C / C++ / MFC

Cedric Moonen wrote:

str1=CString(inet_ntoa(addr));


I guess this is wrong too (and that's probably your problem): if UNICODE is defined (which is what you expect apparently), you are passing a multi-byte characters string to the CString constructor and as UNICODE is defined, it is expecting a wide characters string.

"_$h@nky_" wrote:

Please tell me how can i write this line

Eikthrynir wrote:

Question 1: Is this scenario valid? Can it happen on a 32 bit machine?

Eikthrynir wrote:

Question 2: What if 32 bits get written to EAX, ThreadB resumes and writes to m_i64Value and after that, ThreadC resumes and the other 32 bits (changed by ThreadB) go to EDX? Is this also a possibility on 32 bit machines? If yes, what is the best way to return such a value (__int64, in this example)?

Eikthrynir wrote:

Question 3: But what if we still want to actually return the value and not copy it to the memory pointed by a_pi64Value? Can this be done somehow thread-safely and using the return instruction?

//Add zero to the value and return the initial value.
LONGLONG GetValue(__int64 *a_pi64Value)
{
	return InterlockedExchangeAdd64(a_pi64Value,0);
}

Eikthrynir wrote:

1. You call InterlockedExchange64 with a_pi64Value as the first parameter, so the __int64 variable pointed by a_pi64Value gets 0. Then, you return the previous value of that __int64 variable which is certainly not the one we are interested in, m_i64Value.

__int64 i64Val = InterlockedExchangeAdd64(m_i64Value,0);

Eikthrynir wrote:

2. GetValue returns a LONGLONG value, so we find ourselves in exactly the same situation from Question 2 (concerning the EAX and EDX registers)...

Abinash Mohanty wrote:

But it is returning zero.