Don't drain when setting the mode

[gbaraldi]

No description provided.

[Keno]

Seems potentially dangerous if this is not ordered with respect to writes. Is there a julia issue this fixes?

[vtjnash]

We're changing read parameters since we have the read side of the stream. We should not be adding a synchronization point with writers here, which might not even be our process.

[gbaraldi]

Kinda, on my PR that enables try_write that drain causes deadlocks libuv#4944

[Keno]

      tmp.c_oflag |= (ONLCR);

looks like an output flag to me

[vtjnash]

UV_TTY_MODE_RAW is deprecated because it was implemented wrong. Only nodejs should be still using that (since they never fix bugs)

[Keno]

We're using it:

https://github.com/JuliaLang/julia/blob/24d8ab527067872e360981ce686e09d563fd2c24/src/jl_uv.c#L1185

https://github.com/JuliaLang/libuv/pull/45/files#diff-3fb099bf3dcc5f92fe432f360d31e35a4446c73baf831f9e7c36ea24ac043507R289

[vtjnash]

no, you're misreading that flag name (added in libuv#4688)

[Keno]

See the second link I posted

[vtjnash]

Well, we are apparently very bad at writing software too
JuliaAttic/libuv-archive#27 (comment)

thanks for the heads up. when we rebase again to follow upstream's v1.0, we'll need to remember to switch our flag to use enum value 2.

[vtjnash]

Anyways, libuv is forbidden from running any blocking calls (especially IO) such as TCSADRAIN. If it wants to implement tcdrain because a user wants to call that, it needs to do that in the threadpool.