Function testClientCancel

api/rpc/client_test.go:108–191

This test checks that requests made through CallContext can be canceled by canceling the context.

(transport string, t *testing.T)

// This test checks that requests made through CallContext can be canceled by canceling
// the context.
func testClientCancel(transport string, t *testing.T) {
	server := newTestServer("service", new(Service))
	defer server.Stop()

	// What we want to achieve is that the context gets canceled
	// at various stages of request processing. The interesting cases
	// are:
	//  - cancel during dial
	//  - cancel while performing a HTTP request
	//  - cancel while waiting for a response
	//
	// To trigger those, the times are chosen such that connections
	// are killed within the deadline for every other call (maxKillTimeout
	// is 2x maxCancelTimeout).
	//
	// Once a connection is dead, there is a fair chance it won't connect
	// successfully because the accept is delayed by 1s.
	maxContextCancelTimeout := 300 * time.Millisecond
	fl := &flakeyListener{
		maxAcceptDelay: 1 * time.Second,
		maxKillTimeout: 600 * time.Millisecond,
	}

	var client *Client
	switch transport {
	case "ws", "http":
		c, hs := httpTestClient(server, transport, fl)
		defer hs.Close()
		client = c
	case "ipc":
		c, l := ipcTestClient(server, fl)
		defer l.Close()
		client = c
	default:
		panic("unknown transport: " + transport)
	}

	// These tests take a lot of time, run them all at once.
	// You probably want to run with -parallel 1 or comment out
	// the call to t.Parallel if you enable the logging.
	t.Parallel()

	// The actual test starts here.
	var (
		wg       sync.WaitGroup
		nreqs    = 10
		ncallers = 6
	)
	caller := func(index int) {
		defer wg.Done()
		for i := 0; i < nreqs; i++ {
			var (
				ctx     context.Context
				cancel  func()
				timeout = time.Duration(rand.Int63n(int64(maxContextCancelTimeout)))
			)
			if index < ncallers/2 {
				// For half of the callers, create a context without deadline