31 lines
832 B
C++
31 lines
832 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>();
|
|
}
|
|
};
|