How to use Critical Section in MFC

Abhi MFC

16y6.7k

Hi

I have two worker threads, where one thread(WriteBuf) is writing into buffer and another thread(ReadBuf) is reading from the same buffer.

I have created CriticalSection object like CCriticalSection m_crit created globaly.

My thread code looks like below

UINT WriteBuf(LPVOID pParam)
{

crit.Lock();
buf[0] = 'a'; //Writing to buffer.
return TRUE;
}

UINT ReadBuf(LPVOID pParam)
{

buf1[0] = buf[0]; Reading from the buffer.
TRACE("%c",buf1[0]);
return TRUE;

}

Please let me know is this the rite way to lock the resource(buffer),coz i havent unlocked yet but still i can able to read the buffer from another thread(ReadBuf) .

So please help me to understand the critical section usage here.

Thanks
Abhi

2 Replies

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Sam Hobbs16y ago
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Sam Hobbs16y ago
It is your responsibility to ensure that all access to a resource is done within a critical section. A critical section does not lock the memory or anything else other than the critical section. The processor is unable to prevent access of the buffer buf when it is read without a critical section.