CODEWITHSUNDEEP
c++c
ChromoNomo
ChromoNomo

Reputation: 1

How to diagnose a visual studio project slowing down as time goes on?

Computer:

IDE:

I am including what I am doing in case it is relevant. I am running a visual studio code where I read data off a GSC PCI SIO4B Sync Card 256K. Using the API for this card (Documentation: http://www.generalstandards.com/downloads/GscApi.1.6.10.1.pdf) I read 150 bytes of data at a speed of 100Hz using the code below. That data is then being split into to the message structure my device. I can’t give info on the message structure but the data is then combined into the various words using a union and added to an integer array int Data[100];

Union Example:

union data_set{
       unsigned int  integer;
       unsigned char input[2];

} word;

Example of how the data is read read:

PLX_PHYSICAL_MEM cpRxBuffer;
#define TEST_BUFFER_SIZE 0x400

//allocates memory for the buffer
cpRxBuffer.Size = TEST_BUFFER_SIZE;
status = GscAllocPhysicalMemory(BoardNum, &cpRxBuffer);
status = GscMapPhysicalMemory(BoardNum, &cpRxBuffer);
memset((unsigned char*)cpRxBuffer.UserAddr, 0xa5, sizeof(cpRxBuffer));

//         start data reception:
status = GscSio4ChannelReceivePlxPhysData(BoardNum, iRxChannel, &cpRxBuffer, SetMaxBytes, &messageID);

// wait for Rx operation to complete
status = GscSio4ChannelWaitForTransfer(BoardNum, iRxChannel, 7000, messageID, &amount);
if (status)
            {
                        // If we have an error, "bytesTransferred" will contain the number of bytes that we
                        // actually transmitted.
                        DisplayErrorMessage(status);
                        printf("\n\t%04X bytes out of %04X transferred", amount, SetMaxBytes);
            }

My issue is that this code works fine and keeps up for around 5 minutes then randomly it stops being able to keep up and the FIFO (first in first out) register on the PCI card begins to fill up faster than the code can process the data. To me this seems like a memory leak issue since the code works fine for a long time, then starts to slow down when nothing has changed as all the code is doing it reading the data off the card. We used to save the data in a really large array but even after removing that we had the same issue. I am unsure how to figure out exactly what is happening and I'm hopping for a way to determine if there is a memory leak and how to fix it if there is. It being a data leak is only a guess though and it very well could be something else that is the problem so any out of the box suggestions for diagnosing the problem are also appreciated.

Upvotes: 0

Views: 94

Answers (2)

catnip
catnip

Reputation: 25408

Memory leaks can be detected and reported on (in Debug builds) by calling the _CrtDumpMemoryLeaks function. When running under the debugger, this will tell you (in the output tab) how many allocations you have at the time that it is called and the file and line number that each was allocated from.

Call this right at the end of your program, after you (think you) have freed all the resources you use. Anything left over is a candidate for being a leak.

Upvotes: 1

Vlad Feinstein
Vlad Feinstein

Reputation: 11321

Similar to Paul's answer, but I like to strategically place two (or more) _CrtMemCheckpoint followed by _CrtMemDifference, to cut down the noise.

Upvotes: 1

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