[RESOLVED] Memory problem passing BYTE array to thread

I am trying to pass a BYTE array to a thread. This is done using the PostThreadMessage() function and passing the BYTE array as the WPARAM parameter and the number of bytes in the array as LPARAM parameter.
See below.

Code:

---

BYTE* pData = new BYTE(MB_REQ_BUFSIZE);
        if(pData != NULL)
        {
                FillMemory(pData, MB_REQ_BUFSIZE, 0);
                memcpy(pData, m_aRequest, MB_REQ_BUFSIZE);
               
                m_pSerialWriter->PostThreadMessage(UWM_DATA_SEND, (WPARAM)pData, (LPARAM)MB_REQ_BUFSIZE);
        }

---

In the OnDataSend() handler of the thread i want to retrieve the BYTE* from WPARAM and use it. This all works well, however when i try do delete the array in this handler a assertion message pops up saying "Damage after NORMAL block (#526) at 0x00ADBBC0".

Following this assertion takes me to DBGHEAP.c into the following code:

Code:

---

if (!CheckBytes(pbData(pHead) + pHead->nDataSize, _bNoMansLandFill, nNoMansLandSize))
                _RPT3(_CRT_ERROR, "DAMAGE: after %hs block (#%d) at 0x%08X.\n",
                    szBlockUseName[_BLOCK_TYPE(pHead->nBlockUse)],
                    pHead->lRequest,
                    (BYTE *) pbData(pHead));

---

The way i try to delete the BYTE array is:

Code:

---

OnSendData(WPARAM wParam, LPARAM lParam)
{
  BYTE* pData = (BYTE*)wParam;
  int iNrBytes = (int)lParam;
  ...
  delete[] pData;
}

---

Code:

---

BYTE* pData = new BYTE(MB_REQ_BUFSIZE);

---

this allocates only one byte.

Guess you want

Code:

---

BYTE* pData = new BYTE[MB_REQ_BUFSIZE];

---

Kurt

Wow, you are sharp! Thanx man!

Also memory allocation and deallocation [for a specific] block should ALWAYS be done from the same thread.

Also memory should always be allocated/released from the same thread. There is no guarentee that multiple threads will be using the same heap.

CPUWizard, do you have a suggestion how i can allocate/deallocate the BYTE buffer in this case because PostThreadMessage() does not wait for completion.

Now i allocate memory in main thread, pass it to the workerthread and this will release memory as soon as it has done processing.

You could WFSO (WaitForSingleObject) on the thread, check return code using GetExitCodeThread for success if so delete the memory in the main thread.