Best practice when unable to write to the destination

[robjwells]

I have (adopted) an implementation of defmt for USB serial, which implements Logger::write() by writing to alternating buffers, which are written out asyncronously over USB when full. Potentially both buffers may be full and awaiting flushing to USB, and not accepting writes.

In this case currently writes are silently discarded. The docs say that write() is ‘a “best effort” operation’ — is discarding when unable to write acceptable (if undesirable)?

[jonathanpallant]

I believe defmt-rtt can be configured to be blocking or to drop on overflow. Obviously if you choose to block, you'd want to make sure you're not stopping the USB transfers from happening (e.g. by holding a critical-section whilst blocking).

[robjwells]

Thanks Jonathan, that's very helpful.