feat: 为执行后端增加独立容量池

internal/taskscheduler/poller_test.go

@@ -115,3 +115,52 @@ func TestPollerRetriesAssignedTaskBeforeFetchingAnother(t *testing.T) {
 		t.Fatalf("dispatches=%d fetches-before-dispatch=%d declares=%d", dispatcher.calls, dispatcher.fetchesAtSuccess, client.declared)
 	}
 }
+
+type blockingPollClient struct {
+	mu       sync.Mutex
+	declared int
+	started  chan struct{}
+}
+
+func (c *blockingPollClient) Declare(context.Context, string, []string) error {
+	c.mu.Lock()
+	c.declared++
+	c.mu.Unlock()
+	return nil
+}
+
+func (c *blockingPollClient) FetchTask(ctx context.Context, _ int64) (*runnerv1.FetchTaskResponse, error) {
+	c.started <- struct{}{}
+	<-ctx.Done()
+	return nil, ctx.Err()
+}
+
+func TestPollerStartsConfiguredNumberOfFetchersAfterOneDeclare(t *testing.T) {
+	client := &blockingPollClient{started: make(chan struct{}, 3)}
+	poller := Poller{
+		Client:    client,
+		Scheduler: &Scheduler{TrustDomain: "ddupan.top", Dispatcher: &retryDispatcher{done: make(chan struct{})}},
+		Config: PollerConfig{
+			Version: "dev", Labels: []string{"self-hosted:host", "pod:host", "vm:host"}, Capacity: 3,
+		},
+	}
+	ctx, cancel := context.WithCancel(context.Background())
+	finished := make(chan error, 1)
+	go func() { finished <- poller.Run(ctx) }()
+	for range 3 {
+		select {
+		case <-client.started:
+		case <-time.After(time.Second):
+			t.Fatal("configured fetchers did not start")
+		}
+	}
+	cancel()
+	if err := <-finished; err != nil {
+		t.Fatal(err)
+	}
+	client.mu.Lock()
+	defer client.mu.Unlock()
+	if client.declared != 1 {
+		t.Fatalf("declares = %d", client.declared)
+	}
+}