diff src/share/vm/oops/compiledICHolder.hpp @ 3602:da91efe96a93

6964458: Reimplement class meta-data storage to use native memory Summary: Remove PermGen, allocate meta-data in metaspace linked to class loaders, rewrite GC walking, rewrite and rename metadata to be C++ classes Reviewed-by: jmasa, stefank, never, coleenp, kvn, brutisso, mgerdin, dholmes, jrose, twisti, roland Contributed-by: jmasa <jon.masamitsu@oracle.com>, stefank <stefan.karlsson@oracle.com>, mgerdin <mikael.gerdin@oracle.com>, never <tom.rodriguez@oracle.com>
author coleenp
date Sat, 01 Sep 2012 13:25:18 -0400
parents src/share/vm/oops/compiledICHolderOop.hpp@f95d63e2154a
children
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--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/share/vm/oops/compiledICHolder.hpp	Sat Sep 01 13:25:18 2012 -0400
@@ -0,0 +1,101 @@
+/*
+ * Copyright (c) 1998, 2012, 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_VM_OOPS_COMPILEDICHOLDEROOP_HPP
+#define SHARE_VM_OOPS_COMPILEDICHOLDEROOP_HPP
+
+#include "oops/oop.hpp"
+
+// A CompiledICHolder* is a helper object for the inline cache implementation.
+// It holds an intermediate value (method+klass pair) used when converting from
+// compiled to an interpreted call.
+//
+// These are always allocated in the C heap and are freed during a
+// safepoint by the ICBuffer logic.  It's unsafe to free them earlier
+// since they might be in use.
+//
+
+
+class CompiledICHolder : public CHeapObj<mtCompiler> {
+  friend class VMStructs;
+ private:
+  static volatile int _live_count; // allocated
+  static volatile int _live_not_claimed_count; // allocated but not yet in use so not
+                                               // reachable by iterating over nmethods
+
+  Method* _holder_method;
+  Klass*    _holder_klass;    // to avoid name conflict with oopDesc::_klass
+  CompiledICHolder* _next;
+
+ public:
+  // Constructor
+  CompiledICHolder(Method* method, Klass* klass)
+      : _holder_method(method), _holder_klass(klass) {
+#ifdef ASSERT
+    Atomic::inc(&_live_count);
+    Atomic::inc(&_live_not_claimed_count);
+#endif
+  }
+
+  ~CompiledICHolder() {
+#ifdef ASSERT
+    assert(_live_count > 0, "underflow");
+    Atomic::dec(&_live_count);
+#endif
+  }
+
+  static int live_count() { return _live_count; }
+  static int live_not_claimed_count() { return _live_not_claimed_count; }
+
+  // accessors
+  Method* holder_method() const     { return _holder_method; }
+  Klass*    holder_klass()  const     { return _holder_klass; }
+
+  void set_holder_method(Method* m) { _holder_method = m; }
+  void set_holder_klass(Klass* k)   { _holder_klass = k; }
+
+  // interpreter support (offsets in bytes)
+  static int holder_method_offset()   { return offset_of(CompiledICHolder, _holder_method); }
+  static int holder_klass_offset()    { return offset_of(CompiledICHolder, _holder_klass); }
+
+  CompiledICHolder* next()     { return _next; }
+  void set_next(CompiledICHolder* n) { _next = n; }
+
+  // Verify
+  void verify_on(outputStream* st);
+
+  // Printing
+  void print_on(outputStream* st) const;
+  void print_value_on(outputStream* st) const;
+
+  const char* internal_name() const { return "{compiledICHolder}"; }
+
+  void claim() {
+#ifdef ASSERT
+    Atomic::dec(&_live_not_claimed_count);
+#endif
+  }
+};
+
+#endif // SHARE_VM_OOPS_COMPILEDICHOLDEROOP_HPP