内存泄漏问题

Memory leak problem

本文关键字：问题 泄漏 内存      更新时间：2023-10-16

我有一个简单的程序，它创建一个线程，并在该线程结束时等待，然后程序也结束。当我用C（gcc）编译器编译这个程序，并用valgrind检查它时，没有出现问题，但当我用C++（g++）编译器编译它，并用valgrind检查时，表明我的程序存在内存泄漏。可能是什么问题？

这是我的程序

#include <pthread.h>
#include <errno.h>
#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <string.h>

unsigned char b = 0;

void* threadfunc1( void *pVoid )
{
    while( b == 0 )
    {
    usleep(10000);
    }
    pthread_exit(0);
}

int main(void)
{
    int status;
    pthread_attr_t tattr;
    pthread_t   thread1;
    status = pthread_attr_init(&tattr);
    status = pthread_attr_setdetachstate(&tattr,PTHREAD_CREATE_JOINABLE);
    status = pthread_attr_setscope(&tattr,PTHREAD_SCOPE_SYSTEM);
    if( pthread_create( &thread1, &tattr, threadfunc1, NULL ) != 0 )
    {
        exit(1);
    }
    usleep(1000000);
    b = 1;
    pthread_join( thread1, NULL);
    usleep(2000000);
    return 0;
}

这就是结果，当我使用g++编译它并检查valgrind 时

==7658== HEAP SUMMARY:
==7658==     in use at exit: 28 bytes in 1 blocks
==7658==   total heap usage: 2 allocs, 1 frees, 172 bytes allocated
==7658== 
==7658== 28 bytes in 1 blocks are still reachable in loss record 1 of 1
==7658==    at 0x4024C1C: malloc (vg_replace_malloc.c:195)
==7658==    by 0x400C01E: _dl_map_object_deps (dl-deps.c:506)
==7658==    by 0x40117E0: dl_open_worker (dl-open.c:297)
==7658==    by 0x400D485: _dl_catch_error (dl-error.c:178)
==7658==    by 0x401119F: _dl_open (dl-open.c:586)
==7658==    by 0x428D0C1: do_dlopen (dl-libc.c:86)
==7658==    by 0x400D485: _dl_catch_error (dl-error.c:178)
==7658==    by 0x428D1C0: dlerror_run (dl-libc.c:47)
==7658==    by 0x428D2DA: __libc_dlopen_mode (dl-libc.c:160)
==7658==    by 0x4048876: pthread_cancel_init (unwind-forcedunwind.c:53)
==7658==    by 0x40489EC: _Unwind_ForcedUnwind (unwind-forcedunwind.c:126)
==7658==    by 0x40464B7: __pthread_unwind (unwind.c:130)
==7658== 
==7658== LEAK SUMMARY:
==7658==    definitely lost: 0 bytes in 0 blocks
==7658==    indirectly lost: 0 bytes in 0 blocks
==7658==      possibly lost: 0 bytes in 0 blocks
==7658==    still reachable: 28 bytes in 1 blocks
==7658==         suppressed: 0 bytes in 0 blocks

所以，我做错了什么，是我的错误还是。。。，为什么当我用gcc编译它时没有出现问题，而当我用C++编译它时却存在内存泄漏？

@Kiril Kirov的回答已经指出，您的程序中没有内存泄漏。

但我没有看到对的呼吁

int pthread_attr_destroy(pthread_attr_t *attr);

您的程序没有内存泄漏，您有

==7658==    definitely lost: 0 bytes in 0 blocks
==7658==    indirectly lost: 0 bytes in 0 blocks
==7658==      possibly lost: 0 bytes in 0 blocks

"仍然可访问"不意味着内存泄漏。

这里有很多关于valgrind"仍然可以到达"的问题。其中一些：

  • Valgrind检测到仍然可达到的泄漏
  • 仍然可以到达瓦尔grind
  • Valgrind声称有未解冻的记忆。这不好吗
相关文章：