Server run thread safety fix [changelog skip] #2435
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Log after `server.run` in Single mode since some integration tests use this message for timing stop signals.
| @@ -1141,4 +1141,12 @@ def test_client_quick_close_no_lowlevel_error_handler_call | |||
| sleep 0.5 | |||
| assert_empty @events.stdout.string | |||
| end | |||
|
|
|||
| def test_run_stop_thread_safety | |||
| 100.times do | |||
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How long does this take to run?
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I believe 0.3 sec on JRuby, less on MRI. I should have reviewed this earlier, but...
I suspect I can revert the band-aids for JRuby (the sleep after run). This is the same issue of Server#run getting messed up.
| @notify << message | ||
| rescue IOError, NoMethodError, Errno::EPIPE | ||
| # The server, in another thread, is shutting down | ||
| @notify << message |
MSP-Greg
approved these changes
Oct 19, 2020
wjordan
changed the title
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Description
This PR fixes a race-condition creating the
@check, @notifypipe inServer, which caused various intermittent test failures on JRuby.The issue can be triggered by a call to
#run(which calls#handle_serversin a background-thread) followed immediately by#stop(which calls#notify_safely). This can result in two separate@check, @notifypipes getting created concurrently, causing the signal sent by#stopto not get picked up by the listen-loop in#handle_servers, and therefore fail to exit as expected. This PR adds a testtest_run_stop_thread_safetydemonstrating the race condition that consistently fails on JRuby without this fix (see this test run).The fix moves pipe-creation into
Server#run(before the background thread is spawned), making the behavior more consistent that the server will stop as long as the call to#stopcomes after the call to#runreturns.This PR includes a related timing change in
Single, moving theUse Ctrl-C to stoplog message after the call toServer#run. This is because thewait_for_server_to_bootintegration-test helper uses this log message to determine when the server is 'booted', and some integration tests (e.g.,test_int_refuse) send anINTsignal (which callsstop) immediately after this log message is printed, causing intermittent failures if thestopcall arrived before theruncall finished. The change ensures thatstopalways occurs afterrun, avoiding intermittent failures in this test.Your checklist for this pull request
[changelog skip]or[ci skip]to the pull request title.[ci skip]to the title of the PR.#issue" to the PR description or my commit messages.