You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
236 lines
11 KiB
C++
236 lines
11 KiB
C++
/*
|
|
Copyright 2005-2014 Intel Corporation. All Rights Reserved.
|
|
|
|
This file is part of Threading Building Blocks. Threading Building Blocks is free software;
|
|
you can redistribute it and/or modify it under the terms of the GNU General Public License
|
|
version 2 as published by the Free Software Foundation. Threading Building Blocks 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 Threading Building Blocks; if not, write to the
|
|
Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
|
|
|
|
As a special exception, you may use this file as part of a free software library without
|
|
restriction. Specifically, if other files instantiate templates or use macros or inline
|
|
functions from this file, or you compile this file and link it with other files to produce
|
|
an executable, this file does not by itself cause the resulting executable to be covered
|
|
by the GNU General Public License. This exception does not however invalidate any other
|
|
reasons why the executable file might be covered by the GNU General Public License.
|
|
*/
|
|
|
|
#ifndef __TBB_concurrent_lru_cache_H
|
|
#define __TBB_concurrent_lru_cache_H
|
|
|
|
#if ! TBB_PREVIEW_CONCURRENT_LRU_CACHE
|
|
#error Set TBB_PREVIEW_CONCURRENT_LRU_CACHE to include concurrent_lru_cache.h
|
|
#endif
|
|
|
|
#include <map>
|
|
#include <list>
|
|
|
|
#include "tbb_stddef.h"
|
|
#include "atomic.h"
|
|
#include "internal/_aggregator_impl.h"
|
|
|
|
namespace tbb{
|
|
namespace interface6 {
|
|
|
|
|
|
template <typename key_type, typename value_type, typename value_functor_type = value_type (*)(key_type) >
|
|
class concurrent_lru_cache : internal::no_assign{
|
|
private:
|
|
typedef concurrent_lru_cache self_type;
|
|
typedef value_functor_type value_function_type;
|
|
typedef std::size_t ref_counter_type;
|
|
struct map_value_type;
|
|
typedef std::map<key_type, map_value_type> map_storage_type;
|
|
typedef std::list<typename map_storage_type::iterator> lru_list_type;
|
|
struct map_value_type {
|
|
value_type my_value;
|
|
ref_counter_type my_ref_counter;
|
|
typename lru_list_type::iterator my_lru_list_iterator;
|
|
bool my_is_ready;
|
|
|
|
map_value_type (value_type const& a_value, ref_counter_type a_ref_counter, typename lru_list_type::iterator a_lru_list_iterator, bool a_is_ready)
|
|
: my_value(a_value), my_ref_counter(a_ref_counter), my_lru_list_iterator (a_lru_list_iterator), my_is_ready(a_is_ready)
|
|
{}
|
|
};
|
|
|
|
class handle_object;
|
|
|
|
struct aggregator_operation;
|
|
typedef aggregator_operation aggregated_operation_type;
|
|
typedef tbb::internal::aggregating_functor<self_type,aggregated_operation_type> aggregator_function_type;
|
|
friend class tbb::internal::aggregating_functor<self_type,aggregated_operation_type>;
|
|
typedef tbb::internal::aggregator<aggregator_function_type, aggregated_operation_type> aggregator_type;
|
|
|
|
private:
|
|
value_function_type my_value_function;
|
|
std::size_t const my_number_of_lru_history_items;
|
|
map_storage_type my_map_storage;
|
|
lru_list_type my_lru_list;
|
|
aggregator_type my_aggregator;
|
|
|
|
public:
|
|
typedef handle_object handle;
|
|
|
|
public:
|
|
concurrent_lru_cache(value_function_type f, std::size_t number_of_lru_history_items)
|
|
: my_value_function(f),my_number_of_lru_history_items(number_of_lru_history_items)
|
|
{
|
|
my_aggregator.initialize_handler(aggregator_function_type(this));
|
|
}
|
|
|
|
handle_object operator[](key_type k){
|
|
retrieve_aggregator_operation op(k);
|
|
my_aggregator.execute(&op);
|
|
if (op.is_new_value_needed()){
|
|
op.result().second.my_value = my_value_function(k);
|
|
__TBB_store_with_release(op.result().second.my_is_ready, true);
|
|
}else{
|
|
tbb::internal::spin_wait_while_eq(op.result().second.my_is_ready,false);
|
|
}
|
|
return handle_object(*this,op.result());
|
|
}
|
|
private:
|
|
void signal_end_of_usage(typename map_storage_type::reference value_ref){
|
|
signal_end_of_usage_aggregator_operation op(value_ref);
|
|
my_aggregator.execute(&op);
|
|
}
|
|
|
|
private:
|
|
struct handle_move_t:no_assign{
|
|
concurrent_lru_cache & my_cache_ref;
|
|
typename map_storage_type::reference my_map_record_ref;
|
|
handle_move_t(concurrent_lru_cache & cache_ref, typename map_storage_type::reference value_ref):my_cache_ref(cache_ref),my_map_record_ref(value_ref) {};
|
|
};
|
|
class handle_object {
|
|
concurrent_lru_cache * my_cache_pointer;
|
|
typename map_storage_type::reference my_map_record_ref;
|
|
public:
|
|
handle_object(concurrent_lru_cache & cache_ref, typename map_storage_type::reference value_ref):my_cache_pointer(&cache_ref), my_map_record_ref(value_ref) {}
|
|
handle_object(handle_move_t m):my_cache_pointer(&m.my_cache_ref), my_map_record_ref(m.my_map_record_ref){}
|
|
operator handle_move_t(){ return move(*this);}
|
|
value_type& value(){
|
|
__TBB_ASSERT(my_cache_pointer,"get value from moved from object?");
|
|
return my_map_record_ref.second.my_value;
|
|
}
|
|
~handle_object(){
|
|
if (my_cache_pointer){
|
|
my_cache_pointer->signal_end_of_usage(my_map_record_ref);
|
|
}
|
|
}
|
|
private:
|
|
friend handle_move_t move(handle_object& h){
|
|
return handle_object::move(h);
|
|
}
|
|
static handle_move_t move(handle_object& h){
|
|
__TBB_ASSERT(h.my_cache_pointer,"move from the same object twice ?");
|
|
concurrent_lru_cache * cache_pointer = NULL;
|
|
std::swap(cache_pointer,h.my_cache_pointer);
|
|
return handle_move_t(*cache_pointer,h.my_map_record_ref);
|
|
}
|
|
private:
|
|
void operator=(handle_object&);
|
|
#if __SUNPRO_CC
|
|
// Presumably due to a compiler error, private copy constructor
|
|
// breaks expressions like handle h = cache[key];
|
|
public:
|
|
#endif
|
|
handle_object(handle_object &);
|
|
};
|
|
private:
|
|
//TODO: looks like aggregator_operation is a perfect match for statically typed variant type
|
|
struct aggregator_operation : tbb::internal::aggregated_operation<aggregator_operation>{
|
|
enum e_op_type {op_retive, op_signal_end_of_usage};
|
|
//TODO: try to use pointer to function apply_visitor here
|
|
//TODO: try virtual functions and measure the difference
|
|
e_op_type my_operation_type;
|
|
aggregator_operation(e_op_type operation_type): my_operation_type(operation_type) {}
|
|
void cast_and_handle(self_type& container ){
|
|
if (my_operation_type==op_retive){
|
|
static_cast<retrieve_aggregator_operation*>(this)->handle(container);
|
|
}else{
|
|
static_cast<signal_end_of_usage_aggregator_operation*>(this)->handle(container);
|
|
}
|
|
}
|
|
};
|
|
struct retrieve_aggregator_operation : aggregator_operation, private internal::no_assign {
|
|
key_type my_key;
|
|
typename map_storage_type::pointer my_result_map_record_pointer;
|
|
bool my_is_new_value_needed;
|
|
retrieve_aggregator_operation(key_type key):aggregator_operation(aggregator_operation::op_retive),my_key(key),my_is_new_value_needed(false){}
|
|
void handle(self_type& container ){
|
|
my_result_map_record_pointer = & container.retrieve_serial(my_key,my_is_new_value_needed);
|
|
}
|
|
typename map_storage_type::reference result(){ return * my_result_map_record_pointer; }
|
|
bool is_new_value_needed(){return my_is_new_value_needed;}
|
|
};
|
|
struct signal_end_of_usage_aggregator_operation : aggregator_operation, private internal::no_assign {
|
|
typename map_storage_type::reference my_map_record_ref;
|
|
signal_end_of_usage_aggregator_operation(typename map_storage_type::reference map_record_ref):aggregator_operation(aggregator_operation::op_signal_end_of_usage),my_map_record_ref(map_record_ref){}
|
|
void handle(self_type& container ){
|
|
container.signal_end_of_usage_serial(my_map_record_ref);
|
|
}
|
|
};
|
|
|
|
private:
|
|
void handle_operations(aggregator_operation* op_list){
|
|
while(op_list){
|
|
op_list->cast_and_handle(*this);
|
|
aggregator_operation* tmp = op_list;
|
|
op_list=op_list->next;
|
|
tbb::internal::itt_store_word_with_release(tmp->status, uintptr_t(1));
|
|
}
|
|
}
|
|
|
|
private:
|
|
typename map_storage_type::reference retrieve_serial(key_type k, bool& is_new_value_needed){
|
|
typename map_storage_type::iterator it = my_map_storage.find(k);
|
|
if (it == my_map_storage.end()){
|
|
it = my_map_storage.insert(it,std::make_pair(k,map_value_type(value_type(),0,my_lru_list.end(),false)));
|
|
is_new_value_needed = true;
|
|
}else {
|
|
typename lru_list_type::iterator list_it = it->second.my_lru_list_iterator;
|
|
if (list_it!=my_lru_list.end()) {
|
|
__TBB_ASSERT(!it->second.my_ref_counter,"item to be evicted should not have a live references");
|
|
//item is going to be used. Therefore it is not a subject for eviction
|
|
//so - remove it from LRU history.
|
|
my_lru_list.erase(list_it);
|
|
it->second.my_lru_list_iterator= my_lru_list.end();
|
|
}
|
|
}
|
|
++(it->second.my_ref_counter);
|
|
return *it;
|
|
}
|
|
|
|
void signal_end_of_usage_serial(typename map_storage_type::reference map_record_ref){
|
|
typename map_storage_type::iterator it = my_map_storage.find(map_record_ref.first);
|
|
__TBB_ASSERT(it!=my_map_storage.end(),"cache should not return past-end iterators to outer world");
|
|
__TBB_ASSERT(&(*it) == &map_record_ref,"dangling reference has been returned to outside world? data race ?");
|
|
__TBB_ASSERT( my_lru_list.end()== std::find(my_lru_list.begin(),my_lru_list.end(),it),
|
|
"object in use should not be in list of unused objects ");
|
|
if (! --(it->second.my_ref_counter)){
|
|
//it was the last reference so put it to the LRU history
|
|
if (my_lru_list.size()>=my_number_of_lru_history_items){
|
|
//evict items in order to get a space
|
|
size_t number_of_elements_to_evict = 1 + my_lru_list.size() - my_number_of_lru_history_items;
|
|
for (size_t i=0; i<number_of_elements_to_evict; ++i){
|
|
typename map_storage_type::iterator it_to_evict = my_lru_list.back();
|
|
__TBB_ASSERT(!it_to_evict->second.my_ref_counter,"item to be evicted should not have a live references");
|
|
my_lru_list.pop_back();
|
|
my_map_storage.erase(it_to_evict);
|
|
}
|
|
}
|
|
my_lru_list.push_front(it);
|
|
it->second.my_lru_list_iterator = my_lru_list.begin();
|
|
}
|
|
}
|
|
};
|
|
} // namespace interface6
|
|
|
|
using interface6::concurrent_lru_cache;
|
|
|
|
} // namespace tbb
|
|
#endif //__TBB_concurrent_lru_cache_H
|