--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/share/vm/gc_implementation/shared/mutableSpace.cpp	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,131 @@
+/*
+ * 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.
+ *
+ */
+
+# include "incls/_precompiled.incl"
+# include "incls/_mutableSpace.cpp.incl"
+
+void MutableSpace::initialize(MemRegion mr, bool clear_space) {
+  HeapWord* bottom = mr.start();
+  HeapWord* end    = mr.end();
+
+  assert(Universe::on_page_boundary(bottom) && Universe::on_page_boundary(end),
+         "invalid space boundaries");
+  set_bottom(bottom);
+  set_end(end);
+
+  if (clear_space) clear();
+}
+
+void MutableSpace::clear() {
+  set_top(bottom());
+  if (ZapUnusedHeapArea) mangle_unused_area();
+}
+
+// This version requires locking. */
+HeapWord* MutableSpace::allocate(size_t size) {
+  assert(Heap_lock->owned_by_self() ||
+         (SafepointSynchronize::is_at_safepoint() &&
+          Thread::current()->is_VM_thread()),
+         "not locked");
+  HeapWord* obj = top();
+  if (pointer_delta(end(), obj) >= size) {
+    HeapWord* new_top = obj + size;
+    set_top(new_top);
+    assert(is_object_aligned((intptr_t)obj) && is_object_aligned((intptr_t)new_top),
+           "checking alignment");
+    return obj;
+  } else {
+    return NULL;
+  }
+}
+
+// This version is lock-free.
+HeapWord* MutableSpace::cas_allocate(size_t size) {
+  do {
+    HeapWord* obj = top();
+    if (pointer_delta(end(), obj) >= size) {
+      HeapWord* new_top = obj + size;
+      HeapWord* result = (HeapWord*)Atomic::cmpxchg_ptr(new_top, top_addr(), obj);
+      // result can be one of two:
+      //  the old top value: the exchange succeeded
+      //  otherwise: the new value of the top is returned.
+      if (result != obj) {
+        continue; // another thread beat us to the allocation, try again
+      }
+      assert(is_object_aligned((intptr_t)obj) && is_object_aligned((intptr_t)new_top),
+             "checking alignment");
+      return obj;
+    } else {
+      return NULL;
+    }
+  } while (true);
+}
+
+// Try to deallocate previous allocation. Returns true upon success.
+bool MutableSpace::cas_deallocate(HeapWord *obj, size_t size) {
+  HeapWord* expected_top = obj + size;
+  return (HeapWord*)Atomic::cmpxchg_ptr(obj, top_addr(), expected_top) == expected_top;
+}
+
+void MutableSpace::oop_iterate(OopClosure* cl) {
+  HeapWord* obj_addr = bottom();
+  HeapWord* t = top();
+  // Could call objects iterate, but this is easier.
+  while (obj_addr < t) {
+    obj_addr += oop(obj_addr)->oop_iterate(cl);
+  }
+}
+
+void MutableSpace::object_iterate(ObjectClosure* cl) {
+  HeapWord* p = bottom();
+  while (p < top()) {
+    cl->do_object(oop(p));
+    p += oop(p)->size();
+  }
+}
+
+void MutableSpace::print_short() const { print_short_on(tty); }
+void MutableSpace::print_short_on( outputStream* st) const {
+  st->print(" space " SIZE_FORMAT "K, %d%% used", capacity_in_bytes() / K,
+            (int) ((double) used_in_bytes() * 100 / capacity_in_bytes()));
+}
+
+void MutableSpace::print() const { print_on(tty); }
+void MutableSpace::print_on(outputStream* st) const {
+  MutableSpace::print_short_on(st);
+  st->print_cr(" [" INTPTR_FORMAT "," INTPTR_FORMAT "," INTPTR_FORMAT ")",
+                 bottom(), top(), end());
+}
+
+void MutableSpace::verify(bool allow_dirty) const {
+  HeapWord* p = bottom();
+  HeapWord* t = top();
+  HeapWord* prev_p = NULL;
+  while (p < t) {
+    oop(p)->verify();
+    prev_p = p;
+    p += oop(p)->size();
+  }
+  guarantee(p == top(), "end of last object must match end of space");
+}