feat: unify native API invocation with async callbacks (#1476)

bind/native/invoke_test.go

@@ -0,0 +1,258 @@
+package nativebridge
+
+import (
+	"runtime"
+	"strconv"
+	"sync"
+	"testing"
+	"time"
+)
+
+func TestInvokeExecutorStartsEveryRequestIndependently(t *testing.T) {
+	const taskCount = 64
+	release := make(chan struct{})
+	started := make(chan struct{}, taskCount)
+	executor := newInvokeExecutor(func(request invokeRequest) string {
+		started <- struct{}{}
+		<-release
+		return request.path
+	})
+
+	var completed sync.WaitGroup
+	completed.Add(taskCount)
+	for i := range taskCount {
+		accepted := executor.submit(invokeTask{
+			request: invokeRequest{path: strconv.Itoa(i)},
+			complete: func(string, error) {
+				completed.Done()
+			},
+		})
+		if !accepted {
+			t.Fatalf("request %d was rejected", i)
+		}
+	}
+
+	// Every handler must start before any of them is released. A worker pool
+	// would stall here once all of its workers were occupied.
+	for range taskCount {
+		select {
+		case <-started:
+		case <-time.After(time.Second):
+			t.Fatal("a request waited behind other blocked requests")
+		}
+	}
+
+	close(release)
+	completed.Wait()
+	executor.close()
+}
+
+func TestInvokeExecutorConvertsPanicsToErrors(t *testing.T) {
+	executor := newInvokeExecutor(func(invokeRequest) string {
+		panic("boom")
+	})
+	completed := make(chan error, 1)
+	executor.submit(invokeTask{complete: func(_ string, err error) {
+		completed <- err
+	}})
+	select {
+	case err := <-completed:
+		if err == nil || err.Error() != "invoke panic: boom" {
+			t.Fatalf("unexpected error: %v", err)
+		}
+	case <-time.After(time.Second):
+		t.Fatal("panic result was not completed")
+	}
+	executor.close()
+}
+
+func TestInvokeExecutorSurvivesCallbackPanic(t *testing.T) {
+	executor := newInvokeExecutor(func(request invokeRequest) string {
+		return request.path
+	})
+	executor.submit(invokeTask{complete: func(string, error) {
+		panic("callback failed")
+	}})
+
+	completed := make(chan string, 1)
+	executor.submit(invokeTask{
+		request: invokeRequest{path: "next"},
+		complete: func(result string, _ error) {
+			completed <- result
+		},
+	})
+	select {
+	case result := <-completed:
+		if result != "next" {
+			t.Fatalf("unexpected result: %q", result)
+		}
+	case <-time.After(time.Second):
+		t.Fatal("worker stopped after callback panic")
+	}
+	executor.close()
+}
+
+func TestInvokeExecutorPausesAndDrains(t *testing.T) {
+	release := make(chan struct{})
+	started := make(chan struct{})
+	executor := newInvokeExecutor(func(request invokeRequest) string {
+		if request.path == "running" {
+			close(started)
+			<-release
+		}
+		return request.path
+	})
+	completed := make(chan struct{})
+	if !executor.submit(invokeTask{
+		request: invokeRequest{path: "running"},
+		complete: func(string, error) {
+			close(completed)
+		},
+	}) {
+		t.Fatal("initial task was rejected")
+	}
+	<-started
+
+	drained := make(chan struct{})
+	go func() {
+		executor.pauseAndWait(time.Second)
+		close(drained)
+	}()
+	deadline := time.Now().Add(time.Second)
+	for {
+		executor.mu.Lock()
+		paused := !executor.accepting
+		executor.mu.Unlock()
+		if paused {
+			break
+		}
+		if time.Now().After(deadline) {
+			t.Fatal("executor did not pause")
+		}
+		runtime.Gosched()
+	}
+	select {
+	case <-drained:
+		t.Fatal("pause returned before the running request completed")
+	default:
+	}
+	if executor.submit(invokeTask{}) {
+		t.Fatal("paused executor accepted a new request")
+	}
+
+	close(release)
+	<-completed
+	select {
+	case <-drained:
+	case <-time.After(time.Second):
+		t.Fatal("pause did not return after pending requests drained")
+	}
+
+	executor.resume()
+	resumed := make(chan struct{})
+	if !executor.submit(invokeTask{complete: func(string, error) {
+		close(resumed)
+	}}) {
+		t.Fatal("resumed executor rejected a request")
+	}
+	<-resumed
+	executor.close()
+}
+
+func TestInvokeExecutorPauseTimesOutAndFailsPendingRequests(t *testing.T) {
+	release := make(chan struct{})
+	started := make(chan struct{})
+	executor := newInvokeExecutor(func(request invokeRequest) string {
+		started <- struct{}{}
+		<-release
+		return request.path
+	})
+
+	errors := make(chan error, 2)
+	for _, path := range []string{"first", "second"} {
+		if !executor.submit(invokeTask{
+			request: invokeRequest{path: path},
+			complete: func(_ string, err error) {
+				errors <- err
+			},
+		}) {
+			t.Fatalf("request %q was rejected", path)
+		}
+	}
+	for range 2 {
+		<-started
+	}
+
+	const timeout = 30 * time.Millisecond
+	startedAt := time.Now()
+	if executor.pauseAndWait(timeout) {
+		t.Fatal("pause unexpectedly reported a complete drain")
+	}
+	if elapsed := time.Since(startedAt); elapsed < timeout || elapsed > 10*timeout {
+		t.Fatalf("pause returned after %s, want close to %s", elapsed, timeout)
+	}
+	for range 2 {
+		select {
+		case err := <-errors:
+			if err == nil || err.Error() != errNativeBridgeStopping.Error() {
+				t.Fatalf("unexpected timeout error: %v", err)
+			}
+		case <-time.After(time.Second):
+			t.Fatal("pending request was not failed after the timeout")
+		}
+	}
+
+	close(release)
+	executor.close()
+	select {
+	case err := <-errors:
+		t.Fatalf("request callback ran more than once: %v", err)
+	default:
+	}
+}
+
+func TestStopWithinUsesOneDeadlineForRequestsAndCleanup(t *testing.T) {
+	releaseRequest := make(chan struct{})
+	requestStarted := make(chan struct{})
+	executor := newInvokeExecutor(func(invokeRequest) string {
+		close(requestStarted)
+		<-releaseRequest
+		return "done"
+	})
+	requestResult := make(chan error, 1)
+	executor.submit(invokeTask{complete: func(_ string, err error) {
+		requestResult <- err
+	}})
+	<-requestStarted
+
+	releaseCleanup := make(chan struct{})
+	cleanupStarted := make(chan struct{})
+	cleanup := func() {
+		close(cleanupStarted)
+		<-releaseCleanup
+	}
+
+	const timeout = 40 * time.Millisecond
+	startedAt := time.Now()
+	stopWithin(executor, cleanup, timeout)
+	if elapsed := time.Since(startedAt); elapsed < timeout || elapsed > 10*timeout {
+		t.Fatalf("stop returned after %s, want close to %s", elapsed, timeout)
+	}
+	select {
+	case <-cleanupStarted:
+	case <-time.After(time.Second):
+		t.Fatal("cleanup was not started after the request deadline")
+	}
+	select {
+	case err := <-requestResult:
+		if err == nil || err.Error() != errNativeBridgeStopping.Error() {
+			t.Fatalf("unexpected request result: %v", err)
+		}
+	case <-time.After(time.Second):
+		t.Fatal("timed-out request was not failed")
+	}
+
+	close(releaseRequest)
+	close(releaseCleanup)
+	executor.close()
+}