fix: deadlock in pool

.gitignore

@@ -1,3 +1,4 @@
 /woj
 /config.yaml
 /dsn.txt
+/coverage.*

Makefile

@@ -14,7 +14,7 @@ LDFLAGS += -s -w
 GOBUILD := $(GO) build -ldflags '$(LDFLAGS)'
 GOBIN   := $(shell go env GOPATH)/bin
 
-.PHONY: all build clean dep swagger fmt
+.PHONY: all build clean dep swagger fmt coverage test
 
 default: all
 
@@ -35,3 +35,10 @@ swagger:
 
 fmt:
 	go fmt ./...
+
+coverage:
+	go test ./... -coverprofile=coverage.out
+	go tool cover -html=coverage.out -o coverage.html
+
+test:
+	go test -race ./...

pkg/pool/pool.go

@@ -33,17 +33,18 @@ func (tp *TaskPool) Start() {
 
 func (tp *TaskPool) AddTask(f func()) int {
 	tp.lck.Lock()
-	defer tp.lck.Unlock()
 
 	id := tp.curTaskID
 	tp.curTaskID++
 
-	task := Task{id: id, f: f}
-	tp.queue <- task
-
 	waitChan := make(chan struct{})
 	tp.waitMap[id] = waitChan
 
+	tp.lck.Unlock()
+
+	task := Task{id: id, f: f}
+	tp.queue <- task
+
 	return id
 }
 

pkg/pool/pool_test.go

@@ -60,3 +60,39 @@ func TestTaskPool_WaitForTask(t *testing.T) {
 
 	pool.Stop()
 }
+
+func TestTaskPool_One(t *testing.T) {
+	pool := NewTaskPool(1, 1)
+	pool.Start()
+
+	lck := sync.Mutex{}
+	counter := 0
+
+	ids := make([]int, 0)
+	for i := 1; i <= 10; i++ {
+		f := func(i int) func() {
+			return func() {
+				lck.Lock()
+				t.Log("task", i, "locked")
+				counter += i
+				t.Log("task", i, "unlocked")
+				lck.Unlock()
+
+				time.Sleep(time.Duration(i*10) * time.Millisecond)
+				t.Log("task", i, "finished")
+			}
+		}(i)
+		id := pool.AddTask(f)
+		ids = append(ids, id)
+	}
+
+	for _, id := range ids {
+		pool.WaitForTask(id)
+	}
+
+	if counter != 55 {
+		t.Error("some tasks were not executed")
+	}
+
+	pool.Stop()
+}