39 lines
854 B
C++
39 lines
854 B
C++
#include <atomic>
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#include <memory>
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template<typename T>
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class lock_free_stack
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{
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private:
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struct node;
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struct counted_node_ptr
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{
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int external_count;
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node* ptr;
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};
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struct node
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{
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std::shared_ptr<T> data;
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std::atomic<int> internal_count;
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counted_node_ptr next;
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node(T const& data_):
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data(std::make_shared<T>(data_)),
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internal_count(0)
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{}
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};
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std::atomic<counted_node_ptr> head;
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public:
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~lock_free_stack()
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{
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while(pop());
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}
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void push(T const& data)
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{
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counted_node_ptr new_node;
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new_node.ptr=new node(data);
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new_node.external_count=1;
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new_node.ptr->next=head.load();
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while(!head.compare_exchange_weak(new_node.ptr->next,new_node));
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}
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};
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