Question

我正在尝试使用C ++（使用Ubuntu 10.04中的posix aio库）异步读取和写入磁盘，遵循此处列出的指示：aio tutorial。我可以异步读写，但恐怕有某种小的内存泄漏。我的valgrind输出表明有288个可能丢失的字节和3,648个仍然可达的字节。这些数字似乎与实际从文件中读取的字节数无关。我找不到在哪里或如何消除这种泄漏 - 它甚至看起来像aio库的问题。谁看过这个吗？完整的valgrind输出如下。提前致谢。

==22330== 
==22330== HEAP SUMMARY:
==22330==     in use at exit: 3,936 bytes in 3 blocks
==22330==   total heap usage: 25 allocs, 22 frees, 15,648 bytes allocated
==22330== 
==22330== 64 bytes in 1 blocks are still reachable in loss record 1 of 3
==22330==    at 0x4C274A8: malloc (vg_replace_malloc.c:236)
==22330==    by 0x4C27522: realloc (vg_replace_malloc.c:525)
==22330==    by 0x504CAF1: __aio_enqueue_request (aio_misc.c:127)
==22330==    by 0x504D25A: aio_read (aio_read.c:30)
==22330==    by 0x406EB7: baio::read(std::string, char*, long) (baio_unix.cxx:58)
==22330==    by 0x40613E: test_read_helper(char*) (test_read.cxx:16)
==22330==    by 0x4063E1: test_read() (test_read.cxx:54)
==22330==    by 0x40664C: test_read_main(int, char**) (test_read.cxx:74)
==22330==    by 0x40959D: testlib_run_test_unit(unsigned long, int, char**) (testlib_main.cxx:116)
==22330==    by 0x4097A9: testlib_main(int, char**) (testlib_main.cxx:155)
==22330==    by 0x4060B4: main (test_driver.cxx:12)
==22330== 
==22330== 288 bytes in 1 blocks are possibly lost in loss record 2 of 3
==22330==    at 0x4C267CC: calloc (vg_replace_malloc.c:467)
==22330==    by 0x4012395: _dl_allocate_tls (dl-tls.c:300)
==22330==    by 0x4E34728: pthread_create@@GLIBC_2.2.5 (allocatestack.c:561)
==22330==    by 0x504C9A8: __aio_enqueue_request (aio_misc.h:60)
==22330==    by 0x504D25A: aio_read (aio_read.c:30)
==22330==    by 0x406EB7: baio::read(std::string, char*, long) (baio_unix.cxx:58)
==22330==    by 0x40613E: test_read_helper(char*) (test_read.cxx:16)
==22330==    by 0x4063E1: test_read() (test_read.cxx:54)
==22330==    by 0x40664C: test_read_main(int, char**) (test_read.cxx:74)
==22330==    by 0x40959D: testlib_run_test_unit(unsigned long, int, char**) (testlib_main.cxx:116)
==22330==    by 0x4097A9: testlib_main(int, char**) (testlib_main.cxx:155)
==22330==    by 0x4060B4: main (test_driver.cxx:12)
==22330== 
==22330== 3,584 bytes in 1 blocks are still reachable in loss record 3 of 3
==22330==    at 0x4C267CC: calloc (vg_replace_malloc.c:467)
==22330==    by 0x504CA27: __aio_enqueue_request (aio_misc.c:139)
==22330==    by 0x504D25A: aio_read (aio_read.c:30)
==22330==    by 0x406EB7: baio::read(std::string, char*, long) (baio_unix.cxx:58)
==22330==    by 0x40613E: test_read_helper(char*) (test_read.cxx:16)
==22330==    by 0x4063E1: test_read() (test_read.cxx:54)
==22330==    by 0x40664C: test_read_main(int, char**) (test_read.cxx:74)
==22330==    by 0x40959D: testlib_run_test_unit(unsigned long, int, char**) (testlib_main.cxx:116)
==22330==    by 0x4097A9: testlib_main(int, char**) (testlib_main.cxx:155)
==22330==    by 0x4060B4: main (test_driver.cxx:12)
==22330== 
==22330== LEAK SUMMARY:
==22330==    definitely lost: 0 bytes in 0 blocks
==22330==    indirectly lost: 0 bytes in 0 blocks
==22330==      possibly lost: 288 bytes in 1 blocks
==22330==    still reachable: 3,648 bytes in 2 blocks
==22330==         suppressed: 0 bytes in 0 blocks

Answer 1

第二个块看起来像是与为处理异步读取而创建的库拥有的线程相关联的线程本地存储。

==22330==    by 0x4012395: _dl_allocate_tls (dl-tls.c:300)
==22330==    by 0x4E34728: pthread_create@@GLIBC_2.2.5 (allocatestack.c:561)

第一个和第三个看起来像与未完成的异步读取相关联的内部结构。

如果你只能担心这种情况会持续一段时间，我的本能就是要感激小小的怜悯。该库肯定有一定的自由度来分配持久性内存来关联异步读取的结果。

aio.h aio_read（）并写入内存泄漏

1 个答案: