【发布时间】：2011-01-10 07:14:48
【问题描述】：
今天我只是想检查一下 valgrind 的工作原理。所以我创建了一个简单的程序。
//leak.C
#include<iostream>
class leak
{
int *p;
public:
leak():p(new int[10]()){std::cout<<"Constructor of leak called\n";}
virtual void set()
{
for(int i=0;i<10;++i) p[i]=i*i;
}
virtual void display()
{
std::cout<<"In leak's display()\n";
for(int i=0;i<10;++i) std::cout<<p[i]<<std::endl;
}
virtual ~leak()
{
std::cout<<"Destructor of leak called\n";
delete[] p;
}
};
class exleak: public leak
{
double *r;
public:
exleak():r(new double[5]()){std::cout<<"Constructor of exleak called\n";}
void set()
{
leak::set();
for(int i=0;i<5;i++) r[i]=i*3.0;
}
void display()
{
leak::display();
std::cout<<"In exleak's display()\n";
for(int i=0;i<5;i++) std::cout<<r[i]<<std::endl;
}
~exleak()
{
std::cout<<"Destructor of exleak called\n";
delete[] r;
}
};
int main()
{
leak *x=new exleak();
x->set();
x->display();
delete x;
}
输出符合预期。我预计没有内存泄漏。
我编译了文件leak.C 并生成了一个可执行文件leak。
但是当我输入以下命令valgrind --leak-check=yes --verbose ./leak时，我感到很惊讶。代码有内存泄漏。 :-o
这就是我得到的。
==9320==
==9320== HEAP SUMMARY:
==9320== in use at exit: 12 bytes in 1 blocks
==9320== total heap usage: 3 allocs, 2 frees, 92 bytes allocated
==9320==
==9320== 12 bytes in 1 blocks are definitely lost in loss record 1 of 1
==9320== at 0x40263A0: operator new(unsigned int) (vg_replace_malloc.c:214)
==9320== by 0x8048B0E: main (in /home/prasoon/leak)
==9320==
==9320== LEAK SUMMARY:
==9320== definitely lost: 12 bytes in 1 blocks
==9320== indirectly lost: 0 bytes in 0 blocks
==9320== possibly lost: 0 bytes in 0 blocks
==9320== still reachable: 0 bytes in 0 blocks
==9320== suppressed: 0 bytes in 0 blocks
==9320==
==9320== For counts of detected and suppressed errors, rerun with: -v
==9320== ERROR SUMMARY: 1 errors from 1 contexts (suppressed: 25 from 6)
代码是怎么泄露内存的？
definitely lost: 12 bytes in 1 blocks //WHERE?
编辑：问题已解决。
【问题讨论】：
-
你可以尝试使用leak-check=full，也许它会提供更多信息
-
我的错，可能我当时犯了一个错误。我再次编译了代码，再次生成了一个可执行文件。现在没有内存泄漏。 :-)
-
是的，我也试过了（没有看到“问题已解决”）。 valgrind 没有报告泄漏。
-
顺便说一句，当您复制对象时，此代码会中断。修正你的类定义。