虽然经历在Valgrind的示例代码显示memeory泄漏情况下,我不明白两两件事:负数
- 如何到达或丢失字节的任何内存泄漏的数量是 in negative?字节数是否为 减号是什么意思?
- 什么是一个空函数
breakme()
没有 报表的需要?当它什么都不做时,它的目的是什么?
#include <stdio.h>
#include <stdlib.h>
#include "../memcheck.h"
#include "leak.h"
char *b10;
char *b21;
char *b32_33[2];
static void breakme() {};
void f(void)
{
int i;
b10 = malloc (10);
fprintf(stderr, "expecting details 10 bytes reachable\n"); fflush(stderr); breakme();
VALGRIND_DO_LEAK_CHECK;
fprintf(stderr, "expecting to have NO details\n"); fflush(stderr); breakme();
VALGRIND_DO_ADDED_LEAK_CHECK;
b10--; // lose b10
b21 = malloc (21);
fprintf(stderr, "expecting details +10 bytes lost, +21 bytes reachable\n"); fflush(stderr); breakme();
VALGRIND_DO_ADDED_LEAK_CHECK;
for (i = 0; i < 2; i ++)
b32_33[i] = malloc (32+i);
fprintf(stderr, "expecting details +65 bytes reachable\n"); fflush(stderr); breakme();
VALGRIND_DO_ADDED_LEAK_CHECK;
fprintf(stderr, "expecting to have NO details\n"); fflush(stderr); breakme();
VALGRIND_DO_ADDED_LEAK_CHECK;
b10++;
fprintf(stderr, "expecting details +10 bytes reachable\n"); fflush(stderr); breakme();
VALGRIND_DO_ADDED_LEAK_CHECK;
b10--;
fprintf(stderr, "expecting details -10 bytes reachable, +10 bytes lost\n"); fflush(stderr); breakme();
VALGRIND_DO_CHANGED_LEAK_CHECK;
b10++;
fprintf(stderr, "expecting details -10 bytes lost, +10 bytes reachable\n"); fflush(stderr); breakme();
VALGRIND_DO_CHANGED_LEAK_CHECK;
b32_33[0]--;
fprintf(stderr, "expecting details 32 (+32) bytes lost, 33 (-32) bytes reachable\n"); fflush(stderr); breakme();
VALGRIND_DO_CHANGED_LEAK_CHECK;
fprintf(stderr, "finished\n");
}
int main(void)
{
DECLARE_LEAK_COUNTERS;
GET_INITIAL_LEAK_COUNTS;
f(); // see leak-cases.c
GET_FINAL_LEAK_COUNTS;
PRINT_LEAK_COUNTS(stderr);
return 0;
}
ok谢谢。我得到了第一个问题的答案,即负字节数实际上意味着从先前泄漏或可访问的字节数中减少字节数。你能解释更多关于第二个问题吗?它不太清楚GDB是如何自动启动的,以及空函数如何使回归测试更容易? Regards –
编辑答案,提供有关Valgrind注册信息的更多详细信息 – phd