corelib/include/ebcl/inline/Alloc.hh

/******************************************************************************/
/* ALLOCATORS - INLINE CODE ***************************************************/
/******************************************************************************/

#ifndef _H_LW_LIB_INLINE_ALLOC
#define _H_LW_LIB_INLINE_ALLOC
#include <lw/lib/Alloc.hh>
namespace lw {


/*= T_PoolHelper::T_List =====================================================*/

template< typename T , size_t P >
inline T_PoolHelper::T_List< T , P >::T_List(
		T_List< T , P >*& n ) noexcept
	: next( n ) , free( P )
{
	for ( size_t i = 0 ; i < P ; i ++ ) {
		storage[ i ].list = this;
	}
	for ( size_t i = 0 ; i < BitmapSize ; i ++ ) {
		bitmap[ i ] = 0;
	}
	n = this;
}

template< typename T , size_t P >
inline T* T_PoolHelper::T_List< T , P >::findUnused( ) noexcept
{
	size_t i = 0;
	while ( bitmap[ i ] == 255 ) {
		assert( i < BitmapSize );
		i ++;
	}

	size_t j = 0;
	while ( ( bitmap[ i ] & ( 1 << j ) ) != 0 ) {
		j ++;
	}
	assert( i * 8 + j < P );

	bitmap[ i ] = bitmap[ i ] | ( 1 << j );
	free --;
	return &storage[ i * 8 + j ];
}

template< typename T , size_t P >
inline size_t T_PoolHelper::T_List< T , P >::indexOf(
		T const* const item ) noexcept
{
	assert( item >= &storage[ 0 ] );
	const size_t offset( ( (char*) item ) - ( (char*) &storage[ 0 ] ) );
	assert( offset % sizeof( T ) == 0 );
	const size_t index( offset / sizeof( T ) );
	assert( index < P );
	return index;
}

template< typename T , size_t P >
inline void T_PoolHelper::T_List< T , P >::destroy(
		T_List< T , P >*& head ) noexcept
{
	while ( head != nullptr ) {
		T_Self* const n( head->next );
		delete head;
		head = n;
	}
}


/*= T_PoolHelper::T_Allocator ================================================*/

template< typename T , size_t P , size_t M >
inline T_PoolHelper::T_Allocator< T , P , M >::T_Allocator( ) noexcept
	: free_( nullptr ) , partial_( nullptr ) , full_( nullptr ) ,
		nFree_( 1 )
{
	new T_List_( free_ );
}

template< typename T , size_t P , size_t M >
inline T_PoolHelper::T_Allocator< T , P , M >::~T_Allocator( )
{
	T_List_::destroy( free_ );
	T_List_::destroy( partial_ );
	T_List_::destroy( full_ );
}

/*----------------------------------------------------------------------------*/

template< typename T , size_t P , size_t M >
inline T* T_PoolHelper::T_Allocator< T , P , M >::allocate( ) noexcept
{
	if ( partial_ == nullptr ) {
		if ( free_ == nullptr ) {
			new T_List_( partial_ );
		} else {
			assert( nFree_ > 0 );
			partial_ = free_;
			free_ = free_->next;
			partial_->next = nullptr;
			nFree_ --;
		}
	}

	T* const data( partial_->findUnused( ) );
	if ( partial_->free == 0 ) {
		T_List_* const nf( partial_ );
		partial_ = nf->next;
		nf->next = full_;
		full_ = nf;
	}
	return data;
}

template< typename T , size_t P , size_t M >
void T_PoolHelper::T_Allocator< T , P , M >::free(
		T* const item ) noexcept
{
	T_List_* const list( reinterpret_cast< T_List_* >( item->list ) );
	const size_t index( list->indexOf( item ) );

	list->bitmap[ index / 8 ] = list->bitmap[ index / 8 ] & ~( 1 << ( index & 7 ) );
	list->free ++;

	if ( list->free == 1 ) {
		// Full list is now partial
		moveList( list , full_ , partial_ );
	} else if ( list->free == P ) {
		// Partial list is now free
		if ( nFree_ == M ) {
			T_List_* p( nullptr );
			moveList( list , partial_ , p );
			delete list;
		} else {
			moveList( list , partial_ , free_ );
			nFree_ ++;
		}
	}
}

/*----------------------------------------------------------------------------*/

template< typename T , size_t P , size_t M >
size_t T_PoolHelper::T_Allocator< T , P , M >::countFreeLists( ) const noexcept
{
	return nFree_;
}

template< typename T , size_t P , size_t M >
size_t T_PoolHelper::T_Allocator< T , P , M >::countPartialLists( ) const noexcept
{
	return countLists( partial_ );
}

template< typename T , size_t P , size_t M >
size_t T_PoolHelper::T_Allocator< T , P , M >::countFullLists( ) const noexcept
{
	return countLists( full_ );
}

template< typename T , size_t P , size_t M >
void T_PoolHelper::T_Allocator< T , P , M >::getUsage(
		size_t& total ,
		size_t& free ,
		size_t& used ) const noexcept
{
	free = countFreeLists( ) * P;
	used = countFullLists( ) * P;
	total = free + used;

	T_List_ const* p( partial_ );
	while ( p != nullptr ) {
		free += p->free;
		used += P - p->free;
		total += P;
		p = p->next;
	}
}

/*----------------------------------------------------------------------------*/

template< typename T , size_t P , size_t M >
void T_PoolHelper::T_Allocator< T , P , M >::moveList(
		T_List_* const list ,
		T_List_*& from ,
		T_List_*& to ) noexcept
{
	T_List_** ptr( &from );
	while ( *ptr != list ) {
		ptr = &( (*ptr)->next );
		assert( *ptr != nullptr );
	}
	*ptr = list->next;
	list->next = to;
	to = list;
}

template< typename T , size_t P , size_t M >
size_t T_PoolHelper::T_Allocator< T , P , M >::countLists(
		T_List_ const* head ) noexcept
{
	size_t nLists( 0 );
	while ( head != nullptr ) {
		nLists ++;
		head = head->next;
	}
	return nLists;
}


/*= T_PoolAllocator ==========================================================*/

template< size_t OS , size_t OA , size_t P , size_t M >
inline void* T_PoolAllocator< OS , OA , P , M >::allocate(
		const size_t requested ) noexcept
{
#ifdef LW_CFG_NO_ALLOCATORS
	return ::operator new( requested );
#else
	assert( requested <= OS );
	return reinterpret_cast< char* >( alloc_.allocate( ) );
#endif
}

template< size_t OS , size_t OA , size_t P , size_t M >
void T_PoolAllocator< OS , OA , P , M >::free(
		void* const item ) noexcept
{
#ifdef LW_CFG_NO_ALLOCATORS
	::operator delete( item );
#else
	alloc_.free( reinterpret_cast< T_Storage_* >( item ) );
#endif
}

/*----------------------------------------------------------------------------*/

template< size_t OS , size_t OA , size_t P , size_t M >
size_t T_PoolAllocator< OS , OA , P , M >::countFreeLists( ) const noexcept
{
	return alloc_.countFreeLists( );
}

template< size_t OS , size_t OA , size_t P , size_t M >
size_t T_PoolAllocator< OS , OA , P , M >::countPartialLists( ) const noexcept
{
	return alloc_.countPartialLists( );
}

template< size_t OS , size_t OA , size_t P , size_t M >
size_t T_PoolAllocator< OS , OA , P , M >::countFullLists( ) const noexcept
{
	return alloc_.countFullLists( );
}

template< size_t OS , size_t OA , size_t P , size_t M >
void T_PoolAllocator< OS , OA , P , M >::getUsage(
		size_t& total ,
		size_t& free ,
		size_t& used ) const noexcept
{
	return alloc_.getUsage( total , free , used );
}


/*= T_ThreadedPoolAllocator ==================================================*/

template< size_t OS , size_t OA , size_t P , size_t M >
inline void* T_ThreadedPoolAllocator< OS , OA , P , M >::allocate(
		const size_t requested ) noexcept
{
#ifdef LW_CFG_NO_ALLOCATORS
	return ::operator new( requested );
#else
	assert( requested <= OS );

	T_Storage_* const alloc( ([this](){
			T_Storage_* const fs( takeFromStack( ) );
			return fs ? fs : alloc_.allocate( );
		})() );
	alloc->extra.pool = this;
	return reinterpret_cast< char* >( alloc );
#endif
}

template< size_t OS , size_t OA , size_t P , size_t M >
void T_ThreadedPoolAllocator< OS , OA , P , M >::free(
		void* const item ) noexcept
{
#ifdef LW_CFG_NO_ALLOCATORS
	::operator delete( item );
#else
	T_Storage_* const storage( reinterpret_cast< T_Storage_* >( item ) );
	if ( storage->extra.pool == this ) {
		alloc_.free( storage );
	} else {
		storage->extra.pool->addToStack( storage );
	}

	T_Storage_* const fs( takeFromStack( ) );
	if ( fs ) {
		alloc_.free( fs );
	}
#endif
}

/*----------------------------------------------------------------------------*/

template< size_t OS , size_t OA , size_t P , size_t M >
size_t T_ThreadedPoolAllocator< OS , OA , P , M >::countFreeLists( ) const noexcept
{
	return alloc_.countFreeLists( );
}

template< size_t OS , size_t OA , size_t P , size_t M >
size_t T_ThreadedPoolAllocator< OS , OA , P , M >::countPartialLists( ) const noexcept
{
	return alloc_.countPartialLists( );
}

template< size_t OS , size_t OA , size_t P , size_t M >
size_t T_ThreadedPoolAllocator< OS , OA , P , M >::countFullLists( ) const noexcept
{
	return alloc_.countFullLists( );
}

template< size_t OS , size_t OA , size_t P , size_t M >
void T_ThreadedPoolAllocator< OS , OA , P , M >::getUsage(
		size_t& total ,
		size_t& free ,
		size_t& used ) const noexcept
{
	return alloc_.getUsage( total , free , used );
}

/*----------------------------------------------------------------------------*/

template< size_t OS , size_t OA , size_t P , size_t M >
typename T_ThreadedPoolAllocator< OS , OA , P , M >::T_Storage_*
T_ThreadedPoolAllocator< OS , OA , P , M >::takeFromStack( ) noexcept
{
	T_FreeHead_ o( freeHead_.load( std::memory_order_relaxed ) );
	if ( o.head == nullptr ) {
		return nullptr;
	}

	T_FreeHead_ next;
	do {
		next.aba = o.aba + 1;
		next.head = o.head->extra.next;
	} while ( !freeHead_.compare_exchange_weak( o , next ,
					std::memory_order_acq_rel ,
					std::memory_order_acquire ) );
	return o.head;
}

template< size_t OS , size_t OA , size_t P , size_t M >
void T_ThreadedPoolAllocator< OS , OA , P , M >::addToStack(
		T_Storage_* storage ) noexcept
{
	assert( storage->extra.pool == this );
	T_FreeHead_ o( freeHead_.load( std::memory_order_relaxed ) );
	T_FreeHead_ r;
	do {
		storage->extra.next = o.head;
		r.aba = o.aba + 1;
		r.head = storage;
	} while ( !freeHead_.compare_exchange_weak( o , r ,
				std::memory_order_acq_rel ,
				std::memory_order_acquire ) );
}


}
#endif //_H_LW_LIB_INLINE_ALLOC