Resource leak or not (Mac OS X)?

Question

I'm trying to enumerate local users on Mac os. It works correctly, but i think that there is some resource leak. I can't understand that. Profiling says that there are no memory leaks, but memory usage are constantly grows (Memory Report chart at XCode). In my case since 2.7M to 4.9M (5 * 1000 iterations). Can anybody say what is wrong with my code. Are there any leaks or the behaviour is normal?

This is a simple c++ command line tool project with Objective-c code with default build settings (XCode 5):

/////////////////////////////////////////////
// main.cpp

#include "test.h"

#include <iostream>
#include <thread>

int main(int argc, const char * argv[])
{
  //for (int i = 0; i < 1000; ++i)
  for (int i = 0; i < 5; ++i)
  {
    std::cout << "Iteration # " << i << std::endl;

    for (int j = 0; j < 1000; ++j)
    {
      Execute();
    }

    std::this_thread::sleep_for(std::chrono::seconds(1));
  }

  return 0;
}


/////////////////////////////////////////////
// test.mm

#import <Collaboration/Collaboration.h>
#import <CoreServices/CoreServices.h>
#import <Foundation/Foundation.h>
#import <SystemConfiguration/SCDynamicStore.h>
#import <SystemConfiguration/SCDynamicStoreCopySpecific.h>

#include <iostream>

void Execute()
{
  CSIdentityAuthorityRef identityAuthority = CSGetLocalIdentityAuthority();
  if (!identityAuthority)
  {
    std::cout << "Failed to get identity authority." << std::endl;
    return;
  }

  CSIdentityQueryRef usersQuery(CSIdentityQueryCreate(nil,  kCSIdentityClassUser, identityAuthority));
  if (!usersQuery)
  {
    std::cout << "Failed to create query." << std::endl;
    return;
  }

  /////////////////////////////////////////////////
  // Without CSIdentityQueryExecute(usersQuery, 0, nil) - everething is ok.
  /////////////////////////////////////////////////
  if (!CSIdentityQueryExecute(usersQuery, 0, nil))
  {
    std::cout << "Failed to execute query." << std::endl;
    return;
  }

  CFRelease(usersQuery);
}


#ifndef __MY_TEST_H__
#define __MY_TEST_H__

void Execute();

#endif

Answer 1

尝试在每次return之前执行CFRelease ，因为某些迭代不会释放数据。

Answer 2

I just ran this program, and I'm not seeing any memory growth. I slightly simplified it to be a single-file C++ program (currently it's a mix of C++ and ObjC++).

You do have a memory mistake, but I would only expect it to cause a leak if you were getting errors. This block leaks the query:

if (!CSIdentityQueryExecute(usersQuery, 0, nil))
{
  std::cout << "Failed to execute query." << std::endl;
  return;
}

You should either not return here (you don't technically need to), or you should include a CFRelease(usersQuery) before the return. But again, if this were the problem, you'd see lots of "Failed to execute query" log messages.