[英]valgrind memory leak errors when using pthread_create
I'm writing a program using the pthread library. 我正在使用pthread库编写程序。 When I run my program with the command
valgrind --leak-check=full
, I get the following errors description: 当我使用命令
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. 每次我调用
pthread_create
,使用某个函数 - 我在函数的末尾调用函数pthread_exit
。 So, after verifying this is not the problem, what could be the problem? 因此,在验证这不是问题之后,可能是什么问题?
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
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,你有三个选择:
pthread_detach
), or pthread_detach
),或 pthread_join
). pthread_join
)。 Hth. 心连心。
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。
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). 如果线程不应该连接(或者只是自己过期),可以使线程处于分离状态以避免内存泄漏。
To explicitly create a thread as joinable or detached, the attr argument in the pthread_create() routine is used.
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。 The typical 4 step process is:
典型的4步过程是:
pthread_attr_t
data type pthread_attr_t
数据类型的pthread属性变量 pthread_attr_init()
pthread_attr_init()
初始化属性变量 pthread_attr_setdetachstate()
pthread_attr_setdetachstate()
设置属性分离状态 pthread_attr_destroy()
pthread_attr_destroy()
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
Please note that the default pthread_create behavior is "joinable" NOT DETACHED. 请注意,默认的pthread_create行为是“可连接的”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.
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. 但是,如果你是一个长期的线程,这可能不是真的需要。 for example, if the pthread lives through the whole life of the process.
例如,如果pthread贯穿整个过程的生命。
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