jdk8u321 test run from submitter:

Found one Java-level deadlock:
=============================
"Thread-openJarURLConnectionStream":
  waiting to lock monitor 0x00007f94d00062c8 (object 0x00000000d7d96ab0, a
sun.nio.cs.ext.ExtendedCharsets),
  which is held by "Thread-availableCharsets"
"Thread-availableCharsets":
  waiting to lock monitor 0x00007f94ac0390a8 (object 0x00000000d7e29b48, a
sun.net.www.protocol.jar.JarFileFactory),
  which is held by "Thread-openJarURLConnectionStream"

Java stack information for the threads listed above:
===================================================
"Thread-openJarURLConnectionStream":
        at
sun.nio.cs.AbstractCharsetProvider.charsetForName(AbstractCharsetProvider.java
:160)
        - waiting to lock <0x00000000d7d96ab0> (a
sun.nio.cs.ext.ExtendedCharsets)
        at java.nio.charset.Charset.lookupExtendedCharset(Charset.java:452)
        at java.nio.charset.Charset.lookup2(Charset.java:476)
        at java.nio.charset.Charset.lookup(Charset.java:464)
        at java.nio.charset.Charset.isSupported(Charset.java:505)
        at java.lang.StringCoding.lookupCharset(StringCoding.java:99)
        at java.lang.StringCoding.encode(StringCoding.java:336)
        at java.lang.String.getBytes(String.java:918)
        at java.io.UnixFileSystem.canonicalize0(Native Method)
        at java.io.UnixFileSystem.canonicalize(UnixFileSystem.java:172)
        at java.io.File.getCanonicalPath(File.java:624)
        at java.io.FilePermission$1.run(FilePermission.java:224)
        at java.io.FilePermission$1.run(FilePermission.java:212)
        at java.security.AccessController.doPrivileged(Native Method)
        at java.io.FilePermission.init(FilePermission.java:212)
        at java.io.FilePermission.<init>(FilePermission.java:299)
        at sun.net.www.protocol.file.FileURLConnection.getPermission(FileURLConnection.java:225)
        at sun.net.www.protocol.jar.JarFileFactory.getPermission(JarFileFactory.java:225)
        at sun.net.www.protocol.jar.JarFileFactory.getCachedJarFile(JarFileFactory.java:195)
        at sun.net.www.protocol.jar.JarFileFactory.getOrCreate(JarFileFactory.java:103)
        - locked <0x00000000d7e29b48> (a sun.net.www.protocol.jar.JarFileFactory)
        at sun.net.www.protocol.jar.JarURLConnection.connect(JarURLConnection.java:129)
        at sun.net.www.protocol.jar.JarURLConnection.getInputStream(JarURLConnection.java:172)
        at java.net.URL.openStream(URL.java:1092)
        at DeadlockSampleModified.openJarURLConnectionStream(DeadlockSampleModified.java:57)
        at DeadlockSampleModified.access$100(DeadlockSampleModified.java:6)
        at DeadlockSampleModified$2.run(DeadlockSampleModified.java:27)
        at java.lang.Thread.run(Thread.java:750)

"Thread-availableCharsets":
        at sun.net.www.protocol.jar.JarFileFactory.getOrCreate(JarFileFactory.java:103)
        - waiting to lock <0x00000000d7e29b48> (a sun.net.www.protocol.jar.JarFileFactory)
        at sun.net.www.protocol.jar.JarURLConnection.connect(JarURLConnection.java:129)
        at sun.net.www.protocol.jar.JarURLConnection.getInputStream(JarURLConnection.java:172)
        at java.net.URL.openStream(URL.java:1092)
        at java.lang.ClassLoader.getSystemResourceAsStream(ClassLoader.java:1324)
        at java.lang.Class.getResourceAsStream(Class.java:2221)
        at sun.nio.cs.ext.SJIS_0213$1.run(SJIS_0213.java:81)
        at sun.nio.cs.ext.SJIS_0213$1.run(SJIS_0213.java:79)
        at java.security.AccessController.doPrivileged(Native Method)
        at sun.nio.cs.ext.SJIS_0213.<clinit>(SJIS_0213.java:78)
        at java.lang.Class.forName0(Native Method)
        at java.lang.Class.forName(Class.java:348)
        at sun.nio.cs.AbstractCharsetProvider.lookup(AbstractCharsetProvider.java:142)
        at sun.nio.cs.AbstractCharsetProvider.access$000(AbstractCharsetProvider.java:45)
        at sun.nio.cs.AbstractCharsetProvider$1.next(AbstractCharsetProvider.java:183)
        - locked <0x00000000d7d96ab0> (a sun.nio.cs.ext.ExtendedCharsets)
        at sun.nio.cs.AbstractCharsetProvider$1.next(AbstractCharsetProvider.java:173)
        at java.nio.charset.Charset.put(Charset.java:539)
        at java.nio.charset.Charset.access$200(Charset.java:271)
        at java.nio.charset.Charset$3.run(Charset.java:581)
        at java.nio.charset.Charset$3.run(Charset.java:573)
        at java.security.AccessController.doPrivileged(Native Method)
        at java.nio.charset.Charset.availableCharsets(Charset.java:572)
        at DeadlockSampleModified.availableCharsets(DeadlockSampleModified.java:49)
        at DeadlockSampleModified.access$000(DeadlockSampleModified.java:6)
        at DeadlockSampleModified$1.run(DeadlockSampleModified.java:20)
        at java.lang.Thread.run(Thread.java:750)

Found 1 deadlock.