src/hotspot/share/classfile/metadataOnStackMark.cpp

Concurrent class unloading

*** 45,60 ****
  // Walk metadata on the stack and mark it so that redefinition doesn't delete
  // it.  Class unloading only deletes in-error class files, methods created by
  // the relocator and dummy constant pools.  None of these appear anywhere except
  // in metadata Handles.
  MetadataOnStackMark::MetadataOnStackMark(bool redefinition_walk) {
-   assert(SafepointSynchronize::is_at_safepoint(), "sanity check");
    assert(_used_buffers == NULL, "sanity check");
    assert(!_is_active, "MetadataOnStackMarks do not nest");
    NOT_PRODUCT(_is_active = true;)
  
!   Threads::metadata_handles_do(Metadata::mark_on_stack);
  
    if (redefinition_walk) {
      Threads::metadata_do(Metadata::mark_on_stack);
      CodeCache::metadata_do(Metadata::mark_on_stack);
      CompileBroker::mark_on_stack();
--- 45,62 ----
  // Walk metadata on the stack and mark it so that redefinition doesn't delete
  // it.  Class unloading only deletes in-error class files, methods created by
  // the relocator and dummy constant pools.  None of these appear anywhere except
  // in metadata Handles.
  MetadataOnStackMark::MetadataOnStackMark(bool redefinition_walk) {
    assert(_used_buffers == NULL, "sanity check");
    assert(!_is_active, "MetadataOnStackMarks do not nest");
    NOT_PRODUCT(_is_active = true;)
  
!   if (!UseZGC) {
!     assert(SafepointSynchronize::is_at_safepoint(), "sanity check");
!     Threads::metadata_handles_do(Metadata::mark_on_stack);
!   }
  
    if (redefinition_walk) {
      Threads::metadata_do(Metadata::mark_on_stack);
      CodeCache::metadata_do(Metadata::mark_on_stack);
      CompileBroker::mark_on_stack();
***************
*** 65,75 ****
  #endif
    }
  }
  
  MetadataOnStackMark::~MetadataOnStackMark() {
!   assert(SafepointSynchronize::is_at_safepoint(), "sanity check");
    // Unmark everything that was marked.   Can't do the same walk because
    // redefine classes messes up the code cache so the set of methods
    // might not be the same.
    retire_current_buffer();
  
--- 67,77 ----
  #endif
    }
  }
  
  MetadataOnStackMark::~MetadataOnStackMark() {
!   assert(SafepointSynchronize::is_at_safepoint() || UseZGC, "sanity check");
    // Unmark everything that was marked.   Can't do the same walk because
    // redefine classes messes up the code cache so the set of methods
    // might not be the same.
    retire_current_buffer();