许多线程处于IN_NATIVE状态

Question

我们在tomcat节点上看到了一些奇怪的问题。我使用线程转储来查看线程状态。在tha中，大多数线程处于IN_NATIVE状态。有人能告诉我这是什么原因吗？下面是线程的堆栈跟踪。

Thread 677: (state = IN_NATIVE)
 - java.net.SocketInputStream.socketRead0(java.io.FileDescriptor, byte[], int, int, int) @bci=0 (Compiled frame; information may be imprecise)
 - java.net.SocketInputStream.read(byte[], int, int) @bci=84, line=129 (Compiled frame)
 - com.sun.net.ssl.internal.ssl.InputRecord.readFully(java.io.InputStream, byte[], int, int) @bci=21, line=293 (Compiled frame)
 - com.sun.net.ssl.internal.ssl.InputRecord.read(java.io.InputStream, java.io.OutputStream) @bci=32, line=331 (Compiled frame)
 - com.sun.net.ssl.internal.ssl.SSLSocketImpl.readRecord(com.sun.net.ssl.internal.ssl.InputRecord, boolean) @bci=44, line=789 (Compiled frame)
 - com.sun.net.ssl.internal.ssl.SSLSocketImpl.readDataRecord(com.sun.net.ssl.internal.ssl.InputRecord) @bci=15, line=746 (Compiled frame)
 - com.sun.net.ssl.internal.ssl.AppInputStream.read(byte[], int, int) @bci=30, line=75 (Compiled frame)
 - java.io.BufferedInputStream.fill() @bci=175, line=218 (Compiled frame)
 - java.io.BufferedInputStream.read1(byte[], int, int) @bci=44, line=258 (Compiled frame)
 - java.io.BufferedInputStream.read(byte[], int, int) @bci=49, line=317 (Compiled frame)
 - com.sun.jndi.ldap.Connection.run() @bci=30, line=808 (Compiled frame)
 - java.lang.Thread.run() @bci=11, line=619 (Interpreted frame)


Thread 675: (state = IN_NATIVE)
 - java.net.SocketInputStream.socketRead0(java.io.FileDescriptor, byte[], int, int, int) @bci=0 (Compiled frame; information may be imprecise)
 - java.net.SocketInputStream.read(byte[], int, int) @bci=84, line=129 (Compiled frame)
 - com.sun.net.ssl.internal.ssl.InputRecord.readFully(java.io.InputStream, byte[], int, int) @bci=21, line=293 (Compiled frame)
 - com.sun.net.ssl.internal.ssl.InputRecord.read(java.io.InputStream, java.io.OutputStream) @bci=32, line=331 (Compiled frame)
 - com.sun.net.ssl.internal.ssl.SSLSocketImpl.readRecord(com.sun.net.ssl.internal.ssl.InputRecord, boolean) @bci=44, line=789 (Compiled frame)
 - com.sun.net.ssl.internal.ssl.SSLSocketImpl.readDataRecord(com.sun.net.ssl.internal.ssl.InputRecord) @bci=15, line=746 (Compiled frame)
 - com.sun.net.ssl.internal.ssl.AppInputStream.read(byte[], int, int) @bci=30, line=75 (Compiled frame)
 - java.io.BufferedInputStream.fill() @bci=175, line=218 (Compiled frame)
 - java.io.BufferedInputStream.read1(byte[], int, int) @bci=44, line=258 (Compiled frame)
 - java.io.BufferedInputStream.read(byte[], int, int) @bci=49, line=317 (Compiled frame)
 - com.sun.jndi.ldap.Connection.run() @bci=30, line=808 (Compiled frame)
 - java.lang.Thread.run() @bci=11, line=619 (Interpreted frame)

全线程转储为@ PpQrTQxtIWjWmAlt8AF1ddAOzvisCM/edit?usp=sharing

Answer 1

Java在某种程度上类似于C++的包装语言。一些库仍然使用c++并使用java关键字本机。

这基本上意味着他们调用了一个本地方法，该方法现在正在c/c++代码中执行。

Answer 2

线程被阻止，通过SSL从LDAP服务器读取。看到堆栈跟踪。