src/share/vm/classfile/symbolTable.cpp

rev 4736 : 8015422: Large performance hit when the StringTable is walked twice in Parallel Scavenge
Summary: Combine the calls to StringTable::unlink and StringTable::oops_do in Parallel Scavenge.
Reviewed-by: TBD1, TBD2

*** 735,745 ****
    Handle string;
    oop result = intern(string, chars, length, CHECK_NULL);
    return result;
  }
  
! void StringTable::unlink(BoolObjectClosure* is_alive) {
    // Readers of the table are unlocked, so we should only be removing
    // entries at a safepoint.
    assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
    for (int i = 0; i < the_table()->table_size(); ++i) {
      HashtableEntry<oop, mtSymbol>** p = the_table()->bucket_addr(i);
--- 735,745 ----
    Handle string;
    oop result = intern(string, chars, length, CHECK_NULL);
    return result;
  }
  
! void StringTable::unlink(BoolObjectClosure* is_alive, OopClosure* keep_alive) {
    // Readers of the table are unlocked, so we should only be removing
    // entries at a safepoint.
    assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
    for (int i = 0; i < the_table()->table_size(); ++i) {
      HashtableEntry<oop, mtSymbol>** p = the_table()->bucket_addr(i);
*** 747,756 ****
--- 747,759 ----
      while (entry != NULL) {
        assert(entry->literal() != NULL, "just checking");
        assert(!entry->is_shared(), "CDS not used for the StringTable");
  
        if (is_alive->do_object_b(entry->literal())) {
+         if (keep_alive != NULL) {
+           keep_alive->do_oop((oop*)entry->literal_addr());
+         }
          p = entry->next_addr();
        } else {
          *p = entry->next();
          the_table()->free_entry(entry);
        }