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#include "format.h"
#include <iostream>
#include <cstring>
#include "logfile.h"
#include "compat.h"
/* BASIC ALGORITHM AND STRUCTURE
*
* This is a memory pool manager which works by dividing its memory into
* blocks (all blocks have a size which is a power-of-two). Each block is either
* in use or in its corresponding free list.
*
* The free lists are doubly linked and there are head-pointers in
* the first page of the pool.
*
* POOL ORGANIZATION:
*
* FIRST PAGE
* max_order_: 32 bits
* [pseudo-order 0]: 32 bits
* [pseudo-order 1]: 32 bits
* [pseudo-order 2]: 32 bits
* [list order 3]: 32 bits
* [list order 4]: 32 bits
* [list order 5]: 32 bits
* [list order 5]: 32 bits
* ...
* [list order max_order_]: 32 bits
*
* SUBSEQUENT PAGES:
* nodes*
*
*/
template <typename Traits>
mempool<Traits>::mempool( std::auto_ptr<memory_manager> source ):
manager_( source ),
max_order_( 0 )
{
if ( !manager_->size() ) init_memory();
max_order_.assign( memory_reference<uint32_t>( manager_->rw_base( 0 ) ) );
if ( !max_order_ ) {
max_order_ = order_of( traits_type::max_size() );
}
traits_type::set_manager( manager_.get() );
}
template <typename Traits>
typename mempool<Traits>::data_typeptr mempool<Traits>::allocate( unsigned size ) {
if ( size < traits_type::min_size() ) size = traits_type::min_size();
max_order_ = kMax<uint32_t>( order_of( size ), max_order_ );
const unsigned order = kMax<unsigned>( order_of( size ), min_order_for_free_node );
if ( uint32_t res = free_list( order ) ) {
free_list( order ) = get_node( res )->next();
if ( free_list( order ) ) get_node( free_list( order ) )->set_prev( 0 );
logfile() << format( "%s( %s ): (order %s) Returning %s\n" ) % __PRETTY_FUNCTION__ % size % order % res;
return data_typeptr::cast_from_uint32( res );
} else {
logfile() << format( "For size %s going up to %s\n") % size % max_order_;
for ( unsigned bigger = order + 1; bigger <= max_order_; ++bigger ) {
if ( uint32_t res = free_list( bigger ) ) {
while ( bigger > order ) {
break_up( res );
--bigger;
}
logfile() << format( "%s( %s ): recursing\n" ) % __PRETTY_FUNCTION__ % size;
return allocate( size );
}
}
const unsigned old_size = manager_->size();
manager_->resize( manager_->size() + order_to_size( order ) );
max_order_.assign( memory_reference<uint32_t>( manager_->rw_base( 0 ) ) );
fill_into_list( old_size, order );
return allocate( size );
}
}
template <typename Traits>
void mempool<Traits>::fill_into_list( unsigned next_block, unsigned order ) {
logfile() << format( "%s( %s, %s )\n" ) % __PRETTY_FUNCTION__ % next_block % order;
const unsigned size = manager_->size();
const unsigned min_order =
kMax<unsigned>( min_order_for_free_node, order_of( traits_type::min_size() ) );
while ( next_block < size && order >= min_order ) {
const unsigned block_size = order_to_size( order );
while ( ( size - next_block ) >= block_size ) {
insert_into_list( next_block, order );
next_block += block_size;
}
--order;
}
}
template <typename Traits>
void mempool<Traits>::fill_into_list( unsigned next_block ) {
fill_into_list( next_block, max_order_ );
}
template <typename Traits>
void mempool<Traits>::init_memory() {
manager_->resize( 4096 );
}
template <typename Traits>
void mempool<Traits>::print( std::ostream& out ) const {
uint32_t iterator = 0, end = manager_->size();
out << "free lists:\n";
for ( unsigned i = 0; i != max_order_ + 1; ++i ) {
out << "\t" << i << ": " << free_list( i ) << '\n';
}
out << '\n';
iterator = order_to_size( max_order_ );
while ( iterator < end ) {
data_typeptr p = data_typeptr::cast_from_uint32( iterator );
if ( traits_type::is_free( p ) ) {
out << '[' << iterator << "] free_node:\n";
list_nodeptr node = get_node( iterator );
out << "order:\t" << node->order() << '\n';
out << "prev:\t" << node->prev() << '\n';
out << "next:\t" << node->next() << '\n';
out << '\n';
iterator += order_to_size( node->order() );
} else {
out << format( "size_of(): %s\n" ) % traits_type::size_of( p );
traits_type::print( out, p );
iterator += traits_type::size_of( p );
}
}
}
template <typename Traits>
memory_reference<uint32_t> mempool<Traits>::free_list( unsigned order ) {
assert( order );
return memory_reference<uint32_t>( manager_->rw_base( order * byte_io::byte_length<uint32_t>() ) );
}
template <typename Traits>
typename mempool<Traits>::list_nodeptr mempool<Traits>::get_node( uint32_t p ) const {
assert( p );
list_nodeptr res = list_nodeptr::cast_from_uint32( p + Traits::type_offset() );
res->set_parent( this );
return res;
}
template <typename Traits>
void mempool<Traits>::remove_from_list( uint32_t where, unsigned order ) {
logfile() << format( "%s( %s, %s )\n" ) % __PRETTY_FUNCTION__ % where % order;
list_nodeptr node = get_node( where );
if ( node->next() ) get_node( node->next() )->set_prev( node->prev() );
if ( node->prev() ) get_node( node->prev() )->set_next( node->next() );
if ( free_list( order ) == where ) free_list( order ) = node->next();
}
template <typename Traits>
void mempool<Traits>::insert_into_list( uint32_t where, unsigned order ) {
logfile() << format( "%s( %s, %s )\n" ) % __PRETTY_FUNCTION__ % where % order;
traits_type::mark_free( data_typeptr::cast_from_uint32( where ) );
list_nodeptr new_node = get_node( where );
new_node->set_order( order );
new_node->set_next( free_list( order ) );
new_node->set_prev( 0 );
if ( free_list( order ) ) {
get_node( free_list( order ) )->set_prev( where );
}
free_list( order ) = where;
}
template <typename Traits>
void mempool<Traits>::break_up( uint32_t where ) {
logfile() << "break_up( " << where << " )\n";
assert( traits_type::is_free( data_typeptr::cast_from_uint32( where ) ) );
const unsigned old_order = get_node( where )->order();
assert( old_order );
const unsigned new_order = old_order - 1;
remove_from_list( where, old_order );
insert_into_list( where + order_to_size( new_order ), new_order );
insert_into_list( where, new_order );
}
template <typename Traits>
bool mempool<Traits>::join( data_typeptr& node, unsigned order ) {
logfile() << format( "%s( %s, %s )\n" ) % __PRETTY_FUNCTION__ % node.cast_to_uint32() % order;
const uint32_t byte_idx = node.cast_to_uint32();
const unsigned block_size = order_to_size( order );
const unsigned block_idx = byte_idx / block_size;
uint32_t partner;
if ( block_idx % 2 ) {
partner = byte_idx - block_idx;
} else {
partner = byte_idx + block_idx;
}
if ( partner >= manager_->size() ) return false;
bool res = traits_type::is_free( data_typeptr::cast_from_uint32( partner ) )
&& get_node( partner )->order() == order;
if ( res ) {
node = ( block_idx % 2 ) ? data_typeptr::cast_from_uint32( partner ) : node;
remove_from_list( byte_idx, order );
remove_from_list( partner, order );
insert_into_list( node.cast_to_uint32(), order + 1 );
}
return res;
}
template <typename Traits>
void mempool<Traits>::deallocate( data_typeptr data ) {
logfile() << "deallocate( " << data << " )\n";
unsigned order = order_of( size_of( data ) );
while ( ( order < max_order_ ) && join( data, order ) ) ++order;
deallocate( data, order );
}
template <typename Traits>
void mempool<Traits>::deallocate( data_typeptr data, unsigned order ) {
logfile() << format( "%s( %s, %s )\n" ) % __PRETTY_FUNCTION__ % data.cast_to_uint32() % order;
assert( data );
traits_type::mark_free( data );
insert_into_list( data.cast_to_uint32(), order );
}
template <typename Traits>
typename mempool<Traits>::data_typeptr mempool<Traits>::reallocate( data_typeptr data, unsigned size ) {
logfile() << format( "%s( %s, %s)\n" ) % __PRETTY_FUNCTION__ % data % size;
max_order_ = kMax<uint32_t>( max_order_, order_of( max_order_ ) );
const unsigned original_size = size_of( data );
unsigned char* temporary = static_cast<unsigned char*>( operator new( original_size ) );
std::memmove( temporary, data.raw_pointer(), original_size );
unsigned current = order_of( original_size );
unsigned desired = order_of( size );
while ( desired < current && join( data, current ) ) ++current;
if ( desired != current ) deallocate( data, current );
data = allocate( size );
std::memcpy( data.raw_pointer(), temporary, original_size );
operator delete( temporary );
return data;
}
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