Data race in Stream.numWritten when two goroutines are writing about smux

[xtaci]

I was aware this issue, and it can be easily fixed.

let us think for another question: under which scenario it sounds reasonable for 2 concurrent writers to write on a single stream, assume there is a condition where 2 concurrent writer exists, can they split into two streams?

[xtaci]

Actually, concurrent writing on a single connection leads to indeterministic frame interleaving, I may write a comment for Write() function to state that issue.

And for this particular issue, I just replaced with atomic ops to suppress the error(not to fix).

[Eudi4H]

let us think for another question: under which scenario it sounds reasonable for 2 concurrent writers to write on a single stream, assume there is a condition where 2 concurrent writer exists, can they split into two streams?

I agree, the situation is a little unnatural. In my case, it was in a test program (an echo server), where one goroutine was echoing input, and another goroutine was sending a periodic heartbeat message. I can easily redesign the program to avoid concurrent writes. I mention this only because the contract for net.Conn says "multiple goroutines may invoke methods on a Conn simultaneously."

Anyway thanks, 182ea54 makes the data race message disappear.