src/hotspot/share/gc/shared/stringdedup/stringDedupTable.cpp

rev 57656 : 8236878: Use atomic instruction to update StringDedupTable's entries and entries_removed counters

*** 1,7 ****
  /*
!  * Copyright (c) 2014, 2019, 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) 2014, 2020, 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.
*** 213,223 ****
  const double             StringDedupTable::_max_cache_factor = 0.1; // Cache a maximum of 10% of the table size
  const uintx              StringDedupTable::_rehash_multiple = 60;   // Hash bucket has 60 times more collisions than expected
  const uintx              StringDedupTable::_rehash_threshold = (uintx)(_rehash_multiple * _grow_load_factor);
  
  uintx                    StringDedupTable::_entries_added = 0;
! uintx                    StringDedupTable::_entries_removed = 0;
  uintx                    StringDedupTable::_resize_count = 0;
  uintx                    StringDedupTable::_rehash_count = 0;
  
  StringDedupTable*        StringDedupTable::_resized_table = NULL;
  StringDedupTable*        StringDedupTable::_rehashed_table = NULL;
--- 213,223 ----
  const double             StringDedupTable::_max_cache_factor = 0.1; // Cache a maximum of 10% of the table size
  const uintx              StringDedupTable::_rehash_multiple = 60;   // Hash bucket has 60 times more collisions than expected
  const uintx              StringDedupTable::_rehash_threshold = (uintx)(_rehash_multiple * _grow_load_factor);
  
  uintx                    StringDedupTable::_entries_added = 0;
! volatile uintx           StringDedupTable::_entries_removed = 0;
  uintx                    StringDedupTable::_resize_count = 0;
  uintx                    StringDedupTable::_rehash_count = 0;
  
  StringDedupTable*        StringDedupTable::_resized_table = NULL;
  StringDedupTable*        StringDedupTable::_rehashed_table = NULL;
*** 477,489 ****
      removed += unlink_or_oops_do(cl, table_half + partition_begin, table_half + partition_end, worker_id);
    }
  
    // Delayed update to avoid contention on the table lock
    if (removed > 0) {
!     MutexLocker ml(StringDedupTable_lock, Mutex::_no_safepoint_check_flag);
!     _table->_entries -= removed;
!     _entries_removed += removed;
    }
  }
  
  uintx StringDedupTable::unlink_or_oops_do(StringDedupUnlinkOrOopsDoClosure* cl,
                                            size_t partition_begin,
--- 477,489 ----
      removed += unlink_or_oops_do(cl, table_half + partition_begin, table_half + partition_end, worker_id);
    }
  
    // Delayed update to avoid contention on the table lock
    if (removed > 0) {
!     assert_locked_or_safepoint_weak(StringDedupTable_lock);
!     Atomic::sub(&_table->_entries, removed);
!     Atomic::add(&_entries_removed, removed);
    }
  }
  
  uintx StringDedupTable::unlink_or_oops_do(StringDedupUnlinkOrOopsDoClosure* cl,
                                            size_t partition_begin,