我正在尝试实现管理某些 std::thread 的 monostate 类。线程一直运行直到标志变为等于 false。标志更改为 false 后 - 线程停止。但看起来我必须明确地调用停止方法。在析构函数中调用它会给我带来运行时错误(在 GCC 4.8 for ARM、GCC 4.9 for x86_64 和 MSVC 2017 上测试)。 这种行为是由于
"Static members of a class are not associated with the objects of the class: they are independent objects with static storage duration or regular functions defined in namespace scope, only once in the program."
所以析构函数调用被省略了？
代码示例:
#include <iostream>
#include <chrono>
#include <thread>
#include <atomic>
void runThread(const std::atomic<bool> &_isRunning) {
while (_isRunning) {
std::cout << "Me running.." << std::endl;
std::this_thread::sleep_for(std::chrono::milliseconds(30));
}
}
class test {
static std::thread thread;
static std::atomic<bool> isRunning;
public:
test();
~test();
static void go();
static void stop();
};
std::thread test::thread;
std::atomic<bool> test::isRunning{ false };
test::test() {}
void test::go() {
isRunning = true;
thread = std::thread(runThread, std::ref(isRunning));
}
void test::stop() {
isRunning = false;
if (thread.joinable()) {
thread.join();
}
}
test::~test() {
stop();
}
int main() {
test::go();
std::this_thread::sleep_for(std::chrono::seconds(5));
std::cout << "Done here!!!!!!!!!!!!!!!!!";
// Will not crash anymore if uncomment
//test::stop();
return 0;
}
将 std::async 与 std::feature 一起使用会得到相同的结果但没有错误。线程一直在运行。
附言
使类成为非单态类可以解决运行时错误，但给我留下了这个问题。管理资源对于单态类/静态成员来说是一种不好的做法吗？
最佳答案
~test();
应该在销毁任何“测试”对象之前调用。您没有在代码中创建“测试”对象，所以您是对的，
Static members of a class are not associated with the objects of the class: they are independent objects with static storage duration or regular functions defined in namespace scope, only once in the program.
关于c++ - 在 C++ 中，在单态类/静态成员的析构函数中管理资源是个坏主意吗？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/50339276/