hotspot/src/share/vm/oops/instanceRefKlass.hpp
changeset 1 489c9b5090e2
child 1374 4c24294029a9
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/share/vm/oops/instanceRefKlass.hpp	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,87 @@
+/*
+ * Copyright 1997-2006 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.
+ *
+ */
+
+// An instanceRefKlass is a specialized instanceKlass for Java
+// classes that are subclasses of java/lang/ref/Reference.
+//
+// These classes are used to implement soft/weak/final/phantom
+// references and finalization, and need special treatment by the
+// garbage collector.
+//
+// During GC discovered reference objects are added (chained) to one
+// of the four lists below, depending on the type of reference.
+// The linked occurs through the next field in class java/lang/ref/Reference.
+//
+// Afterwards, the discovered references are processed in decreasing
+// order of reachability. Reference objects eligible for notification
+// are linked to the static pending_list in class java/lang/ref/Reference,
+// and the pending list lock object in the same class is notified.
+
+
+class instanceRefKlass: public instanceKlass {
+ public:
+  // Type testing
+  bool oop_is_instanceRef() const             { return true; }
+
+  // Casting from klassOop
+  static instanceRefKlass* cast(klassOop k) {
+    assert(k->klass_part()->oop_is_instanceRef(), "cast to instanceRefKlass");
+    return (instanceRefKlass*) k->klass_part();
+  }
+
+  // allocation
+  DEFINE_ALLOCATE_PERMANENT(instanceRefKlass);
+
+  // Garbage collection
+  int  oop_adjust_pointers(oop obj);
+  void oop_follow_contents(oop obj);
+
+  // Parallel Scavenge and Parallel Old
+  PARALLEL_GC_DECLS
+
+  int oop_oop_iterate(oop obj, OopClosure* blk) {
+    return oop_oop_iterate_v(obj, blk);
+  }
+  int oop_oop_iterate_m(oop obj, OopClosure* blk, MemRegion mr) {
+    return oop_oop_iterate_v_m(obj, blk, mr);
+  }
+
+#define InstanceRefKlass_OOP_OOP_ITERATE_DECL(OopClosureType, nv_suffix)                \
+  int oop_oop_iterate##nv_suffix(oop obj, OopClosureType* blk);                         \
+  int oop_oop_iterate##nv_suffix##_m(oop obj, OopClosureType* blk, MemRegion mr);
+
+  ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceRefKlass_OOP_OOP_ITERATE_DECL)
+  ALL_OOP_OOP_ITERATE_CLOSURES_3(InstanceRefKlass_OOP_OOP_ITERATE_DECL)
+
+  static void release_and_notify_pending_list_lock(BasicLock *pending_list_basic_lock);
+  static void acquire_pending_list_lock(BasicLock *pending_list_basic_lock);
+
+  // Update non-static oop maps so 'referent', 'nextPending' and
+  // 'discovered' will look like non-oops
+  static void update_nonstatic_oop_maps(klassOop k);
+
+ public:
+  // Verification
+  void oop_verify_on(oop obj, outputStream* st);
+};