* Copyright (c) 1998, 2012, Oracle and/or its affiliates. All rights reserved.

// A CompiledICHolder* is a helper object for the inline cache implementation.

// 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> {

  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;

  // 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; }

  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; }

  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

  }