内存管理和realloc

我正在用valgrind来完成我的程序以寻找内存泄漏.这是一个我不知道该怎么做的.

==15634== 500 (224 direct, 276 indirect) bytes in 2 blocks are definitely lost in loss record 73 of 392
==15634==    at 0x4007070: realloc (vg_replace_malloc.c:429)
==15634==    by 0x807D5C2: hash_set_column(HASH*, int, char const*) (Hash.cpp:243)
==15634==    by 0x807BB15: LCD::PluginDiskstats::PluginDiskstats() (PluginDiskstats.cpp:102)
==15634==    by 0x806E021: LCD::Evaluator::Evaluator() (Evaluator.cpp:27)
==15634==    by 0x8066A87: LCD::LCDControl::LCDControl() (LCDControl.h:16)
==15634==    by 0x80667F5: main (Main.cpp:8)

这是代码:

/* add an entry to the column header table */
void hash_set_column(HASH * Hash, const int number, const char *column)
{
    if (Hash == NULL)
        return;

    Hash->nColumns++;
    Hash->Columns = (HASH_COLUMN *)realloc(Hash->Columns, Hash->nColumns * sizeof(HASH_COLUMN)); // line 243
    Hash->Columns[Hash->nColumns - 1].key = strdup(column);
    Hash->Columns[Hash->nColumns - 1].val = number;

    qsort(Hash->Columns, Hash->nColumns, sizeof(HASH_COLUMN), hash_sort_column);

}

我应该在内存管理方面做点什么吗？

问题是如果realloc()失败,函数将返回NULL,但仍将分配原始块.但是,您刚刚覆盖了指向该块的指针,无法再释放(或使用)它.