Files
concurrency-in-action/source/listing_4.5.cpp
2018-10-18 00:40:34 -05:00

75 lines
1.6 KiB
C++

#include <condition_variable>
#include <memory>
#include <mutex>
#include <queue>
template <typename T>
class threadsafe_queue {
private:
mutable std::mutex mut;
std::queue<T> data_queue;
std::condition_variable data_cond;
public:
threadsafe_queue() {}
threadsafe_queue(threadsafe_queue const& other)
{
std::lock_guard<std::mutex> lk(other.mut);
data_queue = other.data_queue;
}
void push(T new_value)
{
std::lock_guard<std::mutex> lk(mut);
data_queue.push(new_value);
data_cond.notify_one();
}
void wait_and_pop(T& value)
{
std::unique_lock<std::mutex> lk(mut);
data_cond.wait(lk, [this] { return !data_queue.empty(); });
value = data_queue.front();
data_queue.pop();
}
std::shared_ptr<T> wait_and_pop()
{
std::unique_lock<std::mutex> lk(mut);
data_cond.wait(lk, [this] { return !data_queue.empty(); });
std::shared_ptr<T> res(std::make_shared<T>(data_queue.front()));
data_queue.pop();
return res;
}
bool try_pop(T& value)
{
std::lock_guard<std::mutex> lk(mut);
if (data_queue.empty)
return false;
value = data_queue.front();
data_queue.pop();
}
std::shared_ptr<T> try_pop()
{
std::lock_guard<std::mutex> lk(mut);
if (data_queue.empty())
return std::shared_ptr<T>();
std::shared_ptr<T> res(std::make_shared<T>(data_queue.front()));
data_queue.pop();
return res;
}
bool empty() const
{
std::lock_guard<std::mutex> lk(mut);
return data_queue.empty();
}
};
int
main()
{
}