I extracted it and put the jdk-14.0.2\ folder in "C:\Program Files\". For a more complete list of the bug fixes included in this release, see the JDK 10.0.2 Bug Fixes page.The ZIP file "openjdk-14.0.2_windows-圆4_bin.zip" contains one folder ("jdk-14.0.2\") which contains multiple directories and files. This release also contains fixes for security vulnerabilities described in the Oracle Critical Patch Update. This fix for JDK-8187577 informs G1's SATB that a klass has been resurrected and it should not be unloaded. When these JNIHandles were later scanned, it lead to a crash. G1 did not have knowledge of these thread-local JNIHandles, and in the remark phase, it unloaded the classes per its prior knowledge of unreachable classes. In this particular crash, while G1 was doing concurrent marking and had prepared its list of unreachable classes, JVMTI on a Java thread could traverse classes in the CLD and store thread-local JNIHandles for the java_mirror of the loaded classes.
Whenever a klass is resurrected in this manner, the SATB part of G1 needs to be notified about this, otherwise, the concurrent marking remark phase will erroneously unload that klass. A klass that has been considered unreachable by the concurrent marking of G1, can be looked up in the ClassLoaderData/SystemDictionary, and its _java_mirror or _class_loader fields can be stored in a root or any other reachable object making it alive again.
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