fix: reduce CPU usage when stdin is null #246
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jasom
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There are some use-cases in which stdin will not be attached to the shpool client. Right now when that happens, one thread is busy-waiting on stdin. This fix adds a 200ms delay to the polling. refs: shell-pool#243
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ethanpailes
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I'm not sure that this is the best fix for this problem. shpool attach processes should always corrispond to an actually attached terminal, so the right thing to do is probably to just detach from the session when we read an EOF off of stdin.
This is probably worth merging for now, but I think we should leave #243 open until we can write the more principled detach fix.
| loop { | ||
| let nread = stdin.read(&mut buf).context("reading stdin from user")?; | ||
| if nread == 0 { | ||
| thread::sleep(STDIN_POLL_DUR); |
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Do you mind adding a comment here explaining that this is just a tmp mitigation until we can gracefully detach in the face of EOF.
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I think hanging up here may be as simple as just returning Ok(()). It looks like that breaks a few tests, though hopefully just for timing reasons, so it's not entirely trivial. We probably want to write a new test ensuring that shpool attach with a null stdin does create the session as you would expect and the early hangup doesn't cause trouble as well.
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There are some use-cases in which stdin will not be attached to the shpool client. Right now when that happens, one thread is busy-waiting on stdin. This fix adds a 200ms delay to the polling.
Fixes #243