CP.110:不要自已为初始化编写双重检查锁定代码
Since C++11, static local variables are now initialized in a thread-safe way. When combined with the RAII pattern, static local variables can replace the need for writing your own double-checked locking for initialization. std::call_once can also achieve the same purpose. Use either static local variables of C++11 or std::call_once instead of writing your own double-checked locking for initialization.
从C++11开始,静态变量的初始化过程可以保证线程安全了。在和RAII模式结合使用的时候,通过使用静态局部变量,可以消除自己为初始化编写双重检查锁定代码的需求。
Example(示例)
Example with std::call_once.
使用std::call_once的例子。
void f()
{
static std::once_flag my_once_flag;
std::call_once(my_once_flag, []()
{
// do this only once
});
// ...
}
Example with thread-safe static local variables of C++11.
下面的代码是C++中使用线程安全的静态局部变量的示例。
void f()
{
// Assuming the compiler is compliant with C++11
static My_class my_object; // Constructor called only once
// ...
}
class My_class
{
public:
My_class()
{
// do this only once
}
};
??? Is it possible to detect the idiom?
有可能检出这种惯用法么?
原文链接https://github.com/isocpp/CppCoreGuidelines/blob/master/CppCoreGuidelines.md#cp110-do-not-write-your-own-double-checked-locking-for-initialization