自定义分配器 : Valgrind shows 7 allocs, 0 释放，无泄漏

Question

我正在研究 malloc (3) 函数的克隆(malloc、realloc 和 free现在)。

我想添加对 Valgrind 的支持。我正在使用 these docs .但是，在添加对 VALGRIND_MEMPOOL_FREE、VALGRIND_MEMPOOL_ALLOC 和 VALGRIND_CREATE_MEMPOOL 宏的调用后，我从 Valgrind 获得了以下信息:

==22303== HEAP SUMMARY:
==22303==     in use at exit: 0 bytes in 0 blocks
==22303==   total heap usage: 7 allocs, 0 frees, 2,039 bytes allocated
==22303== 
==22303== All heap blocks were freed -- no leaks are possible

这与我的 realloc calling VALGRIND_MEMPOOL_FREE 无关和我的 free calling VALGRIND_MEMPOOL_FREE .

这可能是什么原因？

Answer 1

What could be the cause of this ?

这是由于 valgrind 中的错误。查看link在我对您的回答的评论中添加到 valgrind 错误跟踪器。

来自其他link在我的评论中:

A cursory search through the source code indicates that MEMPOOL_ALLOC calls new_block, which increments cmalloc_n_mallocs, but there is no corresponding change to cmalloc_n_frees in MEMPOOL_FREE.

/* valgrind.c */
#include <valgrind/valgrind.h>

int main(int argc, char *argv[]) {
    char pool[100];

    VALGRIND_CREATE_MEMPOOL(pool, 0, 0);
    VALGRIND_MEMPOOL_ALLOC(pool, pool, 8);
    VALGRIND_MEMPOOL_FREE(pool, pool);
    VALGRIND_DESTROY_MEMPOOL(pool);
    return 0;
}

$ gcc valgrind.c -g
$ valgrind --leak-check=full --show-leak-kinds=all ./a.out
==10186== Memcheck, a memory error detector
==10186== Copyright (C) 2002-2013, and GNU GPL'd, by Julian Seward et al.
==10186== Using Valgrind-3.10.1 and LibVEX; rerun with -h for copyright info
==10186== Command: ./a.out
==10186== 
==10186== 
==10186== HEAP SUMMARY:
==10186==     in use at exit: 0 bytes in 0 blocks
==10186==   total heap usage: 1 allocs, 0 frees, 8 bytes allocated
==10186== 
==10186== All heap blocks were freed -- no leaks are possible
==10186== 
==10186== For counts of detected and suppressed errors, rerun with: -v
==10186== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 0 from 0)
$