+
+// Push is O(1) operation
+// In case of TTL and full channel O(n) worst case, where n is len of the channel
+func (v *Vec) Push(w worker.BaseProcess) {
+	// Non-blocking channel send
+	select {
+	case v.workers <- w:
+		// default select branch is only possible when dealing with TTL
+		// because in that case, workers in the v.workers channel can be TTL-ed and killed
+		// but presenting in the channel
+	default:
+		v.Lock()
+		defer v.Unlock()
+
+		/*
+			we can be in the default branch by the following reasons:
+			1. TTL is set with no requests during the TTL
+			2. Violated Get <-> Release operation (how ??)
+		*/
+		for i := uint64(0); i < v.len; i++ {
+			wrk := <-v.workers
+			switch wrk.State().Value() {
+			// skip good states
+			case worker.StateWorking, worker.StateReady:
+				// put the worker back
+				// generally, while send and receive operations are concurrent (from the channel), channel behave
+				// like a FIFO, but when re-sending from the same goroutine it behaves like a FILO
+				v.workers <- wrk
+				continue
+			default:
+				// kill the current worker (just to be sure it's dead)
+				_ = wrk.Kill()
+				// replace with the new one
+				v.workers <- w
+				return
+			}
+		}
+	}
+}
+
+func (v *Vec) Remove(_ int64) {}
+
+func (v *Vec) Pop(ctx context.Context) (worker.BaseProcess, error) {
+	/*
+		if *addr == old {
+			*addr = new
+			return true
+		}
+	*/
+
+	if atomic.CompareAndSwapUint64(&v.destroy, 1, 1) {
+		return nil, errors.E(errors.WatcherStopped)
+	}
+
+	// used only for the TTL-ed workers
+	v.RLock()
+	defer v.RUnlock()
+
+	select {
+	case w := <-v.workers:
+		return w, nil
+	case <-ctx.Done():
+		return nil, errors.E(ctx.Err(), errors.NoFreeWorkers)
+	}
+}
+
+func (v *Vec) Destroy() {
+	atomic.StoreUint64(&v.destroy, 1)
+}
diff --git a/pkg/worker_watcher/container/interface.go b/pkg/worker_watcher/container/interface.go
deleted file mode 100644
index e10ecdae..00000000
--- a/pkg/worker_watcher/container/interface.go
+++ /dev/null
@@ -1,17 +0,0 @@
-package container
-
-import (
-	"context"
-
-	"github.com/spiral/roadrunner/v2/pkg/worker"
-)
-
-// Vector interface represents vector container
-type Vector interface {
-	// Enqueue used to put worker to the vector
-	Enqueue(worker.BaseProcess)
-	// Dequeue used to get worker from the vector
-	Dequeue(ctx context.Context) (worker.BaseProcess, error)
-	// Destroy used to stop releasing the workers
-	Destroy()
-}
diff --git a/pkg/worker_watcher/container/queue/queue.go b/pkg/worker_watcher/container/queue/queue.go
new file mode 100644
index 00000000..edf81d60
--- /dev/null
+++ b/pkg/worker_watcher/container/queue/queue.go
@@ -0,0 +1,102 @@
+package queue
+
+import (
+	"context"
+	"sync"
+	"sync/atomic"
+
+	"github.com/spiral/roadrunner/v2/pkg/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)}
+}
diff --git a/pkg/worker_watcher/container/vec.go b/pkg/worker_watcher/container/vec.go
deleted file mode 100644
index 24b5fa6d..00000000
--- a/pkg/worker_watcher/container/vec.go
+++ /dev/null
@@ -1,51 +0,0 @@
-package container
-
-import (
-	"context"
-	"sync/atomic"
-
-	"github.com/spiral/errors"
-	"github.com/spiral/roadrunner/v2/pkg/worker"
-)
-
-type Vec struct {
-	destroy uint64
-	workers chan worker.BaseProcess
-}
-
-func NewVector(initialNumOfWorkers uint64) *Vec {
-	vec := &Vec{
-		destroy: 0,
-		workers: make(chan worker.BaseProcess, initialNumOfWorkers),
-	}
-
-	return vec
-}
-
-func (v *Vec) Enqueue(w worker.BaseProcess) {
-	v.workers <- w
-}
-
-func (v *Vec) Dequeue(ctx context.Context) (worker.BaseProcess, error) {
-	/*
-		if *addr == old {
-			*addr = new
-			return true
-		}
-	*/
-
-	if atomic.CompareAndSwapUint64(&v.destroy, 1, 1) {
-		return nil, errors.E(errors.WatcherStopped)
-	}
-
-	select {
-	case w := <-v.workers:
-		return w, nil
-	case <-ctx.Done():
-		return nil, errors.E(ctx.Err(), errors.NoFreeWorkers)
-	}
-}
-
-func (v *Vec) Destroy() {
-	atomic.StoreUint64(&v.destroy, 1)
-}