Hello I am having an issue where I seem to be leaking memory when I am handling my unique_ptr array variables. Now I have isolated where the issue is occurring, but I don't understand why the leak is occurring. I suspect I may be misusing the unique_ptr but researching the internet and this site I have not found what I am doing wrong. The problem occurs among two functions when they pass the unique_ptr between each other. I have pointed out the lines of code that are of interest/importance and omitted irrelevant code.
int doInstruction(SerialPort^ sPort, unsigned char cmdCode,
unique_ptr<unsigned char[]> ¶m, int sizeOfParam,
unique_ptr<char[]> &strMsg,int sizeOfMsg,
unique_ptr<unsigned char[]> &outputData){<<-- I pass in a unique_ptr
by reference in order
to return data
unique_ptr<unsigned char[]> tempOutput; <<--This is where the
unique_ptr starts
unsigned char ack[] = ACK;
unsigned char nack[] = NACK;
unsigned char appErr = ERROR_BYTE;
int a = 0;
int dataPacketLength = 7 + sizeOfParam + sizeOfMsg;
int sizeOfReply, errMsg;
int errTrckr = 0;
array<Byte>^ instruction = generateIns(cmdCode,param,sizeOfParam,
strMsg,sizeOfMsg);
bool ackCheckStage = true;
bool hasResponse = false;
bool ackCheck = true;
bool nackRepeat = false;
switch(cmdCode){
case INS_READCARD:
hasResponse = true;
break;
case INS_RETRANSMIT:
hasResponse = false;
ackCheckStage = false;
break;
}//end switch
tempOutput = move(outputData);
sendInstruction(instruction,dataPacketLength,sPort);
while(a < 1){
a++;
errMsg = 0;
errMsg = receiveMessage(sPort,tempOutput); <<--passes the unique_ptr
to the receiveMessage function, this line
is called twice, the first time it runs
fine but on the second run memory leaks
//extract length of reply..only sent if message received successfully
if(errMsg > 9){
sizeOfReply = errMsg/10;
errMsg = 0;
}//end if
if(errMsg == 0){ //success
if(ackCheckStage){ //looking for acknowledgment
if(sizeOfReply == 2 && tempOutput[0] == ack[0]
&& tempOutput[1] == ack[1]){//acknowledged
if(hasResponse){ <<--This section decides if the while loop
repeats or not, the issues occurs
when the loop repeats the 2nd time
a--;
ackCheckStage = false;
}else{
outputData = move(tempOutput);
return 0;
}//end if
}else if(){
//irrellevant code
}//end if
}else{ //looking at a message
outputData = move(tempOutput); <<--after all is said and done
I return the unique_ptr
return 0;
}//end if
}else{
//irrellevant code
}//end else if
}//end while
return -1;
}//end doInstruction
////////////The second function//////////////////////////////
int receiveMessage(SerialPort^ sPort, unique_ptr<unsigned char[]> &outData){<<--the
unique_ptr being passed by
reference so that data may
returned
int length;
int stopChecking = 0;
unique_ptr<unsigned char[]> mData; <<--I create a temporary unique_ptr
that I will work with within this
function
String^ output = "";
int insReceived = 0; //starts at 0 so if everything is working
it will not change into a 1
mData = unique_ptr<unsigned char[]>(new unsigned char[2]);
^^--initialize the unique_ptr to store 2 bytes
while(stopChecking == 0){
stopChecking = findStartChar(mData,sPort);
}//end while
if(stopChecking == 1){
output = gatherOutput(mData,2);//generating console output
mData = unique_ptr<unsigned char[]>(new unsigned char[3]);
^^--discard old data and resize to store 3 bytes of data
length = readLength(mData,sPort);<<--this seems to be working fine
if(length > 0){
if(!getSum(mData,sPort,3)){
output = output + "," + gatherOutput(mData,3);//console output
mData = unique_ptr<unsigned char[]>(new unsigned char[length+1]);
^^--discard old data and resize to store a generated
number of bytes of data
if(readData(mData,sPort,length+1) == 1){
if(!getSum(mData,sPort,length+1)){
output = output+","+gatherOutput(mData,length+1);
Console::WriteLine(output);
mData[length+1] = length;
outData = move(mData);<<--memory leak occurs here
first when this function
is called a second time
insReceived = length*10;
}else{
cout << "parity error\n";
insReceived = 3;
}//end if
}else{
}//end if
}else{
}//end if
}else{
}//end if
}else{
}//end if
return insReceived;
}//end receiveMessage
So am I misusing the unique_ptr type? or am I forgetting something crucial in its usage. I tried recreating the problem in a simpler program but it ran with no leaks. I have been checking for leaks using VLD and Microsoft's leak detector code.
