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valgrind 的一个小缺陷 -凯发k8官方网

发布时间:2024/10/8 编程问答 0 豆豆
凯发k8官方网 收集整理的这篇文章主要介绍了 valgrind 的一个小缺陷 小编觉得挺不错的,现在分享给大家,帮大家做个参考.

valgrind 在项目中, 通常被用来做内存泄露的检查, 性能分析。

近期在使用valgrind做内存泄露, 忽略了此处testcode中的泄露提醒, 结果将代码提交上去后, 发现还是有内存的泄露, 被同事“嘲笑”了一番。

写了一小段代码, 来表述这个问题

 

class a

{

public:

 a(size_t s)

{

m_pdata = new int[s];

private:

int *m_pdata; 

} ;

 nt main()

{a *pa = new a(5);return 0;}

 

/*****************************************************/

可以看出, 内存泄露的地方有两处, 一个出 main中, 一处是 class a 的构造函数中。 

而再看看valgrind的提示信息[tianduo@search041144.sqa.cm4 c ]$ valgrind --leak-check=yes ./a.out  ==4049== memcheck, a memory error detector.==4049== 凯发k8官方网 copyright (c) 2002-2006, and gnu gpl'd, by julian seward et al.==4049== using libvex rev 1658, a library for dynamic binary translation.==4049== 凯发k8官方网 copyright (c) 2004-2006, and gnu gpl'd, by openworks llp.==4049== using valgrind-3.2.1, a dynamic binary instrumentation framework.==4049== 凯发k8官方网 copyright (c) 2000-2006, and gnu gpl'd, by julian seward et al.==4049== for more details, rerun with: -v==4049== ==4049== ==4049== error summary: 0 errors from 0 contexts (suppressed: 5 from 1)==4049== malloc/free: in use at exit: 28 bytes in 2 blocks.==4049== malloc/free: 2 allocs, 0 frees, 28 bytes allocated.==4049== for counts of detected errors, rerun with: -v==4049== searching for pointers to 2 not-freed blocks.==4049== checked 163,288 bytes.==4049== ==4049== 28 (8 direct, 20 indirect) bytes in 1 blocks are definitely lost in loss record 1 of 2==4049==    at 0x4a06019: operator new(unsigned long) (vg_replace_malloc.c:167)==4049==    by 0x4006aa: main (memory.cpp:14)==4049== ==4049== leak summary:==4049==    definitely lost: 8 bytes in 1 blocks.==4049==    indirectly lost: 20 bytes in 1 blocks.==4049==      possibly lost: 0 bytes in 0 blocks.==4049==    still reachable: 0 bytes in 0 blocks.==4049==         suppressed: 0 bytes in 0 blocks.==4049== reachable blocks (those to which a pointer was found) are not shown.

==4049== to see them, rerun with: --show-reachable=yes 

 粗略一看, 只有  main函数的14行, 如果在测试的时候, 认为忽略这一行, 那就遗漏了 class a中的泄露点。

  

转载于:https://www.cnblogs.com/nosaferyao/archive/2011/12/31/2308781.html

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