deadlock in MockSlaveTest.basics

"AtmostOneTaskExecutor[hudson.model.Queue$1@1f16ef23] [#6]":
  waiting for ownable synchronizer 0x00000007d7f92fd8, (a java.util.concurrent.locks.ReentrantReadWriteLock$NonfairSync),
  which is held by "Executing basics(org.jenkinci.plugins.mock_slave.MockSlaveTest)"
"Executing basics(org.jenkinci.plugins.mock_slave.MockSlaveTest)":
  waiting for ownable synchronizer 0x0000000749a12190, (a java.util.concurrent.locks.ReentrantLock$NonfairSync),
  which is held by "AtmostOneTaskExecutor[hudson.model.Queue$1@1f16ef23] [#6]"
"AtmostOneTaskExecutor[hudson.model.Queue$1@1f16ef23] [#6]":
	at sun.misc.Unsafe.park(Native Method)
	- parking to wait for  <0x00000007d7f92fd8> (a java.util.concurrent.locks.ReentrantReadWriteLock$NonfairSync)
	at java.util.concurrent.locks.LockSupport.park(LockSupport.java:186)
	at java.util.concurrent.locks.AbstractQueuedSynchronizer.parkAndCheckInterrupt(AbstractQueuedSynchronizer.java:834)
	at java.util.concurrent.locks.AbstractQueuedSynchronizer.doAcquireShared(AbstractQueuedSynchronizer.java:964)
	at java.util.concurrent.locks.AbstractQueuedSynchronizer.acquireShared(AbstractQueuedSynchronizer.java:1282)
	at java.util.concurrent.locks.ReentrantReadWriteLock$ReadLock.lock(ReentrantReadWriteLock.java:731)
	at hudson.model.Executor.isParking(Executor.java:609)
	at hudson.model.Queue.maintain(Queue.java:1277)
	at hudson.model.Queue$1.call(Queue.java:334)
	at hudson.model.Queue$1.call(Queue.java:331)
	at jenkins.util.AtmostOneTaskExecutor$1.call(AtmostOneTaskExecutor.java:101)
	at jenkins.util.AtmostOneTaskExecutor$1.call(AtmostOneTaskExecutor.java:91)
	at java.util.concurrent.FutureTask.run(FutureTask.java:262)
	at hudson.remoting.AtmostOneThreadExecutor$Worker.run(AtmostOneThreadExecutor.java:110)
	at java.lang.Thread.run(Thread.java:745)
"Executing basics(org.jenkinci.plugins.mock_slave.MockSlaveTest)":
	at sun.misc.Unsafe.park(Native Method)
	- parking to wait for  <0x0000000749a12190> (a java.util.concurrent.locks.ReentrantLock$NonfairSync)
	at java.util.concurrent.locks.LockSupport.park(LockSupport.java:186)
	at java.util.concurrent.locks.AbstractQueuedSynchronizer.parkAndCheckInterrupt(AbstractQueuedSynchronizer.java:834)
	at java.util.concurrent.locks.AbstractQueuedSynchronizer.acquireQueued(AbstractQueuedSynchronizer.java:867)
	at java.util.concurrent.locks.AbstractQueuedSynchronizer.acquire(AbstractQueuedSynchronizer.java:1197)
	at java.util.concurrent.locks.ReentrantLock$NonfairSync.lock(ReentrantLock.java:214)
	at java.util.concurrent.locks.ReentrantLock.lock(ReentrantLock.java:290)
	at hudson.model.Queue._withLock(Queue.java:1205)
	at hudson.model.Queue.withLock(Queue.java:1143)
	at hudson.model.Computer.removeExecutor(Computer.java:977)
	at hudson.model.Executor.interrupt(Executor.java:187)
	at hudson.model.Executor.interrupt(Executor.java:164)
	at hudson.model.Executor.interruptForShutdown(Executor.java:149)
	at hudson.model.Computer.interrupt(Computer.java:1014)
	at jenkins.model.Jenkins.cleanUp(Jenkins.java:2769)
	at org.jvnet.hudson.test.JenkinsRule.after(JenkinsRule.java:460)
	at …

JENKINS-28840