內存泄漏問題

Question

我有一個簡單的程序創建一個線程，並等待線程結束時，然後程序也結束。當我用C（gcc）編譯器編譯這個程序，並用valgrind檢查它時，沒有發生問題，但是當我用C++（g ++）編譯器編譯它並檢查valgrind時，它顯示我的程序有內存泄漏。可能是什麼問題呢？

這是我的計劃，

#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; 
} 

這就是結果，當我編譯它用G ++，並在Valgrind的檢查

==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 

那麼，究竟我做錯了，是它我的錯誤或...，爲什麼當我用gcc編譯它時沒有發生問題，當我使用C++編譯它時，內存泄漏是存在的？

Answer 1

你的程序沒有內存泄漏，你有

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

「仍可達」不不意味着內存泄漏。

這裏有很多關於valgrind「仍然可以達到」的問題。他們中的一些：

• Still Reachable Leak detected by Valgrind
• Still reachable in valgrind
• Valgrind claims there is unfreed memory. Is this bad?

Answer 2

由於@Kiril基洛夫的答案已經指出的那樣，有在你的程序沒有內存泄漏。

但是，我看到了一個電話：

int pthread_attr_destroy(pthread_attr_t *attr);