使用 valgrind 检查 fftw3

在我的程序的一个步骤中，我需要对图像进行卷积。为此，我正在使用提供的功能fftw3。当我跑步时valgrind在我的程序中，我得到了这个堆栈跟踪。我的函数叫做convolve它运行fftw3's fftw_plan_dft_r2c_2d两次（一次在图像上，一次在卷积核上。为了使其更具可读性，我删除了所有地址和进程ID。

HEAP SUMMARY:
    in use at exit: 62,280 bytes in 683 blocks
  total heap usage: 178,271 allocs, 177,588 frees, 36,617,058 bytes allocated

3,304 (24 direct, 3,280 indirect) bytes in 1 blocks are definitely lost in loss record 129 of 131
   at : malloc (vg_replace_malloc.c:291)
   by : fftw_malloc_plain (in ./prog)
   by : fftw_mkapiplan (in ./prog)
   by : fftw_plan_many_dft_r2c (in ./prog)
   by : fftw_plan_dft_r2c (in ./prog)
   by : fftw_plan_dft_r2c_2d (in ./prog)
   by : convolve (freqdomain.c:199)
   by : convolve (conv.c:290)
   by : main (main.c:332)

3,304 (24 direct, 3,280 indirect) bytes in 1 blocks are definitely lost in loss record 130 of 131
   at : malloc (vg_replace_malloc.c:291)
   by : fftw_malloc_plain (in ./prog)
   by : fftw_mkapiplan (in ./prog)
   by : fftw_plan_many_dft_r2c (in ./prog)
   by : fftw_plan_dft_r2c (in ./prog)
   by : fftw_plan_dft_r2c_2d (in ./prog)
   by : convolve (freqdomain.c:203)
   by : convolve (conv.c:290)
   by : main (main.c:332)

LEAK SUMMARY:
   definitely lost: 48 bytes in 2 blocks
   indirectly lost: 6,560 bytes in 60 blocks
     possibly lost: 0 bytes in 0 blocks
   still reachable: 55,672 bytes in 621 blocks
        suppressed: 0 bytes in 0 blocks
Reachable blocks (those to which a pointer was found) are not shown.
To see them, rerun with: --leak-check=full --show-leak-kinds=all

For counts of detected and suppressed errors, rerun with: -v
ERROR SUMMARY: 3 errors from 3 contexts (suppressed: 4 from 4)

根据手册的建议，完成后我已经使用了fftw_free and fftw_destroy_plan。我想看看我能对此做些什么还是这是一个内部问题fftw3？既然没有释放malloc位于 FFTW 源代码深处。

编辑：包含 fftw_cleanup() 之后

下面你可以看到diff我添加后fftw_cleanup().

[me@mycomputer]$ diff NoCleanup WithCleanup 
2,3c2,3
<     in use at exit: 62,280 bytes in 683 blocks
<   total heap usage: 178,271 allocs, 177,588 frees, 36,617,058 bytes allocated
---
>     in use at exit: 9,008 bytes in 66 blocks
>   total heap usage: 178,271 allocs, 178,205 frees, 36,617,058 bytes allocated
5c5
< 3,304 (24 direct, 3,280 indirect) bytes in 1 blocks are definitely lost in loss record 129 of 131
---
> 3,304 (24 direct, 3,280 indirect) bytes in 1 blocks are definitely lost in loss record 39 of 40
16c16
< 3,304 (24 direct, 3,280 indirect) bytes in 1 blocks are definitely lost in loss record 130 of 131
---
> 3,304 (24 direct, 3,280 indirect) bytes in 1 blocks are definitely lost in loss record 40 of 40
31c31
<    still reachable: 55,672 bytes in 621 blocks
---
>    still reachable: 2,400 bytes in 4 blocks

的数量still reachable退出时使用的字节数显着减少，释放的数量也显着减少mallocs 增加了。但主要错误（3,304 (24 direct, 3,280 indirect) bytes in 1 blocks are definitely lost）仍然存在。

来自FFTW 文档 http://www.fftw.org/doc/Using-Plans.html:

FFTW 的规划器保存了一些其他持久数据，例如积累的智慧和当前配置中可用的算法列表。如果您想释放所有这些并将 FFTW 重置为启动程序时的原始状态，您可以调用：

void fftw_cleanup(void);