Backport to 0.1: Avoid starvation from FuturesUnordered::poll_next #2122
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This backports rust-lang#2049 to the 0.1 branch. Without this change, polling > 200 futures trough a FuturesUnordered on a Tokio 0.2 executor results in a busy loop in Tokio's cooperative scheduling module. See for a repro of where this breaks: tokio-rs/tokio#2390 Tested by running the reproducer I submitted there. Without this change, it hangs forever (spinning on CPU). With the change, it doesn't.
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Thanks for the backport! |
Merged
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This backports #2049 to the
0.1 branch. Without this change, polling > 200 futures trough a
FuturesUnordered on a Tokio 0.2 executor results in a busy loop in
Tokio's cooperative scheduling module.
See for a repro of where this breaks:
tokio-rs/tokio#2390
Tested by running the reproducer I submitted there. Without this change,
it hangs forever (spinning on CPU). With the change, it doesn't.