Files
concurrency-in-action/source/listing_6.1.cpp
2018-10-18 00:40:34 -05:00

53 lines
1.1 KiB
C++

#include <exception>
#include <memory>
#include <mutex>
#include <stack>
struct empty_stack : std::exception {
const char* what() const throw() { return "empty stack"; }
};
template <typename T>
class threadsafe_stack {
private:
std::stack<T> data;
mutable std::mutex m;
public:
threadsafe_stack() {}
threadsafe_stack(const threadsafe_stack& other)
{
std::lock_guard<std::mutex> lock(other.m);
data = other.data;
}
threadsafe_stack& operator=(const threadsafe_stack&) = delete;
void push(T new_value)
{
std::lock_guard<std::mutex> lock(m);
data.push(std::move(new_value));
}
std::shared_ptr<T> pop()
{
std::lock_guard<std::mutex> lock(m);
if (data.empty())
throw empty_stack();
std::shared_ptr<T> const res(std::make_shared<T>(std::move(data.top())));
data.pop();
return res;
}
void pop(T& value)
{
std::lock_guard<std::mutex> lock(m);
if (data.empty())
throw empty_stack();
value = std::move(data.top());
data.pop();
}
bool empty() const
{
std::lock_guard<std::mutex> lock(m);
return data.empty();
}
};