Sleep while polling sockets on Windows #5594
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src/realm/util/network.cpp
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| @@ -1155,6 +1155,8 @@ bool Service::IoReactor::wait_and_advance(clock::time_point timeout, clock::time | |||
| ret++; | |||
| } | |||
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| std::this_thread::sleep_for(std::chrono::milliseconds(10)); | |||
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hmm, i think maybe this should be on line 1151 like
if (m_pollfd_slots.size() > 1) {
...
} else if (m_wakeup_pipe.is_signaled()) {
...
} else {
sleep()
}
Maybe what's going on here is that you don't have any active sync sessions and so you're stuck busy waiting for a sync session to open or the Service to get something posted to it?
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I opted to preserve the old behavior (no else for if (m_wakeup_pipe.is_signaled())) because I don't know enough about networking on Windows and in Core to judge whether it was intentional that we always check for the wakeup pipe, regardless of whether we polled the sockets. Happy to make the suggested change if you believe the original code was wrong though.
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The failing tests seem to be due to timeouts starting stitch and on macos/ubuntu, so they should not be caused by the changes in this PR. |
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We had the discussion. Fee free to merge it. |
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I propose an alternative fix here #5599 |
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I'm going to merge this as is to make our Dart tests reliably green. We can always improve the situation with #5599 whenever that passes review. |
What, How & Why?
This appears to address the issue reported in #5591.
I have no idea if that's a real fix or making things worse, but when testing locally, it made CPU usage go from 100% on both cores to ~10-20%.
☑️ ToDos