Callback Restrictions with Inline Mode

Inline mode requires that callbacks always return quickly. Otherwise, long callbacks could delay message I/O, which would defeat the purpose of inline mode.

For example, the negative consequences of long callbacks could include a large I/O backlog. As a result, the receiving program could lose inbound messages. Furthermore, message buffers at the publishing end of a transport could fill up. To prevent overflow at these buffers, the transport could block programs at the publishing end, delaying their outbound messages.