Linxu
Linux系统下解决内存泄漏可以使用valgrind工具。
下载valgrind
sudo apt-get install valgrindLinux下使用valgrind
g++ -g -o app test.cpp
valgrind --leak-check=full ./app代码如下
#include<iostream>
using namesapce std;
int main()
{
int i = 0;
int * intV = new int[10];
for(int i = 0; i < 10; i++)
{
intV[i] = i;
}
for(int i = 0; i < 10; i++) {
cout << intV[i] <<endl;
}
delete [] intV;
}valgrind打印的泄漏信息
==5155== Memcheck, a memory error detector ==5155== Copyright (C) 2002-2017, and GNU GPL'd, by Julian Seward et al. ==5155== Using Valgrind-3.15.0 and LibVEX; rerun with -h for copyright info ==5155== Command: ./app ==5155== ==5155== ==5155== HEAP SUMMARY: ==5155== in use at exit: 40 bytes in 1 blocks ==5155== total heap usage: 3 allocs, 2 frees, 76,840 bytes allocated ==5155== ==5155== 40 bytes in 1 blocks are definitely lost in loss record 1 of 1 ==5155== at 0x483C583: operator new[](unsigned long) (in /usr/lib/x86_64-linux-gnu/valgrind/vgpreload_memcheck-amd64-linux.so) ==5155== by 0x1091E5: main (test.cpp:7) ==5155== ==5155== LEAK SUMMARY: ==5155== definitely lost: 40 bytes in 1 blocks ==5155== indirectly lost: 0 bytes in 0 blocks ==5155== possibly lost: 0 bytes in 0 blocks ==5155== still reachable: 0 bytes in 0 blocks ==5155== suppressed: 0 bytes in 0 blocks ==5155== ==5155== For lists of detected and suppressed errors, rerun with: -s ==5155== ERROR SUMMARY: 1 errors from 1 contexts (suppressed: 0 from 0)
正常信息
==5719== ==5719== HEAP SUMMARY: ==5719== in use at exit: 0 bytes in 0 blocks ==5719== total heap usage: 3 allocs, 3 frees, 73,768 bytes allocated ==5719== ==5719== All heap blocks were freed -- no leaks are possible ==5719== ==5719== For lists of detected and suppressed errors, rerun with: -s ==5719== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 0 from 0)
Windows
windows下qt可以使用qt自带的一个Leaker插件，安装后即可使用，但是需要进行收费，本文主要介绍VLD方式，通过vs进行内存检测。
首先下载VLD安装包
到GitHub下载最新的VLD程序Release v2.5.1 · KindDragon/vld (github.com)。
会自动适配到本地安装的vs中，之后将里面的lib,include文件打包之后，把bin目录下的dll放到运行的bin目录下，之后配置头文件和库目录，加入#include "vld.h"头文件，程序启动会打印
Visual Leak Detector read settings from: D:\Program Files\Visual Leak Detector\vld.ini Visual Leak Detector Version 2.5.1 installed.
代码如下：
#include <iostream>
using namespace std;
#include "vld.h"
void test()
{
char* pChar = new char[20];
//delete[] pChar;
return;
}
int main()
{
test();
return 0;
}如果存在内存泄漏，程序会输出
WARNING: Visual Leak Detector detected memory leaks! ---------- Block 1 at 0x00000000EDC96DE0: 20 bytes ---------- Leak Hash: 0x5A484AE6, Count: 1, Total 20 bytes Call Stack (TID 6140): ucrtbased.dll!malloc() f:\dd\vctools\crt\vcstartup\src\heap\new_array.cpp (16): LeetCode.exe!operator new[]() d:\visualprograme\leetcode\leetcode\test2.cpp (8): LeetCode.exe!test() + 0xA bytes d:\visualprograme\leetcode\leetcode\test2.cpp (16): LeetCode.exe!main() f:\dd\vctools\crt\vcstartup\src\startup\exe_common.inl (75): LeetCode.exe!invoke_main() f:\dd\vctools\crt\vcstartup\src\startup\exe_common.inl (264): LeetCode.exe!__scrt_common_main_seh() + 0x5 bytes f:\dd\vctools\crt\vcstartup\src\startup\exe_common.inl (309): LeetCode.exe!__scrt_common_main() f:\dd\vctools\crt\vcstartup\src\startup\exe_main.cpp (17): LeetCode.exe!mainCRTStartup() KERNEL32.DLL!BaseThreadInitThunk() + 0x14 bytes ntdll.dll!RtlUserThreadStart() + 0x21 bytes Data: 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 (72 bytes). Largest number used: 72 bytes. Total allocations: 72 bytes. Visual Leak Detector is now exiting.
如果不存在内存泄漏，则会打印如下信息
No memory leaks detected. Visual Leak Detector is now exiting.
还可以将其输出到文件中
vld.ini参数设置说明 默认读取的是安装目录下的vld.ini 文件，当exe所在目录下也有vld.ini文件时会优先读取这份配置。 VLD：选择VLD的打开与关闭。在Debug模式下运行，关闭以后会有一行VLD关闭的提示信息。默认为 on。 AggregateDuplicates：设置为 yes 时，相同地方产生内存泄漏只输出一次，但是会统计发生的次数。默认是 no 。 MaxDataDump：输出的dump数据个数，默认为 256。 MaxTraceFrames：输出的调用栈的层数。默认是 64。 ReportEncoding ：report 文件的编码格式，可选有 ascii, unicode，默认是 ascii 。 ReportFile ：report 文件的路径。默认是 “.\memory_leak_report.txt” ReportTo ：可选有 debugger, file, both，debugger 表示输出到 debug模式下的输出窗口；file 表示只输出到文件中； both顾名思义，全都都输出。默认是 debugger 。 备注：怎么让VLD的文件输出到一个独立的文件中？ vld.ini参数设置说明 答：配置 ReportFile = .\你的程序名称_vldLog.txt 和 ReportTo = both 即可。
配置好路径之后
会在当前目录生成文件
