Bernie asked 3 years ago
Hi – what is the difference between the ESP32 asynchronous web server and presumably a ‘synchronous’ web server?
Is the web server provided in Module 4, Unit 2 a ‘synchronous’ web server?
Thanks
Steve Mercer answered 3 years ago
My understanding is that synchronous would mean that the server will wait for the client to acknowledge receipt of the data before moving on to respond to other requests. This is generally not what you want from a server as there could be multiple clients and/or multiple requests (HTML, Images, Javascript, CSS etc). You don’t want the server to just handle one request from one client at a time.
I don’t believe that there is a library that will do synchronous web serving.
Bernie answered 3 years ago
Thanks Steve. That is what I thought. I think the default for a server is “asynchronous”, i.e. non-blocking. If there is only a single client it is no longer a server, but just network communication, which may or may not block. The definition of a server I believe is that it runs in parallel and is non-blocking and expects calls from multiple clients. The use of “asynchronous” implies that there is a class of servers that are timewise in synchrony with the client, e.g. running off the same clock. If there is such a thing, it should rather be called a blocking server or a serial server. Sorry to all for being so pedantic.
Sara Santos Staff answered 3 years ago
Hi Bernie.
Steve’s explanation is correct.
And yes, The example in Module 4, Unit 2 is a “synchronous” web server.
Regards,
Sara