[JENKINS-72796] stable context classloader for Computer.threadPoolForRemoting #9012

jtnord · 2024-03-04T15:48:03Z

Whilst the threadpool used reset the context classloader at the end of any task, it did not ensure that the initial classloader used was anything sepcific, rather it would use whatever the calling threads contextClassLoader was.

This is now fixed as we use the Jenkins WebApp classloader (same as the Timer) which is used by (A)PeriodicTasks.

Whilst we should really not have a context classloader (aka null) and this should be set where needed by code, almost everywhere in Jenkins the context classloader is already the webapp classloader, and so setting this to be different depending on how things where called would seemingly be a little scary. Arguably this and other context classloaders should be all set to null and any code that wants different should be changed, but this is a larger piece of work that would have potential impact on an unknown number of plugins in the ecosystem, so this fix uses what was set > 90% of the time.

See JENKINS-72796.

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Ensure threads in the Computer.threadPoolForRemotingexecutor service always have the Jenkins webapp ClassLoader set as the context ClassLoader to prevent random class loading issues when code is running in this ExecutorService.

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…Remoting Whilst the threadpool used reset the context classloader at the end of any task, it did not ensure that the initial c;lassloader used was anything sepcific, rather it would use whatever the calling threads contextClassLoader was. This is now fixed as we use the Jenkins WebApp classloader (same as the Timer) which is used by (A)PeriodicTasks. Whilst we should really not have a context classloader (aka null) and this should be set where needed by code, almost everywhere in Jenkins the context classloader is already the webapp classloader, and so setting this to be different depending on how things where called would seemingly be a little scary. Arguably this and other context classloaders should be all set to null and any code that wants different should be changed, but this is a larger piece of work that would have potential impact on an unknown number of plugins in the ecosystem, so this fix uses what was set > 90% of the time.

core/src/test/java/hudson/model/ComputerTest.java

timja

/label ready-for-merge

This PR is now ready for merge, after ~24 hours, we will merge it if there's no negative feedback.

Thanks!

kmartens27 · 2024-03-08T14:10:37Z

Hi @jtnord, would there be a better version of the changelog entry for this PR? If there should not be a changelog entry, we can definitely adjust, but if there should be something included, would you be able to clarify a bit what that would be?

jtnord · 2024-03-08T14:15:50Z

Hi @jtnord, would there be a better version of the changelog entry for this PR? If there should not be a changelog entry, we can definitely adjust, but if there should be something included, would you be able to clarify a bit what that would be?

Hi @kmartens27 thanks for the reminder - I have updated the suggested changelog entry.

JENKINS-72796, Ensure threads in the Computer.threadPoolForRemoting executor service always have the Jenkins webapp ClassLoader set as the context ClassLoader to prevent random class loading issues when code is running in this ExecutorService.

kmartens27 · 2024-03-08T14:21:32Z

Thank you so much!

…Remoting (jenkinsci#9012) * [JENKINS-72796] stable context classloader for Computer.threadPoolForRemoting Whilst the threadpool used reset the context classloader at the end of any task, it did not ensure that the initial c;lassloader used was anything sepcific, rather it would use whatever the calling threads contextClassLoader was. This is now fixed as we use the Jenkins WebApp classloader (same as the Timer) which is used by (A)PeriodicTasks. Whilst we should really not have a context classloader (aka null) and this should be set where needed by code, almost everywhere in Jenkins the context classloader is already the webapp classloader, and so setting this to be different depending on how things where called would seemingly be a little scary. Arguably this and other context classloaders should be all set to null and any code that wants different should be changed, but this is a larger piece of work that would have potential impact on an unknown number of plugins in the ecosystem, so this fix uses what was set > 90% of the time. * Update core/src/test/java/hudson/model/ComputerTest.java --------- Co-authored-by: Tim Jacomb <21194782+timja@users.noreply.github.com> (cherry picked from commit 89195cc)

jtnord requested review from jglick and a team March 4, 2024 15:48

jglick approved these changes Mar 4, 2024

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timja reviewed Mar 4, 2024

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core/src/test/java/hudson/model/ComputerTest.java Outdated Show resolved Hide resolved

Update core/src/test/java/hudson/model/ComputerTest.java

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timja approved these changes Mar 4, 2024

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comment-ops-bot bot added the ready-for-merge The PR is ready to go, and it will be merged soon if there is no negative feedback label Mar 4, 2024

rsandell approved these changes Mar 5, 2024

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jtnord added the bug For changelog: Minor bug. Will be listed after features label Mar 5, 2024

NotMyFault merged commit 89195cc into jenkinsci:master Mar 6, 2024
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jtnord deleted the JENKINS-72796 branch March 8, 2024 14:17

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[JENKINS-72796] stable context classloader for Computer.threadPoolForRemoting #9012

[JENKINS-72796] stable context classloader for Computer.threadPoolForRemoting #9012

jtnord commented Mar 4, 2024 •

edited by MarkEWaite

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timja left a comment

kmartens27 commented Mar 8, 2024

jtnord commented Mar 8, 2024 •

edited

kmartens27 commented Mar 8, 2024

[JENKINS-72796] stable context classloader for Computer.threadPoolForRemoting #9012

[JENKINS-72796] stable context classloader for Computer.threadPoolForRemoting #9012

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jtnord commented Mar 4, 2024 • edited by MarkEWaite

Testing done

Proposed changelog entries

Proposed upgrade guidelines

Submitter checklist

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kmartens27 commented Mar 8, 2024

jtnord commented Mar 8, 2024 • edited

kmartens27 commented Mar 8, 2024

jtnord commented Mar 4, 2024 •

edited by MarkEWaite

jtnord commented Mar 8, 2024 •

edited