How to pass int parameter to CreateThread callback function? I try it:
DWORD WINAPI mHandler(LPVOID sId) {
...
arr[(int)sId]
...
}
int id=1;
CreateThread(NULL, NULL, mHandler, (LPVOID)id, NULL, NULL);
But I get warnings:
warning C4311: 'type cast' : pointer truncation from 'LPVOID' to 'int'
warning C4312: 'type cast' : conversion from 'int' to 'LPVOID' of greater size
Pass the address of the integer instead of its value:
// parameter on the heap to avoid possible threading bugs
int* id = new int(1);
CreateThread(NULL, NULL, mHandler, id, NULL, NULL);
DWORD WINAPI mHandler(LPVOID sId) {
// make a copy of the parameter for convenience
int id = *static_cast<int*>(sId);
delete sId;
// now do something with id
}