You need the API functions for critical sections:
InitializeCriticalSection
Call once, from any thread, but typically the main thread, to initialize the lock. Initialize before you do anything else with it.
EnterCriticalSection
Call from any thread to acquire the lock. If another thread has the lock, it will block until it can acquire the lock. Critical sections are re-entrant meaning a thread successfully acquires the lock even if it already holds it.
LeaveCriticalSection
Release the lock. Each call to EnterCriticalSection
must be paired with a matching call to LeaveCriticalSection
. Don't let exceptions stop these acquire/release calls being paired up.
DeleteCriticalSection
Call once, from any thread, but typically the main thread, to finalize the lock. Do this when no threads hold the lock. After you call this the lock is invalid and you can't attempt to acquire it again.
MSDN helpfully provide a trivial example.
If you are using MFC then you would probably use CCriticalSection
which wraps up the Win32 critical section APIs in a class.
As for how you do it with your array. Well, your threads will only execute blocks of code protected by the lock one at a time. You need the lock to stop race conditions where two threads try to read/write to the same memory location simultaneously, or indeed other more subtle conditions that can break your algorithm.
If you were to describe the array, its contents, and how you operate on it, then it might be possible to give you some specific advice. Exactly how you operate on this array will have a large bearing on the ideal synchronisation strategy, and in certain cases you may be able to use lock-free methods.
与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…