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  1. Jenkins
  2. JENKINS-22767

AbstractLazyLoadRunMap.getById subject to race condition with .load

      If Run.onLoad takes a little while to run, or generally if RunMap.retrieve is not instantaneous, a race condition can arise. Say thread 1 calls getByNumber for a Run which in fact exists on disk (with a numeric symlink). search will call load(int, null), which will delegate to load(File, null) which acquires the lock; and then blocks for a while in retrieve. Then thread 2 calls getById with the ID of the same build. index.byId is still empty, so it jumps to load(String, null) and then blocks waiting to enter load(File, null). Now thread 1 finishes retrieve, stores the newly loaded Run in the index, and returns. When the lock is released, thread 2 enters it, loads another copy of the same Run, and stores it in the index, clobbering the first entry, and returns that.

      Seems to be fixable by making getById double-check the index while holding the lock, forcing it to wait for the first thread to store an entry. (Or could just check under lock whether snapshot != index, and if so, retry.)

      Also load(File, null) should assert that there is no current entry for a build before it stores one.

          [JENKINS-22767] AbstractLazyLoadRunMap.getById subject to race condition with .load

          Jesse Glick created issue -
          Jesse Glick made changes -
          Link New: This issue is related to JENKINS-24380 [ JENKINS-24380 ]
          Jesse Glick made changes -
          Resolution New: Duplicate [ 3 ]
          Status Original: Open [ 1 ] New: Resolved [ 5 ]
          Jesse Glick made changes -
          Link New: This issue is related to JENKINS-27532 [ JENKINS-27532 ]
          Jesse Glick made changes -
          Resolution Original: Duplicate [ 3 ]
          Status Original: Resolved [ 5 ] New: Reopened [ 4 ]
          Jesse Glick made changes -
          Status Original: Reopened [ 4 ] New: Open [ 1 ]
          Jesse Glick made changes -
          Status Original: Open [ 1 ] New: In Progress [ 3 ]
          Jesse Glick made changes -
          Remote Link New: This issue links to "PR 1989 (Web Link)" [ 13757 ]
          Jesse Glick made changes -
          Labels Original: lazy-loading threads New: lazy-loading lts-candidate threads
          SCM/JIRA link daemon made changes -
          Resolution New: Fixed [ 1 ]
          Status Original: In Progress [ 3 ] New: Resolved [ 5 ]
          Jesse Glick made changes -
          Link New: This issue is related to JENKINS-26761 [ JENKINS-26761 ]

            jglick Jesse Glick
            jglick Jesse Glick
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