// When wait returns, either the new transport is up or ClientConn is
// closing. Used to avoid working on a dying transport. It updates and
// returns the transport and its version when there is no error.
func (cc *ClientConn) wait(ctx context.Context, ts int) (transport.ClientTransport, int, error) {
for {
cc.mu.Lock()
switch {
case cc.state == Shutdown:
cc.mu.Unlock()
return nil, 0, ErrClientConnClosing
case ts < cc.transportSeq:
// Worked on a dying transport. Try the new one immediately.
defer cc.mu.Unlock()
return cc.transport, cc.transportSeq, nil
default:
ready := cc.ready
if ready == nil {
ready = make(chan struct{})
cc.ready = ready
}
cc.mu.Unlock()
select {
case <-ctx.Done():
return nil, 0, transport.ContextErr(ctx.Err())
// Wait until the new transport is ready or failed.
case <-ready:
}
}
}
}
func TestContextErr(t *testing.T) {
for _, test := range []struct {
// input
errIn error
// outputs
errOut transport.StreamError
}{
{context.DeadlineExceeded, transport.StreamErrorf(codes.DeadlineExceeded, "%v", context.DeadlineExceeded)},
{context.Canceled, transport.StreamErrorf(codes.Canceled, "%v", context.Canceled)},
} {
err := transport.ContextErr(test.errIn)
if err != test.errOut {
t.Fatalf("ContextErr{%v} = %v \nwant %v", test.errIn, err, test.errOut)
}
}
}