LUMIERA.clone/src/lib/typed-allocation-manager.hpp

324 lines
11 KiB
C++

/*
TYPED-ALLOCATION-MANAGER.hpp - abstract backbone to build custom memory managers
Copyright (C) Lumiera.org
2009, Hermann Vosseler <Ichthyostega@web.de>
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.
This program 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 for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
/** @file typed-allocation-manager.hpp
** Abstract foundation for building custom allocation managers.
** Currently (as of 8/09) this is a draft, factored out of the command-registry.
** The expectation is that we'll face several similar situations, and thus it
** would be good to build up a common set of operations and behaviour.
** @todo WIP WIP.
**
** \par Concept Summary
** The idea is rather to tie the memory manager to a very specific usage situation,
** then to provide a general-purpose allocator to be used by any instance of a given
** type. Typically, the goal is to handle memory management for an index or registry,
** holding implementation objects to be shielded from the client code. Moreover, we'll
** have to deal with families of types rather then with individual types; usually
** there will be some common or combined handling for all family members.
**
** The intention is for this TypedAllocationManager template to be used both as a base
** class providing the implementation skeleton for the actual custom allocation manager,
** and as an abstract interface, which can be forwarded to the \em implementation classes
** in case there is some cooperation required to get the allocation done (for example,
** there might be some type erasure involved, leaving the (otherwise opaque) implementation
** class as the only entity with a limited knowledge about the actual memory layout, and
** thus the only way of creating a clone properly would be to forward down into this
** implementation class).
**
** Thus, TypedAllocationManager provides the classical operations of an allocator
** - allocate
** - construct
** - deallocate
** But each of these operations is to be invoked in a \em typed context. Besides,
** there is a facility allowing to create ref-counting handles and smart-pointers,
** which are internally tied to this memory manager through a deleter function.
**
** @todo using a quick-n-dirty heap allocation implementation for now (8/09),
** but should write a custom allocator based on cehteh's mpool!
**
** @see CommandRegistry
** @see AllocationCluster (another custom allocation scheme, which could be united)
**
*/
#ifndef CONTROL_TYPED_ALLOCATION_MANAGER_H
#define CONTROL_TYPED_ALLOCATION_MANAGER_H
//#include "pre.hpp"
#include "lib/error.hpp"
#include "lib/format.hpp"
#include "lib/typed-counter.hpp"
#include "include/logging.h"
#include <tr1/memory>
namespace lib {
using std::tr1::shared_ptr;
/**
* Foundation for a custom allocation manager,
* tracking the created objects by smart-ptrs.
* The public interface provides forwarding functions
* to invoke the ctor of the objects to be created, thereby
* placing them into the storage maintained by a low-level
* allocator or pooled storage manager. The created smart-ptr
* owns the new object and is wired internally to #releaseSlot.
* Subclasses may also directly allocate and de-allocate
* such a (typed) storage slot.
*
* @todo currently (as of 8/09) the low-level pooled allocator
* isn't implemented; instead we do just heap allocations.
* see Ticket 231
*/
class TypedAllocationManager
{
typedef TypedAllocationManager _TheManager;
public:
template<class XX>
size_t numSlots() const;
/* ======= managing the created objects ============= */
/** opaque link to the manager, to be used by handles and
* smart-ptrs to trigger preconfigured destruction. */
template<class XOX>
class Killer
{
_TheManager* manager_;
public:
void
operator() (XOX* victim)
{
REQUIRE (manager_);
///////////////////////////////////////////////TODO: clean behaviour while in App shutdown (Ticket #196)
manager_->destroyElement (victim);
}
protected:
Killer(_TheManager* m)
: manager_(m)
{ }
};
/** a token representing a newly opened slot
* capable for holding an object of type XOX .
* The receiver is responsible for
* - either calling releaseSlot
* - or building a smart-ptr / handle wired to
* the \link #getDeleter deleter function \endlink
*/
template<class XOX>
struct Slot
: private Killer<XOX>
{
/** pointer to the allocated storage
* with \c sizeof(XOX) bytes */
void* const storage_;
/** build a refcounting smart-ptr,
* complete with back-link to the manager
* for de-allocation */
shared_ptr<XOX>
build (XOX* toTrack)
{
return shared_ptr<XOX> (toTrack, getDeleter());
}
Killer<XOX> const&
getDeleter()
{
return *this;
}
protected:
Slot(_TheManager* don, void* mem)
: Killer<XOX>(don)
, storage_(mem)
{ }
friend class TypedAllocationManager;
};
/* ==== build objects with managed allocation ==== */
#define _EXCEPTION_SAFE_INVOKE(_CTOR_) \
\
Slot<XX> slot = allocateSlot<XX>(); \
try \
{ \
return slot.build (new(slot.storage_) _CTOR_ ); \
} \
catch(...) \
{ \
releaseSlot<XX>(slot.storage_); \
throw; \
}
template< class XX>
shared_ptr<XX> //_____________________
create () ///< invoke default ctor
{
_EXCEPTION_SAFE_INVOKE ( XX() )
}
template< class XX, typename P1>
shared_ptr<XX> //___________________
create (P1& p1) ///< invoke 1-arg ctor
{
_EXCEPTION_SAFE_INVOKE ( XX (p1) )
}
template< class XX
, typename P1
, typename P2
>
shared_ptr<XX> //___________________
create (P1& p1, P2& p2) ///< invoke 2-arg ctor
{
_EXCEPTION_SAFE_INVOKE ( XX (p1,p2) )
}
template< class XX
, typename P1
, typename P2
, typename P3
>
shared_ptr<XX> //___________________
create (P1& p1, P2& p2, P3& p3) ///< invoke 3-arg ctor
{
_EXCEPTION_SAFE_INVOKE ( XX (p1,p2,p3) )
}
template< class XX
, typename P1
, typename P2
, typename P3
, typename P4
>
shared_ptr<XX> //___________________
create (P1& p1, P2& p2, P3& p3, P4& p4) ///< invoke 4-arg ctor
{
_EXCEPTION_SAFE_INVOKE ( XX (p1,p2,p3,p4) )
}
template< class XX
, typename P1
, typename P2
, typename P3
, typename P4
, typename P5
>
shared_ptr<XX> //___________________
create (P1& p1, P2& p2, P3& p3, P4& p4, P5& p5) ///< invoke 5-arg ctor
{
_EXCEPTION_SAFE_INVOKE ( XX (p1,p2,p3,p4,p5) )
}
#undef _EXCEPTION_SAFE_INVOKE
protected: /* ======= Managed Allocation Implementation ========== */
template<class XX>
Slot<XX>
allocateSlot ()
{
////////////////////////////////////////////////TICKET #231 :redirect to the corresponding pool allocator
TRACE (memory, "allocate %s", util::tyStr<XX>().c_str());
void* space = new char[sizeof(XX)];
allocCnt_.inc<XX>();
return Slot<XX> (this, space);
}
template<class XX>
void
releaseSlot (void* entry)
{
////////////////////////////////////////////////TICKET #231 :redirect to the corresponding pool allocator
TRACE (memory, "release %s", util::tyStr<XX>().c_str());
typedef char Storage[sizeof(XX)];
delete[] reinterpret_cast<Storage*> (entry);
allocCnt_.dec<XX>();
}
template<class XX>
void
destroyElement (XX* entry)
{
if (!entry) return;
////////////////////////////////////////////////TODO: when actually implementing a custom allocation, please assert here that the entry is indeed managed by us
try
{
entry->~XX();
}
catch(...)
{
lumiera_err errorID = lumiera_error();
WARN (command_dbg, "dtor of %s failed: %s", util::tyStr(entry).c_str()
, errorID );
}
releaseSlot<XX> (entry);
}
template<class>
friend class Killer; ///< especially all Killers are entitled to desroyElement()
private:
lib::TypedCounter allocCnt_;
};
template<class XX>
size_t
TypedAllocationManager::numSlots() const
{
return allocCnt_.get<XX>();
}
} // namespace lib
#endif