使用pthread_create时valgrind内存泄漏错误

I'm writing a program using the pthread library. When i run my program with the command valgrind --leak-check=full, i get the following errors description:

我正在使用pthread库编写程序。当我用命令valgrind --leak-check = full运行我的程序时,我得到以下错误描述:

==11784==  
==11784== **HEAP SUMMARY:**  
==11784==     in use at exit: 4,952 bytes in 18 blocks  
==11784==   total heap usage: 1,059 allocs, 1,041 frees, 51,864 bytes allocated  
==11784==  
==11784== **288 bytes** in 1 blocks are possibly lost in loss record 2 of 3  
==11784==    at 0x4C2380C: calloc (vg_replace_malloc.c:467)  
==11784==    by 0x4010D2E: _dl_allocate_tls (dl-tls.c:300)  
==11784==    by 0x55DC218: **pthread_create**@@GLIBC_2.2.5 (allocatestack.c:570)  
==11784==    by 0x401BC0: initdevice(char*) (in /a/fr-01/vol/home/stud/lim/workspace  /Ex3/l)  
==11784==    by 0x406D05: main (in /a/fr-01/vol/home/stud/lim/workspace/Ex3/l)  
==11784==  
==11784== **4,608 bytes** in 16 blocks are possibly lost in loss record 3 of 3  
==11784==    at 0x4C2380C: calloc (vg_replace_malloc.c:467)  
==11784==    by 0x4010D2E: _dl_allocate_tls (dl-tls.c:300)  
==11784==    by 0x55DC218: **pthread_create**@@GLIBC_2.2.5 (allocatestack.c:570)    
==11784==    by 0x40268F: write2device(char*, int) (in /a/fr-01/vol/home/stud/lim/workspace/Ex3/l)  
==11784==    by 0x406D7B: main (in /a/fr-01/vol/home/stud/lim/workspace/Ex3/l)  
==11784==  
==11784== **LEAK SUMMARY:**  
==11784==    definitely lost: 0 bytes in 0 blocks  
==11784==    indirectly lost: 0 bytes in 0 blocks  
==11784==      possibly lost: 4,896 bytes in 17 blocks  
==11784==    still reachable: 56 bytes in 1 blocks  
==11784==         suppressed: 0 bytes in 0 blocks  
==11784== Reachable blocks (those to which a pointer was found) are not shown.  
==11784== To see them, rerun with: --leak-check=full --show-reachable=yes  
==11784==  
==11784== For counts of detected and suppressed errors, rerun with: -v  
==11784== ERROR SUMMARY: 2 errors from 2 contexts (suppressed: 4 from 4)

Every time i call pthread_create, with a certain function - i call the function pthread_exit in the end of the function. So, after verifying this is not the problem, what could be the problem?

每当我调用pthread_create时,使用某个函数 - 我在函数的末尾调用函数pthread_exit。因此,在验证这不是问题之后,可能是什么问题?

5 个解决方案

#1

A thread's resources are not immediately released at termination, unless the thread was created with the detach state attribute set to PTHREAD_CREATE_DETACHED, or if pthread_detach is called for its pthread_t.

除非在将detach state属性设置为PTHREAD_CREATE_DETACHED的情况下创建线程,或者为其pthread_t调用pthread_detach,否则线程的资源不会在终止时立即释放。

An undetached thread will remain terminated state until its identifier is passed to pthread_join or pthread_detach.

未分离的线程将保持终止状态,直到其标识符传递给pthread_join或pthread_detach。

To sum it up, you have three options:

总结一下,您有三种选择:

create your thread with detached attribute set(PTHREAD_CREATE_DETACHED attribute)

创建具有分离属性集的线程(PTHREAD_CREATE_DETACHED属性)

Detach your thread after creation (by calling pthread_detach), or

创建后分离线程(通过调用pthread_detach),或

Join with the terminated threads to recycle them (by calling pthread_join).

加入已终止的线程以回收它们(通过调用pthread_join)。

Hth.

#2

when not working with joinable threads the exiting thread needs to call pthread_detach(pthread_self()) in order to release all its resources.

当不使用可连接线程时,退出线程需要调用pthread_detach(pthread_self())以释放其所有资源。

#3

Ot you can make the thread in detached state to avoid the memory leak if the thread should not be joined (or just expires on it's own)

你可以让线程处于分离状态,以避免内存泄漏,如果线程不应该连接(或只是自己过期)

To explicitly create a thread as joinable or detached, the attr argument in the pthread_create() routine is used. The typical 4 step process is:

要将线程显式创建为可连接或已分离,请使用pthread_create()例程中的attr参数。典型的4步流程是:

Declare a pthread attribute variable of the pthread_attr_t data type

声明pthread_attr_t数据类型的pthread属性变量

Initialize the attribute variable with pthread_attr_init()

使用pthread_attr_init()初始化属性变量

Set the attribute detached status with pthread_attr_setdetachstate()

使用pthread_attr_setdetachstate()设置属性分离状态

When done, free library resources used by the attribute with pthread_attr_destroy()

完成后,该属性使用的免费库资源与pthread_attr_destroy()

#4

In addition to the correct answers given you by other users, I suggest you to read this:

除了其他用户给出的正确答案之外,我建议你阅读:

Tracking down a memory leak in multithreaded C application

跟踪多线程C应用程序中的内存泄漏

#5

Please note that the default pthread_create behavior is "joinable" NOT DETACHED. Therefore some OS resources would still remain in the process after pthread finished, which would result in zombie pthread and leads to increased VIRTUAL/resident memory usage.

请注意,默认的pthread_create行为是“可连接的”NOT DETACHED。因此,在pthread完成后,某些OS资源仍将保留在进程中,这将导致僵尸pthread并导致VIRTUAL /驻留内存使用量增加。

The four solution @sehe mentioned would fix this problem.

@sehe提到的四个解决方案可以解决这个问题。

However if you thread is a long-standing one, this might not be really needed. for example, if the pthread lives through the whole life of the process.

但是,如果你是一个长期的线程,这可能不是真的需要。例如,如果pthread贯穿整个过程的生命。

#1