6711316: Open source the Garbage-First garbage collector

First mercurial integration of the code for the Garbage-First garbage collector.

Reviewed-by: apetrusenko, iveresov, jmasa, sgoldman, tonyp, ysr

hotspot/src/share/vm/gc_implementation/g1/heapRegion.inline.hpp

@@ -0,0 +1,60 @@
+/*
+ * Copyright 2001-2007 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ *
+ */
+
+inline HeapWord* G1OffsetTableContigSpace::allocate(size_t size) {
+  HeapWord* res = ContiguousSpace::allocate(size);
+  if (res != NULL) {
+    _offsets.alloc_block(res, size);
+  }
+  return res;
+}
+
+// Because of the requirement of keeping "_offsets" up to date with the
+// allocations, we sequentialize these with a lock.  Therefore, best if
+// this is used for larger LAB allocations only.
+inline HeapWord* G1OffsetTableContigSpace::par_allocate(size_t size) {
+  MutexLocker x(&_par_alloc_lock);
+  // This ought to be just "allocate", because of the lock above, but that
+  // ContiguousSpace::allocate asserts that either the allocating thread
+  // holds the heap lock or it is the VM thread and we're at a safepoint.
+  // The best I (dld) could figure was to put a field in ContiguousSpace
+  // meaning "locking at safepoint taken care of", and set/reset that
+  // here.  But this will do for now, especially in light of the comment
+  // above.  Perhaps in the future some lock-free manner of keeping the
+  // coordination.
+  HeapWord* res = ContiguousSpace::par_allocate(size);
+  if (res != NULL) {
+    _offsets.alloc_block(res, size);
+  }
+  return res;
+}
+
+inline HeapWord* G1OffsetTableContigSpace::block_start(const void* p) {
+  return _offsets.block_start(p);
+}
+
+inline HeapWord*
+G1OffsetTableContigSpace::block_start_const(const void* p) const {
+  return _offsets.block_start_const(p);
+}