Order of sending/receving message with tokio::mpsc

[vnghia]

I would like to ask if there are any guarantee about the order of sent and received message (FIFO) with tokio::mpsc in the case of spsc. Will message that is sent first always be received first (given that the capacity is bigger than 1) ?

Thank you very much!

[Darksonn]

Yes, if msg1 is sent before msg2, then msg1 is received before msg2. This holds with any number of senders.

[vnghia]

Thank you. Is there any doc state that or it is just an implementation detail ?

[Darksonn]

The documentation says that it's a queue. It would not be a queue if it behaved any other way. It is guaranteed to not change in the future.