【Visual Leak Detector】配置项 SkipHeapFreeLeaks

说明

使用 VLD 内存泄漏检测工具辅助开发时整理的学习笔记。本篇介绍 VLD 配置文件中配置项 SkipHeapFreeLeaks 的使用方法。同系列文章目录可见 《内存泄漏检测工具》目录


1. 配置文件使用说明

在程序中通过 #include "vld.h" 的方式检测内存泄漏时,VLD 首先会尝试在程序的生成目录下读取 vld.ini 文件,若未读取成功,则会尝试在 VLD 的安装目录下读取 vld.ini 文件,若仍未读取成功,则会使用内置的默认配置,内置的默认配置如果不动源码是无法更改的,因此通过修改相应目录下的 vld.ini 文件来定制 VLD 功能是最好的选择。当配置参数等号右边为空,或者给配置了不合法值时,在使用过程中会被程序重置到默认值。

2. 设置是否跳过堆内存泄漏检测

参数名SkipHeapFreeLeaks

有效赋值yesno

默认值no

功能说明文档原话 如下:

Determines whether or not report memory leaks when missing HeapFree calls.

用于跳过堆摧毁前未调用 HeapFree() 而导致的内存泄漏。

2.1 测试代码

#include <QCoreApplication>
#include "Windows.h"
#include "vld.h"

void testFun(int i)
{
    int *ptr = new int(i);
    printf("ptr = %08x, *ptr = %08x.\n", ptr, *ptr);

    HANDLE hHeap = HeapCreate(0, 0, 0);
    int *pData= (int *) HeapAlloc(hHeap, HEAP_ZERO_MEMORY, sizeof(int));
    printf("pData = %08x, *pData = %08x.\n", pData, *pData);

//    HeapFree(hHeap, 0, pData);
    HeapDestroy(hHeap);
}

int main(int argc, char *argv[])
{
    QCoreApplication a(argc, argv);

    testFun(1);

    return a.exec();
}

测试环境:QT 5.9.2MSVC 2015 32bitDebug 模式,VLD 版本为 2.5.1,VLD 配置文件只对该参数做修改,测试工程所在路径为:E:\Cworkspace\Qt 5.9\QtDemo\testVLD

2.2 SkipHeapFreeLeaks = no 时的输出

标准输出窗显示:

ptr = 00fec568, *ptr = 00000001.
pData = 031a05b8, *pData = 00000000.

VLD 输出报告:

Visual Leak Detector read settings from: D:\Program Files (x86)\Visual Leak Detector\vld.ini
Visual Leak Detector Version 2.5.1 installed.
WARNING: Visual Leak Detector detected memory leaks!
---------- Block 2 at 0x031A05B8: 4 bytes ----------
  Leak Hash: 0x409D89FF, Count: 1, Total 4 bytes
  Call Stack (TID 16664):
    ntdll.dll!RtlAllocateHeap()
    e:\cworkspace\qt 5.9\qtdemo\testvld\main.cpp (11): testVLD.exe!testFun() + 0xE bytes
    e:\cworkspace\qt 5.9\qtdemo\testvld\main.cpp (22): testVLD.exe!main() + 0x7 bytes
    f:\dd\vctools\crt\vcstartup\src\startup\exe_common.inl (74): testVLD.exe!invoke_main() + 0x1B bytes
    f:\dd\vctools\crt\vcstartup\src\startup\exe_common.inl (264): testVLD.exe!__scrt_common_main_seh() + 0x5 bytes
    f:\dd\vctools\crt\vcstartup\src\startup\exe_common.inl (309): testVLD.exe!__scrt_common_main()
    f:\dd\vctools\crt\vcstartup\src\startup\exe_main.cpp (17): testVLD.exe!mainCRTStartup()
    KERNEL32.DLL!BaseThreadInitThunk() + 0x19 bytes
    ntdll.dll!RtlGetAppContainerNamedObjectPath() + 0x11E bytes
    ntdll.dll!RtlGetAppContainerNamedObjectPath() + 0xEE bytes
  Data:
    00 00 00 00                                                  ........ ........


Visual Leak Detector detected 1 memory leak in heap 0x031A0000
WARNING: Visual Leak Detector detected memory leaks!
---------- Block 1 at 0x00FEC568: 4 bytes ----------
  Leak Hash: 0xC20678CD, Count: 1, Total 4 bytes
  Call Stack (TID 16664):
    ucrtbased.dll!malloc()
    f:\dd\vctools\crt\vcstartup\src\heap\new_scalar.cpp (19): testVLD.exe!operator new() + 0x9 bytes
    e:\cworkspace\qt 5.9\qtdemo\testvld\main.cpp (7): testVLD.exe!testFun() + 0x7 bytes
    e:\cworkspace\qt 5.9\qtdemo\testvld\main.cpp (22): testVLD.exe!main() + 0x7 bytes
    f:\dd\vctools\crt\vcstartup\src\startup\exe_common.inl (74): testVLD.exe!invoke_main() + 0x1B bytes
    f:\dd\vctools\crt\vcstartup\src\startup\exe_common.inl (264): testVLD.exe!__scrt_common_main_seh() + 0x5 bytes
    f:\dd\vctools\crt\vcstartup\src\startup\exe_common.inl (309): testVLD.exe!__scrt_common_main()
    f:\dd\vctools\crt\vcstartup\src\startup\exe_main.cpp (17): testVLD.exe!mainCRTStartup()
    KERNEL32.DLL!BaseThreadInitThunk() + 0x19 bytes
    ntdll.dll!RtlGetAppContainerNamedObjectPath() + 0x11E bytes
    ntdll.dll!RtlGetAppContainerNamedObjectPath() + 0xEE bytes
  Data:
    01 00 00 00                                                  ........ ........


Visual Leak Detector detected 1 memory leak (40 bytes).
Largest number used: 44 bytes.
Total allocations: 44 bytes.
Visual Leak Detector is now exiting.

2.3 SkipHeapFreeLeaks = yes 时的输出

标准输出窗显示:

ptr = 00719b50, *ptr = 00000001.
pData = 02c005b8, *pData = 00000000.

VLD 输出报告:

Visual Leak Detector read settings from: D:\Program Files (x86)\Visual Leak Detector\vld.ini
Visual Leak Detector Version 2.5.1 installed.
WARNING: Visual Leak Detector detected memory leaks!
---------- Block 1 at 0x00719B50: 4 bytes ----------
  Leak Hash: 0xC20678CD, Count: 1, Total 4 bytes
  Call Stack (TID 736):
    ucrtbased.dll!malloc()
    f:\dd\vctools\crt\vcstartup\src\heap\new_scalar.cpp (19): testVLD.exe!operator new() + 0x9 bytes
    e:\cworkspace\qt 5.9\qtdemo\testvld\main.cpp (7): testVLD.exe!testFun() + 0x7 bytes
    e:\cworkspace\qt 5.9\qtdemo\testvld\main.cpp (22): testVLD.exe!main() + 0x7 bytes
    f:\dd\vctools\crt\vcstartup\src\startup\exe_common.inl (74): testVLD.exe!invoke_main() + 0x1B bytes
    f:\dd\vctools\crt\vcstartup\src\startup\exe_common.inl (264): testVLD.exe!__scrt_common_main_seh() + 0x5 bytes
    f:\dd\vctools\crt\vcstartup\src\startup\exe_common.inl (309): testVLD.exe!__scrt_common_main()
    f:\dd\vctools\crt\vcstartup\src\startup\exe_main.cpp (17): testVLD.exe!mainCRTStartup()
    KERNEL32.DLL!BaseThreadInitThunk() + 0x19 bytes
    ntdll.dll!RtlGetAppContainerNamedObjectPath() + 0x11E bytes
    ntdll.dll!RtlGetAppContainerNamedObjectPath() + 0xEE bytes
  Data:
    01 00 00 00                                                  ........ ........


Visual Leak Detector detected 1 memory leak (40 bytes).
Largest number used: 44 bytes.
Total allocations: 44 bytes.
Visual Leak Detector is now exiting.

2.4 输出结果对比

  • SkipHeapFreeLeaks = no 时输出了检测到的全部内存泄漏,包括已摧毁的堆上的泄漏(摧毁前未调用 HeapFree() 释放内存)。
  • SkipHeapFreeLeaks = yes 时跳过了已摧毁的堆上的泄漏(从显示的泄漏地址来判断)。还有一点需注意,使用 new 分配堆内存时,会额外添加 36 bytes 大小的内存用于追踪管理,但使用 HeapAlloc() 函数分配堆内存时,则没有额外的内存使用,因此上述测试例的 Total allocations44 bytes,而不是 80 bytes
posted @ 2023-03-30 01:09  木三百川  阅读(51)  评论(0编辑  收藏  举报