arthas shutdown 保存command history失败，抛出ConcurrentModificationException，导致后续attach不上

[lcllive]

2020-10-22 12:04:32 [arthas-NettyHttpTelnetBootstrap-3-3] INFO  c.t.a.core.shell.term.impl.Helper -Loaded arthas keymap file from com/taobao/arthas/core/shell/term/readline/inputrc
2020-10-22 12:04:32 [arthas-command-execute] INFO  c.t.a.c.c.klass100.RedefineCommand -Try redefine class name: com.ct1.game.normalactivity.NormalActivityService, ClassLoader: jdk.internal.loader.ClassLoaders$AppClassLoader@799f7e29
2020-10-22 12:04:32 [arthas-command-execute] INFO  c.t.arthas.core.advisor.Enhancer -Success to reset classes: []
2020-10-22 12:04:32 [arthas-command-execute] ERROR c.t.a.c.s.system.impl.ProcessImpl -Error during processing the command:
java.util.ConcurrentModificationException: null
        at java.base/java.util.ArrayList$Itr.checkForComodification(ArrayList.java:1042)
        at java.base/java.util.ArrayList$Itr.next(ArrayList.java:996)
        at com.taobao.arthas.core.util.FileUtils.saveCommandHistory(FileUtils.java:109)
        at com.taobao.arthas.core.shell.term.impl.TermImpl.close(TermImpl.java:186)
        at com.taobao.arthas.core.shell.impl.ShellImpl.close(ShellImpl.java:169)
        at com.taobao.arthas.core.shell.impl.ShellServerImpl.close(ShellServerImpl.java:229)
        at com.taobao.arthas.core.shell.ShellServer.close(ShellServer.java:98)
        at com.taobao.arthas.core.server.ArthasBootstrap.destroy(ArthasBootstrap.java:413)
        at com.taobao.arthas.core.command.basic1000.ShutdownCommand.shutdown(ShutdownCommand.java:47)
        at com.taobao.arthas.core.command.basic1000.ShutdownCommand.process(ShutdownCommand.java:31)
        at com.taobao.arthas.core.shell.command.impl.AnnotatedCommandImpl.process(AnnotatedCommandImpl.java:82)
        at com.taobao.arthas.core.shell.command.impl.AnnotatedCommandImpl.access$100(AnnotatedCommandImpl.java:18)
        at com.taobao.arthas.core.shell.command.impl.AnnotatedCommandImpl$ProcessHandler.handle(AnnotatedCommandImpl.java:111)
        at com.taobao.arthas.core.shell.command.impl.AnnotatedCommandImpl$ProcessHandler.handle(AnnotatedCommandImpl.java:108)
        at com.taobao.arthas.core.shell.system.impl.ProcessImpl$CommandProcessTask.run(ProcessImpl.java:385)
        at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:515)
        at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
        at java.base/java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:304)
        at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
        at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
        at java.base/java.lang.Thread.run(Thread.java:834)
Arthas server already stared, skip attach.
Arthas server already stared, skip attach.
Arthas server already stared, skip attach.
Arthas server already stared, skip attach.

[hengyunabc]

这里的确有问题，没有考虑到并发。

[lcllive]

恩，我们先修改我们自己本地的试试。