Memory allocation error OpenCV cvReleaseMat

Question

CvMat* traindata=cvCreateMat(1000,36,CV_32FC1);

当我尝试使用cvReleaseMat(&trainData)释放这个矩阵时

我在任务管理器中找到内存，而不是decreased...instead。这个释放命令对任务管理器中该应用程序的内存没有任何影响。

我怀疑is...does cvReleaseMat是否也释放了内存？或者它只是让这个矩阵在未来变得不可逆转？

Answer 1

是的，cvReleaseMat确实释放了内存。任务管理器实际上不是用于查看CvMat*分配的内存的工具。不过，如果你想让矩阵变得更大，你可能会注意到。该矩阵占用1,000* 36 *4= 144000字节。

您可以在valgrind分析的以下代码的输出中看到它：

CvMat* traindata = cvCreateMat(1000, 36, CV_32FC1);
//cvReleaseMat(&traindata);

相关的valgrind输出为：

==4967== HEAP SUMMARY:
==4967==     in use at exit: 144,108 bytes in 2 blocks
==4967==   total heap usage: 10 allocs, 8 frees, 144,772 bytes allocated
==4967== 
==4967== LEAK SUMMARY:
==4967==    definitely lost: 64 bytes in 1 blocks
==4967==    indirectly lost: 144,044 bytes in 1 blocks
==4967==      possibly lost: 0 bytes in 0 blocks
==4967==    still reachable: 0 bytes in 0 blocks
==4967==         suppressed: 0 bytes in 0 blocks

但是如果你真的发布了CvMat

CvMat* traindata = cvCreateMat(1000, 36, CV_32FC1);
cvReleaseMat(&traindata);

现在你会得到这个输出，请注意valgrind的输出：

==4957== HEAP SUMMARY:
==4957==     in use at exit: 0 bytes in 0 blocks
==4957==   total heap usage: 10 allocs, 10 frees, 144,772 bytes allocated
==4957== 
==4957== All heap blocks were freed -- no leaks are possible