21. What is DuplicateHandle (API)?

Takes an entry in one process’s handle table and makes a copy of the entry into another process’s handle table

22. What is a thread?

A thread describes a path of execution within a process. Every time a process is initialized, the system creates a primary thread. This thread begins executing with the C/C++ run-time library’s startup code, which in turn calls your entry-point function ( main , Wmain , WinMain , or WWinMain ) and continues executing until the entry-point function returns and the C/C++ run-time library’s startup code calls ExitProcess

23. What is the limit on per process for creating a thread?

The number of threads a process can create is limited by the available virtual memory and depends on the default stack size

24. What is Synchronization Objects?

Synchronization object s are use to co-ordinate the execution of multiple threads. Which kernel objects are use for Thread Synchronization on different processes? - Event, Mutex, Semaphore

25. What is Event Object and why it is used?

Event is the thread synchronization object to set signaled state or non-signaled state.

26. What is signaled and non signaled state?

An event is in signaled state means that it has the capacity to release the threads waiting for this event to be signaled. An event is in non signaled state means that it will not release any thread that is waiting for this particular event.example in our project: when user clicks the image application icon double simultaneously. Two image application windows were created. so PAIG created an event and set it to non-signaled state. Then the image application will reset the event to signaled state, after this all the threads are released.