This is a problem aout "Communication among process". You can solve it by using "singal, mutex,memory share ect"

well, you could have another array of 6 bools that marks that the corresponding object in the info array is locked or not ( a flags array, or something ), only be very carefull about syncronization... the locking of an object from the array and setting the corresponding flag are 2 different operations... u must make them atomic!! if not, if a context switch is made between them and another process might then check the flags, it will find an object unlocked while it is actually locked but the flag is not properly set because of the context switch that happend between the locking of the object and the flag setting.

thanks for the replies

i want to know how to check whether an object is being locked by a process or not

That depends on your OS in C++. C++ itself doesn't have functions for that. Maybe some library does have crossplatform functions for it. If you're on Windows, go to MSDN and lookup the threading functions there.