src/hotspot/share/oops/klass.cpp

*** 1,7 ****
  /*
!  * Copyright (c) 1997, 2017, Oracle and/or its affiliates. All rights reserved.
   * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   *
   * This code is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 only, as
   * published by the Free Software Foundation.
--- 1,7 ----
  /*
!  * Copyright (c) 1997, 2018, Oracle and/or its affiliates. All rights reserved.
   * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   *
   * This code is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 only, as
   * published by the Free Software Foundation.
*** 617,626 ****
--- 617,639 ----
  // Unless overridden, jvmti_class_status has no flags set.
  jint Klass::jvmti_class_status() const {
    return 0;
  }
  
+ // Tell the GC to keep this klass alive
+ void Klass::ensure_klass_alive(oop o) {
+   // A klass that was previously considered dead can be looked up in the 
+   // CLD/SD, and its _java_mirror or _class_loader can be stored in a root
+   // or a reachable object making it alive again.
+   // The SATB part of G1 needs to get notified about this
+   // potential resurrection, otherwise the marking might not find the object.
+ #if INCLUDE_ALL_GCS
+   if (UseG1GC && o != NULL) {
+     G1SATBCardTableModRefBS::enqueue(o);
+   }
+ #endif
+ }
  
  // Printing
  
  void Klass::print_on(outputStream* st) const {
    ResourceMark rm;