CareerCup

what about a global static? do u just declare it as a synchronized variable? is there even such thing called synchronized variable in c++?

global static is like that nobody can change it rather i can be used by many.whereas synchronised method makes variable to be accessed by only one computation at a time like semaphores in operating system,so tha data remains protected. no i dnt think that such methods are there in C++;

thanks~

i have forgotten lots of c++ specifics... have to pick up the slack

anything declared globally is has the lifetime of the program; declaring a global variable static means it only internal linkage and cannot be accessed from the same translation unit

if ever something global needs to be changed safely, maybe choose singleton pattern with proper multi-threading safety?

thanks~

i have forgotten lots of c++ specifics... have to pick up the slack

anything declared globally is has the lifetime of the program; declaring a global variable static means it only internal linkage and cannot be accessed from the same translation unit

if ever something global needs to be changed safely, maybe choose singleton pattern with proper multi-threading safety?

Something like that:

OurSingleton* GetInstance()
{
      if (pInstance == NULL)
      {
            EnterCriticalSection(&cs);
            if (pInstance == NULL)
            {
                  try
                     {
                      pInstance = new OurSingleton();
                     }
                  catch(...)
                     {
                       // do something
                     } 
            }
            LeaveCriticalSection(&cs);
      }
      return pInstance;
}

Hi Sergey,
I found an article which says that the double-locking should be avoid. Would you like to check it out?
www dot ibm dot com/developerworks/java/library/j-dcl/index.html