33 lines
888 B
C++
33 lines
888 B
C++
#include <atomic>
|
|
#include <memory>
|
|
|
|
template<typename T>
|
|
class lock_free_stack
|
|
{
|
|
private:
|
|
struct node
|
|
{
|
|
std::shared_ptr<T> data;
|
|
std::shared_ptr<node> next;
|
|
node(T const& data_):
|
|
data(std::make_shared<T>(data_))
|
|
{}
|
|
};
|
|
std::shared_ptr<node> head;
|
|
public:
|
|
void push(T const& data)
|
|
{
|
|
std::shared_ptr<node> const new_node=std::make_shared<node>(data);
|
|
new_node->next=head.load();
|
|
while(!std::atomic_compare_exchange_weak(
|
|
&head,&new_node->next,new_node));
|
|
}
|
|
std::shared_ptr<T> pop()
|
|
{
|
|
std::shared_ptr<node> old_head=std::atomic_load(&head);
|
|
while(old_head && !std::atomic_compare_exchange_weak(
|
|
&head,&old_head,old_head->next));
|
|
return old_head ? old_head->data : std::shared_ptr<T>();
|
|
}
|
|
};
|