cap_alloc

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// -*- Mode: C++ -*-
// vim:ft=cpp
/*
 * (c) 2008-2009 Adam Lackorzynski <adam@os.inf.tu-dresden.de>,
 *               Alexander Warg <warg@os.inf.tu-dresden.de>
 *     economic rights: Technische Universität Dresden (Germany)
 *
 * License: see LICENSE.spdx (in this directory or the directories above)
 */
 
#pragma once
 
#include <l4/re/util/cap_alloc_impl.h>
#include <l4/re/util/item_alloc>
#include <l4/sys/smart_capability>
#include <l4/sys/task>
#include <l4/re/consts>
 
namespace L4Re { namespace Util {

 
template<unsigned Num_caps>
class Reply_cap_alloc final : public L4::Reply_cap_alloc
{
public:
  static constexpr unsigned Capacity = Num_caps;
 
  explicit Reply_cap_alloc(unsigned bias) noexcept
  : _bias(bias)
  {}
 
  L4::Reply_cap alloc() noexcept override
  {
    if (long slot = _alloc.alloc(); slot >= 0) [[likely]]
      {
        auto idx = (static_cast<l4_cap_idx_t>(slot) + _bias) << L4_CAP_SHIFT;
        return L4::Reply_cap(L4::Reply_cap_idx(idx), this);
      }
    else
      return L4::Reply_cap();
  }
 
protected:
  void free(L4::Reply_cap_idx cap) noexcept override
  { _alloc.free((cap.cap() >> L4_CAP_SHIFT) - _bias); }
 
private:
  unsigned _bias;
  Item_alloc<Capacity> _alloc;
};
 
using Def_reply_cap_alloc = Reply_cap_alloc<CONFIG_L4RE_CAP_DFL_ALLOCATOR_MAX>;

extern _Cap_alloc cap_alloc;

extern Def_reply_cap_alloc reply_cap_alloc;

template< unsigned long Unmap_flags = L4_FP_ALL_SPACES >
class Smart_cap_auto
{
public:
  static void free(L4::Cap_base &c)
  {
    if (c.is_valid())
      {
        cap_alloc.free(L4::Cap<void>(c.cap()), This_task, Unmap_flags);
        c.invalidate();
      }
  }

  static void invalidate(L4::Cap_base &c)
  {
    if (c.is_valid())
      c.invalidate();
  }
 
};
 

template< unsigned long Unmap_flags = L4_FP_ALL_SPACES >
class Smart_count_cap
{
public:
  static void free(L4::Cap_base &c) noexcept
  {
    if (c.is_valid())
      {
        if (cap_alloc.release(L4::Cap<void>(c.cap()), This_task, Unmap_flags))
    c.invalidate();
      }
  }

  static void invalidate(L4::Cap_base &c) noexcept
  {
    if (c.is_valid())
      c.invalidate();
  }

  static L4::Cap_base copy(L4::Cap_base const &src)
  {
    cap_alloc.take(L4::Cap<void>(src.cap()));
    return src;
  }
};
 

template< typename T >
struct Ref_cap
{
  typedef L4::Smart_cap<T, Smart_count_cap<L4_FP_ALL_SPACES> > Cap;
};

template< typename T >
struct Ref_del_cap
{
  typedef L4::Smart_cap<T, Smart_count_cap<L4_FP_DELETE_OBJ> > Cap;
};

template< typename T >
typename Ref_cap<T>::Cap
make_ref_cap() { return typename Ref_cap<T>::Cap(cap_alloc.alloc<T>()); }

template< typename T >
typename Ref_del_cap<T>::Cap
make_ref_del_cap()
{ return typename Ref_del_cap<T>::Cap(cap_alloc.alloc<T>()); }

 
}}