关于java:JVM虚拟机性能监控与故障处理工具

定位线上问题时，常识和教训是要害根底，数据是根据，数据包含运行日志，异样堆栈，GC日志，线程快照(threaddump/javacore文件)，堆转储快照(headdump/hprof文件)等

JDK监控和故障解决工具

命令	作用
jps	显示指定零碎内所有HotSpot虚拟机过程
jstat	收集HotSpot虚拟机各方面运行数据
jinfo	显示虚拟机配置信息
jmap	生成虚拟机的外部转储快照(heapdump文件)
jhat	剖析heapdump文件
jstack	显示虚拟机线程快照

jps：虚拟机过程情况工具

显示指定零碎内所有HotSpot虚拟机过程

罕用选项

选项	作用
-q	只输入LVMID
-m	输入虚拟机启动时传递给主类main函数的参数
-l	输入主类全名
-v	显示虚拟机启动时的JVM参数

[oracle@wcdev ~]$ jps20560 Server24748 Rcu17387 Server14824 Jps20635 Server27844 Server10658 Server5713 Server10738 Server6594 NodeManager10705 Server29681 Server[oracle@wcdev ~]$

jstat：虚拟机统计信息监督工具

收集HotSpot虚拟机各方面运行数据

罕用选项

选项	作用
-class	监督类装载，卸载数量，总空间以及类装载所消耗的工夫
-gc	监督JAVA堆情况，包含Eden区，两个survivor区，老年代，永恒代等

查问过程20560的信息，1000毫秒一次，执行10次

[oracle@wcdev ~]$ jstat -gc 20560 1000 10HeapSize NurserySize UsedHeapSize   YC     OC    YCTime   OCTime   GCTime  YCPauseTime OCPauseTime PauseTime4194304.0   1528649.8    1132960.1   2735    501  309.990  173.831  483.821     310.056     173.843   483.8994194304.0   1528649.8    1132960.1   2735    501  309.990  173.831  483.821     310.056     173.843   483.8994194304.0   1528649.8    1132960.1   2735    501  309.990  173.831  483.821     310.056     173.843   483.8994194304.0   1528649.8    1132960.1   2735    501  309.990  173.831  483.821     310.056     173.843   483.8994194304.0   1528649.8    1132960.1   2735    501  309.990  173.831  483.821     310.056     173.843   483.8994194304.0   1528649.8    1132960.1   2735    501  309.990  173.831  483.821     310.056     173.843   483.8994194304.0   1528649.8    1132960.1   2735    501  309.990  173.831  483.821     310.056     173.843   483.8994194304.0   1528649.8    1132960.1   2735    501  309.990  173.831  483.821     310.056     173.843   483.8994194304.0   1528649.8    1132960.1   2735    501  309.990  173.831  483.821     310.056     173.843   483.8994194304.0   1528649.8    1132960.1   2735    501  309.990  173.831  483.821     310.056     173.843   483.899[oracle@wcdev ~]$

jinfo：JAVA配置信息工具

jinfo能够查看和调整虚拟机各项参数，应用 jinfo 能够在不重启虚拟机的状况下，能够动静的批改 jvm 的参数

罕用选项

选项	作用
-flag	输入对应名称的参数
-flag [+/-]name	开启或者敞开对应名称的参数

jinfo pid

C:\Users\zero>jps -l12080 com.example.offer.leecode.t20201015.CanJump16112 sun.tools.jps.Jps6292 org.jetbrains.idea.maven.server.RemoteMavenServer3612940 org.jetbrains.kotlin.daemon.KotlinCompileDaemon16284 org.jetbrains.jps.cmdline.Launcher17388C:\Users\zero>jinfo 12080Attaching to process ID 12080, please wait...Debugger attached successfully.Server compiler detected.JVM version is 25.102-b14Java System Properties:java.runtime.name = Java(TM) SE Runtime Environmentjava.vm.version = 25.102-b14sun.boot.library.path = C:\Program Files\Java\Java1.8.1\jre\binjava.vendor.url = http://java.oracle.com/java.vm.vendor = Oracle Corporationpath.separator = ;file.encoding.pkg = sun.iojava.vm.name = Java HotSpot(TM) 64-Bit Server VMsun.os.patch.level =sun.java.launcher = SUN_STANDARDuser.script =user.country = CNuser.dir = F:\GitCode\zero\TestExceljava.vm.specification.name = Java Virtual Machine Specificationjava.runtime.version = 1.8.0_102-b14java.awt.graphicsenv = sun.awt.Win32GraphicsEnvironmentos.arch = amd64java.endorsed.dirs = C:\Program Files\Java\Java1.8.1\jre\lib\endorsedline.separator =java.io.tmpdir = C:\Users\zero\AppData\Local\Temp\java.vm.specification.vendor = Oracle Corporationuser.variant =os.name = Windows 10sun.jnu.encoding = GBKjava.library.path = C:\Program Files\Java\Java1.8.1\bin;C:\Windows\Sun\Java\bin;C:\Windows\system32;C:\Windows;C:\Program Files (x86)\Common Files\Oracle\Java\javapath;F:\oracleExe\app\oracle\product\11.2.0\server\bin;C:\Program Files (x86)\Intel\iCLS Client\;C:\Program Files\Intel\iCLS Client\;C:\Windows\system32;C:\Windows;C:\Windows\System32\Wbem;C:\Windows\System32\WindowsPowerShell\v1.0\;C:\Program Files\Intel\WiFi\bin\;C:\Program Files\Common Files\Intel\WirelessCommon\;C:\Program Files (x86)\NVIDIA Corporation\PhysX\Common;C:\Program Files (x86)\Intel\Intel(R) Management Engine Components\DAL;C:\Program Files\Intel\Intel(R) Management Engine Components\DAL;C:\Program Files (x86)\Intel\Intel(R) Management Engine Components\IPT;C:\Program Files\Intel\Intel(R) Management Engine Components\IPT;C:\Program Files\Java\Java1.8.1\bin;C:\Program Files\TortoiseSVN\bin;F:\APP;F:\Git\Git\cmd;C:\Program Files\Redis\;F:\NvmFolder\nvm;F:\NvmFolder\nodejs;C:\Program Files\Intel\WiFi\bin\;C:\Program Files\Common Files\Intel\WirelessCommon\;F:\Microsoft VS Code\Microsoft VS Code\bin;F:\Idea\IntelliJ IDEA 2017.1.1\plugins\maven\lib\maven3\bin;C:\Program Files\gradle\gradle-4.6\bin;F:\NvmFolder\nvm;F:\NvmFolder\nodejs;C:\Users\zero\AppData\Local\BypassRuntm;F:\NvmFolder\nvm;F:\NvmFolder\nodejs;F:\JetBrains\IntelliJ IDEA 2019.2.1\plugins\maven\lib\maven3\bin;.java.specification.name = Java Platform API Specificationjava.class.version = 52.0sun.management.compiler = HotSpot 64-Bit Tiered Compilersos.version = 10.0user.home = C:\Users\zerouser.timezone = Asia/Shanghaijava.awt.printerjob = sun.awt.windows.WPrinterJobfile.encoding = UTF-8java.specification.version = 1.8user.name = zerojava.class.path = C:\Program Files\Java\Java1.8.1\jre\lib\charsets.jar;C:\Program Files\Java\Java1.8.1\jre\lib\deploy.jar;C:\Program Files\Java\Java1.8.1\jre\lib\ext\access-bridge-64.jar;C:\Program Files\Java\Java1.8.1\jre\lib\ext\cldrdata.jar;C:\Program Files\Java\Java1.8.1\jre\lib\ext\dnsns.jar;C:\Program Files\Java\Java1.8.1\jre\lib\ext\jaccess.jar;C:\Program Files\Java\Java1.8.1\jre\lib\ext\jfxrt.jar;C:\Program Files\Java\Java1.8.1\jre\lib\ext\localedata.jar;C:\Program Files\Java\Java1.8.1\jre\lib\ext\nashorn.jar;C:\Program Files\Java\Java1.8.1\jre\lib\ext\sunec.jar;C:\Program Files\Java\Java1.8.1\jre\lib\ext\sunjce_provider.jar;C:\Program Files\Java\Java1.8.1\jre\lib\ext\sunmscapi.jar;C:\Program Files\Java\Java1.8.1\jre\lib\ext\sunpkcs11.jar;C:\Program Files\Java\Java1.8.1\jre\lib\ext\zipfs.jar;C:\Program Files\Java\Java1.8.1\jre\lib\javaws.jar;C:\Program Files\Java\Java1.8.1\jre\lib\jce.jar;C:\Program Files\Java\Java1.8.1\jre\lib\jfr.jar;C:\Program Files\Java\Java1.8.1\jre\lib\jfxswt.jar;C:\Program Files\Java\Java1.8.1\jre\lib\jsse.jar;C:\Program Files\Java\Java1.8.1\jre\lib\management-agent.jar;C:\Program Files\Java\Java1.8.1\jre\lib\plugin.jar;C:\Program Files\Java\Java1.8.1\jre\lib\resources.jar;C:\Program Files\Java\Java1.8.1\jre\lib\rt.jar;F:\Jclasslib\jclasslib\jclasslib\bin\jclasslib.jar;F:\GitCode\zero\TestExcel\target\classes;F:\workSpace\Maven\repository\org\springframework\boot\spring-boot-starter-web\2.2.6.RELEASE\spring-boot-starter-web-2.2.6.RELEASE.jar;F:\workSpace\Maven\repository\org\springframework\boot\spring-boot-starter\2.2.6.RELEASE\spring-boot-starter-2.2.6.RELEASE.jar;F:\workSpace\Maven\repository\org\springframework\boot\spring-boot\2.2.6.RELEASE\spring-boot-2.2.6.RELEASE.jar;F:\workSpace\Maven\repository\org\springframework\boot\spring-boot-autoconfigure\2.2.6.RELEASE\spring-boot-autoconfigure-2.2.6.RELEASE.jar;F:\workSpace\Maven\repository\org\springframework\boot\spring-boot-starter-logging\2.2.6.RELEASE\spring-boot-starter-logging-2.2.6.RELEASE.jar;F:\workSpace\Maven\repository\ch\qos\logback\logback-classic\1.2.3\logback-classic-1.2.3.jar;F:\workSpace\Maven\repository\ch\qos\logback\logback-core\1.2.3\logback-core-1.2.3.jar;F:\workSpace\Maven\repository\org\slf4j\slf4j-api\1.7.30\slf4j-api-1.7.30.jar;F:\workSpace\Maven\repository\org\apache\logging\log4j\log4j-to-slf4j\2.12.1\log4j-to-slf4j-2.12.1.jar;F:\workSpace\Maven\repository\org\apache\logging\log4j\log4j-api\2.12.1\log4j-api-2.12.1.jar;F:\workSpace\Maven\repository\org\slf4j\jul-to-slf4j\1.7.30\jul-to-slf4j-1.7.30.jar;F:\workSpace\Maven\repository\jakarta\annotation\jakarta.annotation-api\1.3.5\jakarta.annotation-api-1.3.5.jar;F:\workSpace\Maven\repository\org\springframework\spring-core\5.2.5.RELEASE\spring-core-5.2.5.RELEASE.jar;F:\workSpace\Maven\repository\org\springframework\spring-jcl\5.2.5.RELEASE\spring-jcl-5.2.5.RELEASE.jar;F:\workSpace\Maven\repository\org\yaml\snakeyaml\1.25\snakeyaml-1.25.jar;F:\workSpace\Maven\repository\org\springframework\boot\spring-boot-starter-json\2.2.6.RELEASE\spring-boot-starter-json-2.2.6.RELEASE.jar;F:\workSpace\Maven\repository\com\fasterxml\jackson\core\jackson-databind\2.10.3\jackson-databind-2.10.3.jar;F:\workSpace\Maven\repository\com\fasterxml\jackson\core\jackson-annotations\2.10.3\jackson-annotations-2.10.3.jar;F:\workSpace\Maven\repository\com\fasterxml\jackson\core\jackson-core\2.10.3\jackson-core-2.10.3.jar;F:\workSpace\Maven\repository\com\fasterxml\jackson\datatype\jackson-datatype-jdk8\2.10.3\jackson-datatype-jdk8-2.10.3.jar;F:\workSpace\Maven\repository\com\fasterxml\jackson\datatype\jackson-datatype-jsr310\2.10.3\jackson-datatype-jsr310-2.10.3.jar;F:\workSpace\Maven\repository\com\fasterxml\jackson\module\jackson-module-parameter-names\2.10.3\jackson-module-parameter-names-2.10.3.jar;F:\workSpace\Maven\repository\org\springframework\boot\spring-boot-starter-tomcat\2.2.6.RELEASE\spring-boot-starter-tomcat-2.2.6.RELEASE.jar;F:\workSpace\Maven\repository\org\apache\tomcat\embed\tomcat-embed-core\9.0.33\tomcat-embed-core-9.0.33.jar;F:\workSpace\Maven\repository\org\apache\tomcat\embed\tomcat-embed-el\9.0.33\tomcat-embed-el-9.0.33.jar;F:\workSpace\Maven\repository\org\apache\tomcat\embed\tomcat-embed-websocket\9.0.33\tomcat-embed-websocket-9.0.33.jar;F:\workSpace\Maven\repository\org\springframework\boot\spring-boot-starter-validation\2.2.6.RELEASE\spring-boot-starter-validation-2.2.6.RELEASE.jar;F:\workSpace\Maven\repository\jakarta\validation\jakarta.validation-api\2.0.2\jakarta.validation-api-2.0.2.jar;F:\workSpace\Maven\repository\org\hibernate\validator\hibernate-validator\6.0.18.Final\hibernate-validator-6.0.18.Final.jar;F:\workSpace\Maven\repository\org\jboss\logging\jboss-logging\3.4.1.Final\jboss-logging-3.4.1.Final.jar;F:\workSpace\Maven\repository\com\fasterxml\classmate\1.5.1\classmate-1.5.1.jar;F:\workSpace\Maven\repository\org\springframework\spring-web\5.2.5.RELEASE\spring-web-5.2.5.RELEASE.jar;F:\workSpace\Maven\repository\org\springframework\spring-beans\5.2.5.RELEASE\spring-beans-5.2.5.RELEASE.jar;F:\workSpace\Maven\repository\org\springframework\spring-webmvc\5.2.5.RELEASE\spring-webmvc-5.2.5.RELEASE.jar;F:\workSpace\Maven\repository\org\springframework\spring-aop\5.2.5.RELEASE\spring-aop-5.2.5.RELEASE.jar;F:\workSpace\Maven\repository\org\springframework\spring-context\5.2.5.RELEASE\spring-context-5.2.5.RELEASE.jar;F:\workSpace\Maven\repository\org\springframework\spring-expression\5.2.5.RELEASE\spring-expression-5.2.5.RELEASE.jar;F:\workSpace\Maven\repository\org\apache\poi\poi-ooxml\3.10-FINAL\poi-ooxml-3.10-FINAL.jar;F:\workSpace\Maven\repository\org\apache\poi\poi\3.10-FINAL\poi-3.10-FINAL.jar;F:\workSpace\Maven\repository\commons-codec\commons-codec\1.13\commons-codec-1.13.jar;F:\workSpace\Maven\repository\dom4j\dom4j\1.6.1\dom4j-1.6.1.jar;F:\workSpace\Maven\repository\xml-apis\xml-apis\1.0.b2\xml-apis-1.0.b2.jar;F:\workSpace\Maven\repository\org\apache\poi\poi-ooxml-schemas\3.10-FINAL\poi-ooxml-schemas-3.10-FINAL.jar;F:\workSpace\Maven\repository\org\apache\xmlbeans\xmlbeans\2.3.0\xmlbeans-2.3.0.jar;F:\workSpace\Maven\repository\stax\stax-api\1.0.1\stax-api-1.0.1.jar;F:\workSpace\Maven\repository\com\alibaba\fastjson\1.2.53\fastjson-1.2.53.jar;F:\workSpace\Maven\repository\com\rabbitmq\amqp-client\3.4.1\amqp-client-3.4.1.jar;F:\workSpace\Maven\repository\org\json\json\20140107\json-20140107.jar;F:\workSpace\Maven\repository\junit\junit\4.12\junit-4.12.jar;F:\workSpace\Maven\repository\org\hamcrest\hamcrest-core\2.1\hamcrest-core-2.1.jar;F:\workSpace\Maven\repository\org\hamcrest\hamcrest\2.1\hamcrest-2.1.jar;F:\workSpace\Maven\repository\io\netty\netty-all\4.1.20.Final\netty-all-4.1.20.Final.jar;F:\workSpace\Maven\repository\org\msgpack\msgpack\0.6.12\msgpack-0.6.12.jar;F:\workSpace\Maven\repository\com\googlecode\json-simple\json-simple\1.1.1\json-simple-1.1.1.jar;F:\workSpace\Maven\repository\org\javassist\javassist\3.18.1-GA\javassist-3.18.1-GA.jar;F:\JetBrains\IntelliJ IDEA 2019.2.1\lib\idea_rt.jarjava.vm.specification.version = 1.8sun.arch.data.model = 64sun.java.command = com.example.offer.leecode.t20201015.CanJumpjava.home = C:\Program Files\Java\Java1.8.1\jreuser.language = zhjava.specification.vendor = Oracle Corporationawt.toolkit = sun.awt.windows.WToolkitjava.vm.info = mixed modejava.version = 1.8.0_102java.ext.dirs = C:\Program Files\Java\Java1.8.1\jre\lib\ext;C:\Windows\Sun\Java\lib\extsun.boot.class.path = C:\Program Files\Java\Java1.8.1\jre\lib\resources.jar;C:\Program Files\Java\Java1.8.1\jre\lib\rt.jar;C:\Program Files\Java\Java1.8.1\jre\lib\sunrsasign.jar;C:\Program Files\Java\Java1.8.1\jre\lib\jsse.jar;C:\Program Files\Java\Java1.8.1\jre\lib\jce.jar;C:\Program Files\Java\Java1.8.1\jre\lib\charsets.jar;C:\Program Files\Java\Java1.8.1\jre\lib\jfr.jar;C:\Program Files\Java\Java1.8.1\jre\classesjava.vendor = Oracle Corporationfile.separator = \java.vendor.url.bug = http://bugreport.sun.com/bugreport/sun.io.unicode.encoding = UnicodeLittlesun.cpu.endian = littlesun.desktop = windowssun.cpu.isalist = amd64VM Flags:Non-default VM flags: -XX:CICompilerCount=4 -XX:InitialHeapSize=268435456 -XX:MaxHeapSize=4273995776 -XX:MaxNewSize=1424490496 -XX:MinHeapDeltaBytes=524288 -XX:NewSize=89128960 -XX:OldSize=179306496 -XX:+UseCompressedClassPointers -XX:+UseCompressedOops -XX:+UseFastUnorderedTimeStamps -XX:-UseLargePagesIndividualAllocation -XX:+UseParallelGCCommand line:  -javaagent:F:\JetBrains\IntelliJ IDEA 2019.2.1\lib\idea_rt.jar=55312:F:\JetBrains\IntelliJ IDEA 2019.2.1\bin -Dfile.encoding=UTF-8C:\Users\zero>

jinfo -flag name pid

查看指定JVM参数的值

C:\Users\zero>jinfo -flag InitialHeapSize 6880-XX:InitialHeapSize=268435456

jinfo -flag [+|-]name pid

动静批改JVM参数的值

C:\Users\zero>jinfo -flag +PrintGC 8932C:\Users\zero>jinfo -flag PrintGC 8932-XX:+PrintGCC:\Users\zero>jinfo -flag -PrintGC 8932C:\Users\zero>jinfo -flag PrintGC 8932-XX:-PrintGCC:\Users\zero>

jmap：JAVA内存映像工具

jmap用于生成堆转储快照(heapdump或dump文件)

生成dump文件的办法，设置虚拟机参数，让虚拟机在OOM异样后主动生成dump文件，或者kill -3 dip，或者应用jmap获取，然而应用jmap命令会造成服务器停用，影响可能会很重大

#呈现 OOME 时生成堆 dump: -XX:+HeapDumpOnOutOfMemoryError#生成堆文件地址：-XX:HeapDumpPath=/home/liuke/jvmlogs/

罕用选项

选项	作用
-dump	生成JAVA堆转储快照
-heap	显示JAVA堆详细信息

应用jmap生成dump文件

C:\Users\zero>jmap -dump:format=b,file=work 5892Dumping heap to C:\Users\zero\work ...Heap dump file created

危险操作

最次要的危险操作是上面这三种：

jmap -dump

这个命令执行，JVM会将整个heap的信息dump写入到一个文件，heap如果比拟大的话，就会导致这个过程比拟耗时，并且执行的过程中为了保障dump的信息是牢靠的，所以会暂停利用。

jmap -permstat
这个命令执行，JVM会去统计perm区的情况，这整个过程也会比拟的耗时，并且同样也会暂停利用。
jmap -histo:live
这个命令执行，JVM会先触发gc，而后再统计信息。

jstack：JAVA堆栈跟踪工具

jstack命令用于生成虚拟机以后时刻的线程快照(threaddump或者javacore文件)

罕用选项

选项	作用
-l	除堆栈外，显示无关锁的附加信息
-m	调用本地办法的话，能够显示C/C++的堆栈

应用jstack查看线程堆栈

C:\Users\zero>jstack 140242020-10-21 22:06:55Full thread dump Java HotSpot(TM) 64-Bit Server VM (25.102-b14 mixed mode):"Service Thread" #11 daemon prio=9 os_prio=0 tid=0x000000001f982800 nid=0x3c2c runnable [0x0000000000000000]   java.lang.Thread.State: RUNNABLE"C1 CompilerThread3" #10 daemon prio=9 os_prio=2 tid=0x000000001f0e9800 nid=0x604 waiting on condition [0x0000000000000000]   java.lang.Thread.State: RUNNABLE"C2 CompilerThread2" #9 daemon prio=9 os_prio=2 tid=0x000000001f0e4800 nid=0x3b24 waiting on condition [0x0000000000000000]   java.lang.Thread.State: RUNNABLE"C2 CompilerThread1" #8 daemon prio=9 os_prio=2 tid=0x000000001f0e4000 nid=0x32fc waiting on condition [0x0000000000000000]   java.lang.Thread.State: RUNNABLE"C2 CompilerThread0" #7 daemon prio=9 os_prio=2 tid=0x000000001f0dd000 nid=0x428 waiting on condition [0x0000000000000000]   java.lang.Thread.State: RUNNABLE"Monitor Ctrl-Break" #6 daemon prio=5 os_prio=0 tid=0x000000001f081000 nid=0x2c08 runnable [0x000000001f55e000]   java.lang.Thread.State: RUNNABLE        at java.net.SocketInputStream.socketRead0(Native Method)        at java.net.SocketInputStream.socketRead(SocketInputStream.java:116)        at java.net.SocketInputStream.read(SocketInputStream.java:170)        at java.net.SocketInputStream.read(SocketInputStream.java:141)        at sun.nio.cs.StreamDecoder.readBytes(StreamDecoder.java:284)        at sun.nio.cs.StreamDecoder.implRead(StreamDecoder.java:326)        at sun.nio.cs.StreamDecoder.read(StreamDecoder.java:178)        - locked <0x000000076b44f888> (a java.io.InputStreamReader)        at java.io.InputStreamReader.read(InputStreamReader.java:184)        at java.io.BufferedReader.fill(BufferedReader.java:161)        at java.io.BufferedReader.readLine(BufferedReader.java:324)        - locked <0x000000076b44f888> (a java.io.InputStreamReader)        at java.io.BufferedReader.readLine(BufferedReader.java:389)        at com.intellij.rt.execution.application.AppMainV2$1.run(AppMainV2.java:64)"Attach Listener" #5 daemon prio=5 os_prio=2 tid=0x000000001edf1800 nid=0x10c4 waiting on condition [0x0000000000000000]   java.lang.Thread.State: RUNNABLE"Signal Dispatcher" #4 daemon prio=9 os_prio=2 tid=0x000000001ed9d000 nid=0x1d14 runnable [0x0000000000000000]   java.lang.Thread.State: RUNNABLE"Finalizer" #3 daemon prio=8 os_prio=1 tid=0x000000001ed80800 nid=0x3c38 in Object.wait() [0x000000001f25f000]   java.lang.Thread.State: WAITING (on object monitor)        at java.lang.Object.wait(Native Method)        - waiting on <0x000000076b188e98> (a java.lang.ref.ReferenceQueue$Lock)        at java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:143)        - locked <0x000000076b188e98> (a java.lang.ref.ReferenceQueue$Lock)        at java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:164)        at java.lang.ref.Finalizer$FinalizerThread.run(Finalizer.java:209)"Reference Handler" #2 daemon prio=10 os_prio=2 tid=0x000000000340c000 nid=0x3500 in Object.wait() [0x000000001ed5f000]   java.lang.Thread.State: WAITING (on object monitor)        at java.lang.Object.wait(Native Method)        - waiting on <0x000000076b186b40> (a java.lang.ref.Reference$Lock)        at java.lang.Object.wait(Object.java:502)        at java.lang.ref.Reference.tryHandlePending(Reference.java:191)        - locked <0x000000076b186b40> (a java.lang.ref.Reference$Lock)        at java.lang.ref.Reference$ReferenceHandler.run(Reference.java:153)"main" #1 prio=5 os_prio=0 tid=0x0000000003314800 nid=0x3fa8 waiting on condition [0x000000000309f000]   java.lang.Thread.State: TIMED_WAITING (sleeping)        at java.lang.Thread.sleep(Native Method)        at com.example.offer.leecode.t20201015.CanJump.main(CanJump.java:57)"VM Thread" os_prio=2 tid=0x000000001ce69800 nid=0x1f18 runnable"GC task thread#0 (ParallelGC)" os_prio=0 tid=0x000000000332a800 nid=0x2b64 runnable"GC task thread#1 (ParallelGC)" os_prio=0 tid=0x000000000332c000 nid=0x514 runnable"GC task thread#2 (ParallelGC)" os_prio=0 tid=0x000000000332e000 nid=0x19f8 runnable"GC task thread#3 (ParallelGC)" os_prio=0 tid=0x0000000003330800 nid=0x2608 runnable"GC task thread#4 (ParallelGC)" os_prio=0 tid=0x0000000003332800 nid=0x2c84 runnable"GC task thread#5 (ParallelGC)" os_prio=0 tid=0x0000000003333800 nid=0x406c runnable"GC task thread#6 (ParallelGC)" os_prio=0 tid=0x0000000003337000 nid=0x2c38 runnable"GC task thread#7 (ParallelGC)" os_prio=0 tid=0x0000000003338000 nid=0x2c54 runnable"VM Periodic Task Thread" os_prio=2 tid=0x000000001fa2c000 nid=0x21d4 waiting on conditionJNI global references: 33C:\Users\zero>jstack -l 140242020-10-21 22:07:00Full thread dump Java HotSpot(TM) 64-Bit Server VM (25.102-b14 mixed mode):"Service Thread" #11 daemon prio=9 os_prio=0 tid=0x000000001f982800 nid=0x3c2c runnable [0x0000000000000000]   java.lang.Thread.State: RUNNABLE   Locked ownable synchronizers:        - None"C1 CompilerThread3" #10 daemon prio=9 os_prio=2 tid=0x000000001f0e9800 nid=0x604 waiting on condition [0x0000000000000000]   java.lang.Thread.State: RUNNABLE   Locked ownable synchronizers:        - None"C2 CompilerThread2" #9 daemon prio=9 os_prio=2 tid=0x000000001f0e4800 nid=0x3b24 waiting on condition [0x0000000000000000]   java.lang.Thread.State: RUNNABLE   Locked ownable synchronizers:        - None"C2 CompilerThread1" #8 daemon prio=9 os_prio=2 tid=0x000000001f0e4000 nid=0x32fc waiting on condition [0x0000000000000000]   java.lang.Thread.State: RUNNABLE   Locked ownable synchronizers:        - None"C2 CompilerThread0" #7 daemon prio=9 os_prio=2 tid=0x000000001f0dd000 nid=0x428 waiting on condition [0x0000000000000000]   java.lang.Thread.State: RUNNABLE   Locked ownable synchronizers:        - None"Monitor Ctrl-Break" #6 daemon prio=5 os_prio=0 tid=0x000000001f081000 nid=0x2c08 runnable [0x000000001f55e000]   java.lang.Thread.State: RUNNABLE        at java.net.SocketInputStream.socketRead0(Native Method)        at java.net.SocketInputStream.socketRead(SocketInputStream.java:116)        at java.net.SocketInputStream.read(SocketInputStream.java:170)        at java.net.SocketInputStream.read(SocketInputStream.java:141)        at sun.nio.cs.StreamDecoder.readBytes(StreamDecoder.java:284)        at sun.nio.cs.StreamDecoder.implRead(StreamDecoder.java:326)        at sun.nio.cs.StreamDecoder.read(StreamDecoder.java:178)        - locked <0x000000076b44f888> (a java.io.InputStreamReader)        at java.io.InputStreamReader.read(InputStreamReader.java:184)        at java.io.BufferedReader.fill(BufferedReader.java:161)        at java.io.BufferedReader.readLine(BufferedReader.java:324)        - locked <0x000000076b44f888> (a java.io.InputStreamReader)        at java.io.BufferedReader.readLine(BufferedReader.java:389)        at com.intellij.rt.execution.application.AppMainV2$1.run(AppMainV2.java:64)   Locked ownable synchronizers:        - None"Attach Listener" #5 daemon prio=5 os_prio=2 tid=0x000000001edf1800 nid=0x10c4 waiting on condition [0x0000000000000000]   java.lang.Thread.State: RUNNABLE   Locked ownable synchronizers:        - None"Signal Dispatcher" #4 daemon prio=9 os_prio=2 tid=0x000000001ed9d000 nid=0x1d14 runnable [0x0000000000000000]   java.lang.Thread.State: RUNNABLE   Locked ownable synchronizers:        - None"Finalizer" #3 daemon prio=8 os_prio=1 tid=0x000000001ed80800 nid=0x3c38 in Object.wait() [0x000000001f25f000]   java.lang.Thread.State: WAITING (on object monitor)        at java.lang.Object.wait(Native Method)        - waiting on <0x000000076b188e98> (a java.lang.ref.ReferenceQueue$Lock)        at java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:143)        - locked <0x000000076b188e98> (a java.lang.ref.ReferenceQueue$Lock)        at java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:164)        at java.lang.ref.Finalizer$FinalizerThread.run(Finalizer.java:209)   Locked ownable synchronizers:        - None"Reference Handler" #2 daemon prio=10 os_prio=2 tid=0x000000000340c000 nid=0x3500 in Object.wait() [0x000000001ed5f000]   java.lang.Thread.State: WAITING (on object monitor)        at java.lang.Object.wait(Native Method)        - waiting on <0x000000076b186b40> (a java.lang.ref.Reference$Lock)        at java.lang.Object.wait(Object.java:502)        at java.lang.ref.Reference.tryHandlePending(Reference.java:191)        - locked <0x000000076b186b40> (a java.lang.ref.Reference$Lock)        at java.lang.ref.Reference$ReferenceHandler.run(Reference.java:153)   Locked ownable synchronizers:        - None"main" #1 prio=5 os_prio=0 tid=0x0000000003314800 nid=0x3fa8 waiting on condition [0x000000000309f000]   java.lang.Thread.State: TIMED_WAITING (sleeping)        at java.lang.Thread.sleep(Native Method)        at com.example.offer.leecode.t20201015.CanJump.main(CanJump.java:57)   Locked ownable synchronizers:        - None"VM Thread" os_prio=2 tid=0x000000001ce69800 nid=0x1f18 runnable"GC task thread#0 (ParallelGC)" os_prio=0 tid=0x000000000332a800 nid=0x2b64 runnable"GC task thread#1 (ParallelGC)" os_prio=0 tid=0x000000000332c000 nid=0x514 runnable"GC task thread#2 (ParallelGC)" os_prio=0 tid=0x000000000332e000 nid=0x19f8 runnable"GC task thread#3 (ParallelGC)" os_prio=0 tid=0x0000000003330800 nid=0x2608 runnable"GC task thread#4 (ParallelGC)" os_prio=0 tid=0x0000000003332800 nid=0x2c84 runnable"GC task thread#5 (ParallelGC)" os_prio=0 tid=0x0000000003333800 nid=0x406c runnable"GC task thread#6 (ParallelGC)" os_prio=0 tid=0x0000000003337000 nid=0x2c38 runnable"GC task thread#7 (ParallelGC)" os_prio=0 tid=0x0000000003338000 nid=0x2c54 runnable"VM Periodic Task Thread" os_prio=2 tid=0x000000001fa2c000 nid=0x21d4 waiting on conditionJNI global references: 33C:\Users\zero>jstack -m 14024Attaching to process ID 14024, please wait...Debugger attached successfully.Server compiler detected.JVM version is 25.102-b14Deadlock Detection:No deadlocks found.----------------- 0 -----------------0x00007ffb6fa55154      ntdll!ZwWaitForSingleObject + 0x140xec8b485741564155              ????????sun.jvm.hotspot.debugger.DebuggerException: Windbg Error: ReadVirtual failed!        at sun.jvm.hotspot.debugger.windbg.WindbgDebuggerLocal.readBytesFromProcess0(Native Method)        at sun.jvm.hotspot.debugger.windbg.WindbgDebuggerLocal.readBytesFromProcess(WindbgDebuggerLocal.java:490)        at sun.jvm.hotspot.debugger.DebuggerBase$Fetcher.fetchPage(DebuggerBase.java:80)        at sun.jvm.hotspot.debugger.PageCache.getPage(PageCache.java:178)        at sun.jvm.hotspot.debugger.PageCache.getLong(PageCache.java:100)        at sun.jvm.hotspot.debugger.DebuggerBase.readCInteger(DebuggerBase.java:364)        at sun.jvm.hotspot.debugger.DebuggerBase.readAddressValue(DebuggerBase.java:462)        at sun.jvm.hotspot.debugger.windbg.WindbgDebuggerLocal.readAddress(WindbgDebuggerLocal.java:316)        at sun.jvm.hotspot.debugger.windbg.WindbgAddress.getAddressAt(WindbgAddress.java:72)        at sun.jvm.hotspot.debugger.windows.amd64.WindowsAMD64CFrame.sender(WindowsAMD64CFrame.java:60)        at sun.jvm.hotspot.tools.PStack.run(PStack.java:161)        at sun.jvm.hotspot.tools.PStack.run(PStack.java:58)        at sun.jvm.hotspot.tools.PStack.run(PStack.java:53)        at sun.jvm.hotspot.tools.JStack.run(JStack.java:66)        at sun.jvm.hotspot.tools.Tool.startInternal(Tool.java:260)        at sun.jvm.hotspot.tools.Tool.start(Tool.java:223)        at sun.jvm.hotspot.tools.Tool.execute(Tool.java:118)        at sun.jvm.hotspot.tools.JStack.main(JStack.java:92)        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)        at java.lang.reflect.Method.invoke(Method.java:498)        at sun.tools.jstack.JStack.runJStackTool(JStack.java:140)        at sun.tools.jstack.JStack.main(JStack.java:106)----------------- 1 ---------------------------------- 2 ---------------------------------- 3 -----------------0x00007ffb6fa55c24      ntdll!NtWaitForMultipleObjects + 0x14----------------- 4 ---------------------------------- 5 ---------------------------------- 6 ---------------------------------- 7 ---------------------------------- 8 ---------------------------------- 9 ---------------------------------- 10 ---------------------------------- 11 ---------------------------------- 12 -----------------0x00007ffb6fa55154      ntdll!ZwWaitForSingleObject + 0x14----------------- 13 -----------------0x00007ffb6fa55154      ntdll!ZwWaitForSingleObject + 0x14----------------- 14 -----------------0x00007ffb6fa55154      ntdll!ZwWaitForSingleObject + 0x14----------------- 15 -----------------0x00007ffb6fa55154      ntdll!ZwWaitForSingleObject + 0x14----------------- 16 -----------------0x00007ffb6fa55154      ntdll!ZwWaitForSingleObject + 0x14----------------- 17 -----------------0x00007ffb6fa55154      ntdll!ZwWaitForSingleObject + 0x14----------------- 18 -----------------0x00007ffb6fa55154      ntdll!ZwWaitForSingleObject + 0x14----------------- 19 -----------------0x00007ffb6fa55154      ntdll!ZwWaitForSingleObject + 0x14----------------- 20 -----------------0x00007ffb6fa55154      ntdll!ZwWaitForSingleObject + 0x14----------------- 21 -----------------0x00007ffb6fa55154      ntdll!ZwWaitForSingleObject + 0x14----------------- 22 ---------------------------------- 23 -----------------0x00007ffb6fa55154      ntdll!ZwWaitForSingleObject + 0x14