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 MaxDataDump 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. 设置每个泄漏块数据显示的最大字节数
参数名:MaxDataDump
。
有效赋值:0~4294967295
。
默认值:256
。
功能说明:设置每个泄漏块数据显示的最大字节数。如果为零,则完全不显示内存数据,只显示调用堆栈。当泄漏块很大时,把这个值设置得比较小可以使输出看起来逻辑更清晰。
2.1 测试代码
#include <QCoreApplication>
#include "vld.h"
void testFun(int i)
{
int *ptr = new int[i];
printf("ptr = %08x.\n", ptr);
}
int main(int argc, char *argv[])
{
QCoreApplication a(argc, argv);
testFun(10);
return a.exec();
}
测试环境:QT 5.9.2,MSVC 2015 32bit,Debug 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 MaxDataDump 为空时的输出
标准输出窗显示:
ptr = 007b2380.
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 0x007B2380: 40 bytes ----------
Leak Hash: 0xEA2B3F1B, Count: 1, Total 40 bytes
Call Stack (TID 20816):
ucrtbased.dll!malloc()
f:\dd\vctools\crt\vcstartup\src\heap\new_array.cpp (15): testVLD.exe!operator new[]() + 0x9 bytes
e:\cworkspace\qt 5.9\qtdemo\testvld\main.cpp (6): testVLD.exe!testFun() + 0x19 bytes
e:\cworkspace\qt 5.9\qtdemo\testvld\main.cpp (14): 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:
CD CD CD CD CD CD CD CD CD CD CD CD CD CD CD CD ........ ........
CD CD CD CD CD CD CD CD CD CD CD CD CD CD CD CD ........ ........
CD CD CD CD CD CD CD CD ........ ........
Visual Leak Detector detected 1 memory leak (76 bytes).
Largest number used: 76 bytes.
Total allocations: 76 bytes.
Visual Leak Detector is now exiting.
2.3 MaxDataDump = 0 时的输出
标准输出窗显示:
ptr = 013d1f78.
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.
Suppressing data dumps.
WARNING: Visual Leak Detector detected memory leaks!
---------- Block 1 at 0x013D1F78: 40 bytes ----------
Leak Hash: 0xEA2B3F1B, Count: 1, Total 40 bytes
Call Stack (TID 24860):
ucrtbased.dll!malloc()
f:\dd\vctools\crt\vcstartup\src\heap\new_array.cpp (15): testVLD.exe!operator new[]() + 0x9 bytes
e:\cworkspace\qt 5.9\qtdemo\testvld\main.cpp (6): testVLD.exe!testFun() + 0x19 bytes
e:\cworkspace\qt 5.9\qtdemo\testvld\main.cpp (14): 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
Visual Leak Detector detected 1 memory leak (76 bytes).
Largest number used: 76 bytes.
Total allocations: 76 bytes.
Visual Leak Detector is now exiting.
2.4 MaxDataDump = 10 时的输出
标准输出窗显示:
ptr = 00541870.
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.
Limiting data dumps to 10 bytes.
WARNING: Visual Leak Detector detected memory leaks!
---------- Block 1 at 0x00541870: 40 bytes ----------
Leak Hash: 0xEA2B3F1B, Count: 1, Total 40 bytes
Call Stack (TID 18640):
ucrtbased.dll!malloc()
f:\dd\vctools\crt\vcstartup\src\heap\new_array.cpp (15): testVLD.exe!operator new[]() + 0x9 bytes
e:\cworkspace\qt 5.9\qtdemo\testvld\main.cpp (6): testVLD.exe!testFun() + 0x19 bytes
e:\cworkspace\qt 5.9\qtdemo\testvld\main.cpp (14): 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:
CD CD CD CD CD CD CD CD CD CD ........ ........
Visual Leak Detector detected 1 memory leak (76 bytes).
Largest number used: 76 bytes.
Total allocations: 76 bytes.
Visual Leak Detector is now exiting.
2.5 输出结果对比
- 当
MaxDataDump
为空时,使用默认值256
,由于泄漏块大小小于256 bytes
,因此泄漏内存中的数据40 bytes
全部显示了出来。 - 当
MaxDataDump = 0
时,不显示内存数据,只显示调用堆栈。 - 当
MaxDataDump = 10
时,只显示前10 bytes
的内存数据。