NoteBook

Appearance

Mutex in unreal engine ​

Unreal engine has a mutex class called FCriticalSection which is a wrapper around FCriticalSectionBase which is a wrapper around FCriticalSectionPosix or FCriticalSectionWindows depending on the platform.

They are two types of mutexes in unreal engine:

  • FCriticalSection which is a mutex that can be locked and unlocked
  • FScopeLock which is a mutex that is locked when created and unlocked when destroyed

FCriticalSection Example ​

cpp
class A
{
public:
    FCriticalSection m;
    mutable int a;

    void change() const
    {
        m.Lock();
        a = 10;
        m.Unlock();
    }
};

FScopeLock Example ​

cpp
class A
{
public:
    FCriticalSection m;
    mutable int a;

    void change() const
    {
        FScopeLock lock(&m);
        a = 10;
    }
};

FScopeLock is a class that locks a mutex when created and unlocks it when destroyed.

References ​