src/hotspot/share/gc/z/zBitMap.inline.hpp
changeset 50525 767cdb97f103
child 50875 2217b2fc29ea
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/gc/z/zBitMap.inline.hpp	Tue Jun 12 17:40:28 2018 +0200
@@ -0,0 +1,75 @@
+/*
+ * Copyright (c) 2016, 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.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+#ifndef SHARE_GC_Z_ZBITMAP_INLINE_HPP
+#define SHARE_GC_Z_ZBITMAP_INLINE_HPP
+
+#include "gc/z/zBitMap.hpp"
+#include "runtime/atomic.hpp"
+#include "utilities/bitMap.inline.hpp"
+#include "utilities/debug.hpp"
+
+inline ZBitMap::ZBitMap(idx_t size_in_bits) :
+    CHeapBitMap(size_in_bits, mtGC, false /* clear */) {}
+
+inline BitMap::bm_word_t ZBitMap::bit_mask_pair(idx_t bit) {
+  assert(bit_in_word(bit) < BitsPerWord - 1, "Invalid bit index");
+  return (bm_word_t)3 << bit_in_word(bit);
+}
+
+inline bool ZBitMap::par_set_bit_pair_finalizable(idx_t bit, bool& inc_live) {
+  inc_live = par_set_bit(bit);
+  return inc_live;
+}
+
+inline bool ZBitMap::par_set_bit_pair_strong(idx_t bit, bool& inc_live) {
+  verify_index(bit);
+  volatile bm_word_t* const addr = word_addr(bit);
+  const bm_word_t pair_mask = bit_mask_pair(bit);
+  bm_word_t old_val = *addr;
+
+  do {
+    const bm_word_t new_val = old_val | pair_mask;
+    if (new_val == old_val) {
+      inc_live = false;
+      return false;     // Someone else beat us to it.
+    }
+    const bm_word_t cur_val = Atomic::cmpxchg(new_val, addr, old_val);
+    if (cur_val == old_val) {
+      const bm_word_t marked_mask = bit_mask(bit);
+      inc_live = !(old_val & marked_mask);
+      return true;      // Success.
+    }
+    old_val = cur_val;  // The value changed, try again.
+  } while (true);
+}
+
+inline bool ZBitMap::par_set_bit_pair(idx_t bit, bool finalizable, bool& inc_live) {
+  if (finalizable) {
+    return par_set_bit_pair_finalizable(bit, inc_live);
+  } else {
+    return par_set_bit_pair_strong(bit, inc_live);
+  }
+}
+
+#endif // SHARE_GC_Z_ZBITMAP_INLINE_HPP