RecordControl: Exit when input stream closes

[shlevy]

No description provided.

[jonnew]

Thanks, Shea. I'm not able to reproduce the fix, though. My test case was

oat record -p pos --interactive &
oat posigen rand2D pos

I then interrupt the position generator and expect oat-record to exit, but it doesn't until I manually provide an endline through stdin.

[shlevy]

That's just the way job control works in the shell, it won't report that backgrounded processes exit until you next leave and enter the prompt (e.g. try:

$ sleep 10 &
$ cat
<interrupt>
$ <wait ten seconds> <enter>

If you type control-D, it will close stdin for the active process. So just run oat record --interactive, enter as many commands as you want, then hit control-D.

[jonnew]

Well, I lied a bit. I actually did run the two processes in separate shells. I just wrote that out of expediency. I'm probably still just missing something.

[jonnew]

The 'comment' and 'close' buttons are awfully close together in PR interface...

[shlevy]

Hmm, this was blind-coded after fixing something on Hector's machine, I'll test when I get back in to the office on Tuesday and report back.

[shlevy]

Oh, this is just the command input that oat is listening on in interactive mode, nothing to do with the position inputs.

[jonnew]

Yeah, the position input is just to provide a dummy source to the recorder. I think I see where I was confused:

The default behavior in oat components is to close when the upstream data source exits. When oat-record is in interactive mode, it does not do this because std::getline blocks. It requires the user to put some input into the terminal so std::getline() unblocks, which is what I thought you were getting at.

I think actually you were addressing something else, which I now understand. When the stream is explicitly ended by some client, the record controller should exit. Is that right?

[shlevy]

This was originally inspired by using oat record --interactive in a pipeline. If you run echo -e start \n pause | oat record --interactive, Oat will see the first two commands but then loop forever getting no input when doing getline because standard input is closed. This patch fixes that.

[jonnew]

Yes, I understand now. Thanks for the clarification. I'm going to open an issue for my other issue. Thanks for the fix!