Add Inner Ring code

cmd/neofs-node/modules/fix/worker/worker.go

@@ -0,0 +1,79 @@
+package worker
+
+import (
+	"context"
+	"sync"
+	"sync/atomic"
+	"time"
+)
+
+type (
+	// Workers is an interface of worker tool.
+	Workers interface {
+		Start(context.Context)
+		Stop()
+
+		Add(Job Handler)
+	}
+
+	workers struct {
+		cancel  context.CancelFunc
+		started *int32
+		wg      *sync.WaitGroup
+		jobs    []Handler
+	}
+
+	// Handler is a worker's handling function.
+	Handler func(ctx context.Context)
+
+	// Jobs is a map of worker names to handlers.
+	Jobs map[string]Handler
+
+	// Job groups the parameters of worker's job.
+	Job struct {
+		Disabled    bool
+		Immediately bool
+		Timer       time.Duration
+		Ticker      time.Duration
+		Handler     Handler
+	}
+)
+
+// New is a constructor of workers.
+func New() Workers {
+	return &workers{
+		started: new(int32),
+		wg:      new(sync.WaitGroup),
+	}
+}
+
+func (w *workers) Add(job Handler) {
+	w.jobs = append(w.jobs, job)
+}
+
+func (w *workers) Stop() {
+	if !atomic.CompareAndSwapInt32(w.started, 1, 0) {
+		// already stopped
+		return
+	}
+
+	w.cancel()
+	w.wg.Wait()
+}
+
+func (w *workers) Start(ctx context.Context) {
+	if !atomic.CompareAndSwapInt32(w.started, 0, 1) {
+		// already started
+		return
+	}
+
+	ctx, w.cancel = context.WithCancel(ctx)
+	for _, job := range w.jobs {
+		w.wg.Add(1)
+
+		go func(handler Handler) {
+			defer w.wg.Done()
+			handler(ctx)
+		}(job)
+	}
+}