ubuntu 内存泄漏 调试 valgrind

Ubuntu下的C/C++工程经常会遇到内存泄漏、阻塞、溢出等问题。进行问题的查找和问题代码的定位很重要。

推荐 valgrind，终端开始安装：

sudo apt-get install valgrind

写好的代码生成可执行文件，用valgrind运行debug：

valgrind --tool=memcheck --leak-check=full ./Test

出来一堆调试信息，拉到最后看leak summary：

==10216== 
==10216== LEAK SUMMARY:
==10216==    definitely lost: 0 bytes in 0 blocks
==10216==    indirectly lost: 0 bytes in 0 blocks
==10216==      possibly lost: 2,492 bytes in 21 blocks
==10216==    still reachable: 169,710 bytes in 1,220 blocks
==10216==                       of which reachable via heuristic:
==10216==                         newarray           : 1,536 bytes in 16 blocks
==10216==         suppressed: 0 bytes in 0 blocks
==10216== Reachable blocks (those to which a pointer was found) are not shown.
==10216== To see them, rerun with: --leak-check=full --show-leak-kinds=all
==10216== 
==10216== For counts of detected and suppressed errors, rerun with: -v
==10216== ERROR SUMMARY: 21 errors from 21 contexts (suppressed: 0 from 0)

工程很大，possibly lost很多，但主要看前两行，definitely lost和indirectly lost，这两个如果都是0 bytes则说明工程大致上是OK的，不需要专门进行内存泄漏的细节修改；如果前两个lost不为0，则必有内存泄漏，需要好好定位查找了。