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【Visual Leak Detector】配置项 SkipHeapFreeLeaks

来源:博客园

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

目录
  • 说明
  • 1. 配置文件使用说明
  • 2. 设置是否跳过堆内存泄漏检测
    • 2.1 测试代码
    • 2.2 SkipHeapFreeLeaks = no 时的输出
    • 2.3 SkipHeapFreeLeaks = yes 时的输出
    • 2.4 输出结果对比

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


(资料图片仅供参考)

有效赋值yesno

默认值no

功能说明:文档原话 是 Determines whether or not report memory leaks when missing HeapFree calls.但是当我把这个变量设置为 yes时仍可以检测到堆上的内存泄漏,这个配置项的实际作用有待进一步研究。

2.1 测试代码

#include #include "Windows.h"#include "vld.h"void testFun(int i){    int *ptr = new int(i);    printf("ptr = %08x, *ptr = %08x.\n", ptr, *ptr);    int *pData= (int *)HeapAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY, sizeof(int));    printf("pData = %08x, *pData = %08x.\n", pData, *pData);}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 = 00539498, *ptr = 00000001.pData = 00535720, *pData = 00000000.

VLD 输出报告:

Visual Leak Detector read settings from: D:\Program Files (x86)\Visual Leak Detector\vld.iniVisual Leak Detector Version 2.5.1 installed.WARNING: Visual Leak Detector detected memory leaks!---------- Block 2 at 0x00535720: 4 bytes ----------  Leak Hash: 0x426C3DE0, Count: 1, Total 4 bytes  Call Stack (TID 30052):    ntdll.dll!RtlAllocateHeap()    e:\cworkspace\qt 5.9\qtdemo\testvld\main.cpp (10): testVLD.exe!testFun() + 0x11 bytes    e:\cworkspace\qt 5.9\qtdemo\testvld\main.cpp (18): 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                                                  ........ ........---------- Block 1 at 0x00539498: 4 bytes ----------  Leak Hash: 0x19BB156F, Count: 1, Total 4 bytes  Call Stack (TID 30052):    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 (18): 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 2 memory leaks (44 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 = 014e9450, *ptr = 00000001.pData = 014e84b0, *pData = 00000000.

VLD 输出报告:

Visual Leak Detector read settings from: D:\Program Files (x86)\Visual Leak Detector\vld.iniVisual Leak Detector Version 2.5.1 installed.WARNING: Visual Leak Detector detected memory leaks!---------- Block 2 at 0x014E84B0: 4 bytes ----------  Leak Hash: 0x7C37FF93, Count: 1, Total 4 bytes  Call Stack (TID 7564):    ntdll.dll!RtlAllocateHeap()    e:\cworkspace\qt 5.9\qtdemo\testvld\main.cpp (10): testVLD.exe!testFun() + 0x11 bytes    e:\cworkspace\qt 5.9\qtdemo\testvld\main.cpp (18): 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                                                  ........ ........---------- Block 1 at 0x014E9450: 4 bytes ----------  Leak Hash: 0x8876C556, Count: 1, Total 4 bytes  Call Stack (TID 7564):    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 (18): 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 2 memory leaks (44 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 = noSkipHeapFreeLeaks = yes的输出结果似乎没有什么实质性的差异,不过有一点需注意,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

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