94 lines
1.7 KiB
C++
94 lines
1.7 KiB
C++
#include <iostream>
|
|
#include <memory>
|
|
#include <mutex>
|
|
#include <queue>
|
|
#include <thread>
|
|
|
|
template <typename T>
|
|
class queue {
|
|
private:
|
|
struct node {
|
|
std::shared_ptr<T> data;
|
|
std::unique_ptr<node> next;
|
|
};
|
|
|
|
std::mutex head_mutex;
|
|
std::unique_ptr<node> head;
|
|
std::mutex tail_mutex;
|
|
node* tail;
|
|
|
|
node* get_tail()
|
|
{
|
|
std::lock_guard<std::mutex> tail_lock(tail_mutex);
|
|
return tail;
|
|
}
|
|
|
|
std::unique_ptr<node> pop_head()
|
|
{
|
|
std::lock_guard<std::mutex> head_lock(head_mutex);
|
|
if (head.get() == get_tail()) {
|
|
return nullptr;
|
|
}
|
|
std::unique_ptr<node> old_head = std::move(head);
|
|
head = std::move(old_head->next);
|
|
return old_head;
|
|
}
|
|
|
|
public:
|
|
queue() : head(new node), tail(head.get()) {}
|
|
|
|
queue(const queue& other) = delete;
|
|
queue& operator=(const queue& other) = delete;
|
|
|
|
std::shared_ptr<T> try_pop()
|
|
{
|
|
std::unique_ptr<node> old_head = pop_head();
|
|
return old_head ? old_head->data : std::shared_ptr<T>();
|
|
}
|
|
|
|
void push(T new_value)
|
|
{
|
|
std::shared_ptr<T> new_data(std::make_shared<T>(std::move(new_value)));
|
|
std::unique_ptr<node> p(new node);
|
|
node* const new_tail = p.get();
|
|
std::lock_guard<std::mutex> tail_lock(tail_mutex);
|
|
tail->data = new_data;
|
|
tail->next = std::move(p);
|
|
tail = new_tail;
|
|
}
|
|
};
|
|
|
|
void
|
|
push(queue<int>* q)
|
|
{
|
|
for (int i = 0; i < 10; ++i) {
|
|
printf("pushing %d\n", i);
|
|
q->push(i);
|
|
}
|
|
}
|
|
|
|
void
|
|
pop(queue<int>* q)
|
|
{
|
|
int i = 0;
|
|
while (true) {
|
|
if (std::shared_ptr<int> p = q->try_pop()) {
|
|
printf("poping %d\n", *p);
|
|
++i;
|
|
}
|
|
if (i == 10)
|
|
break;
|
|
}
|
|
}
|
|
|
|
int
|
|
main()
|
|
{
|
|
queue<int> q;
|
|
std::thread th1(push, &q);
|
|
std::thread th2(pop, &q);
|
|
th1.join();
|
|
th2.join();
|
|
return 0;
|
|
}
|